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Table of Contents

IP Routing Protocols Commands

IP Routing Protocols Commands

Cisco's implementation of the Internet Protocol (IP) suite provides all major services contained in the Transmission Control Protocol (TCP)/IP specifications.

Use the commands in this chapter to configure and monitor the IP routing protocols. For IP routing protocol configuration information and examples, refer to the "Configuring IP Routing Protocols" chapter of the Network Protocols Configuration Guide, Part 1.

accept-lifetime

To set the time period during which the authentication key on a key chain is received as valid, use the accept-lifetime key chain key configuration command. To revert to the default value, use the no form of this command.

accept-lifetime start-time {infinite | end-time | duration seconds}
no accept-lifetime [start-time {infinite | end-time | duration seconds}]
Syntax Description

start-time

Beginning time that the key specified by the key command is valid to be received. The syntax can be either of the following:

               hh:mm:ss Month date year

               hh:mm:ss date Month year

hh---hours

mm---minutes

ss---seconds

date---date (1-31)

Month---first three letters of the month

year---year (four digits)

The default start time and the earliest acceptable date is January 1, 1993.

infinite

Key is valid to be received from the start-time on.

end-time

Key is valid to be received from the start-time until end-time. The end-time must be after the start-time. The syntax is the same as that for start-time. The default end time is an infinite time period.

duration seconds

Length of time (in seconds) that the key is valid to be received.

Default

Forever (Starting time is January 1, 1993, and ending time is infinite.)

Command Mode

Key chain key configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Only RIP Version 2 uses key chains.

Specify a start-time and one of the following: infinite, end-time, or duration seconds.

We recommend running NTP or some other time synchronization method if you assign a lifetime to a key.

If the last key expires, authentication will continue and an error message will be generated. To disable authentication, you must manually delete the last valid key.

Examples

The following example configures a key chain called trees. In this example, the software will always accept and send willow as a valid key.

interface ethernet 0
  ip rip authentication key-chain trees
  ip rip authentication mode md5
!
router rip
  network 172.19.0.0
  version 2
!
key chain trees
  key 1
     key-string willow
 

In the following example, the key chestnut will be accepted from 1:30 p.m. to 3:30 p.m. and be sent from 2:00 p.m. to 3:00 p.m. The key birch will be accepted from 2:30 p.m. to 4:40 p.m. and be sent from 3:00 p.m. to 4:00 p.m. The overlap allows for migration of keys or discrepancies in the router's set time. There is a half  hour leeway on each side to handle time differences.

interface ethernet 0
  ip rip authentication key-chain trees
  ip rip authentication mode md5
!
router rip
  network 172.19.0.0
  version 2
!
key chain trees
    key 1
     key-string chestnut
     accept-lifetime 13:30:00 Jan 25 1996 duration 7200
     send-lifetime 14:00:00 Jan 25 1996 duration 3600
  key 2
     key-string birch
     accept-lifetime 14:30:00 Jan 25 1996 duration 7200
     send-lifetime 15:00:00 Jan 25 1996 duration 3600
Related Commands

key
key chain
key-string
send-lifetime
show key chain

aggregate-address

To create an aggregate entry in a BGP routing table, use the aggregate-address router configuration command. To disable this feature, use the no form of this command.

aggregate-address address mask [as-set] [summary-only] [suppress-map map-name]
[advertise-map map-name] [attribute-map map-name]
no aggregate-address address mask [as-set] [summary-only] [suppress-map map-name]
[advertise-map map-name] [attribute-map map-name]
Syntax Description

address

Aggregate address.

mask

Aggregate mask.

as-set

(Optional) Generates autonomous system set path information.

summary-only

(Optional) Filters all more specific routes from updates.

suppress-map map-name

(Optional) Name of route map used to select the routes to be suppressed.

advertise-map map-name

(Optional) Name of route map used to select the routes to create AS-SET origin communities.

attribute-map map-name

(Optional) Name of route map used to set the attribute of the aggregate route.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You can implement aggregate routing in BGP either by redistributing an aggregate route into BGP or by using this conditional aggregate routing feature.

Using the aggregate-address command with no arguments will create an aggregate entry in the BGP routing table if there are any more-specific BGP routes available that fall in the specified range. The aggregate route will be advertised as coming from your autonomous system and has the atomic aggregate attribute set to show that information might be missing. (By default, the atomic aggregate attribute is set unless you specify the as-set keyword.)

Using the as-set keyword creates an aggregate entry using the same rules that the command follows without this keyword, but the path advertised for this route will be an AS_SET consisting of all elements contained in all paths that are being summarized. Do not use this form of aggregate-address when aggregating many paths, because this route must be continually withdrawn and re-updated as autonomous system path reachability information for the summarized routes changes.

Using the summary-only keyword not only creates the aggregate route (for example, 193.*.*.*) but will also suppress advertisements of more-specific routes to all neighbors. If you only want to suppress advertisements to certain neighbors, you may use the neighbor distribute-list command, with caution. If a more specific route leaks out, all BGP speakers will prefer that route over the less-specific aggregate you are generating (using longest-match routing).

Using the suppress-map keyword creates the aggregate route but suppresses advertisement of specified routes. You can use the match clauses of route maps to selectively suppress some more specific routes of the aggregate and leave others unsuppressed. IP access lists and autonomous system path access lists match clauses are supported.

Example

In the following example, an aggregate address is created. The path advertised for this route will be an AS_SET consisting of all elements contained in all paths that are being summarized.

router bgp 5
aggregate-address 193.0.0.0 255.0.0.0 as-set
Related Commands

match as-path
match ip address
route-map

area authentication

To enable authentication for an OSPF area, use the area authentication router configuration command. To remove an area's authentication specification or a specified area from the configuration, use the no form of this command.

area area-id authentication [message-digest]
no area area-id authentication
no area
area-id
Syntax Description

area-id

Identifier of the area for which authentication is to be enabled. The identifier can be specified as either a decimal value or an IP  address.

message-digest

(Optional) Enables MD5 authentication on the area specified by area-id.

Default

Type 0 authentication (no authentication)

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The message-digest keyword first appeared in Cisco IOS Release 11.0.

Specifying authentication for an area sets the authentication to Type 1 (simple password) as specified in RFC 1247. If this command is not included in the configuration file, authentication of Type 0 (no authentication) is assumed.

The authentication type must be the same for all routers and access servers in an area. The authentication password for all OSPF routers on a network must be the same if they are to communicate with each other via OSPF. Use the ip ospf authentication-key command to specify this password.

If you enable MD5 authentication with the message-digest keyword, you must configure a password with the ip ospf message-digest-key command.

To remove the area's authentication specification, use the no form of this command with the authentication keyword. To remove the specified area from the software configuration, use the command no area area-id (with no other keywords).


Note To remove the specified area from the software configuration, use the command no area area-id (with no other keywords). That is, no area area-id removes all area options, such as area authentication, area default-cost, area nssa, area range, area stub, and area virtual-link.
Example

The following example mandates authentication for areas 0 and 36.0.0.0 of OSPF routing process  201. Authentication keys are also provided.

interface ethernet 0
ip address 131.119.251.201 255.255.255.0
ip ospf authentication-key adcdefgh
!
interface ethernet 1
ip address 36.56.0.201 255.255.0.0
ip ospf authentication-key ijklmnop
!
router ospf 201
network 36.0.0.0 0.255.255.255 area 36.0.0.0
network 131.119.0.0 0.0.255.255 area 0
area 36.0.0.0 authentication
area 0 authentication
Related Commands

area default-cost
area stub
ip ospf authentication-key
ip ospf message-digest-key

area default-cost

To specify a cost for the default summary route sent into a stub area, use the area default-cost router configuration command. To remove the assigned default route cost, use the no form of this command.

area area-id default-cost cost
no area area-id default-cost cost
no area area-id
Syntax Description

area-id

Identifier for the stub area. The identifier can be specified as either a decimal value or as an IP address.

cost

Cost for the default summary route used for a stub area. The acceptable value is a 24-bit number.

Default

Cost of 1

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The command is used only on an area border router attached to a stub area.

There are two stub area router configuration commands: the stub and default-cost options of the area command. In all routers and access servers attached to the stub area, the area should be configured as a stub area using the stub option of the area command. Use the default-cost option only on an area border router attached to the stub area. The default-cost option provides the metric for the summary default route generated by the area border router into the stub area.


Note To remove the specified area from the software configuration, use the command no area area-id (with no other keywords). That is, no area area-id removes all area options, such as area authentication, area default-cost, area nssa, area range, area stub, and area virtual-link.
Example

The following example assigns a default-cost of 20 to stub network 36.0.0.0:

interface ethernet 0
ip address 36.56.0.201 255.255.0.0
!
router ospf 201
network 36.0.0.0 0.255.255.255 area 36.0.0.0
area 36.0.0.0 stub
area 36.0.0.0 default-cost 20
Related Commands

area authentication
area stub

area nssa

To configure an area as a not so stubby area (NSSA), use the area nssa router configuration command. To remove the nssa distinction from the area, use the no form of this command.

area area-id nssa [no-redistribution] [default-information-originate]
no area area-id nssa
no area
area-id
Syntax Description

area-id

Identifier of the area for which authentication is to be enabled. The identifier can be specified as either a decimal value or an IP  address.

no-redistribution

(Optional) Used when the router is a NSSA ABR and you want the redistribute command to import routes only into the normal areas, but not into the NSSA area.

default-information-
originate

(Optional) Used to generate a Type 7 default into the NSSA area. This argument only takes effect on NSSA ABR.

Default

No NSSA area is defined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.


Note To remove the specified area from the software configuration, use the command no area area-id (with no other keywords). That is, no area area-id removes all area options, such as area authentication, area default-cost, area nssa, area range, area stub, and area virtual-link.
Example

In the following example, NSSA authentication is enabled on area 1:

router ospf1
redistribute rip subnets
network 172.19.92.0.0.0.0.255 area 1
area 1 nssa

area-password

To configure the IS-IS area authentication password, use the area-password router configuration command. To disable the password, use the no form of this command.

area-password password
no area-password [password]
Syntax Description

password

Password you assign.

Default

No area password is defined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This password is inserted in Level 1 (station router level) link state PDUs (LSPs), complete sequence number PDUs (CSNPs), and partial sequence number PDUs (PSNP).

Example

The following example assigns an area authentication password:

router isis
area-password angel
Related Command

domain-password

area range

To consolidate and summarize routes at an area boundary, use the area range router configuration command. To disable this function, use the no form of this command.

area area-id range address mask
no area area-id range address mask
no area area-id
Syntax Description

area-id

Identifier of the area about which routes are to be summarized. It can be specified as either a decimal value or as an IP address.

address

IP address.

mask

IP mask.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The area range command is used only with area border routers (ABRs). It is used to consolidate or summarize routes for an area. The result is that a single summary route is advertised to other areas by the ABR. Routing information is condensed at area boundaries. External to the area, a single route is advertised for each address range. This is called route summarization.

Multiple area router configuration commands specifying the range option can be configured. Thus, OSPF can summarize addresses for many different sets of address ranges.


Note To remove the specified area from the software configuration, use the command no area area-id (with no other keywords). That is, no area area-id removes all area options, such as area authentication, area default-cost, area nssa, area range, area stub, and area virtual-link.
Example

The following example specifies one summary route to be advertised by the ABR to other areas for all subnets on network 36.0.0.0 and for all hosts on network 192.42.110.0:

interface ethernet 0
ip address 192.42.110.201 255.255.255.0
!
interface ethernet 1
ip address 36.56.0.201 255.255.0.0
!
router ospf 201
network 36.0.0.0 0.255.255.255 area 36.0.0.0
network 192.42.110.0 0.0.0.255 area 0
area 36.0.0.0 range 36.0.0.0 255.0.0.0
area 0 range 192.42.110.0 255.255.255.0

area stub

To define an area as a stub area, use the area stub router configuration command. To disable this function, use the no form of this command.

area area-id stub [no-summary]
no area area-id stub
no area
area-id
Syntax Description

area-id

Identifier for the stub area. The identifier can be either a decimal value or an IP address.

no-summary

(Optional) Prevents an ABR from sending summary link advertisements into the stub area.

Default

No stub area is defined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You must configure the area stub command on all routers and access servers in the stub area. Use the area router configuration command with the default-cost option to specify the cost of a default internal router sent into a stub area by an area border router.

There are two stub area router configuration commands: the stub and default-cost options of the area router configuration command. In all routers attached to the stub area, the area should be configured as a stub area using the stub option of the area command. Use the default-cost option only on an ABR attached to the stub area. The default-cost option provides the metric for the summary default route generated by the area border router into the stub area.

To further reduce the number of link state advertisements (LSA) sent into a stub area, you can configure no-summary on the ABR to prevent it from sending summary LSAs (LSA type 3) into the stub area.


Note To remove the specified area from the software configuration, use the command no area area-id (with no other keywords). That is, no area area-id removes all area options, such as area authentication, area default-cost, area nssa, area range, area stub, and area virtual-link.
Example

The following example assigns a default cost of 20 to stub network 36.0.0.0:

interface ethernet 0
ip address 36.56.0.201 255.255.0.0
!
router ospf 201
network 36.0.0.0 0.255.255.255 area 36.0.0.0
area 36.0.0.0 stub
area 36.0.0.0 default-cost 20
Related Commands

area authentication
area default-cost

area virtual-link

To define an OSPF virtual link, use the area virtual-link router configuration command with the optional parameters. To remove a virtual link, use the no form of this command.

area area-id virtual-link router-id [hello-interval seconds] [retransmit-interval seconds]
[transmit-delay seconds] [dead-interval seconds] [[authentication-key key] |
[message-digest-key keyid md5 key]]
no area area-id virtual-link router-id [hello-interval seconds] [retransmit-interval seconds]
[transmit-delay seconds] [dead-interval seconds] [[authentication-key key] |
[message-digest-key keyid md5 key]]
no area area-id
Syntax Description

area-id

Area ID assigned to the transit area for the virtual link. This can be either a decimal value or a valid IP address. There is no default.

router-id

Router ID associated with the virtual link neighbor. The router ID appears in the show ip ospf display. It is internally derived by each router from the router's interface IP addresses. This value must be entered in the format of an IP address. There is no default.

hello-interval seconds

(Optional) Time in seconds between the hello packets that the Cisco IOS software sends on an interface. Unsigned integer value to be advertised in the software's hello packets. The value must be the same for all routers and access servers attached to a common network. The default is 10  seconds.

retransmit-interval seconds

(Optional) Time in seconds between link state advertisement retransmissions for adjacencies belonging to the interface. Expected round-trip delay between any two routers on the attached network. The value must be greater than the expected round-trip delay. The default is 5  seconds.

transmit-delay seconds

(Optional) Estimated time in seconds it takes to transmit a link state update packet on the interface. Integer value that must be greater than zero. Link state advertisements in the update packet have their age incremented by this amount before transmission. The default value is 1 second.

dead-interval seconds

(Optional) Time in seconds that a software's hello packets are not seen before its neighbors declare the router down. Unsigned integer value. The default is four times the hello interval, or 40  seconds. As with the hello interval, this value must be the same for all routers and access servers attached to a common network.

authentication-key key

(Optional) Password to be used by neighboring routers. Any continuous string of characters that you can enter from the keyboard up to 8 bytes long. This string acts as a key that will allow the authentication procedure to generate or verify the authentication field in the OSPF header. This key is inserted directly into the OSPF header when originating routing protocol packets. A separate password can be assigned to each network on a per-interface basis. All neighboring routers on the same network must have the same password to be able to route OSPF traffic. The password is encrypted in the configuration file if the service password-encryption command is enabled. There is no default value.

message-digest-key keyid md5 key

(Optional) Key identifier and password to be used by neighboring routers and this router for MD5 authentication. The keyid is a number in the range 1 to 255. The key is an alphanumeric string of up to 16 characters. All neighboring routers on the same network must have the same key identifier and key to be able to route OSPF traffic. There is no default value.

Defaults

area-id: No area ID is predefined.
router-id: No router ID is predefined.
hello-interval seconds: 10 seconds
retransmit-interval seconds: 5 seconds
transmit-delay seconds: 1 second
dead-interval seconds: 40 seconds
authentication-key key: No key is predefined.
message-digest-key keyid md5 key: No key is predefined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The following keywords and arguments first appeared in Cisco IOS Release 11.0: message-digest-key keyid md5 key.

In OSPF, all areas must be connected to a backbone area. If the connection to the backbone is lost, it can be repaired by establishing a virtual link.

The smaller the hello interval, the faster topological changes will be detected, but more routing traffic will ensue.

The setting of the retransmit interval should be conservative, or needless retransmissions will result. The value should be larger for serial lines and virtual links.

The transmit delay value should take into account the transmission and propagation delays for the interface.

The Cisco IOS software will use the specified authentication key only when authentication is enabled for the backbone with the area area-id authentication router configuration command.

The two authentication schemes, simple text and MD5 authentication, are mutually exclusive. You can specify one or the other or neither. Any keywords and arguments you specify after authentication-key key or message-digest-key keyid md5 key are ignored. Therefore, specify any optional arguments before such a keyword-argument combination.


Note Each virtual link neighbor must include the transit area ID and the corresponding virtual link neighbor's router ID in order for a virtual link to be properly configured. Use the show ip ospf EXEC command to see the router ID.

Note To remove the specified area from the software configuration, use the command no area area-id (with no other keywords). That is, no area area-id removes all area options, such as area authentication, area default-cost, area nssa, area range, area stub, and area virtual-link.
Examples

The following example establishes a virtual link with default values for all optional parameters:

router ospf 201
network 36.0.0.0 0.255.255.255 area 36.0.0.0
area 36.0.0.0 virtual-link 36.3.4.5
 

The following example establishes a virtual link with MD5 authentication:

router ospf 201
network 36.0.0.0 0.255.255.255 area 36.0.0.0
area 36.0.0.0 virtual-link 36.3.4.5 message-digest-key 3 md5 sa5721bk47
Related Commands

A dagger () indicates that the command is documented outside this chapter.

area authentication
service password-encryption

show ip ospf

autonomous-system (EGP)

To specify the local autonomous system that the Cisco IOS software resides in for EGP, use the autonomous-system global configuration command. To remove the autonomous system number,  use the no form of this command.

autonomous-system local-as
no autonomous-system local-as
Syntax Description

local-as

Local autonomous system number to which the router belongs.

Default

No local autonomous system is specified.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Before you can set up EGP routing, you must specify an autonomous system number. The local autonomous system number will be included in EGP messages sent by the software.

Example

The following sample configuration specifies an autonomous system number of 110:

autonomous-system 110
Related Command

router egp

auto-summary

To restore the default behavior of automatic summarization of subnet routes into network-level routes, use the auto-summary router configuration command. To disable this feature and transmit subprefix routing information across classful network boundaries, use the no form of this command.

auto-summary
no auto-summary

Syntax Description

This command has no arguments or keywords.

Default

Enabled (the software summarizes subprefixes to the classful network boundary when crossing classful network boundaries).

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Route summarization reduces the amount of routing information in the routing tables.

By default, BGP does not accept subnets redistributed from IGP. To advertise and carry subnet routes in BGP, use an explicit network command or the no auto-summary command. If you disable auto-summarization and have not entered a network command, you will not advertise network routes for networks with subnet routes unless they contain a summary route.

IP Enhanced IGRP summary routes are given an administrative distance value of 5. You cannot configure this value.

RIP Version 1 always uses automatic summarization. If you are using RIP Version 2, you can turn off automatic summarization by specifying no auto-summary. Disable automatic summarization if you must perform routing between disconnected subnets. When automatic summarization is off, subnets are advertised.

Examples

In the following example, network numbers are not summarized automatically:

router bgp 6
no auto-summary
 

The following example disables automatic summarization for process eigrp 109:

router eigrp 109
no auto-summary
Related Command

ip summary-address eigrp

bgp always-compare-med

To allow the comparison of the Multi Exit Discriminator (MED) for paths from neighbors in different autonomous systems, use the bgp always-compare-med router configuration command. To disallow the comparison, use the no form of this command.

bgp always-compare-med
no
bgp always-compare-med
Syntax Description

This command has no arguments or keywords.

Default

The Cisco IOS software does not compare MEDs for paths from neighbors in different autonomous systems.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The MED is one of the parameters that is considered when selecting the best path among many alternative paths. The path with a lower MED is preferred over a path with a higher MED.

By default, during the best-path selection process, MED comparison is done only among paths from the same autonomous system. This command changes the default behavior by allowing comparison of MEDs among paths regardless of the autonomous system from which the paths are received.

Example

In the following example, the BGP speaker in autonomous system 100 is configured to compare MEDs among alternative paths, regardless of the autonomous system from which the paths are received:

router bgp 109
bgp always-compare-med

bgp client-to-client reflection

To restore route reflection from a BGP route reflector to clients, use the bgp client-to-client reflection router configuration command. To disable client-to-client reflection, use the no form of this command.

bgp client-to-client reflection
no bgp client-to-client reflection

Syntax Description

This command has no arguments or keywords.

Default

When a route reflector is configured, the route reflector reflects routes from a client to other clients.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

By default, the clients of a route reflector are not required to be fully meshed and the routes from a client are reflected to other clients. However, if the clients are fully meshed, route reflection is not required. Use the no bgp client-to-client reflection command to disable client-to-client reflection.

If client-to-client reflection is enabled, the clients of a route reflector cannot be members of a peer group.

Example

In the following example, the local router is a route reflector. The three neighbors are fully meshed, so client-to-client reflection is disabled.

router bgp 5
neighbor 155.24.95.22 route-reflector-client
neighbor 155.24.95.23 route-reflector-client
neighbor 155.24.95.24 route-reflector-client
no bgp client-to-client reflection
Related Commands

bgp cluster-id
neighbor route-reflector-client
show ip bgp

bgp cluster-id

To configure the cluster ID if the BGP cluster has more than one route reflector, use the bgp  cluster-id router configuration command. To remove the cluster ID, use the no form of this command.

bgp cluster-id cluster-id
no bgp cluster-id cluster-id
Syntax Description

cluster-id

Cluster ID of this router acting as a route reflector; maximum of 4 bytes.

Default

The router ID of the single route reflector in a cluster

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Together, a route reflector and its clients form a cluster.

Usually a cluster of clients will have a single route reflector. In that case, the cluster is identified by the router ID of the route reflector. In order to increase redundancy and avoid a single point of failure, a cluster might have more than one route reflector. In this case, all route reflectors in the cluster must be configured with the 4-byte cluster ID so that a route reflector can recognize updates from route reflectors in the same cluster.

If the cluster has more than one route reflector, use this command to configure the cluster ID.

Example

In the following example, the local router is one of the route reflectors serving the cluster. It is configured with the cluster ID to identify the cluster.

router bgp 5
neighbor 198.92.70.24 route-reflector-client
bgp cluster-id 50000
Related Commands

bgp client-to-client reflection
neighbor route-reflector-client
show ip bgp

bgp confederation identifier

To specify a BGP confederation identifier, use the bgp confederation identifier router configuration command. To remove the confederation identifier, use the no form of this command.

bgp confederation identifier autonomous-system
no bgp confederation identifier autonomous-system
Syntax Description

autonomous-system

Autonomous system number that internally includes multiple autonomous systems.

Default

No confederation identifier is configured.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Another way to reduce the IBGP mesh is to divide an autonomous system into multiple autonomous systems and group them into a single confederation. Each autonomous system is fully meshed within itself, and has a few connections to another autonomous system in the same confederation. Even though the peers in different autonomous systems have EBGP sessions, they exchange routing information as if they are IBGP peers. Specifically, the next-hop and local preference information is preserved. This enables to you to retain a single Interior Gateway Protocol (IGP) for all the autonomous systems. To the outside world, the confederation looks like a single autonomous system.

Example

In the following example, the autonomous system is divided into autonomous systems 4001, 4002, 4003, 4004, 4005, 4006, and 4007 and identified by the confederation identifier 5. Neighbor 1.2.3.4 is someone inside your routing domain confederation. Neighbor 3.4.5.6 is someone outside your routing domain confederation. To the outside world, there appears to be a single autonomous system with the number 5.

router bgp 4001
bgp confederation identifier 5
bgp confederation peers 4002 4003 4004 4005 4006 4007
neighbor 1.2.3.4 remote-as 4002
neighbor 3.4.5.6 remote-as 510
Related Command

bgp confederation peers

bgp confederation peers

To configure the autonomous systems that belong to the confederation, use the bgp  confederation  peers router configuration command. To remove an autonomous system from the confederation, use the no form of this command.

bgp confederation peers autonomous-system [autonomous-system]
no bgp confederation peers autonomous-system [autonomous-system]
Syntax Description

autonomous-system

Autonomous system number.

Default

No confederation peers are configured.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The autonomous systems specified in this command are visible internally to a confederation. Each autonomous system is fully meshed within itself. The bgp confederation identifier command specifies the confederation to which the autonomous systems belong.

Example

The following example specifies that autonomous systems 1090, 1091, 1092, and 1093 belong to a single confederation:

router bgp 1090
bgp confederation peers 1091 1092 1093
Related Command

bgp confederation identifier

bgp default local-preference

To change the default local preference value, use the bgp default local-preference router configuration command. To return to the default setting, use the no form of this command.

bgp default local-preference value
no bgp default local-preference value
Syntax Description

value

Local preference value. Higher is more preferred. Integer from 0 to 4294967295.

Default

Local preference value of 100

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Generally, the default value of 100 allows you to easily define a particular path as less preferable than paths with no local preference attribute. The preference is sent to all routers and access servers in the local autonomous system.

Example

In the following example, the default local preference value is raised from the default of 100 to 200:

router bgp 200
bgp default local-preference 200
Related Command

set local-preference

bgp fast-external-fallover

To immediately reset the BGP sessions of any directly adjacent external peers if the link used to reach them goes down, use the bgp fast-external-fallover router configuration command. To disable this feature, use the no form of this command.

bgp fast-external-fallover
no
bgp fast-external-fallover
Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, the automatic resetting of BGP sessions is disabled:

router bgp 109
no bgp fast-external-fallover

clear arp-cache

To remove all dynamic entries from the ARP cache and to clear the fast-switching cache, use the clear arp-cache EXEC command.

clear arp-cache
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example removes all dynamic entries from the ARP cache and clears the fast-switching cache:

clear arp-cache

clear ip bgp

To reset a BGP connection using BGP soft reconfiguration, use the clear ip bgp EXEC command at the system prompt.

clear ip bgp {* | address | peer-group name} [soft [in | out]]
Syntax Description

*

Resets all current BGP sessions.

address

Resets only the identified BGP neighbor.

peer-group-name

Resets the specified BGP peer group.

soft

(Optional) Soft reconfiguration.

in | out

(Optional) Triggers inbound or outbound soft reconfiguration. If the in or out option is not specified, both inbound and outbound soft reconfiguration are triggered.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you specify BGP soft reconfiguration, by including the soft keyword, the sessions are not reset and the router sends all routing updates again. To generate new inbound updates without resetting the BGP session, the local BGP speaker should store all received updates without modification regardless of whether it is accepted by the inbound policy. This process is memory intensive and should be avoided if possible. Outbound BGP soft configuration does not have any memory overhead. You can trigger an outbound reconfiguration on the other side of the BGP session to make the new inbound policy take effect.

Use this command whenever any of the following changes occur:

Example

The following example resets all current BGP sessions:

clear ip bgp *
Related Commands

show ip bgp
timers bgp

clear ip bgp peer-group

To remove all the members of a BGP peer group, use the clear ip bgp peer-group EXEC command.

clear ip bgp peer-group tag
Syntax Description

tag

Name of the BGP peer group to clear.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Example

The following example removes all members from the BGP peer group internal:

clear ip bgp peer-group internal
Related Command

neighbor peer-group (assigning members)

clear ip cgmp

To clear all group entries from the Catalyst switches' caches, use the clear ip  cgmp EXEC command.

clear ip cgmp [type number]
Syntax Description

type number

(Optional) Interface type and number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

This command sends a CGMP Leave message with a group address of 0000.0000.0000 and a unicast address of 0000.0000.0000. This instructs the switches to clear all group entries they have cached.

If an interface type and number are specified, the Leave message is sent only on that interface. Otherwise, it is sent on all CGMP-enabled interfaces.

Example

The following example clears the CGMP cache:

clear ip cgmp
Related Command

ip cgmp

clear ip dvmrp route

To delete routes from the DVMRP routing table, use the clear ip dvmrp route EXEC command.

clear ip dvmrp route {* | route}
Syntax Description

*

Clears all routes from the DVMRP table.

route

Clears the longest matched route. Can be an IP address, a network number, or an IP DNS name.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Examples

The following example deletes route 10.1.1.1 from the DVMRP routing table:

clear ip dvmrp route 10.1.1.1
 

The following example deletes network 10.0.0.0 from the DVMRP routing table:

clear ip dvmrp route 10.0.0.0

clear ip eigrp neighbors

To delete entries from the neighbor table, use the clear ip eigrp neighbors EXEC command.

clear ip eigrp neighbors [ip-address | type number]
Syntax Description

ip-address

(Optional) Address of the neighbor.

type number

(Optional) Interface type and number. Specifying these arguments removes from the neighbor table all entries learned via this interface.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example removes the neighbor whose address is 160.20.8.3:

clear ip eigrp neighbors 160.20.8.3
Related Command

show ip eigrp interfaces

clear ip igmp group

To delete entries from the IGMP cache, use the clear ip igmp group EXEC command.

clear ip igmp group [group-name | group-address | type number]
Syntax Description

group-name

(Optional) Name of the multicast group, as defined in the DNS hosts table or with the ip host command.

group-address

(Optional) Address of the multicast group. This is a multicast IP address in four-part, dotted notation.

type number

(Optional) Interface type and number.

Default

When the command is used with no arguments, all entries are deleted from the IGMP cache.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The IGMP cache contains a list of the multicast groups of which hosts on the directly connected LAN are members. If the router has joined a group, it is also listed in the cache.

To delete all entries from the IGMP cache, specify the clear ip igmp group command with no arguments.

Example

The following example clears entries for the multicast group 224.0.255.1 from the IGMP cache:

clear ip igmp group 224.0.255.1
Related Commands

A dagger () indicates that the command is documented outside this chapter.

ip host
show ip igmp groups
show ip igmp interface

clear ip mroute

To delete entries from the IP multicast routing table, use the clear ip mroute EXEC command.

clear ip mroute {* | group [source]}
Syntax Description

*

Deletes all entries from the IP multicast routing table.

group

Can be either one of the following:

· Name of the multicast group, as defined in the DNS hosts table or with the ip host command.

· IP address of the multicast group. This is a multicast IP address in four-part, dotted notation.

source

(Optional) If you specify a group name or address, you can also specify a name or address of a multicast source that is transmitting to the group. A source does not need to be a member of the group.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Examples

The following example deletes all entries from the IP multicast routing table:

clear ip mroute *
 

The following example deletes from the IP multicast routing table all sources on the 10.3.0.0 subnet that are transmitting to the multicast group 224.2.205.42. Note that this example deletes all sources on network 10.3, not individual sources.

clear ip mroute 224.2.205.42 10.3.0.0
Related Commands

A dagger () indicates that the command is documented outside this chapter.

ip host
show ip mroute

clear ip route

To remove one or more routes from the IP routing table, use the clear ip route EXEC command.

clear ip route {network [mask] | *}
Syntax Description

network

Network or subnet address to remove.

mask

(Optional) Network mask associated with the IP address you wish to remove.

*

Removes all entries.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example removes a route to network 132.5.0.0 from the IP routing table:

clear ip route 132.5.0.0
Related Command

show ip route

clear ip sdr

To delete an sdr cache entry or the entire sdr cache, use the clear ip  sdr EXEC command.

clear ip sdr [group-address | "session-name"]
Syntax Description

group-address

(Optional) Deletes all sessions associated with the IP group address.

"session-name"

(Optional) Deletes only the sdr cache entry with the specified name.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

If no arguments or keywords are used with this command, the system deletes the entire sdr cache.

Example

The following example clears the sdr cache:

clear ip sdr
Related Commands

ip sdr cache-timeout
ip sdr listen
show ip sdr

default-information

To control the candidate default routing information between IGRP or Enhanced IGRP processes, use the default-information router configuration command. To suppress IGRP or Enhanced IGRP candidate information in incoming updates, use the no default-information in command. To suppress IGRP or Enhanced IGRP candidate information in outbound updates, use the no default-information allowed out command.

default-information {in | out} {access-list-number | name}
no default-information {in | out}
Syntax Description

in

Allows IGRP or Enhanced IGRP exterior or default routes to be received by an IGRP process.

out

Allows IGRP or Enhanced IGRP exterior routes to be advertised in updates.

access-list-number | name

Number or name of an access list. It can be a number in the range 1 to 99 or an access list name.

Default

Normally, exterior routes are always accepted and default information is passed between IGRP or Enhanced IGRP processes when doing redistribution.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The access-list-number and name arguments first appeared in Cisco IOS Release 11.2.

The default network of 0.0.0.0 used by RIP cannot be redistributed by IGRP or Enhanced IGRP.

Examples

The following example allows IGRP exterior or default routes to be received by the IGRP process in autonomous system 23:

router igrp 23
default-information in
 

The following example allows IP Enhanced IGRP exterior or default routes to be received by the IP Enhanced IGRP process in autonomous system 23:

router eigrp 23
 default-information in
 

default-information originate (BGP)

To allow the redistribution of network 0.0.0.0 into BGP, use the default-information originate router configuration command. To disable this feature, use the no form of this command.

default-information originate
no default-information originate

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The same functionality will result from the network 0.0.0.0 command, using the network router configuration command.

Example

The following example configures BGP to redistribute network 0.0.0.0 into BGP:

router bgp 164
default-information originate

default-information originate (EGP)

To explicitly configure EGP to generate a default route, use the default-information originate router configuration command. To disable this feature, use the no form of this command.

default-information originate
no default-information originate

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Because EGP can use network 0.0.0.0 as a default route, EGP must be explicitly configured to generate a default route. If the next hop for the default route can be advertised as a third party, it will be included as a third party.

Example

The following example configures EGP to generate a default route:

autonomous system 109
router egp 164
network 131.108.0.0
network 192.31.7.0
neighbor 10.2.0.2
default-information originate

default-information originate (IS-IS)

To generate a default route into an IS-IS routing domain, use the default-information originate router configuration command. To disable this feature, use the no form of this command.

default-information originate [route-map map-name]
no default-information originate [route-map map-name]
Syntax Description

route-map map-name

(Optional) Routing process will generate the default route if the route map is satisfied.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If a router configured with this command has a route to 0.0.0.0 in the routing table, IS-IS will originate an advertisement for 0.0.0.0 in its LSPs.

Example

In the following configuration, the Cisco IOS software is forced to generate a default external route into an IS-IS  domain:

router isis
! BGP routes will be distributed into IS-IS
redistribute bgp 120
! access list 2 is applied to outgoing routing updates
distribute-list 2 out
default-information originate
! access list 2 defined as giving access to network 100.105.0.0 
access-list 2 permit 100.105.0.0 0.0.255.255
Related Commands

isis metric
redistribute

default-information originate (OSPF)

To generate a default route into an OSPF routing domain, use the default-information originate router configuration command. To disable this feature, use the no form of this command.

default-information originate [always] [metric metric-value] [metric-type type-value]
{level-1 | level-1-2 | level-2} [route-map map-name]
no default-information originate [always] [metric metric-value] [metric-type type-value]
{level-1 | level-1-2 | level-2} [route-map map-name]
Syntax Description

originate

Causes the Cisco IOS software to generate a default external route into an OSPF domain if the software already has a default route and you want to propagate to other routers.

always

(Optional) Always advertises the default route regardless of whether the software has a default route.

metric metric-value

(Optional) Metric used for generating the default route. If you omit a value and do not specify a value using the default-metric router configuration command, the default metric value is 10. The value used is specific to the protocol.

metric-type type-value

(Optional) External link type associated with the default route advertised into the OSPF routing domain. It can be one of the following values:

1---Type 1 external route

2---Type 2 external route

The default is Type 2 external route.

level-1

Level 1 routes are redistributed into other IP routing protocols independently. It specifies if IS-IS advertises network 0.0.0.0 into the Level 1 area.

level-1-2

Both Level 1 and Level 2 routes are redistributed into other IP routing protocols. It specifies if IS-IS advertises network 0.0.0.0 into both levels in a single command.

level-2

Level 2 routes are redistributed into other IP routing protocols independently. It specifies if IS-IS advertises network 0.0.0.0 into the Level 2 subdomain.

route-map map-name

(Optional) Routing process will generate the default route if the route map is satisfied.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Whenever you use the redistribute or the default-information router configuration commands to redistribute routes into an OSPF routing domain, the Cisco IOS software automatically becomes an autonomous system boundary router (ASBR). However, an ASBR does not, by default, generate a default route into the OSPF routing domain. The software still must have a default route for itself before it generates one, except when you have specified the always keyword.

When you use this command for the OSPF process, the default network must reside in the routing table and you must satisfy the route-map map-name keyword. Use the default-information originate always route-map map-name form of the command when you do not want the dependency on the default network in the routing table.

Example

The following example specifies a metric of 100 for the default route redistributed into the OSPF routing domain and an external metric type of Type 1:

router ospf 109
redistribute igrp 108 metric 100 subnets
default-information originate metric 100 metric-type 1
Related Command

redistribute

default-metric (BGP, EGP, OSPF, and RIP)

To set default metric values for the BGP, EGP, OSPF, and RIP routing protocols, use this form of the default-metric router configuration command. To return to the default state, use the no form of this command.

default-metric number
no default-metric
Syntax Description

number

Default metric value appropriate for the specified routing protocol.

Default

Built-in, automatic metric translations, as appropriate for each routing protocol

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The default-metric command is used in conjunction with the redistribute router configuration command to cause the current routing protocol to use the same metric value for all redistributed routes. A default metric helps solve the problem of redistributing routes with incompatible metrics. Whenever metrics do not convert, using a default metric provides a reasonable substitute and enables the redistribution to proceed.

In BGP, this sets the Multi Exit Discriminator (MED) metric. (The name of this metric for BGP Versions 2 and 3 is INTER_AS.)

Example

The following example shows a router in autonomous system 109 using both the RIP and the OSPF routing protocols. The example advertises OSPF-derived routes using the RIP protocol and assigns the OSPF-derived routes a RIP metric of 10.

router rip
default-metric 10
redistribute ospf 109
Related Command

redistribute

default-metric (IGRP and Enhanced IGRP only)

To set metrics for IGRP or Enhanced IGRP, use this form of the default-metric router configuration command. To remove the metric value and restore the default state, use the no form of this command.

default-metric bandwidth delay reliability loading mtu
no default-metric bandwidth delay reliability loading mtu
Syntax Description

bandwidth

Minimum bandwidth of the route in kilobits per second. It can be 0 or any positive integer.

delay

Route delay in tens of microseconds. It can be 0 or any positive number that is a multiple of 39.1 nanoseconds.

reliability

Likelihood of successful packet transmission expressed as a number between 0 and 255. The value 255 means 100 percent reliability; 0 means no reliability.

loading

Effective bandwidth of the route expressed as a number from 0 to 255 (255 is 100 percent loading).

mtu

Minimum maximum transmission unit (MTU) size of the route in bytes. It can be 0 or any positive integer.

Default

Only connected routes and interface static routes can be redistributed without a default metric.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

A default metric is required to redistribute a protocol into IGRP or Enhanced IGRP, unless you use the redistribute command. Automatic metric translations occur between IGRP and Enhanced IGRP. You do not need default metrics to redistributed IGRP or Enhanced IGRP into itself.

Metric defaults have been carefully set to work for a wide variety of networks. Take great care in changing these values.

Keeping the same metrics is supported only when redistributing from IGRP, Enhanced IGRP, or static routes.

Example

The following example takes redistributed RIP metrics and translates them into IGRP metrics with values as follows: bandwidth = 1000, delay = 100, reliability = 250, loading = 100, and mtu =1500.

router igrp 109
network 131.108.0.0
redistribute rip
default-metric 1000 100 250 100 1500
Related Command

redistribute

distance

To define an administrative distance, use the distance router configuration command. To remove a distance definition, use the no form of this command.

distance weight [address mask [access-list-number | name]] [ip]
no distance weight [address mask [access-list-number]] [ip]
Syntax Description

weight

Administrative distance. This can be an integer from 10 to 255. (The values 0 to 9 are reserved for internal use.) Used alone, the argument weight specifies a default administrative distance that the Cisco IOS software uses when no other specification exists for a routing information source. Routes with a distance of 255 are not installed in the routing table.

address

(Optional) IP address in four-part, dotted notation.

mask

(Optional) IP address mask in four-part, dotted-decimal format. A bit set to 1 in the mask argument instructs the software to ignore the corresponding bit in the address value.

access-list-number | name

(Optional) Number or name of a standard IP access list to be applied to incoming routing updates.

ip

(Optional) IP-derived routes for IS-IS. It can be applied independently for IP routes and ISO CLNS routes.

Default

Table 28 lists default administrative distances.


Table 28: Default Administrative Distances
Route Source Default Distance

Connected interface

0

Static route

1

Enhanced IGRP summary route

5

External BGP

20

Internal Enhanced IGRP

90

IGRP

100

OSPF

110

IS-IS

115

RIP

120

EGP

140

Internal BGP

200

Unknown

255

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The access-list-name argument first appeared in Cisco IOS Release 11.2.

Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.

When the optional access list number is used with this command, it is applied when a network is being inserted into the routing table. This behavior allows filtering of networks according to the IP address of the router supplying the routing information. This could be used, as an example, to filter out possibly incorrect routing information from routers not under your administrative control.

The order in which you enter distance commands can affect the assigned administrative distances in unexpected ways (see the "Example" section for further clarification).

Weight values are also subjective; there is no quantitative method for choosing weight values.

For BGP, the distance command sets the administrative distance of the External BGP route.

The show ip protocols EXEC command displays the default administrative distance for a specified routing process.

Example

In the following example, the router igrp global configuration command sets up IGRP routing in autonomous system number 109. The network router configuration commands specify IGRP routing on networks 192.31.7.0 and 128.88.0.0. The first distance router configuration command sets the default administrative distance to 255, which instructs the Cisco IOS software to ignore all routing updates from routers for which an explicit distance has not been set. The second distance command sets the administrative distance for all routers on the Class C network 192.31.7.0 to 90. The third distance command sets the administrative distance for the router with the address 128.88.1.3 to 120.

router igrp 109
network 192.31.7.0
network 128.88.0.0
distance 255
distance 90 192.31.7.0 0.0.0.255
distance 120 128.88.1.3 0.0.0.0
Related Command

distance bgp

distance bgp

To allow the use of external, internal, and local administrative distances that could be a better route to a node, use the distance bgp router configuration command. To return to the default values, use the no form of this command.

distance bgp external-distance internal-distance local-distance
no distance bgp
Syntax Description

external-distance

Administrative distance for BGP external routes. External routes are routes for which the best path is learned from a neighbor external to the autonomous system. Acceptable values are from 1 to 255. The default is 20. Routes with a distance of 255 are not installed in the routing table.

internal-distance

Administrative distance for BGP internal routes. Internal routes are those routes that are learned from another BGP entity within the same autonomous system. Acceptable values are from 1 to 255. The default is 200. Routes with a distance of 255 are not installed in the routing table.

local-distance

Administrative distance for BGP local routes. Local routes are those networks listed with a network router configuration command, often as back doors, for that router or for networks that are being redistributed from another process. Acceptable values are from 1 to 255. The default is 200. Routes with a distance of 255 are not installed in the routing table.

Defaults

external-distance: 20
internal-distance: 200
local-distance: 200

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.

Use this command if another protocol is known to be able to provide a better route to a node than was actually learned via external BGP, or if some internal routes should really be preferred by BGP.


Note Changing the administrative distance of BGP internal routes is considered dangerous and is not recommended. One problem that can arise is the accumulation of routing table inconsistencies, which can break routing.
Example

In the following example, internal routes are known to be preferable to those learned through the IGP, so the administrative distance values are set accordingly:

router bgp 109
network 131.108.0.0
neighbor 129.140.6.6 remote-as 123
neighbor 128.125.1.1 remote-as 47
distance bgp 20 20 200
Related Command

distance bgp

distance eigrp

To allow the use of two administrative distances---internal and external---that could be a better route to a node, use the distance eigrp router configuration command. To reset these values to their defaults, use the no form of this command.

distance eigrp internal-distance external-distance
no distance eigrp

Syntax Description

internal-distance

Administrative distance for Enhanced IGRP internal routes. Internal routes are those that are learned from another entity within the same autonomous system. It can be a value from 1 to  255.

external-distance

Administrative distance for Enhanced IGRP external routes. External routes are those for which the best path is learned from a neighbor external to the autonomous system. It can be a value from 1 to 255.

Default

internal-distance: 90
external-distance: 170

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

An administrative distance is a rating of the trustworthiness of a routing information source, such as an individual router or a group of routers. Numerically, an administrative distance is an integer between 0 and 255. In general, the higher the value, the lower the trust rating. An administrative distance of 255 means the routing information source cannot be trusted at all and should be ignored.

Use the distance eigrp command if another protocol is known to be able to provide a better route to a node than was actually learned via external Enhanced IGRP or if some internal routes should really be preferred by Enhanced IGRP.

Table 28 in the distance command section lists the default administrative distances.

To display the default administrative distance for a specified routing process, use the show ip protocols EXEC command.

Example

In the following example, the router eigrp global configuration command sets up Enhanced IGRP routing in autonomous system number 109. The network router configuration commands specify Enhanced IGRP routing on networks 192.31.7.0 and 128.88.0.0. The first distance router configuration command sets the default administrative distance to 255, which instructs the Cisco  IOS software to ignore all routing updates from routers for which an explicit distance has not been set. The second distance router configuration command sets the administrative distance for all routers on the Class C network 192.31.7.0 to 90. The third distance router configuration command sets the administrative distance for the router with the address 128.88.1.3 to 120.

router eigrp 109
network 192.31.7.0
network 128.88.0.0
distance 255
!
! use caution when executing the next two commands!
!
distance 90 192.31.7.0 0.0.0.255
distance 120 128.88.1.3 0.0.0.0
Related Command

show ip protocols

distribute-list in

To filter networks received in updates, use the distribute-list in router configuration command. To change or cancel the filter, use the no form of this command.

distribute-list access-list-number | name in [type number]
no distribute-list
access-list-number in [type number]
Syntax Description

access-list-number | name

Standard IP access list number or name. The list defines which networks are to be received and which are to be suppressed in routing updates.

in

Applies the access list to incoming routing updates.

type

(Optional) Interface type.

number

(Optional) Interface number on which the access list should be applied to incoming updates. If no interface is specified, the access list will be applied to all incoming updates.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The access-list-name, type, and number arguments first appeared in Cisco IOS Release 11.2.

This command is not supported in IS-IS.

Example

In the following example, the Enhanced IGRP routing process accepts only two networks---network 0.0.0.0 and network 131.108.0.0:

access-list 1 permit 0.0.0.0
access-list 1 permit 131.108.0.0
access-list 1 deny 0.0.0.0 255.255.255.255
router eigrp
network 131.108.0.0
distribute-list 1 in
Related Commands

A dagger () indicates that the command is documented outside this chapter.

access-list (extended)
access-list (standard)
distribute-list out
redistribute

distribute-list out

To suppress networks from being advertised in updates, use the distribute-list out router configuration command. To cancel this function, use the no form of this command.

distribute-list access-list-number | name out [interface-name | routing-process |
autonomous-system-number]
no distribute-list access-list-number out [interface-name | routing-process |
autonomous-system-number]
Syntax Description

access-list-number | name

Standard IP access list number or name. The list defines which networks are to be sent and which are to be suppressed in routing updates.

out

Applies the access list to outgoing routing updates.

interface-name

(Optional) Name of a particular interface.

routing-process

(Optional) Name of a particular routing process, or the keyword static or connected.

autonomous-system-number

(Optional) Autonomous system number.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The access-list-name argument first appeared in Cisco IOS Release 11.2.

When redistributing networks, a routing process name can be specified as an optional trailing argument to the distribute-list command. This causes the access list to be applied to only those routes derived from the specified routing process. After the process-specific access list is applied, any access list specified by a distribute-list command without a process name argument will be applied. Addresses not specified in the distribute-list command will not be advertised in outgoing routing updates.


Note To filter networks received in updates, use the
distribute-list in command.
Examples

The following example would cause only one network to be advertised by a RIP routing process: network 131.108.0.0.

access-list 1 permit 131.108.0.0
access-list 1 deny 0.0.0.0 255.255.255.255
router rip
network 131.108.0.0
distribute-list 1 out
 

In the following example, access list 1 is applied to outgoing routing updates and IS-IS is enabled on Ethernet interface 0. Only network 131.131.101.0 will be advertised in outgoing IS-IS routing updates.

router isis
redistribute ospf 109
distribute-list 1 out
interface Ethernet 0
ip router isis
access-list 1 permit 131.131.101.0 0.0.0.255
Related Commands

A dagger () indicates that the command is documented outside this chapter.

access-list (extended)
access-list (standard)
distribute-list in
redistribute

domain-password

To configure the IS-IS routing domain authentication password, use the domain-password router configuration command. To disable a password, use the no form of this command.

domain-password password
no domain-password [password]
Syntax Description

password

Password you assign.

Default

No password is specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This password is inserted in Level 2 (area router level) link state PDUs (LSPs), complete sequence number PDUs (CSNPs), and partial sequence number PDUs (PSNPs).

Example

The following example assigns an authentication password to the routing domain:

router isis
domain-password flower
Related Command

area-password

eigrp log-neighbor-changes

To enable the logging of changes in Enhanced IGRP neighbor adjacencies, use the eigrp log-neighbor-change router configuration command. To disable the logging of changes in Enhanced IGRP neighbor adjacencies, use the no form of this command.

eigrp log-neighbor-changes
no eigrp log-neighbor-changes

Syntax Description

This command has not arguments or keywords.

Default

No adjacency changes are logged.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Enables the logging of neighbor adjacency changes to monitor the stability of the routing system and to help detect problems.

Example

The following configuration will log neighbor changes for Enhanced IGRP process 209:

router eigrp 209
eigrp log-neighbor-changes

ip as-path access-list

To define a BGP-related access list, use the ip as-path access-list global configuration command. To disable use of the access list, use the no form of this command.

ip as-path access-list access-list-number {permit | deny} as-regular-expression
no ip as-path access-list access-list-number {permit | deny} as-regular-expression
Syntax Description

access-list-number

Integer from 1 to 199 that indicates the regular expression access list number.

permit

Permits access for matching conditions.

deny

Denies access to matching conditions.

as-regular-expression

Autonomous system in the access list using a regular expression. See the "Regular Expressions" appendix in the Access Services Command Reference for information about forming regular expressions.

Default

No access lists are defined.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in This command first appeared in Cisco IOS Release IOS Release  10.0.

You can specify an access list filter on both inbound and outbound BGP routes. In addition, you can assign weights based on a set of filters. Each filter is an access list based on regular expressions. If the regular expression matches the representation of the autonomous system path of the route as an ASCII string, then the permit or deny condition applies. The autonomous system path does not contain the local autonomous system number. Use the ip  as-path  access-list global configuration command to define an BGP access list, and the neighbor router configuration command to apply a specific access list.

Example

The following example specifies that the BGP neighbor with IP address 128.125.1.1 is not sent advertisements about any path through or from the adjacent autonomous system 123:

ip as-path access-list 1 deny _123_
ip as-path access-list 1 deny ^123$
 
router bgp 109
network 131.108.0.0
neighbor 129.140.6.6 remote-as 123
neighbor 128.125.1.1 remote-as 47
neighbor 128.125.1.1 filter-list 1 out
Related Commands

neighbor distribute-list
neighbor filter-list

ip bandwidth-percent eigrp

To configure the percentage of bandwidth that may be used by enhanced IGRP on an interface, use the ip bandwidth-percent eigrp interface configuration command. To restore the default value, use the no form of this command.

ip bandwidth-percent eigrp as-number percent
no ip bandwidth-percent eigrp as-number percent

Syntax Description

as-number

Autonomous system number.

percent

Percent of bandwidth that enhanced IGRP may use.

Default

50 percent

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Enhanced IGRP will use up to 50 percent of the bandwidth of a link, as defined by the bandwidth interface configuration command. This command may be used if some other fraction of the bandwidth is desired. Note that values greater than 100 percent may be configured; this may be useful if the bandwidth is set artificially low for other reasons.

Example
The following example allows enhanced IGRP to use up to 75 percent (42 kbps) of a 56-kbps serial link in autonomous system 209:
 
interface serial 0
bandwidth 56
ip bandwidth-percent eigrp 209 75
Related Command

A dagger () indicates that the command is documented outside this chapter.

bandwidth

ip cgmp

To enable CGMP on an interface of a router connected to a Catalyst 5000 switch, use the ip cgmp interface configuration command. To disable CGMP routing, use the no form of this command.

ip cgmp [proxy]
no ip cgmp
Syntax Description

proxy

(Optional) Enables CGMP and the CGMP proxy function.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

When enabled on an interface, this command triggers a CGMP Join message. This command should only be used on 802 and ATM media. When a no ip cgmp command is issued, a triggered CGMP Leave message is sent for the router's MAC address on the interface for group 0000.0000.0000 (all groups).

When the proxy keyword is specified, the CGMP proxy function is enabled. That is, any router that is not CGMP-capable will be advertised by the proxy router. The proxy router advertises the existence of other non CGMP-capable routers by sending a CGMP Join message with the non CGMP-capable router's MAC address and a group address of 0000.0000.0000.

Examples

In the following example, CGMP is enabled:

ip cgmp
 

In the following example, CGMP and CGMP proxy are enabled:

ip cgmp proxy

ip community-list

To create a community list for BGP and control access to it, use the ip community-list global configuration command. To delete the community list, use the no form of this command.

ip community-list community-list-number {permit | deny} community-number
no ip community-list community-list-number
Syntax Description

community-list-number

Integer from 1 to 99 that identifies one or more permit or deny groups of communities.

permit

Permits access for a matching condition.

deny

Denies access for a matching condition.

community-number

Community number configured by a set community command. Valid value is one of the following:

· A number from 1 to 4294967200. You can specify a single number or multiple numbers separated by a space.

· internet---The Internet community.

· no-export---Do not advertise this route to an EBGP peer.

· no-advertise---Do not advertise this route to any peer (internal or external).

Default

Once you permit a value for the community number, the community list defaults to an implicit deny for everything else.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Example

In the following example, the Cisco IOS software permits all routes except the routes with the communities 5 and 10 or 10 and 15:

ip community-list 1 deny 5 10
ip community-list 1 deny 10 15
ip community-list 1 permit internet
Related Command

set community

ip default-network

To select a network as a candidate route for computing the gateway of last resort, use the ip  default-network global configuration command. To remove a route, use the no form of this command.

ip default-network network-number
no ip default-network network-number
Syntax Description

network-number

Number of the network.

Default

If the router has a directly connected interface onto the specified network, the dynamic routing protocols running on that router will generate (or source) a default route. For RIP, this is flagged as the pseudonetwork 0.0.0.0; for IGRP, it is the network itself, flagged as an exterior route.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The Cisco IOS software uses both administrative distance and metric information to determine the default route. Multiple ip default-network commands can be given. All candidate default routes, both static (that is, flagged by ip default-network) and dynamic, appear in the routing table preceded by an asterisk.

If the IP routing table indicates that the specified network number is subnetted and a non-zero subnet number is specified, then the system will automatically configure a static summary route. This static summary route is configured instead of a default network. The effect of the static summary route is to cause traffic destined for subnets that are not explicitly listed in the IP routing table to be routed using the specified subnet.

Examples

The following example defines a static route to network 10.0.0.0 as the static default route:

ip route 10.0.0.0 255.0.0.0 131.108.3.4
ip default-network 10.0.0.0

If the following command was issued on a router not connected to network 129.140.0.0, the software might choose the path to that network as a default route when the network appeared in the routing table:

ip default-network 129.140.0.0
Related Command

show ip route

ip dvmrp accept-filter

To configure an acceptance filter for incoming DVMRP reports, use the ip dvmrp accept-filter interface configuration command. To disable this feature, use the no form of this command.

ip dvmrp accept-filter access-list-number [distance] neighbor-list access-list-number
no ip dvmrp accept-filter access-list-number [distance] neighbor-list access-list-number
Syntax Description

access-list-number

Number of a standard IP access list. This can be a number from 0 to 99. A value of 0 means that all sources are accepted with the configured distance.

neighbor-list
access-list number

Number of a neighbor list. DVMRP reports are accepted only by those neighbors on the list.

distance

(Optional) Administrative distance to the destination.

Default

All destination reports are accepted with a distance of 0. Default settings accept reports from all neighbors.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The neighbor-list keyword and access-list-number argument first appeared in Cisco IOS 11.2.

Any sources that match the access list are stored in the DVMRP routing table with distance.

The distance is used to compare with the same source in the unicast routing table. The route with the lower distance (either the route in the unicast routing table or that in the DVMRP routing table) takes precedence when computing the Reverse Path Forwarding (RPF) interface for a source of a multicast packet.

By default, the administrative distance for DVMRP routes is 0. This means that they always take precedence over unicast routing table routes. If you have two paths to a source, one through unicast routing (using PIM as the multicast routing protocol) and another path using DVMRP (unicast and multicast routing), and if you want to use the PIM path, use the ip dvmrp accept-filter command to increase the administrative distance for DVMRP routes. For example, if the unicast routing protocol is Enhanced IGRP, which has a default administrative distance of 90, you could define and apply the following access list so the RPF interface used to accept multicast packets will be through the Enhanced IGRP/PIM path:

ip dvmrp accept-filter 1 100
access-list 1 permit 0.0.0.0 255.255.255.255
Example

The following example applies access list 57 to the interface and sets a distance of 4:

access-list 57 permit 131.108.0.0 0.0.255.255
access-list 57 permit 198.92.37.0 0.0.0.255
access-list 57 deny 0.0.0.0 255.255.255.255
ip dvmrp accept-filter 57 4
Related Commands

A dagger () indicates that the command is documented outside this chapter.

distance
ip dvmrp metric
show ip dvmrp route

tunnel mode

ip dvmrp auto-summary

To enable DVMRP auto-summarization if it was disabled, use the ip dvmrp auto-summary interface configuration command. To disable the feature, use the no form of this command.

ip dvmrp auto-summary
no ip dvmrp auto-summary

Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

DVMRP auto-summarization occurs when a unicast subnet route is collapsed into a classful network number route. This occurs when the subnet is a different network number than the IP address of the interface (or tunnel) over which the advertisement is sent. If the interface is unnumbered, the network number of the numbered interface the unnumbered interface points to is compared.

You might want to disable this feature if the information you want to send using the ip dvmrp summary-address command is the same as the information that would be sent using DVMRP auto-summarization.

Example

The following example disables DVMRP auto-summarization:

no ip dvmrp auto-summary
Related Command

ip dvmrp summary-address

ip dvmrp default-information

To advertise network 0.0.0.0 to DVMRP neighbors on an interface, use the ip dvmrp default-information interface configuration command. To prevent the advertisement, use the no form of this command.

ip dvmrp default-information {originate | only}
no ip dvmrp default-information {originate | only}
Syntax Description

originate

Other routes more specific than 0.0.0.0 can also be advertised.

only

No DVMRP routes other than 0.0.0.0 are advertised.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command should only be used when the router is a neighbor to mrouted version 3.6 machines. The mrouted protocol is a public domain implementation of DVMRP.

You can use the ip dvmrp metric command with the ip dvmrp default-information command to tailor the metric used when advertising the default route 0.0.0.0. By default, metric 1 is used.

Example

The following example configures the Cisco IOS software to advertise network 0.0.0.0, in addition to other networks, to DVMRP neighbors:

ip dvmrp default-information originate
Related Command

ip dvmrp metric

ip dvmrp metric

To configure the metric associated with a set of destinations for DVMRP reports, use the ip dvmrp metric interface configuration command. To disable this function, use the no form of this command.

ip dvmrp metric metric [list access-list-number] [[protocol process-id] | dvmrp]
ip dvmrp metric metric route-map map-name

no ip dvmrp metric metric [list access-list-number] [[protocol process-id] | dvmrp]
no ip dvmrp metric metric route-map map-name
Syntax Description

metric

Metric associated with a set of destinations for DVMRP reports. It can be a value from 0 to 32. A value of 0 means that the route is not advertised. A value of 32 is equivalent to infinity (unreachable).

list access-list-number

(Optional) Number of an access list. If you specify this argument, only the multicast destinations that match the access list are reported with the configured metric. Any destinations not advertised because of split horizon do not use the configured metric.

protocol

(Optional) Name of unicast routing protocol, such as bgp, eigrp, igrp, isis, ospf, rip, or static or dvmrp.

If you specify these arguments, only routes learned by the specified routing protocol are advertised in DVMRP report messages.

process-id

(Optional) Process ID number of the unicast routing protocol.

dvmrp

(Optional) Allows routes from the DVMRP routing table to be advertised with the configured metric or filtered.

route-map map-name

Unicast routes are subject to route-map conditions before being injected into DVMRP. Route-maps cannot be used for DVMRP routes.

Default

No metric is preconfigured. Only directly connected subnets and networks are advertised to neighboring DVMRP routers.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.2. The route-map keyword first appeared in Cisco IOS Release 11.1.

When PIM is configured on an interface and DVMRP neighbors are discovered, the Cisco IOS software sends DVMRP report messages for directly connected networks. The ip dvmrp metric command enables DVMRP report messages for multicast destinations that match the access list. Usually, the metric for these routes is 1. Under certain circumstances, you might want to tailor the metric used for various unicast routes. This command lets you configure the metric associated with a set of destinations for Reports sent out this interface.

You can use the access-list-number argument in conjunction with the protocol process-id arguments to selectively list the destinations learned from a given routing protocol.

To display DVMRP activity, use the debug ip dvmrp command.

Example

The following example connects a PIM cloud to a DVMRP cloud. Access list 1 permits the sending of DVMRP reports to the DVMRP routers advertising all sources in the 198.92.35.0 network with a metric of 1. Access list 2 permits all other destinations, but the metric of 0 means that no DVMRP reports are sent for these destinations.

access-list 1 permit 198.92.35.0 0.0.0.255
access-list 1 deny 0.0.0.0 255.255.255.255
access-list 2 permit 0.0.0.0 255.255.255.255
interface tunnel 0
ip dvmrp metric 1 list 1
ip dvmrp metric 0 list 2
Related Commands

Two daggers () indicate that the command is documented in the Debug Command Reference.

debug ip dvmrp
ip dvmrp accept-filter

ip dvmrp metric-offset

To change the metrics of advertised DVMRP routes and thus favor or not favor a certain route, use the ip dvmrp metric-offset interface configuration command. To restore the default values, use the no form of this command.

ip dvmrp metric-offset [in | out] increment
no ip dvmrp metric-offset
Syntax Description

in

(Optional) The increment value is added to incoming DVMRP reports and is reported in mrinfo replies. The default for in is 1.

out

(Optional) The increment value is added to outgoing DVMRP reports for routes from the DVMRP routing table. The default for out is 0.

increment

Value added to the metric of a DVMRP route advertised in a Report message.

Defaults

If neither in nor out is specified, in is the default.
The default for in is 1.
The default for out is 0.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use this command to influence which routes are used, as you prefer. The DVMRP metric is in hop count.

Example

The following example adds 10 to the incoming DVMRP reports:

ip dvmrp metric-offset 10

ip dvmrp reject-non-pruners

To configure the router so that it will not peer with a DVMRP neighbor if that neighbor does not support DVMRP pruning or grafting, use the ip dvmrp reject-non-pruners interface configuration command. To disable the feature, use the no form of this command.

ip dvmrp reject-non-pruners
no ip dvmrp reject-non-pruners

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

By default, the router accepts all DVMRP neighbors as peers, regardless of their DVMRP capability or lack thereof.

Use this command to prevent a router from peering with a DVMRP neighbor if that neighbor does not support DVMRP pruning or grafting. If the router receives a DVMRP Probe or Report message without the Prune-Capable flag set, the router logs a syslog message and discards the message.

Note that this command prevents peering with neighbors only. If there are any non-pruning routers multiple hops away (downstream toward potential receivers) that are not rejected, then a non-pruning DVMRP network might still exist.

Example

The following example configures the router not to peer with DVMRP neighbors that do not support pruning or grafting:

ip dvmrp reject-non-pruners

ip dvmrp routehog-notification

To change the number of DVMRP routes allowed before a syslog warning message is issued, use the ip  dvmrp routehog-notification global configuration command. To restore the default value, use the no form of this command.

ip dvmrp routehog-notification route-count
no ip dvmrp routehog-notification
Syntax Description

route-count

Number of routes allowed before a syslog message is triggered.

Default

10,000 routes

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.2.

This command configures how many DVMRP routes are accepted on each interface within an approximate one-minute interval before a syslog message is issued, warning that there might be a route surge occurring. The warning is typically used to detect quickly when people have misconfigured their routers to inject a large number of routes into the MBONE.

The show ip igmp interface command displays a running count of routes. When the count is exceeded, an "*** ALERT ***" is appended to the line.

Example

The following example lowers the threshold to 8000 routes:

ip dvmrp routehog-notification 8000
Related Command

show ip igmp interface

ip dvmrp route-limit

To change the limit on the number of DVMRP routes that can be advertised over an interface enabled to run DVMRP, use the ip dvmrp route-limit global configuration command. To configure no limit, use the no form of this command.

ip dvmrp route-limit count
no ip dvmrp route-limit
Syntax Description

count

Number of DVMRP routes that can be advertised.

Default

7000 routes

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Interfaces enabled to run DVMRP include a DVMRP tunnel, an interface where a DVMRP neighbor has been discovered, or an interface configured to run ip dvmrp unicast-routing.

The ip dvmrp route-limit command is automatically generated to the configuration file when at least one interface is enabled for multicast routing. This command is necessary to prevent misconfigured ip  dvmrp metric commands from causing massive route injection into the multicast backbone (MBONE).

Example

The following example changes the limit to 5000 DVMRP routes allowed to be advertised:

ip dvmrp route-limit 5000
Related Command

ip dvmrp unicast-routing

ip dvmrp summary-address

To configure a DVMRP summary address to be advertised out the interface, use the ip dvmrp summary-address interface configuration command. To remove the summary address, use the no form of this command.

ip dvmrp summary-address address mask [metric value]
no ip dvmrp summary-address address mask [metric value]
Syntax Description

address

Summary IP address that is advertised instead of the more specific route.

mask

Mask on the summary IP address.

metric value

(Optional) Metric that is advertised with the summary address. The default is 1.

Default

metric value is 1

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

If there is at least a single, more specific route in the unicast routing table that matches the specified address and mask, the summary is advertised. Routes in the DVMRP routing table are not candidates for summarization.

When the metric keyword is specified, the summary is advertised with that metric value.

Multiple summary address can be configured on an interface. When multiple overlapping summary addresses are configured on an interface, the one with the longest mask takes preference.

Example

The following example configures the DVMRP summary address 171.69.0.0 to be advertised out the interface:

ip dvmrp summary-address 171.69.0.0 255.255.0.0 metric 1
Related Command

ip dvmrp auto-summary

ip dvmrp unicast-routing

To enable DVMRP unicast routing on an interface, use the ip dvmrp unicast-routing interface configuration command. To disable the feature, use the no form of this command.

ip dvmrp unicast-routing
no ip dvmrp unicast-routing

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Enabling DVMRP unicast routing means that routes in DVMRP Report messages are cached by the router in a DVMRP routing table. When PIM is running, these routes may get preference over routes in the unicast routing table. This allows PIM to run on the MBONE topology when it is different from the unicast topology.

DVMRP unicast routing can run on all interfaces, including GRE tunnels. On DVMRP tunnels, it runs by virtue of doing DVMRP multicast routing. This command does not enable DVMRP multicast routing among Cisco routers. However, if there is a DVMRP-capable multicast router, the Cisco router will do PIM/DVMRP multicast routing interaction.

Example

The following example enables DVMRP unicast routing:

ip dvmrp unicast-routing
Related Command

ip dvmrp route-limit

ip gdp

To enable GDP routing on an interface, use the ip gdp interface configuration command. To disable GDP routing, use the no form of this command.

ip gdp [priority number | reporttime seconds | holdtime seconds]
no ip gdp
Syntax Description

priority number

(Optional) Alters the GDP priority; default is a priority of 100. A larger number indicates a higher priority.

reporttime seconds

(Optional) Alters the GDP reporting interval; the default is 5  seconds for broadcast media such as Ethernets, and never for nonbroadcast media such as X.25.

holdtime seconds

(Optional) Alters the GDP default hold time of 15 seconds.

Defaults

priority: 100
reporttime: 5 seconds for broadcast media; 0 for nonbroadcast media
holdtime: 15 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

When enabled on an interface, GDP updates report the primary and secondary IP addresses of that interface.


Note In future Cisco IOS software releases the Gateway Discovery Protocol will not be supported.
Example

In the following example, GDP is enabled on Ethernet interface 1 with a report time of 10 seconds, and priority and hold time set to their defaults (because none are specified):

ip gdp reporttime 10

ip hello-interval eigrp

To configure the hello interval for the Enhanced IGRP routing process designated by an autonomous system number, use the ip hello-interval eigrp interface configuration command. To restore the default value, use the no form of this command.

ip hello-interval eigrp autonomous-system-number seconds
no ip hello-interval eigrp autonomous-system-number seconds

Syntax Description

autonomous-system-number

Autonomous system number.

seconds

Hello interval, in seconds.

Defaults

For low-speed, NBMA networks: 60 seconds
For all other networks: 5 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The default of 60 seconds applies only to low-speed, nonbroadcast, multiaccess (NBMA) media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command. Note that for the purposes of Enhanced IGRP, Frame Relay and SMDS networks may or may not be considered to be NBMA. These networks are considered NBMA if the interface has not been configured to use physical multicasting; otherwise they are considered not to be NBMA.

Example

The following example sets the hello interval for Ethernet interface 0 to 10 seconds:

interface ethernet 0
ip hello-interval eigrp 109 10
Related Command

ip hold-time eigrp

ip hold-time eigrp

To configure the hold time for a particular Enhanced IGRP routing process designated by the autonomous system number, use the ip hold-time eigrp interface configuration command. To restore the default value, use the no form of this command.

ip hold-time eigrp autonomous-system-number seconds
no ip hold-time eigrp autonomous-system-number seconds

Syntax Description

autonomous-system-number

Autonomous system number.

seconds

Hold time, in seconds.

Defaults

For low-speed, NBMA networks: 180 seconds
For all other networks: 15 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

On very congested and large networks, the default hold time might not be sufficient time for all routers and access servers to receive hello packets from their neighbors. In this case, you may want to increase the hold time.

We recommend that the hold time be at least three times the hello interval. If a router does not receive a hello packet within the specified hold time, routes through this router are considered unavailable.

Increasing the hold time delays route convergence across the network.

The default of 180 seconds hold time and 60 seconds hello interval apply only to low-speed, nonbroadcast, multiaccess (NBMA) media. Low speed is considered to be a rate of T1 or slower, as specified with the bandwidth interface configuration command.

Example

The following example sets the hold time for Ethernet interface 0 to 40 seconds:

interface ethernet 0
ip hold-time eigrp 109 40
Related Command

ip hello-interval eigrp

ip igmp access-group

To control the multicast groups that hosts on the subnet serviced by an interface can join, use the ip  igmp access-group interface configuration command. To disable groups on an interface, use the no form of this command.

ip igmp access-group access-list-number version
no ip igmp access-group access-list-number version

Syntax Description

access-list-number

Number of a standard IP access list. This can be a number from 1 to 99.

version

Changes IGMP version. Default is version 2.

Default

All groups are allowed on an interface.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, hosts serviced by Ethernet interface 0 can join the group 225.2.2.2 only:

access-list 1 225.2.2.2 0.0.0.0
interface ethernet 0
ip igmp access-group 1
Related Command

ip igmp join-group

ip igmp join-group

To have the router join a multicast group, use the ip igmp join-group interface configuration command. To cancel membership in a multicast group, use the no form of this command.

ip igmp join-group group-address
no ip igmp join-group group-address

Syntax Description

group-address

Address of the multicast group. This is a multicast IP address in four-part, dotted notation.

Default

No multicast group memberships are predefined.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

IP packets that are addressed to the group address are passed to the IP client process in the Cisco IOS software.

If all the multicast-capable routers and access servers that you administer are members of a multicast group, pinging that group causes all routers to respond. This can be a useful administrative and debugging tool.

Another reason to have a router join a multicast group is when other hosts on the network have a bug in IGRP that prevents them from correctly answering IGMP queries. Having the router join the multicast group causes upstream routers to maintain multicast routing table information for that group and keep the paths for that group active.

Example

In the following example, the router joins multicast group 225.2.2.2:

ip igmp join-group 225.2.2.2
Related Commands

A dagger () indicates that the command is documented outside this chapter.

ip igmp access-group
ping (privileged)
ping (user)

ip igmp query-interval

To configure the frequency at which the Cisco IOS software sends IGMP host-query messages, use the ip igmp query-interval interface configuration command. To return to the default frequency, use the no form of this command.

ip igmp query-interval seconds
no ip igmp query-interval

Syntax Description

seconds

Frequency, in seconds, at which to transmit IGMP host-query messages. The can be a number from 0 to 65535. The default is 60  seconds.

Default

60 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Multicast routers send host membership query messages (referred to as host-query messages) to discover which multicast groups have members on the router's attached networks. Hosts respond with IGMP report messages indicating that they wish to receive multicast packets for specific groups (that is, indicating that the host wants to become a member of the group). Host-query messages are addresses to the all-hosts multicast group, which has the address 224.0.0.1, and have an IP TTL value of 1.

The designated router for a LAN is the only router that sends IGMP host-query messages.

If the router hears no queries for the timeout period, it becomes the querier.


Note Changing this value may severely impact multicast forwarding.
Example

The following example changes the frequency at which the designated router sends IGMP host-query messages to 2 minutes:

interface tunnel 0
ip igmp query-interval 120
Related Commands

ip pim query-interval
show ip igmp groups

ip igmp query-max-response-time

To configure the maximum response time advertised in IGMP queries, use the ip igmp query-max-response-time interface configuration command. To restore the default value, use the no form of this command.

ip igmp query-max-response-time seconds
no ip igmp query-max-response-time
Syntax Description

seconds

Maximum response time, in seconds, advertised in IGMP queries. The default value is 10 seconds.

Default

10 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

This command is valid only when IGMP Version 2 is running.

This command controls how long the responder has to respond to an IGMP Query message before the router deletes the group. Configuring a value less than 10 seconds enables the router to prune groups faster.

Keep in mind that if the hosts do not respond fast enough, they might be pruned when you don't want them to be. Therefore, the hosts must know to respond faster than 10 seconds (or the value you configure).

Example

The following example configures a maximum response time of 8 seconds:

ip igmp query-max-response-time 8
Related Commands

ip pim query-interval
show ip igmp groups

ip igmp query-timeout

To configure the timeout time before the router takes over as the querier for the interface, after the previous querier has stopped querying, use the ip  igmp query-timeout interface configuration command. To restore the default value, use the no form of this command.

ip igmp query-timeout seconds
no ip igmp query-timeout
Syntax Description

seconds

Number of seconds that the router waits after the previous querier has stopped querying and before it takes over as the querier.

Default

2 * the query interval

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1. It requires IGMP Version 2.

By default, the router waits 2 * the query interval specified by the ip igmp query-interval command, after which, if it has heard no queries, it becomes the querier. By default, the ip igmp query-interval defaults to 30 seconds, which means the ip igmp query-timeout defaults to 60 seconds.

Example

The following example configures the router to wait 30 seconds from the time it received the last query before it takes over as the querier for the interface:

ip igmp query-timeout 30
Related Command

ip igmp query-interval

ip igmp static-group

To configure the router to be a statically connected member of the specified group on the interface, use the ip  igmp static-group interface configuration command. To remove the router as a member of the group, use the no form of this command.

ip igmp static-group group-address
no ip igmp static-group group-address
Syntax Description

group-address

IP multicast group address of a group that the router is a member of.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

When this command is configured, packets to the group are fast-switched out this interface, provided that packets were received on the correct RPF interface. This is unlike configuring the ip igmp join-group command, which also causes packets to be passed up to the process level.

If the ip igmp join-group command is configured for the same group address as the ip  igmp  static-group command, the ip igmp join-group command takes precedence, and the group behaves like a locally joined group.

Example

The following example configures 239.100.100.101 on Ethernet 0:

interface ethernet 0
ip igmp static-group 239.100.100.101
Related Command

ip igmp join-group

ip igmp version

To configure which version of IGMP the router uses, use the ip  igmp version interface configuration command. To restore the default value, use the no form of this command.

ip igmp version {2 | 1}
no ip version
Syntax Description

2

IGMP Version 2.

1

IGMP Version 1.

Default

Version 2

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

All systems on the subnet must support the same version. The router does not automatically detect Version 1 systems and switch to Version 1, as did prior releases of the Cisco IOS software.

You would configure Version 1 if your hosts do not support Version 2.

Some commands require IGMP Version 2, such as the ip igmp query-max-response-time and ip igmp query-timeout commands.

Example

The following example configures the router to use IGMP Version 1:

ip igmp version 1
Related Commands

ip igmp query-max-response-time
ip igmp query-timeout
show ip igmp groups
show ip igmp interface

ip irdp

To enable ICMP Router Discovery Protocol (IRDP) processing on an interface, use the ip irdp interface configuration command. To disable IRDP routing, use the no form of this command.

ip irdp [multicast | holdtime seconds | maxadvertinterval seconds | minadvertinterval
seconds | preference number | address address [number]]
no ip irdp
Syntax Description

multicast

(Optional) Use the multicast address (224.0.0.1) instead of IP broadcasts.

holdtime seconds

(Optional) Length of time in seconds advertisements are held valid. Default is three times the maxadvertinterval value. Must be greater than maxadvertinterval and cannot be greater than 9000 seconds.

maxadvertinterval seconds

(Optional) Maximum interval in seconds between advertisements. The default is 600 seconds.

minadvertinterval seconds

(Optional) Minimum interval in seconds between advertisements. The default is 0.75 times the maxadvertinterval. If you change the maxadvertinterval value, this value defaults to three-quarters of the new value.

preference number

(Optional) Preference value. The allowed range is -231 to 231. The default is 0. A higher value increases the router's preference level. You can modify a particular router so that it will be the preferred router to which others home.

address address [number]

(Optional) IP address (address) to proxy-advertise, and optionally, its preference value (number).

Default

Disabled

When enabled, IRDP uses these defaults:

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you change maxadvertinterval, the other two values also change, so it is important to change maxadvertinterval first before changing either holdtime or minadvertinterval.

The ip irdp multicast command allows for compatibility with Sun Microsystems Solaris, which requires IRDP packets to be sent out as multicasts. Many implementations cannot receive these multicasts; ensure end-host ability before using this command.

Example

The following example illustrates how to set the various IRDP processes:

! enable irdp on interface Ethernet 0
interface ethernet 0
ip irdp
! send IRDP advertisements to the multicast address ip irdp multicast
! increase router preference from 100 to 50 ip irdp preference 50
! set maximum time between advertisements to 400 secs ip irdp maxadvertinterval 400
! set minimum time between advertisements to 100 secs ip irdp minadvertinterval 100
! advertisements are good for 6000 seconds ip irdp holdtime 6000
! proxy-advertise 131.108.14.5 with default router preference ip irdp address 131.108.14.5
! proxy-advertise 131.108.14.6 with preference of 50 ip irdp address 131.108.14.6 50

ip local policy route-map

To identify a route map to use for local policy routing, use the ip local policy route-map global configuration command. To disable local policy routing, use the no form of this command.

ip local policy route-map map-tag
no ip local policy route-map map-tag
Syntax Description

map-tag

Name of the route map to use for local policy routing. The name must match a map-tag specified by a route-map command.

Default

Packets that are generated by the router are not policy-routed.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1

Packets that are generated by the router are not normally policy-routed. However, you can use this command to policy-route such packets. You might enable local policy routing if you want packets originated at the router to take a route other than the obvious shortest path.

The ip local policy route-map command identifies a route map to use for local policy routing. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which packets should be policy-routed. The set commands specify the set actions---the particular policy routing actions to perform if the criteria enforced by the match commands are met. The no ip local policy route-map command deletes the reference to the route map and disables local policy routing.

Example

In the following example, packets with a destination IP address matching that allowed by extended access list 131 are sent to the router at IP address 174.21.3.20:

ip local policy route-map xxx
!
route-map xxx
match ip address 131
set ip next-hop 174.21.3.20
Related Commands

match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop
show ip local policy

ip mroute

To configure a multicast static route (mroute), use the ip mroute global configuration command. To remove the route, use the no form of this command.

ip mroute source mask [protocol as-number] {rpf-address | interface} [distance]
no ip mroute source mask [protocol as-number] {rpf-address | interface} [distance]
Syntax Description

source

IP address of the multicast source.

mask

Mask on the IP address of the multicast source.

protocol

(Optional) Unicast routing protocol that you are using.

as-number

(Optional) Autonomous system number of the routing protocol you are using, if applicable.

rpf-address

Incoming interface for the mroute. If the Reverse Path Forwarding address rpf-address is a PIM neighbor, PIM Joins, Grafts, and Prunes are sent to it. The rpf-address can be a host IP address of a directly connected system or a network/subnet number. When it is a route, a recursive lookup is done from the unicast routing table to find a directly connected system. If rpf-address is not specified, the interface type number is used as the incoming interface.

interface

Interface type and number for the mroute.

distance

(Optional) Determines whether a unicast route, a DVMRP route, or a static mroute should be used for the RPF lookup. The lower distances have better preference. If the static mroute has the same distance as the other two RPF sources, the static mroute will take precedence. The default is 0.

Default

distance: 0

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

This command allows you to statically configure where multicast sources are located (even though the unicast routing table says something different).

When a source range is specified, the rpf-address applies only to those sources.

Examples

The following example configures all sources via a single interface (in this case, a tunnel):

ip mroute 0.0.0.0 255.255.255.255 tunnel0
 

The following example configures all specific sources within a network number are reachable through 171.68.10.13:

ip mroute 171.69.0.0 255.255.0.0 171.68.10.13
 

The following example causes this multicast static route to take effect if the unicast routes for any given destination go away:

ip mroute 0.0.0.0 255.255.255.255 serial0 200

ip mroute-cache

To configure IP multicast fast switching, use the ip mroute-cache interface configuration command. To disable IP multicast fast switching, use the no form of this command.

ip mroute-cache
no ip mroute-cache
Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

If fast switching is disabled on an incoming interface for a multicast routing table entry, the packet will be sent at process level for all interfaces in the outgoing interface list.

If fast switching is disabled on an outgoing interface for a multicast routing table entry, the packet is process level switched for that interface, but might be fast-switched for other interfaces in the outgoing interface list.

When fast switching is enabled (like unicast routing), debug messages are not logged. If you want to log debug messages, disable fast switching.

Example

The following example disables IP multicast fast switching on the interface:

no ip mroute-cache

ip multicast boundary

To configure an administratively scoped boundary, use the ip  multicast boundary interface configuration command. To remove the boundary, use the no form of this command.

ip multicast boundary access-list-number
no ip multicast boundary
Syntax Description

access-list-number

Standard IP access list number identifying an access list that controls the range of group addresses affected by the boundary.

Default

There is no boundary.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

You might set up a boundary to keep multicast packets from being forwarded.

Example

The following example sets up a boundary for all administratively scoped addresses:

access-list 1 deny 239.0.0.0 0.255.255.255
access-list 1 permit 224.0.0.0 15.255.255.255
interface ethernet 0
ip multicast boundary 1
Related Command

access-list (standard)

ip multicast cache-headers

To allocate a circular buffer to store IP multicast packet headers that the router receives, use the ip  multicast cache-headers global configuration command. To disable the feature, use the no form of this command.

ip multicast cache-headers
no
ip multicast cache-headers
Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

You can store IP multicast packet headers in a cache and then display them to find out:


Note This feature allocates a circular buffer of approximately 32 kilobytes. Do not configure this feature if you are low on memory.

Use the show ip mpacket command to display the buffer.

Example

The following example allocates a buffer to store IP multicast packet headers:

ip multicast cache-headers

Related Command

show ip mpacket

ip multicast helper-map

To allow IP multicast routing in a multicast-capable internetwork between two broadcast-only internetworks, use the ip multicast helper-map interface configuration command. To prevent this feature, use the no form of this command.

ip multicast helper-map {group-address | broadcast} {broadcast-address |
multicast-address} extended-access-list-number
no multicast helper-map {group-address | broadcast} {broadcast-address |
multicast-address} extended-access-list-number
Syntax Description

group-address

Multicast group address of traffic to be converted to broadcast traffic. Use this with the broadcast-address.

broadcast

Specifies the traffic is being converted from broadcast to multicast. Use this with the multicast-address.

broadcast-address

Address to which broadcast traffic is sent. Use this with the group-address.

multicast-address

Specifies the IP multicast address to which the converted traffic is directed. Use this with the broadcast keyword.

extended-access-list number

IP extended access list that controls which broadcast packets are translated, based on the UDP port number.

Default

No conversion between broadcast and multicast occurs.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

When a multicast-capable internetwork is between two broadcast-only internetworks, you can convert broadcast traffic to multicast at the first hop router, and convert it back to broadcast at the last hop router before delivering the packets to the broadcast clients. Thus, you can take advantage of the multicast capability of the intermediate multicast internetwork. This feature prevents unnecessary replication at the intermediate routers and allows multicast fast switching in the multicast internetwork.

Example

The following example illustrates how a helper address on two routers converts from broadcast to multicast and back to broadcast.

The configuration on the first hop router converts a broadcast stream arriving at incoming interface Ethernet 0 destined to UDP port 4000 to a multicast stream. The access list denies other traffic from being forwarded into the multicast cloud. The traffic is sent to group address 224.5.5.5. Because fast switching does not perform such a conversion, the ip  forward-protocol command causes the proper process level to perform the conversion.

The configuration on the last hop router converts the multicast stream at incoming interface Ethernet  1 back to broadcast. Again, all multicast traffic emerging from the multicast cloud is not supposed to be converted to broadcast, only the traffic destined for UDP port 4000.

First Hop Router
interface ethernet 0
ip multicast helper-map broadcast 224.5.5.5 120
ip pim dense-mode
!
access-list 120 permit any any udp 4000
access-list 120 deny any any udp
ip forward-protocol udp 4000
Last Hop Router
interface ethernet 1
ip multicast helper-map 224.5.5.5 178.21.34.255 135
ip pim dense-mode
!
access-list 135 permit any any udp 4000
access-list 135 deny any any udp
ip forward-protocol udp 4000
Related Command

ip forward-protocol

ip multicast rate-limit

To control the rate a sender from the source-list can send to a multicast group in the group-list, use the ip multicast rate-limit interface configuration command. To remove the control, use the no form of this command.

ip multicast rate-limit {in | out} [video | whiteboard] [group-list access-list] [source-list
access-list] kbps
no multicast rate-limit {in | out} [video | whiteboard] [group-list access-list] [source-list
access-list] kbps
Syntax Description

in

Only packets at the rate of kbps or slower are accepted on the interface.

out

Only a maximum of kbps will be transmitted on the interface.

video

(Optional) Rate limiting is performed based on the UDP port number used by video traffic. Video traffic is identified by consulting the sdr cache.

whiteboard

(Optional) Rate limiting is performed based on the UDP port number used by whiteboard traffic. Whiteboard traffic is identified by consulting the sdr cache.

group-list access-list

(Optional) Specifies the access list number that controls which multicast groups are subject to the rate limit.

source-list access-list

(Optional) Specifies the access list number that controls which senders are subject to the rate limit.

kbps

Kilobits-per-second transmission rate. Any packets sent at greater than this value are silently discarded. If this command is configured, the default value is 0, meaning that no traffic is permitted. Therefore, set this to a positive value if you use this command.

Default

If this command is not configured, there is no rate limit.
If this command is configured, kbps defaults to 0, meaning that no traffic is permitted.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

If a router receives a packet and in the last second the user has sent over the limit, the packet is dropped; otherwise, it is forwarded.

For video or whiteboard to work, the ip sdr listen command must be enabled so the port number can be obtained from the sdr cache. If ip sdr listen is not enabled, or the group address is not in the sdr cache, no rate-limiting is done for the group.

Example

In the following example, packets to any group from sources in network 171.69.0.0 will have their packets rate-limited to 64 kbps:

interface serial 0
ip multicast rate-limit out group-list 1 source-list 2 64
access-list 1 permit 0.0.0.0 255.255.255.255
access-list 2 permit 171.69.0.0 0.0.255.255
Related Command

ip sdr listen

ip multicast-routing

To enable IP multicast routing, use the ip multicast-routing global configuration command. To disable IP multicast routing, use the no form of this command.

ip multicast-routing
no ip multicast-routing

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When IP multicast routing is disabled, the Cisco IOS software does not forward any multicast packets.

Example

The following example enables IP multicast routing:

ip multicast-routing
Related Command

ip pim

ip multicast ttl-threshold

To configure the time-to-live (TTL) threshold of packets being forwarded out an interface, use the ip multicast ttl-threshold interface configuration command. To return to the default TTL threshold, use the no form of this command.

ip multicast ttl-threshold ttl-value
no ip multicast ttl-threshold [ttl-value]
Syntax Description

ttl-value

Time-to-live value, in hops. It can be a value from 0 to 255. The default value is 0, which means that all multicast packets are forwarded out the interface.

Default

0, which means that all multicast packets are forwarded out the interface.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Only multicast packets with a TTL value greater than the threshold are forwarded out the interface.

You should configure the TTL threshold only on border routers. Conversely, routers on which you configure a TTL threshold value automatically become border routers.

This command replaces the ip multicast-threshold command, which is obsolete.

Example

In the following example, you set the TTL threshold on a border router to 200, which is a very high value. This means that multicast packets must have a TTL greater than 200 in order to be forwarded out this interface. Multicast applications generally set this value well below 200. Therefore, setting a value of 200 means that no packets will be forwarded out the interface.

interface tunnel 0
ip multicast ttl-threshold 200

ip ospf authentication-key

To assign a password to be used by neighboring routers that are using OSPF's simple password authentication, use the ip ospf authentication-key interface configuration command. To remove a previously assigned OSPF password, use the no form of this command.

ip ospf authentication-key password
no ip ospf authentication-key
Syntax Description

password

Any continuous string of characters that can be entered from the keyboard up to 8 bytes in length.

Default

No password is specified.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The password created by this command is used as a "key" that is inserted directly into the OSPF header when the Cisco IOS software originates routing protocol packets. A separate password can be assigned to each network on a per-interface basis. All neighboring routers on the same network must have the same password to be able to exchange OSPF information.


Note The Cisco IOS software will use this key only when authentication is enabled for an area with the
area authentication router configuration command.
Example

In the following example, the authentication key is enabled with the string yourpass:

ip ospf authentication-key yourpass
Related Command

area authentication

ip ospf cost

To explicitly specify the cost of sending a packet on an interface, use the ip ospf cost interface configuration command. To reset the path cost to the default value, use the no form of this command.

ip ospf cost cost
no ip ospf cost
Syntax Description

cost

Unsigned integer value expressed as the link state metric. It can be a value in the range 1 to 65535.

Default

No default cost is predefined.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You can set the metric manually using this command, if you need to change the default. Using the bandwidth command changes the link cost as long as this command is not used.

The link state metric is advertised as the link cost in the router link advertisement. We do not support type of service (TOS), so you can assign only one cost per interface.

In general, the path cost is calculated using the following formula:

108 ÷ Bandwidth

Using this formula, the default path costs were calculated as noted in the following list. If these values do not suit your network, you can use your own method of calculating path costs.

Example

The following example sets the interface cost value to 65:

ip ospf cost 65

ip ospf dead-interval

To set how long hello packets must not have been seen before its neighbors declare the router down, use the ip ospf dead-interval interface configuration command. To return to the default time, use the no form of this command.

ip ospf dead-interval seconds
no ip ospf dead-interval
Syntax Description

seconds

Unsigned integer that specifies the interval in seconds; the value must be the same for all nodes on the network.

Default

Four times the interval set by the ip ospf hello-interval command

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The interval is advertised in the router's hello packets. This value must be the same for all routers and access servers on a specific network.

Example

The following example sets the OSPF dead interval to 60 seconds:

interface ethernet 1
ip ospf dead-interval 60
Related Command

ip ospf hello-interval

ip ospf demand-circuit

To configure OSPF to treat the interface as an OSPF demand circuit, use the ip ospf demand-circuit interface configuration command. To remove the demand circuit designation from the interface, use the no form of this command.

ip ospf demand-circuit
no ip ospf demand-circuit

Syntax Description

This command has no arguments or keywords.

Default

The circuit is not a demand circuit.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

On point-to-point interfaces, only one end of the demand circuit must be configured with this command. Periodic hellos are suppressed and periodic refreshes of LSAs do not flood the demand circuit. It allows the underlying datalink layer to be closed when the topology is stable. In point-to-multipoint topology, only the multipoint end must configured with this command.

Example

The following example sets the configures an ISDN on demand circuit:

router ospf1
network 18.0.3.0.0.0.0.25 area 0
interface BRIO
ip ospf demand-circuit

ip ospf hello-interval

To specify the interval between hello packets that the Cisco IOS software sends on the interface, use the ip ospf hello-interval interface configuration command. To return to the default time, use the no form of this command.

ip ospf hello-interval seconds
no ip ospf hello-interval
Syntax Description

seconds

Unsigned integer that specifies the interval in seconds. The value must be the same for all nodes on a specific network.

Default

10 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This value is advertised in the hello packets. The smaller the hello interval, the faster topological changes will be detected, but more routing traffic will ensue. This value must be the same for all routers and access servers on a specific network.

Example

The following example sets the interval between hello packets to 15 seconds:

interface ethernet 1
ip ospf hello-interval 15
Related Command

ip ospf dead-interval

ip ospf message-digest-key

To enable OSPF MD5 authentication, use the ip ospf message-digest-key interface configuration command. To remove an old MD5 key, use the no form of this command.

ip ospf message-digest-key keyid md5 key
no ip ospf message-digest-key keyid
Syntax Description

keyid

An identifier in the range 1 to 255.

key

Alphanumeric password of up to 16 bytes.

Default

OSPF MD5 authentication is disabled.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Usually, one key per interface is used to generate authentication information when sending packets and to authenticate incoming packets. The same key identifier on the neighbor router must have the same key value.

The process of changing keys is as follows. Suppose the current configuration is as follows:

interface ethernet 1
ip ospf message-digest-key 100 md5 OLD
 

You change the configuration to the following:

interface ethernet 1
ip ospf message-digest-key 101 md5 NEW
 

The system assumes its neighbors do not have the new key yet, so it begins a rollover process. It sends multiple copies of the same packet, each authenticated by different keys. In this example, the system sends out two copies of the same packet---the first one authenticated by key 100 and the second one authenticated by key 101.

Rollover allows neighboring routers to continue communication while the network administrator is updating them with the new key. Rollover stops once the local system finds that all its neighbors know the new key. The system detects that a neighbor has the new key when it receives packets from the neighbor authenticated by the new key.

After all neighbors have been updated with the new key, the old key should be removed. In this example, you would enter the following:

interface ethernet 1
no ip ospf message-digest-key 100
 

Then, only key 101 is used for authentication on Ethernet interface 1.

We recommend that you not keep more than one key per interface. Every time you add a new key, you should remove the old key to prevent the local system from continuing to communicate with a hostile system that knows the old key. Removing the old key also reduces overhead during rollover.

Example

The following example sets a new key 19 with the password 8ry4222:

interface ethernet 1
ip ospf message-digest-key 10 md5 xvv560qle
ip ospf message-digest-key 19 md5 8ry4222
Related Command

area authentication

ip ospf name-lookup

To configure OSPF to look up Domain Name System (DNS) names for use in all OSPF show EXEC command displays, use the ip ospf name-lookup global configuration command. To disable this feature, use the no form of this command.

ip ospf name-lookup
no ip ospf name-lookup

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This feature makes it easier to identify a router because it is displayed by name rather than by its router ID or neighbor ID.

Example

The following example configures OSPF to look up DNS names for use in all OSPF show EXEC command displays:

ip ospf name-lookup
Sample Display

The following is sample output from the show ip ospf database EXEC command, for example, once you have enabled the DNS name lookup feature:

Router# show ip ospf database
 
       OSPF Router with id (160.89.41.1) (Autonomous system 109)
 
 
                Router Link States (Area 0.0.0.0)
 
Link ID         ADV Router      Age    Seq#       Checksum Link count
160.89.41.1     router          381    0x80000003 0x93BB   4
160.89.34.2     neon            380    0x80000003 0xD5C8   2
 
                Net Link States (Area 0.0.0.0)
 
Link ID         ADV Router      Age    Seq#       Checksum
160.89.32.1     router          381    0x80000001 0xC117

ip ospf network

To configure the OSPF network type to a type other than the default for a given media, use the ip  ospf network interface configuration command. To return to the default value, use the no form of this command.

ip ospf network {broadcast | non-broadcast | point-to-multipoint}
no ip ospf network

Syntax Description

broadcast

Sets the network type to broadcast.

non-broadcast

Sets the network type to nonbroadcast.

point-to-multipoint

Sets the network type to point-to-multipoint.

Default

Depends on the network type.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The point-to-multipoint keyword first appeared in Cisco IOS Release 10.3.

Using this feature, you can configure broadcast networks as nonbroadcast multiaccess (NBMA) networks when, for example, you have routers in your network that do not support multicast addressing. You can also configure nonbroadcast multiaccess networks (such as X.25, Frame Relay, and SMDS) as broadcast networks. This feature saves you from having to configure neighbors.

Configuring NBMA networks as either broadcast or nonbroadcast assumes that there are virtual circuits from every router to every router or fully meshed network. This is not true for some cases, for example, because of cost constraints or when you have only a partially meshed network. In these cases, you can configure the OSPF network type as a point-to-multipoint network. Routing between two routers that are not directly connected will go through the router that has virtual circuits to both routers. Note that you do not need to configure neighbors when using this feature.

If this command is issued on an interface that does not allow it, it will be ignored.

Example

The following example sets your OSPF network as a broadcast network:

interface serial 0
ip address 160.89.77.17 255.255.255.0 ip ospf network broadcast encapsulation frame-relay
Related Commands

A dagger () indicates that the command is documented outside this chapter.

frame-relay map
neighbor (OSPF)
x25 map

ip ospf priority

To set the router priority, which helps determine the designated router for this network, use the ip  ospf priority interface configuration command. To return to the default value, use the no form of this command.

ip ospf priority number
no ip ospf priority
Syntax Description

number

8-bit unsigned integer that specifies the priority. The range is from 0 to 255.

Default

Priority of 1

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When two routers attached to a network both attempt to become the designated router, the one with the higher router priority takes precedence. If there is a tie, the router with the higher router ID takes precedence. A router with a router priority set to zero is ineligible to become the designated router or backup designated router. Router priority is only configured for interfaces to multiaccess networks (in other words, not point-to-point networks).

This priority value is used when you configure OSPF for nonbroadcast networks using the neighbor router configuration command for OSPF.

Example

The following example sets the router priority value to 4:

interface ethernet 0
ip ospf priority 4
Related Commands

ip ospf network
neighbor (OSPF)

ip ospf retransmit-interval

To specify the time between link state advertisement retransmissions for adjacencies belonging to the interface, use the ip ospf retransmit-interval interface configuration command. To return to the default value, use the no form of this command.

ip ospf retransmit-interval seconds
no ip ospf retransmit-interval
Syntax Description

seconds

Time in seconds between retransmissions. It must be greater than the expected round-trip delay between any two routers on the attached network. The range is 1 to 65535 seconds. The default is 5 seconds.

Default

5 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When a router sends a link state advertisement (LSA) to its neighbor, it keeps the LSA until it receives back the acknowledgment. If it receives no acknowledgment in seconds, it will retransmit the LSA.

The setting of this parameter should be conservative, or needless retransmission will result. The value should be larger for serial lines and virtual links.

Example

The following example sets the retransmit-interval value to 8 seconds:

interface ethernet 2
ip ospf retransmit-interval 8

ip ospf transmit-delay

To set the estimated time it takes to transmit a link state update packet on the interface, use the ip  ospf transmit-delay interface configuration command. To return to the default value, use the no form of this command.

ip ospf transmit-delay seconds
no ip ospf transmit-delay
Syntax Description

seconds

Time in seconds that it takes to transmit a link state update. It can be an integer in the range is 1 to 65535 seconds. The default is 1  second.

Default

1 second

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Link state advertisements in the update packet must have their ages incremented by the amount specified in the seconds argument before transmission. The value assigned should take into account the transmission and propagation delays for the interface.

If the delay is not added before transmission over a link, the time in which the LSA propagates over the link is not considered. This setting has more significance on very low speed links.

Example

The following example sets the retransmit-delay value to 3 seconds:

interface ethernet 0
ip ospf transmit-delay 3

ip pim

To enable PIM on an interface, use the ip pim interface configuration command. To disable PIM on the interface, use the no form of this command.

ip pim {dense-mode | sparse-mode | sparse-dense-mode}
no ip pim
Syntax Description

dense-mode

Enables dense mode of operation.

sparse-mode

Enables sparse mode of operation.

sparse-dense-mode

The interface is treated in the mode in which the group operates.

Default

IP multicast routing is disabled on all interfaces.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The sparse-dense-mode keyword first appeared in Cisco IOS Release 11.1.

Enabling PIM on an interface also enables IGMP operation on that interface. An interface can be configured to be in dense mode, sparse mode, or sparse-dense mode. The mode describes how the Cisco IOS software populates its multicast routing table and how the software forwards multicast packets it receives from its directly connected LANs. In populating the multicast routing table, dense-mode interfaces are always added to the table. Sparse-mode interfaces are added to the table only when periodic join messages are received from downstream routers, or there is a directly connected member on the interface.

Dense Mode

Initially, a dense-mode interface forwards multicast packets until the router determines that there are group members or downstream routers, or until a prune message is received from a downstream router. Then, the dense-mode interface periodically forwards multicast packets out the interface until the same conditions occur. Dense mode assumes that there are multicast group members present. Dense-mode routers never send a join message. They do send prune messages as soon as they determine they have no members or downstream PIM routers. A dense-mode interface is subject to multicast flooding by default.

Sparse Mode

A sparse-mode interface is used for multicast forwarding only if a join message is received from a downstream router or if there are group members directly connected to the interface. Sparse mode assumes that there are no other multicast group members present. When sparse-mode routers want to join the shared path, they periodically send join messages toward the rendezvous point (RP). When sparse-mode routers want to join the source path, they periodically send join messages toward the source; they also send periodic prune messages toward to RP to prune the shared path.

Sparse-Dense Mode

An alternative to choosing just dense mode or just sparse mode is to run PIM in a single region in sparse mode for some groups and dense mode for other groups.

In sparse-dense mode, if the group is in dense mode, the interface will be treated as dense mode. If the group is in sparse mode, the interface will be treated in sparse mode. The group is "sparse" if the router knows about an RP for that group.

When an interface is treated in dense mode, it is populated in a multicast routing table's outgoing integrated list when either

When an interface is treated in sparse mode, it is populated in a multicast routing table's outgoing interface when either

Examples

The following commands enables sparse-mode PIM on tunnel interface 0 and sets the address of the RP router to 226.0.0.8:

ip pim rp-address 226.0.0.8
interface tunnel 0
ip pim sparse-mode
 

The following commands enable dense-mode PIM on Ethernet interface 1:

interface ethernet 1
ip pim dense-mode
Related Commands

ip multicast-routing
ip pim rp-address
show ip pim interface

ip pim accept-rp

To configure a router to accept Joins or Prunes destined for a specified RP and for a specific list of groups, use the ip pim accept-rp global configuration command. To remove that check, use the no form of this command.

ip pim accept-rp {address | auto-rp} [group-access-list-number]
no ip pim accept-rp {ip-address | auto-rp} [group-access-list-number]
Syntax Description

address

RP address of the RP allowed to send Join messages to groups in the range specified by the group access list.

auto-rp

Join and Register messages are accepted only for RPs that are in the Auto-RP cache.

group-access-list-number

(Optional) Access list that defines which groups are subject to the check.

Default

Disabled, so all Join messages and Prune messages are processed.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.2.

This command causes the router to accept only (*,G) Join messages destined for the specified RP address. Additionally, the group address must be in the range specified by the access list.

When address is one of the system's addresses, the system will be the RP only for the specified group range specified by the access list. When the group address is not in the group range, the RP will not accept Join or Register messages and will respond immediately to Registers with Register-Stop messages.

Example

The following example states that the router will accept Join or Prune messages destined for the RP at address 100.1.1.1 for the multicast group 224.2.2.2:

ip pim accept-rp 100.1.1.1 3
access-list 3 permit 224.2.2.2
Related Command

access-list (standard)

ip pim message-interval

To configure the frequency at which a sparse-mode PIM router sends periodic sparse-mode join/prune PIM messages, use the ip pim message-interval global configuration command. To  return to the default interval, use the no form of this command.

ip pim message-interval seconds
no ip pim message-interval [seconds]

Syntax Description

seconds

Interval, in seconds, at which periodic sparse-mode join and prune PIM messages are sent. It can be a number from 1 to 65535. The default is 60 seconds.

Default

60 seconds

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

The join-and-prune message interval should be the same for all routers in the internetwork.

A router is pruned from a group if a join message is not heard from it in three times the message interval specified by the seconds argument. By default, this is 3 minutes.


Note Changing this value may severely impact multicast forwarding.
Example

The following example changes the PIM message interval to 90 seconds:

ip pim message-interval 90
Related Commands

ip igmp query-interval
ip pim query-interval

ip pim nbma-mode

To configure a multiaccess WAN interface to be in nonbroadcast, multiaccess mode, use the ip  pim nbma-mode interface configuration command. To disable this feature, use the no form of this command.

ip pim nbma-mode
no ip pim nbma-mode

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use this command on Frame Relay, SMDS, or ATM only, especially when these media do not have native multicast available. Do not use this command on multicast-capable LANs such as Ethernet or FDDI.

When this command is configured, each PIM Join message is kept track of in the outgoing interface list of a multicast routing table entry. Therefore, only PIM WAN neighbors that have joined for the group will get packets sent as data link unicasts. This command should only be used when ip  pim  sparse-mode is configured on the interface. This command is not recommended for LANs that have natural multicast capabilities.

Example

The following example configures an interface to be in nonbroadcast, multiaccess mode:

ip pim nbma-mode
Related Command

ip pim sparse-mode

ip pim query-interval

To configure the frequency of PIM router-query messages, use the ip pim query-interval interface configuration command. To return to the default interval, use the no form of this command.

ip pim query-interval seconds
no ip pim query-interval [seconds]

Syntax Description

seconds

Interval, in seconds, at which periodic PIM router-query messages are sent. It can be a number from 1 to 65535. The default is 30 seconds.

Default

30 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Routers configured for IP multicast send PIM router-query messages to determine which router will be the designated router for each LAN segment (subnet). The designated router is responsible for sending IGMP host-query messages to all hosts on the directly connected LAN. When operating in sparse mode, the designated router is responsible for sending source registration messages to the RP. The designated router is the router with the largest IP address.

Example

The following example changes the PIM router-query message interval to 45 seconds:

interface tunnel 0
ip pim query-interval 45
Related Command

ip igmp query-interval

ip pim rp-address

To configure the address of a PIM rendezvous point (RP) for a particular group, use the ip pim rp-address global configuration command. To remove an RP address, use the no form of this command.

ip pim rp-address ip-address [group-access-list-number] [override]
no ip pim rp-address ip-address [access-list-number]
Syntax Description

ip-address

IP address of a router to be a PIM RP. This is a unicast IP address in four-part, dotted notation.

group-access-list-number

(Optional) Number of an access list that defines for which multicast groups the RP should be used. This is a standard IP access list. The number can be from 1 to 100.

override

Indicates that if there is a conflict between the RP configured with this command and one learned by Auto-RP, the RP configured with this command prevails.

Default

No PIM RPs are preconfigured.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.2.

You must configure the IP address of RPs in leaf designated routers (DRs) only. Leaf routers are those routers that are directly connected either to a multicast group member or to a sender of multicast messages. Leaf DRs are the only ones that need to know about RPs. Even potential DRs (that might be elected if the primary DR fails) need to be configured to know about RPs.

First-hop routers send register packets to the RP address on behalf of source multicast hosts. Routers also use this address on behalf of multicast hosts that want to become members of a group. These routers send Join and Prune messages towards the RP. The RP must be a PIM router; however, it does not require any special configuration to recognize that it is the RP. Also, RPs are not members of the multicast group; rather, they serve as a "meeting place" for multicast sources and group members.

You can configure the Cisco IOS software to use a single RP for more than one group. The conditions specified by the access list determine which groups the RP can be used for. If no access list is configured, the RP is used for all groups.

A PIM router can use multiple RPs, but only one per group.

If there is no RP configured for a group, the router will treat the group as dense using the dense-mode PIM techniques.

If the RP for a group is learned through a dynamic mechanism, such as Auto-RP, then this command might not be required. If there is a conflict between the RP configured with this command and one learned by Auto-RP, the Auto-RP information is used, unless the override keyword is specified.

Examples

The following example sets the PIM RP address to 198.92.37.33 for all multicast groups:

ip pim rp-address 198.92.37.33
 

The following example sets the PIM RP address to 147.106.6.22 for the multicast group 225.2.2.2 only:

access list 1 225.2.2.2 0.0.0.0
ip pim rp-address 147.106.6.22 1
Related Command

access-list (standard)

ip pim rp-announce-filter

To filter incoming Auto-RP announcement messages coming from the RP, use the ip pim rp-announce-filter global configuration command. To remove the filter, use the no form of this command.

ip pim rp-announce-filter rp-list access-list-number group-list access-list-number
no ip rp-announce-filter rp-list access-list-number group-list access-list-number
Syntax Description

rp-list access-list-number

Standard access list of RP addresses that are allowable for the group ranges supplied in the group-list access-list-number.

group-list access-list-number

Standard access list that describes the multicast groups the RPs serve.

Default

All RP announcements are accepted.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Configure this command on the PIM RP-mapping agent. If you are going to use more than one RP-mapping agent, make the filters among them consistent so that there are no conflicts in mapping state when the announcing agent goes down.

Example

The following example configures the router to accept RP announcements from RPs in access list 1 for group ranges described in access-list 2:

ip pim rp-announce-filter rp-list 1 group-list 2
exit
access-list 1 permit 10.0.0.1
access-list 1 permit 10.0.0.2
access-list 2 permit 224.0.0.0 15.255.255.255
Related Command

access-list (standard)

ip pim send-rp-announce

To use Auto-RP to configure which groups the router is willing to act as RP for, use the ip pim send-rp-announce global configuration command. To deconfigure this router to be the RP, use the no form of this command.

ip pim send-rp-announce type number scope ttl group-list access-list-number
no ip pim send-rp-announce
Syntax Description

type number

Interface type and number that identify the RP address.

scope ttl

Time-to-live value that limits the announcements.

group-list access-list-number

Access list that describes the group ranges for which this router is the RP.

Default

Auto-RP is disabled.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Use this command in the router you want to be an RP. This command causes the router to send an Auto-RP announcement message to the well-known group CISCO-RP-ANNOUNCE (224.0.1.39). This message announces the router as a candidate RP for the groups in the range described by the access list.

Example

The following example sends RP announcements out all PIM-enabled interfaces for a maximum of 31 hops. The IP address the router wants to be identified by as RP is the IP address associated with Ethernet interface 0. Access-list 5 describes for which groups this router serves as RP.

ip pim send-rp-announce ethernet0 scope 31 group-list 5
access-list 5 permit 224.0.0.0 15.255.255.255
Related Command

access-list (standard)

ip pim send-rp-discovery

To configure the router to be an RP-mapping agent, use the ip pim send-rp-discovery global configuration command. To restore the default value, use the no form of this command.

ip pim send-rp-discovery scope ttl
no ip pim send-rp-discovery
Syntax Description

scope ttl

Time-to-live value in the IP header that keeps the discovery messages within this number of hops.

Default

The router is not an RP mapping agent.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Configure this command on the router designated as an RP-mapping agent. Specify a TTL large enough to cover your PIM domain.

When Auto-RP is used, the following steps occur:

    1. The RP-mapping agent listens on well-known group address CISCO-RP-ANNOUNCE (224.0.1.39), which candidate RPs send to.

    2. The RP-mapping agent sends RP-to-group mappings in an Auto-RP RP discovery message to the well-known group CISCO-RP-DISCOVERY (224.0.1.40). The TTL value limits how many hops the message can take.

    3. PIM designated routers listen to this group and use the RPs they learn about from the discovery message.

Example

The following example limits Auto-RP RP Discovery messages to 20 hops:

ip pim send-rp-discovery scope 20

ip pim spt-threshold

To configure when a PIM leaf router should join the shortest path source-tree for the specified group, use the ip  pim spt-threshold global configuration command. To restore the default value, use the no form of this command.

ip pim spt-threshold {kbps | infinity} [group-list access-list-number]
no ip pim spt-threshold
Syntax Description

kbps

Traffic rate in kilobits per second.

infinity

Causes all sources for the specified group to use the shared-tree.

group-list access-list-number

(Optional) Indicates what groups the threshold applies to. Must be a standard IP access list number. If the value is 0 or is omitted, the threshold applies to all groups.

Default

When this command is not used, the PIM leaf router joins the shortest path tree immediately after the first packet arrives from a new source.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

If a source sends at a rate greater than or equal to kbps, a PIM Join message is triggered toward the source to construct a source-tree.

If infinity is specified, all sources for the specified group will use the shared-tree. Specifying a group-list access list indicates what groups the threshold applies to.

If the traffic rate from the source drops below the threshold kbps, the leaf router will, after some amount of time, switch back to the shared tree and send a Prune toward the source.

Example

The following example sets a threshold of 4 kbps, above which traffic to a group from a source will cause the router to switch to the shortest path tree to that source:

ip pim spt-threshold 4

ip policy route-map

To identify a route map to use for policy routing on an interface, use the ip policy route-map interface configuration command. To disable policy routing on the interface, use the no form of this command.

ip policy route-map map-tag
no ip policy route-map map-tag
Syntax Description

map-tag

Name of the route map to use for policy routing. Must match a map-tag specified by a route-map command.

Default

No policy routing occurs on the interface.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

You might enable policy routing if you want your packets to take a route other than the obvious shortest path.

The ip policy route-map command identifies a route map to use for policy routing. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which policy routing is allowed for the interface. The set commands specify the set actions---the particular policy routing actions to perform if the criteria enforced by the match commands are met. The no ip policy route-map command deletes the pointer to the route map.

Example

In the following example, packets with the destination IP address of 174.95.16.18 are sent to a router at IP address 174.21.3.20:

interface serial 0
ip policy route-map wethersfield
!
route-map wethersfield
match ip address 174.95.16.18
set ip next-hop 174.21.3.20
Related Commands

match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop

ip rip authentication key-chain

To enable authentication for RIP Version 2 packets and to specify the set of keys that can be used on an interface, use the ip rip authentication key-chain interface configuration command. Use the no form of this command to prevent authentication.

ip rip authentication key-chain name-of-chain
no ip rip authentication key-chain [name-of-chain ]
Syntax Description

name-of-chain

Enables authentication and specifies the group of keys that are valid.

Default

No authentication is provided for RIP packets.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

If no key chain is configured with the key-chain command, no authentication is performed on the interface (not even the default authentication).

Example

The following example configures the interface to accept and send any key belonging to the key chain named trees:

ip rip authentication key-chain trees
Related Command

key chain

ip rip authentication mode

To specify the type of authentication used in RIP Version 2 packets, use the ip rip authentication mode interface configuration command. Use the no form of this command to restore clear text authentication.

ip rip authentication mode {text | md5}
no ip rip authentication mode
Syntax Description

text

Clear text authentication.

md5

Keyed MD5 authentication.

Default

Clear text authentication is provided for RIP packets.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

RIP Version 1 does not support authentication.

Example

The following example configures the interface to use MD5 authentication:

ip rip authentication mode md5
Related Commands

ip rip authentication key-chain
key chain

ip rip receive version

To specify a RIP version to receive on an interface basis, use the ip rip receive version interface configuration command. Use the no form of this command to follow the global version rules.

ip rip receive version [1] [2]
no ip rip receive version
Syntax Description

1

(Optional) Accepts only RIP Version 1 packets on the interface.

2

(Optional) Accepts only RIP Version 2 packets on the interface.

Default

The software behaves according to the version command.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Use this command to override the default behavior of RIP as specified by the version command. This command applies only to the interface being configured. You can configure the interface to accept both RIP versions.

Examples

The following example configures the interface to receive both RIP Version 1 and Version 2 packets:

ip rip receive version 1 2
 

The following example configures the interface to receive only RIP Version 1 packets:

ip rip receive version 1
Related Commands

ip rip send version
version

ip rip send version

To specify a RIP version to send on an interface basis, use the ip rip send version interface configuration command. Use the no form of this command to follow the global version rules.

ip rip send version [1] [2]
no ip rip send version
Syntax Description

1

(Optional) Sends only RIP Version 1 packets out the interface.

2

(Optional) Sends only RIP Version 2 packets out the interface.

Default

The software behaves according to the router version command.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Use this command to override the default behavior of RIP as specified by the router version command. This command applies only to the interface being configured.

Examples

The following example configures the interface to send both RIP Version 1 and Version 2 packets out the interface:

ip rip send version 1 2
 

The following example configures the interface to send only RIP Version 2 packets out the interface:

ip rip send version 2
Related Commands

ip rip receive version
version

ip route

To establish static routes, use the ip route global configuration command. To remove static routes, use the no form of this command.

ip route prefix mask {address | interface} [distance] [tag tag] [permanent]
no ip route prefix mask
Syntax Description

prefix

IP route prefix for the destination.

mask

Prefix mask for the destination.

address

IP address of the next hop that can be used to reach that network.

interface

Network interface to use.

distance

(Optional) An administrative distance.

tag tag

(Optional) Tag value that can be used as a "match" value for controlling redistribution via route maps.

permanent

(Optional) Specifies that the route will not be removed, even if the interface shuts down.

Default

No static routes are established.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

A static route is appropriate when the Cisco IOS software cannot dynamically build a route to the destination.

If you specify an administrative distance, you are flagging a static route that can be overridden by dynamic information. For example, IGRP-derived routes have a default administrative distance of 100. To have a static route that would be overridden by an IGRP dynamic route, specify an administrative distance greater than 100. Static routes have a default administrative distance of 1.

Static routes that point to an interface will be advertised via RIP, IGRP, and other dynamic routing protocols, regardless of whether redistribute static commands were specified for those routing protocols. This is because static routes that point to an interface are considered in the routing table to be connected and hence lose their static nature. However, if you define a static route to an interface that is not one of the networks defined in a network command, no dynamic routing protocols will advertise the route unless a redistribute static command is specified for these protocols.

Examples

In the following example, an administrative distance of 110 was chosen. In this case, packets for network 10.0.0.0 will be routed through to a router at 131.108.3.4 if dynamic information with administrative distance less than 110 is not available.

ip route 10.0.0.0 255.0.0.0 131.108.3.4 110

In the following example, packets for network 131.108.0.0 will be routed to a router at 131.108.6.6:

ip route 131.108.0.0 255.255.0.0 131.108.6.6 

ip router isis

To configure an IS-IS routing process for IP on an interface, use the ip router isis interface configuration command. To disable IS-IS for IP, use the no form of this command.

ip router isis [tag]
no ip router isis
[tag]
Syntax Description

tag

(Optional) Defines a meaningful name for a routing process. If not specified, a null tag is assumed. It must be unique among all IP router processes for a given router. Use the same text for the argument tag as specified in the router  isis global configuration command.

Default

No routing processes are specified.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example specifies IS-IS as an IP routing protocol for a process named Finance, and specifies that the Finance process will be routed on interfaces Ethernet 0 and serial 0:

router isis Finance
interface Ethernet 0
ip router isis Finance
interface serial 0
ip router isis Finance
Related Command

router isis

ip rsvp bandwidth

To enable the use of the Resource Reservation Protocol (RSVP) protocol for IP on an interface, use the ip rsvp bandwidth interface configuration command. To disable this feature, use the no form of the command.

ip rsvp bandwidth [interface-kbps] [single-flow-kbps]
no ip rsvp bandwidth [
interface-kbps] [single-flow-kbps]
Syntax Description

interface-kbps

(Optional) Amount of bandwidth on interface to be reserved.

single-flow-kbps

(Optional) Amount of bandwidth allocated to single flow.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to enable the use of the RSVP for IP on an interface. The default is for RSVP to be disabled to allow backward compatibility with systems that do not implement RSVP.

Example

The following example shows a T1 (1536 kbps) link configured to permit RSVP reservation of up to 1158 kbps, but no more than 100 kbps for any given flow on interfaces Ethernet 0 and serial 0. Fair queuing is configured with 15 reservable queues to support those reserved flows should they be required.

interface Ethernet 0
ip rsvp bandwidth 1158 100
interface serial 0
fair-queue 64 256 15
Related Commands

ip rsvp neighbors
ip rsvp reservation
ip rsvp sender
ip rsvp udp-multicast

ip rsvp neighbors

To enable neighbors to offer a reservation, use the ip rsvp neighbors interface configuration command. To disable this feature, use the no form of the command.

ip rsvp neighbors access-list-number
no ip rsvp neighbors access-list-number

Syntax Description

access-list-number

Number of a standard or extended access list. It can be an integer from 1 to 199.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in IOS Release 11.2.

Use this command to allow RSVP neighbors to make a reservation. If no limits are specified, any neighbor can offer a reservation. If an access list is specified, only neighbors meeting the specified access list requirements can make a reservation.

Related Commands

ip rsvp bandwidth
ip rsvp udp-multicast
ip rsvp sender
ip rsvp reservation

ip rsvp reservation

To enable a router to simulate Resource Reservation Protocol RSVP) RESV message reception from the sender, use the ip rsvp reservation interface configuration command. To disable this feature, use the no form of the command.

ip rsvp reservation session-ip-address sender-ip-address [tcp | udp | ip-protocol]
session-dport sender-sport next-hop-ip address nexthop-interface {ff | se | wf} {rate | load}
[
bandwidth] [burst-size]
no ip rsvp reservation session-ip-address sender-ip-address [tcp | udp | ip-protocol]
session-dport sender-sport next-hop-ip address nexthop-interface {ff | se | wf} {rate | load}
[
bandwidth] [burst-size]
Syntax Description

session-ip-address

For unicast sessions, this is the address of the intended receiver;
for multicast sessions, it is the IP multicast address of the session.

sender-ip-address

For unicast sessions, this is the address of the sender;
for multicast sessions, it is the IP multicast address of the session.

tcp | udp | ip-protocol

TCP, UDP, or IP protocol in the range 0 to 255.

session-dport
sender-sport

Session-dport is the destination ports. Sender-sport is the source port. Port numbers are specified in all cases, as the use of 16-bit ports following the IP header is not limited to UDP or TCP. If destination is zero, source must be zero, and the implication is that ports are not checked. If destination is non-zero, source must be non-zero.

next-hop-ip-address

Address of the receiver or the router closest to the receiver.

next-hop-interface

Next hop interface or subinterface number.

ff | se | wf

Reservation style:
   Fixed Filter (ff) is single reservation.
   Shared Explicit (se) is shared reservation, limited scope.
   Wild Card (wf) is shared reservation, unlimited scope.

rate | load

QOS: guaranteed bit rate service or controlled load service.

bandwidth

Average bit rate (kbps) to reserve up to 75 percent of total on interface. Range is 1 to 10,000,000.

burst-size

Maximum burst size (Kilobytes of data in queue). Range is 1 to 65,535.

Default

The router cannot simulate receiving an RSVP RESV Message.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to force the router to act like it is receiving RSVP RESV messages from the sender.

Examples

The following example specifies the use of a Shared Explicit Filter style of reservation and the Controlled Load Service, and with token buckets of 100 or 150 kbps and 60 or 65K maximum queue depth:

ip rsvp reservation 224.250.0.2 132.240.1.1 UDP 20 30 132.240.4.1 Et1 se load 100 60
ip rsvp reservation 224.250.0.2 132.240.2.1 TCP 20 30 132.240.4.1 Et1 se load 150 65
 

The following example specifies the use of a Wild Card Filter style of reservation and the Guaranteed Bit Rate Service, and with token buckets of 300 or 350 kbps and 60 or 65K maximum queue depth:

ip rsvp reservation 224.250.0.3 0.0.0.0 UDP 20 0 132.240.4.1  Et1 wf rate 300 60
ip rsvp reservation 224.250.0.3 0.0.0.0 UDP 20 0 132.240.4.1  Et1 wf rate 350 65
 

Note that the Wild Card Filter does not admit the specification of the sender; it accepts all senders. This is denoted by setting the source address and port to zero. If, in any filter style, the destination port is specified to be zero, RSVP does not permit the source port to be anything else; it understands that such protocols do not use ports or that the specification applies to all ports.

Related Commands

ip rsvp bandwidth
ip rsvp neighbors
ip rsvp sender
ip rsvp udp-multicast

ip rsvp sender

To enable a router to simulate Resource Reservation Protocol RSVP) PATH message reception from the sender, use the ip rsvp sender interface configuration command. To disable this feature, use the no form of the command.

ip rsvp sender session-ip-address sender-ip-address [tcp | udp | ip-protocol] session-dport
sender-sport previous-hop-ip-address previous-hop-interface
[bandwidth] [burst-size]
no ip rsvp sender session-ip-address sender-ip-address [tcp | udp | ip-protocol] session-dport
sender-sport previous-hop-ip-address previous-hop-interface
[bandwidth] [burst-size]
Syntax Description

session-ip-address

For unicast sessions, this is the address of the intended receiver; for multicast sessions, it is the IP multicast address of the session.

sender-ip-address

For unicast sessions, this is the address of the sender; for multicast sessions, it is the IP multicast address of the session.

tcp | udp | ip-protocol

TCP, UDP, or IP protocol in the range 0 to 255.

session-dport sender-sport

Destination/source ports. Port numbers are specified in all cases, as the use of 16-bit ports following the IP header is not limited to UDP or TCP. If destination is zero, source must be zero, and the implication is that ports are not checked. If destination is non-zero, source must be non-zero.

previous-hop-ip-address

Address of the sender or the router closest to the sender.

previous-hop-interface

Address of the previous hop interface or subinterface. Interface type can be ethernet, loopback, null, or serial.

bandwidth

Average bit rate (kbps) to reserve up to 75 percent of total on interface.

burst-size

Maximum burst size (kilobytes of data in queue).

Default

The router cannot simulate RSVP Path message reception.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to force the router to act like it is receiving RSVP PATH messages from the sender.

Example

The following example sets up the router to act like it receiving RSVP messages using UDP over the Eth1 serial interface.

ip rsvp sender 224.250.0.1 132.240.2.1 UDP 20 30 132.240.2.1 Lo1 50 5
ip rsvp sender 224.250.0.2 132.240.2.1 UDP 20 30 132.240.2.1 Lo1 50 5
ip rsvp sender 224.250.0.2 132.240.2.28 UDP 20 30 132.240.2.28 Lo1 50 5
Related Commands

ip rsvp bandwidth
ip rsvp neighbors
ip rsvp reservation
ip rsvp udp-multicast

ip rsvp udp-multicast

To instruct the router to generate UDP-encapsulated Resource Reservation Protocol (RSVP) multicasts whenever it generates an IP multicast, use the ip rsvp udp-multicast interface configuration command. To disable this feature, use the no form of the command.

ip rsvp udp-multicast [multicast-address]
no ip rsvp udp-multicast [multicast-address]

Syntax Description

multicast-address

(Optional) Host name or UDP multicast address of router.

Default

The generation of UDP multicasts is not enabled. If a system sends a UDP-encapsulated RSVP message to the router, the router starts using UDP for contact with the neighboring system. The router uses multicast address 224.0.0.14 and starts sending to UDP port 1699. If the command is entered without specifying a multicast address, the router uses the same multicast address.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to instruct a router to generate UDP-encapsulated RSVP multicasts whenever it generates an IP-encapsulated multicast packet. Some hosts require this trigger from the router.

Example

The following example reserves up to 7500 kbps on the Ethernet 2, with up to 1 Mbps per flow. The router is configured to use UDP encapsulation with the multicast address 224.0.0.14.

interface Ethernet 2
 ip rsvp bandwidth 7500 1000
 ip rsvp udp-multicast 224.0.0.14
Related Commands

ip rsvp bandwidth
ip rsvp neighbors
ip rsvp sender
ip rsvp reservation

ip sdr cache-timeout

To limit how long an sdr cache entry stays active in the cache, use the ip  sdr cache-timeout global configuration command. To restore the default value, use the no form of this command.

ip sdr cache-timeout minutes
no ip sdr cache-timeout
Syntax Description

minutes

Time, in minutes, that an sdr cache entry is active in the cache.

Default

Disabled, which means entries are never deleted from the cache.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Example

The following example causes sdr cache entries to remain in the cache for only 30 minutes:

ip sdr cache-timeout 30
Related Commands

clear ip sdr
show ip sdr

ip sdr listen

To enable the Cisco IOS software to listen to session directory advertisements, use the ip  sdr listen interface configuration command. To disable the feature, use the no form of this command.

ip sdr listen
no
ip sdr listen
Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1. This command replaces the ip sd listen command, which is obsolete.

Session Directory Protocol (sdr) is a multicast application for setting up desktop conferencing sessions. It allocates group addresses and allows the user to specify the scope of the group and whether audio, video, or whiteboard applications will be invoked when users open the session.

Use this command to store session advertisements sent to the group. The ip sdr listen command merely enables the software to listen to session directory advertisements. The router joins the default session directory group (group 224.2.127.254) on the interface. Use this command to get contact information.

Example

The following example enables a router to listen to session directory advertisements:

ip sdr listen
Related Commands

clear ip sdr
show ip sdr

ip split-horizon

To enable the split horizon mechanism, use the ip split-horizon interface configuration command. To disable the split horizon mechanism, use the no form of this command.

ip split-horizon
no ip split-horizon

Syntax Description

This command has no arguments or keywords.

Default

Varies with media

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

For all interfaces except those for which either Frame Relay or SMDS encapsulation is enabled, the default condition for this command is ip  split-horizon; in other words, the split horizon feature is active. If the interface configuration includes either the encapsulation  frame-relay or encapsulation smds commands, then the default is for split horizon to be disabled. Split horizon is not disabled by default for interfaces using any of the X.25 encapsulations.


Note For networks that include links over X.25 PSNs, the neighbor router configuration command can be used to defeat the split horizon feature. You can as an alternative explicitly specify the no  ip  split-horizon command in your configuration. However, if you do so you must similarly disable split horizon for all routers in any relevant multicast groups on that network.

If split horizon has been disabled on an interface and you wish to enable it, use the ip  split-horizon command to restore the split horizon mechanism.


Note In general, changing the state of the default for the ip split-horizon command is not recommended, unless you are certain that your application requires a change in order to properly advertise routes. If split horizon is disabled on a serial interface (and that interface is attached to a packet-switched network), you must disable split horizon for all routers and access servers in any relevant multicast groups on that network.
Example

The following simple example disables split horizon on a serial link. The serial link is connected to an X.25 network:

interface serial 0
encapsulation x25
no ip split-horizon
Related Commands

ip split-horizon eigrp
neighbor

ip split-horizon eigrp

To enable Enhanced IGRP split horizon, use the ip split-horizon eigrp interface configuration command. To disable split horizon, use the no form of this command.

ip split-horizon eigrp autonomous-system-number
no ip split-horizon eigrp autonomous-system-number

Syntax Description

autonomous-system-number

Autonomous system number.

Default

Enabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

For networks that include links over X.25 PSNs, you can use the neighbor router configuration command to defeat the split horizon feature. As an alternative, you can explicitly specify the no  ip  split-horizon eigrp command in your configuration. However, if you do so, you must similarly disable split horizon for all routers and access servers in any relevant multicast groups on that network.

In general, it is recommended that you not change the default state of split horizon unless you are certain that your application requires the change in order to properly advertise routes. Remember that if split horizon is disabled on a serial interface and that interface is attached to a packet-switched network, you must disable split horizon for all routers and access servers in any relevant multicast groups on that network.

Example

The following example disables split horizon on a serial link connected to an X.25 network:

interface serial 0
encapsulation x25
no ip split-horizon eigrp
Related Commands

ip split-horizon
neighbor (EGP, IGRP, RIP)

ip summary-address eigrp

To configure a summary aggregate address for a specified interface, use the ip summary-address eigrp interface configuration command. To disable a configuration, use the no form of this command.

ip summary-address eigrp autonomous-system-number address mask
no ip summary-address eigrp autonomous-system-number address mask

Syntax Description

autonomous-system-number

Autonomous system number.

address

IP summary aggregate address to apply to an interface.

mask

Subnet mask.

Default

No summary aggregate addresses are predefined.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Enhanced IGRP summary routes are given an administrative distance value of 5. You cannot configure this value.

Example

The following example sets the IP summary aggregate address for Ethernet interface 0:

interface ethernet 0
ip summary-address eigrp 109 192.1.0.0 255.255.0.0
Related Command

auto-summary

isis circuit-type

To configure the type of adjacency, use the isis circuit-type interface configuration command. To reset the circuit type to Level l and Level 2, use the no form of this command.

isis circuit-type {level-1 | level-1-2 | level-2-only}
no isis circuit-type

Syntax Description

level-1

A Level 1 adjacency may be established if there is at least one area address in common between this system and its neighbors.

level-1-2

A Level 1 and Level 2 adjacency is established if the neighbor is also configured as level-1-2 and there is at least one area in common. If there is no area in common, a Level 2 adjacency is established. This is the default.

level-2-only

A Level 2 adjacency is established if and only if the neighbor is configured exclusively to be a Level 2 router.

Default

A Level 1 and Level 2 adjacency is established.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, a router is configured to require Level 1 adjacency if there is at least one area address in common between this system and its neighbors:

ip router isis
interface serial 0
isis circuit-type level-1

isis csnp-interval

To configure the IS-IS complete sequence number PDUs (CSNP) interval, use the isis csnp-interval interface configuration command. To restore the default value, use the no form of this command.

isis csnp-interval seconds {level-1 | level-2}
no isis csnp-interval {level-1 | level-2}

Syntax Description

seconds

Interval of time between transmission of CSNPs on multiaccess networks. This interval only applies for the designated router. The default is 10 seconds.

level-1

Configures the interval of time between transmission of CSNPs for Level 1 independently.

level-2

Configures the interval of time between transmission of CSNPs for Level 2 independently.

Default

10 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command only applies for the designated router (DR) for a specified interface. Only DRs send CSNP packets in order to maintain database synchronization. The CSNP interval can be configured independently for Level 1 and Level 2. This feature does not apply to serial point-to-point interfaces. It does apply to WAN connections if the WAN is viewed as a multiaccess meshed network.

Example

In the following example, serial interface 0 is configured for transmitting CSN PDUs every 5  seconds. The router is configured to act as a station router.

interface serial 0
isis csnp-interval 5 level-1

isis hello-interval

To specify the length of time between hello packets that the Cisco IOS software sends, use the isis hello-interval interface configuration command. To restore the default value, use the no form of this command.

isis hello-interval seconds {level-1 | level-2}
no isis hello-interval {level-1 | level-2}

Syntax Description

seconds

Unsigned integer value. A value three times the hello interval seconds is advertised as the holdtime in the hello packets transmitted. It must be the same for all routers and access servers attached to a common network. With smaller hello intervals, topological changes are detected faster, but there is more routing traffic. The default is 10 seconds.

level-1

Configures the hello interval for Level 1 independently. Use this on X.25, SMDS, and Frame Relay multiaccess networks.

level-2

Configures the hello interval for Level 2 independently. Use this on X.25, SMDS, and Frame Relay multiaccess networks.

Default

10 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The hello interval can be configured independently for Level 1 and Level 2, except on serial point-to-point interfaces. (Because there is only a single type of hello packet sent on serial links, it is independent of Level 1 or Level 2.) The level-1 and level-2 keywords are used on X.25, SMDS, and Frame Relay multiaccess networks.

Example

In the following example, serial interface 0 is configured to advertise hello packets every 5 seconds. The router is configured to act as a station router. This will cause more traffic than configuring a longer interval, but topological changes will be detected faster.

interface serial 0
isis hello-interval 5 level-1

isis metric

To configure the metric for an interface, use the isis metric interface configuration command. To restore the default metric value, use the no form of this command.

isis metric default-metric [delay-metric [expense-metric [error-metric]]] {level-1 | level-2}
no isis metric {level-1 | level-2}
Syntax Description

default-metric

Metric used for the redistributed route. The default metric is used as a value for the IS-IS metric. This is the value assigned when there is no QOS routing performed. Only this metric is supported by Cisco routers and access servers. You can configure this metric for Level 1 and/or Level 2 routing. The range is from 0 to 63. The default value is 10.

delay-metric

Not supported.

expense-metric

Not supported.

error-metric

Not supported.

level-1

Router acts as a station router (Level 1) only.

level-2

Router acts as an area router (Level 2) only.

Default

default-metric = 10

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Specifying the level-1 or level-2 keywords resets the metric only for Level 1 or Level 2 routing, respectively.

Example

In the following example, serial interface 0 is configured for a default link-state metric cost of 15 for Level 1:

interface serial 0
isis metric 15 level-1
Related Commands

default-information
redistribute

isis password

To configure the authentication password for an interface, use the isis password interface configuration command. To disable authentication for IS-IS, use the no form of this command.

isis password password {level-1 | level-2}
no isis password {level-1 | level-2}

Syntax Description

password

Authentication password you assign for an interface.

level-1

Configures the authentication password for Level 1 independently. For Level 1 routing, the router acts as a station router only.

level-2

Configures the authentication password for Level 2 independently. For Level 2 routing, the router acts as an area router only.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Different passwords can be assigned for different routing levels using the level-1 and level-2 keyword arguments.

Specifying the level-1 or level-2 keywords disables the password only for Level 1 or Level 2 routing, respectively. If no keyword is specified, the default is level-1.

Example

The following example configures a password for serial interface 0 at Level 1:

interface serial 0
isis password frank level-1

isis priority

To configure the priority of designated routers, use the isis priority interface configuration command. To reset the default priority, use the no form of this command.

isis priority value {level-1 | level-2}
no isis priority {level-1 | level-2}

Syntax Description

value

Sets the priority of a router and is a number from 0 to 127. The default value is 64.

level-1

Sets the priority for Level 1 independently.

level-2

Sets the priority for Level 2 independently.

Default

Priority of 64

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Priorities can be configured for Level 1 and Level 2 independently. Specifying the level-1 or
level-2 keywords resets priority only for Level 1 or Level 2 routing, respectively.

Example

The following example shows Level 1 routing given priority by setting the priority level to 50:

interface serial 0
isis priority 50 level-1

isis retransmit-interval

To configure the time between retransmission of IS-IS link-state PDU (LSP) retransmission for point-to-point links, use the isis retransmit-interval interface configuration command. To restore the default value, use the no form of this command.

isis retransmit-interval seconds
no isis retransmit-interval seconds
Syntax Description

seconds

Time in seconds between retransmission of IS-IS LSP retransmissions. It is an integer that should be greater than the expected round-trip delay between any two routers on the attached network. The default is 5 seconds.

Default

5 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The setting of the seconds argument should be conservative, or needless retransmission will result. The value should be larger for serial lines and virtual links.

Example

The following example configures serial interface 0 for retransmission of IS-IS LSP every 10  seconds for a large serial line:

interface serial 0
isis retransmit-interval 10
Related Commands

A dagger () indicates that the command is documented outside this chapter.

encapsulation ppp
frame-relay keepalive
smds dxi

is-type

To configure the IS-IS level at which the Cisco IOS software operates, use the is-type router configuration command. To reset the default value, use the no form of this command.

is-type {level-1 | level-1-2 | level-2-only}
no is-type {level-1 | level-1-2 | level-2-only}

Syntax Description

level-1

Router acts as a station router.

level-1-2

Router acts as both a station router and an area router.

level-2-only

Router acts as an area router only.

Default

Router acts as both a station router and an area router.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in IOS Release 10.3.

Example

The following example specifies an area router:

router isis 
is-type level-2-only

key

To identify an authentication key on a key chain, use the key key chain configuration command. To remove the key from the key chain, use the no form of this command.

key number
no key number
Syntax Description

number

Identification number of an authentication key on a key chain. The range of keys is 0 to 2147483647. The key identification numbers need not be consecutive.

Default

No key exists on the key chain.

Command Mode

Key chain configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Currently, only RIP Version 2 uses authentication keys. It is useful to have multiple keys on a key chain so that the software can sequence through the keys as they become invalid after time, based on the accept-lifetime and send-lifetime settings.

Each key has its own key identifier, which is stored locally. The combination of the key identifier and the interface associated with the message uniquely identifies the authentication algorithm and MD5 authentication key in use. Only one authentication packet is sent, regardless of the number of valid keys. The software starts looking at the lowest key identifier number and uses the first valid key.

If the last key expires, authentication will continue and an error message will be generated. To disable authentication, you must manually delete the last valid key.

To remove all keys, remove the key chain by using the no key chain command.

Example

The following example configures a key chain called trees. The key chestnut will be accepted from 1:30 p.m. to 3:30 p.m. and be sent from 2:00 p.m. to 3:00 p.m. The key birch will be accepted from 2:30 p.m. to 4:40 p.m. and be sent from 3:00 p.m. to 4:00 p.m. The overlap allows for migration of keys or a discrepancy in the router's set time. There is a half  hour leeway on each side to handle time-of-day differences.

interface ethernet 0
  ip rip authentication key-chain trees
  ip rip authentication mode md5
!
router rip
  network 172.19.0.0
  version 2
!
key chain trees
    key 1
     key-string chestnut
     accept-lifetime 13:30:00 Jan 25 1996 duration 7200
     send-lifetime 14:00:00 Jan 25 1996 duration 3600
  key 2
     key-string birch
     accept-lifetime 14:30:00 Jan 25 1996 duration 7200
     send-lifetime 15:00:00 Jan 25 1996 duration 3600
Related Commands

accept-lifetime
key chain
key-string
send-lifetime
show key chain

key chain

To enable authentication for routing protocols, identify a group of authentication keys by using the key chain global configuration command. To remove the key chain, use the no form of this command.

key chain name-of-chain
no key chain name-of-chain
Syntax Description

name-of-chain

Name of a key chain. A key chain must have at least one key, and can have up to 2147483647 keys.

Default

No key chain exists.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Currently only RIP Version 2 uses authentication keys. You must configure a key chain with keys to enable authentication on RIP packets.

You can identify multiple key chains, but it makes sense to use one key chain per interface per routing protocol. Upon specifying the key chain command, you enter key chain mode.

Example

The following example configures a key chain called trees. The key chestnut will be accepted from 1:30 p.m. to 3:30 p.m. and be sent from 2:00 p.m. to 3:00 p.m. The key birch will be accepted from 2:30 p.m. to 4:40 p.m. and be sent from 3:00 p.m. to 4:00 p.m. The overlap allows for migration of keys or a discrepancy in the router's set time. There is a half  hour leeway on each side to handle time-of-day differences.

interface ethernet 0
  ip rip authentication key-chain trees
  ip rip authentication mode md5
!
router rip
  network 172.19.0.0
  version 2
!
key chain trees
    key 1
     key-string chestnut
     accept-lifetime 13:30:00 Jan 25 1996 duration 7200
     send-lifetime 14:00:00 Jan 25 1996 duration 3600
  key 2
     key-string birch
     accept-lifetime 14:30:00 Jan 25 1996 duration 7200
     send-lifetime 15:00:00 Jan 25 1996 duration 3600
Related Commands

accept-lifetime
ip rip authentication key-chain
key
key-string
send-lifetime
show key chain

key-string

To specify the authentication string for a key, use the key-string key chain key configuration command. To remove the authentication string, use the no form of this command.

key-string text
no key-string [text]
Syntax Description

text

Authentication string that must be sent and received in the packets using the routing protocol being authenticated. The string can contain from 1 to 80 uppercase and lowercase alphanumeric characters, except that the first character cannot be a number.

Default

No key exists.

Command Mode

Key chain key configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Currently only RIP Version 2 uses authentication keys. Each key can have only one key string.

If password encryption is configured (with the service password-encryption command), the software saves the key string as encrypted text. When you write to the terminal with the show  running-config command, the software displays key-string 7 encrypted text.

Example

The following example configures a key chain called trees. The key chestnut will be accepted from 1:30 p.m. to 3:30 p.m. and be sent from 2:00 p.m. to 3:00 p.m. The key birch will be accepted from 2:30 p.m. to 4:40 p.m. and be sent from 3:00 p.m. to 4:00 p.m. The overlap allows for migration of keys or a discrepancy in the router's set time. There is a half  hour leeway on each side to handle time-of-day differences.

interface ethernet 0
  ip rip authentication key-chain trees
  ip rip authentication mode md5
!
router rip
  network 172.19.0.0
  version 2
!
key chain trees
    key 1
     key-string chestnut
     accept-lifetime 13:30:00 Jan 25 1996 duration 7200
     send-lifetime 14:00:00 Jan 25 1996 duration 3600
  key 2
     key-string birch
     accept-lifetime 14:30:00 Jan 25 1996 duration 7200
     send-lifetime 15:00:00 Jan 25 1996 duration 3600
Related Commands

A dagger () indicates that the command is documented outside this chapter.

accept-lifetime
key
key chain
send-lifetime
service password-encryption

show key chain

match as-path

To match a BGP autonomous system path access list, use the match as-path route-map configuration command. To remove a path list entry, the no form of this command.

match as-path path-list-number
no match as-path path-list-number
Syntax Description

path-list-number

Autonomous system path access list. An integer from 1 to  199.

Default

No path lists are defined.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The values set by the match and set commands override global values. For example, the weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.

The implemented weight is based on the first matched autonomous system path.

Example

In the following example, the autonomous system path is set to match BGP autonomous system path access list 20:

route-map igp2bgp
match as-path 20
Related Commands

match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

match community-list

To match a BGP community, use the match community-list route-map configuration command. To remove the community list entry, use the no form of this command.

match community-list community-list-number [exact]
no match community-list community-list-number [exact]
Syntax Description

community-list-number

Community list number in the range 1 to 99.

exact

(Optional) Indicates an exact match is required. All of the communities and only those communities in the community list must be present.

Default

No community list is defined.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.

Matching based on community list is one of the types of match clauses applicable to BGP.

Examples

In the following example, the routes that match community list 1 will have the weight set to 100. Any route that has community 109 will have the weight set to 100.

ip community-list 1 permit 109
!
route-map set_weight
match community-list 1
set weight 100
 

In the following example, the routes that match community list 1 will have the weight set to 200. Any route that has community 109 alone will have the weight set to 200.

ip community-list 1 permit 109
!
route-map set_weight
match community-list 1 exact
set weight 200
Related Commands

route-map
set weight

match interface

To distribute any routes that have their next hop out one of the interfaces specified, use the match interface route-map configuration command. To remove the match interface entry, use the no form of this command.

match interface type number...type number
no match interface type number...type number
Syntax Description

type

Interface type.

number

Interface number.

Default

No match interfaces are defined.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.

Example

In the following example, routes that have their next hop out Ethernet interface 0 will be distributed:

route-map name
match interface ethernet 0
Related Commands

match as-path
match community-list
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

match ip address

To distribute any routes that have a destination network number address that is permitted by a standard or extended access list, or to perform policy routing on packets, use the match ip address route-map configuration command. To remove the match ip address entry, use the no form of this command.

match ip address access-list-number | name...access-list-number | name
no match ip address access-list-number | name...access-list-number | name
Syntax Description

access-list-number | name

Number or name of a standard or extended access list. It can be an integer from 1 to 199.

Default

No access list numbers are specified.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use route maps to redistribute routes or to subject packets to policy routing. Both purposes are described in this section.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The related match commands are listed in the section "Related Commands for Redistribution." The match commands can be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
When you are passing routes through a route map, a route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
Another purpose of route maps is to enable policy routing. Use the ip policy route-map interface configuration command, in addition to the route-map global configuration command, and the match and set route-map configuration commands to define the conditions for policy routing packets. Each route-map command has a list of match and set commands associated with it. The related match and set commands are listed in the section "Related Commands for Policy Routing." The match commands specify the match criteria---the conditions under which policy routing occurs. The set commands specify the set actions---the particular routing actions to perform if the criteria enforced by the match commands are met. You might want to policy route packets based on their source, for example, using an access list.
Examples

In the following example, routes that have addresses specified by access list numbers 5 or 80 will be matched:

route-map name
match ip address 5 80
 

In the following policy routing example, packets that have addresses specified by access list numbers 6 or 25 will be routed to Ethernet interface 0:

interface serial 0
ip policy route-map chicago
!
route-map chicago
match ip address 6 25 
set interface ethernet 0
Related Commands for Redistribution

match as-path
match community-list
match interface
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

Related Commands for Policy Routing

ip policy route-map
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop

match ip next-hop

To redistribute any routes that have a next-hop router address passed by one of the access lists specified, use the match ip next-hop route-map configuration command. To remove the next-hop entry, use the no form of this command.

match ip next-hop {access-list-number | name}[...access-list-number | name]
no match ip next-hop {access-list-number | name}[...access-list-number | name]
Syntax Description

access-list-number | name

Number or name of a standard or extended access list. It can be an integer from 1 to 199.

Default

Routes are distributed freely, without being required to match a next-hop address.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.

Example

In the following example, routes that have a next-hop router address passed by access list 5 or 80 will be distributed:

route-map name
match ip next-hop 5 80
Related Commands

match as-path
match community-list
match interface
match ip address
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

match ip route-source

To redistribute routes that have been advertised by routers and access servers at the address specified by the access lists, use the match ip route-source route-map configuration command. To remove the route-source entry, use the no form of this command.

match ip route-source {access-list-number | name}[...access-list-number | name]
no match ip route-source {access-list-number | name}[...access-list-number | name]
Syntax Description

access-list-number | name

Number or name of a standard or extended access list. It can be an integer from 1 to 199.

Default

No filtering on route source.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.

There are situations in which a route's next hop and source router address are not the same.

Example

In the following example, routes that have been advertised by routers and access servers at the addresses specified by access lists 5 and 80 will be distributed:

route-map name
match ip route-source 5 80
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

match length

To base policy routing on the Level 3 length of a packet, use the match length route-map configuration command. To remove the entry, use the no form of this command.

match length min max
no match length min max
Syntax Description

min

Minimum Level 3 length of the packet, inclusive, allowed for a match. Range is 0 to 0x7FFFFFFF.

max

Maximum Level 3 length of the packet, inclusive, allowed for a match. Range is 0 to 0x7FFFFFFF.

Default

No policy routing on the length of a packet.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which policy routing occurs. The set commands specify the set actions---the particular routing actions to perform if the criteria enforced by the match commands are met.

The match route-map configuration command has multiple formats. The match commands can be given in any order, and all match commands must "pass" to cause the packet to be routed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

You might want to base your policy routing on the length of packets so that your interactive traffic and bulk traffic are directed to different routers.

Example

In the following example, packets 3 to 200 bytes long, inclusive, will be routed to FDDI interface 0:

interface serial 0
ip policy route-map interactive
!
route-map interactive
match length 3 200
set interface fddi 0
Related Commands

ip policy route-map
match ip address
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop

match metric

To redistribute routes with the metric specified, use the match metric route-map configuration command. To remove the entry, use the no form of this command.

match metric metric-value
no match metric metric-value
Syntax Description

metric-value

Route metric, which can be an IGRP five-part metric. It is a metric value from 0 to 4294967295.

Default

No filtering on a metric value.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.

Example

In the following example, routes with the metric 5 will be redistributed:

route-map name
match metric 5
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

match route-type

To redistribute routes of the specified type, use the match route-type route-map configuration command. To remove the route-type entry, use the no form of this command.

match route-type {local | internal | external [type-1 | type-2] | level-1 | level-2}
no match route-type {local
| internal | external [type-1 | type-2] | level-1 | level-2}
Syntax Description

local

Locally generated BGP routes.

internal

OSPF intra-area and interarea routes or enhanced IGRP internal routes.

external [type-1 | type-2]

OSPF external routes, or enhanced IGRP external routes. For OSPF, external type-1 matches only Type 1 external routes and external type-2 matches only Type 2 external routes.

level-1

IS-IS Level 1 routes.

level-2

IS-IS Level 2 routes.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The following keywords first appeared in Cisco IOS Release 11.2: local and external [type-1 | type-2].

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.

Example

In the following example, internal routes will be redistributed:

route-map name
match route-type internal
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

match tag

To redistribute routes in the routing table that match the specified tags, use the match tag route-map configuration command. To remove the tag entry, use the no form of this command.

match tag tag-value...tag-value
no match tag tag-value...tag-value
Syntax Description

tag-value

List of one or more route tag values. Each can be an integer from 0 to 4294967295.

Default

No match tag values are defined.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands may be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

A route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure second route-map section with an explicit match specified.

Example

In the following example, routes stored in the routing table with tag 5 will be redistributed:

route-map name
match tag 5
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

maximum-paths

To control the maximum number of parallel routes an IP routing protocol can support, use the maximum-paths router configuration command. To restore the default value, use the no form of this command.

maximum-paths maximum
no maximum-paths
Syntax Description

maximum

Maximum number of parallel routes an IP routing protocol installs in a routing table, in the range 1 to 6.

Defaults

The default for BGP is 1 path. The default for all other IP routing protocols is 4 paths.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Example

The following example allows a maximum of 2 paths to a destination:

maximum-paths 2

mbranch

To trace a branch of a multicast tree for a specific group, use the mbranch EXEC command.

mbranch {group-address | group-name} branch [ttl]
Syntax Description

group-address

Address of the multicast group. This is a multicast IP address in four-part, dotted notation.

group-name

Name of the multicast group, as defined in the DNS hosts table or with the ip host command.

branch

Address or name of a router that is on the tree branch. The address is a unicast IP address in four-part, dotted notation.

ttl

(Optional) Time-to-live value, in hops, that is used in trace request packets sent to the branch router. The default value is  30.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The mbranch command sends multicast IGMP trace request packets to the specified branch router. It displays information about the branch starting with the local (requesting) router and ending with the branch router. This is considered to be the forward direction.

The information returned shows how a multicast packet sourced by this router will be forwarded by each router on the path to the router with the branch address.

The router with the address branch-address is the only router that responds to the trace request packets. The response is unicast to the source.

It is important to specify a value for the ttl argument if you are tracing through a router on which a multicast threshold has been set with the ip multicast ttl-threshold interface configuration command.

Sample Display

The following is sample output from the mbranch command. This trace is between the same routers as shown in the example for the mbranch command. Note the order of responses. Also note that the outgoing interface list is the same.

PIM2# mbranch 224.0.255.2 198.92.118.2
 
Type escape sequence to abort.
Tracing route to group CBONE-WB (224.0.255.2) to 198.92.118.2
 
Response from 10.17.118.10, 76 msec
  1 PIM9 (10.1.22.9) <- PIM2 (10.1.37.2)
      Interface list: 131.108.62.0/24 131.108.22.0/24 10.7.0.0/16
  2 PIM-CR (131.108.62.18) <- PIM9 (131.108.62.52)
      Interface list: 131.108.20.0/24 131.108.53.0/24 131.108.50.0/24
                      10.16.0.0/16 10.17.0.0/16
  3 10.17.118.10 <- 10.17.20.31
      Interface list: 198.92.118.0/26 198.92.118.192/26
 

The mbranch command is interactive if you specify only the word mbranch. The following output shows sample responses to the system prompts:

Router# mbranch 
Target IP group address or name:224.0.255.1
Target IP router address or name:sj-eng-f2
Ttl [30]:10
Source address or name:<CR>
Interface:ethernet0
Type escape sequence to abort.
Tracing route to group cbone-audio.cisco.com (224.0.255.1) to 171.69.4.139
Response from sj-eng-f2.cisco.com (171.69.4.139), 4 msec
   1 sj-eng-cc2.cisco.com (171.69.121.2)<- 0.0.0.0
      Interface list: 171.69.4.0/24
   2 sj-eng-f2.cisco.com (171.69.4.139)<- sj-eng-cc2.cisco.com (171.69.4.135)
      Interface list: 171.69.60.128/26
 

Table 29 describes the fields shown in the first display.


Table 29: Mbranch Field Descriptions
Field Description

Response from 10.17.118.10

Address of the router from which the response to the trace request packets came. This is a different interface on the router to which you sent the packet.

76 msec

How long it took to receive the response.

1

Order number of routers in the trace path. In this example, the request went through three routers to reach the router that responded to the request.

PIM9 (10.1.22.9) <- PIM2 (10.1.37.2)

Route of the trace request. In this example, the request went from the router PIM2 to the router PIM9 (PIM2 is considered to be PIM9's RPF neighbor), then from PIM9 to PIM-CR, and finally to the router at 10.17.118.10.

Interface list: 131.108.62.0/24 131.108.22.0/24 10.7.0.0/16

Interfaces out which a multicast packet forwarded by the router listed on the right side of the previous line (here, PIM2) will be forwarded. In this example, you interpret this line as follows: When the trace packet reached PIM9, it was replicated three times and one copy was sent out each of the three interfaces listed (131.108.62.0, 131.108.22.0, and 10.7.0.0). The interface list shows the subnet number and the mask rather than the interface name. This allows you to more easily figure out the packet's path because you can connect all like-numbered subnets together as a tree in order to detect loops. The source of the multicast packet is always the address of the router that started the mbranch (in this case, 10.1.37.2). The list does not include interfaces that failed access list conditions or TTL threshold criteria.

Related Commands

ip multicast ttl-threshold
mrbranch

metric holddown

To keep new IGRP routing information from being used for a certain period of time, use the metric holddown router configuration command. To disable this feature, use the no form of this command.

metric holddown
no metric holddown

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Holddown keeps new routing information from being used for a certain period of time. This can prevent routing loops caused by slow convergence. It is sometimes advantageous to disable holddown to increase the network's ability to quickly respond to topology changes; this command provides this function.

Use the metric holddown command if other routers or access servers within the IGRP autonomous system are not configured with no metric holddown. If all routers are not configured the same way, you increase the possibility of routing loops.

Example

The following example disables metric holddown:

router igrp 15
network 131.108.0.0
network 192.31.7.0
no metric holddown
Related Commands

metric maximum-hops
metric weights
timers basic (EGP, RIP, IGRP)

metric maximum-hops

To have the IP routing software to advertise as unreachable those routes with a hop count higher than is specified by the command (IGRP only), use the metric maximum-hops router configuration command. To reset the value to the default, use the no form of this command.

metric maximum-hops hops
no metric maximum-hops hops
Syntax Description

hops

Maximum hop count (in decimal). The default value is 100 hops; the maximum number of hops that can be specified is 255.

Default

100 hops

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command provides a safety mechanism that breaks any potential count-to-infinity problems. It causes the IP routing software to advertise as unreachable routes with a hop count greater than the value assigned to the hops argument.

Example

In the following example, a router in autonomous system 71 attached to network 15.0.0.0 wants a maximum hop count of 200, doubling the default. The network administrators decided to do this because they have a complex WAN that can generate a large hop count under normal (nonlooping) operations.

router igrp 71
network 15.0.0.0
metric maximum-hops 200
Related Commands

metric holddown
metric weights

metric weights

To allow the tuning of the IGRP or Enhanced IGRP metric calculations, use the metric weights router configuration command. To reset the values to their defaults, use the no form of this command.

metric weights tos k1 k2 k3 k4 k5
no metric weights
Syntax Description

tos

Type of service. Currently, it must always be zero.

k1-k5

Constants that convert an IGRP or enhanced IGRP metric vector into a scalar quantity.

Defaults

tos: 0
k1: 1
k2: 0
k3: 1
k4: 0
k5: 0

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use this command to alter the default behavior of IGRP routing and metric computation and allow the tuning of the IGRP metric calculation for a particular type of service (TOS).

If k5 equals 0, the composite IGRP or enhanced IGRP metric is computed according to the following formula:

metric = [k1 * bandwidth + (k2 * bandwidth)/(256 - load) + k3 * delay]
 

If k5 does not equal zero, an additional operation is done:

metric = metric * [k5 / (reliability + k4)]
 

Bandwidth is inverse minimum bandwidth of the path in bits per second scaled by a factor of 2.56  ¥  1012. The range is from a 1200-bps line to 10 terabits per second.

Delay is in units of 10 microseconds. This gives a range of 10 microseconds to 168 seconds. A delay of all ones indicates that the network is unreachable.

The delay parameter is stored in a 32-bit field, in increments of 39.1 nanoseconds. This gives a range of 1 (39.1 nanoseconds) to hexadecimal FFFFFFFF (decimal 4,294,967,040 nanoseconds). A delay of all ones (that is, a delay of hexadecimal FFFFFFFF) indicates that the network is unreachable.

Table 30 lists the default values used for several common media.


Table 30: Bandwidth Values by Media Type
Media Type Delay Bandwidth

Satellite

5120 (2 seconds)

5120 (500 Mbits)

Ethernet

25600 (1 ms)

256000 (10 Mbits)

1.544 Mbps

512000 (20,000 ms)

1,657,856 bits

64 kbps

512000 (20,000 ms)

40,000,000 bits

56 kbps

512000 (20,000 ms)

45,714,176 bits

10 kbps

512000 (20,000 ms)

256,000,000 bits

1 kbps

512000 (20,000 ms)

2,560,000,000 bits

Reliability is given as a fraction of 255. That is, 255 is 100 percent reliability or a perfectly stable link.

Load is given as a fraction of 255. A load of 255 indicates a completely saturated link.

Example

The following example sets the metric weights to slightly different values than the defaults:

router igrp 109
network 131.108.0.0
metric weights 0 2 0 2 0 0
Related Commands

A dagger () indicates that the command is documented outside this chapter.

bandwidth
delay
metric holddown
metric maximum-hops

mrbranch

To trace a branch of a multicast tree for a group in the reverse direction, use the mrbranch EXEC command.

mrbranch {group-address | group-name} branch-address [ttl]
Syntax Description

group-address

Address of the multicast group. This is a multicast IP address in four-part, dotted notation.

group-name

Name of the multicast group, as defined in the DNS hosts table or with the ip host command.

branch-address

Address of a router on the tree branch. This is a unicast IP address in four-part, dotted notation.

ttl

(Optional) Time-to-live value, in hops, that is used in trace request packets sent to the branch router. The default value is  30.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The mrbranch command sends trace request packets to the specified branch router. Queries are sent recursively to all the routers and access servers in the branch. This command displays information about the branch starting with the router farthest away and working toward the requesting router. This is considered to be the reverse direction.

The information returned shows how a multicast packet sourced by this router will be forwarded by each router along the branch.

The router with the address branch-address responds to the trace request packets. The requesting router then sends a query to the router that is the first router's RPF neighbor. Both the request and response packets have unicast addresses.

The number of packets generated by this command is two times the number of routers between the source router and the specified branch router.

Sample Display

The following is sample output from the mrbranch command. This example is between the same router as shown in the mbranch command. Note the order of the responses. Also note that the outgoing interface list is the same.

PIM2# mrbranch 224.0.255.2 10.17.118.10
 
Type escape sequence to abort.
Tracing route to group CBONE-WB (224.0.255.2) from 10.17.118.10
 
Response from 10.17.118.10, 68 msec
  1 10.17.118.10 <- 10.17.20.31
      Interface list: 198.92.118.0/26 198.92.118.192/26
Response from PIM-CR (131.108.62.18), 12 msec
  1 PIM-CR (131.108.62.18) <- PIM9 (131.108.62.52)
      Interface list: 131.108.20.0/24 131.108.53.0/24 131.108.50.0/24
                      10.16.0.0/16 10.17.0.0/16
Response from PIM9 (131.108.62.52), 8 msec
  1 PIM9 (131.108.62.52) <- PIM2 (10.1.37.2)
      Interface list: 131.108.22.0/24 131.108.62.0/24 10.7.0.0/16
 

The mrbranch command is interactive if you specify only the word mrbranch. The following output shows sample responses to the system prompts:

Router# mrbranch 
Target IP group address or name:224.0.255.1
Target IP router address or name:sj-eng-f2
Ttl [30]:10
Source address or name:<CR>
Interface:ethernet0
Type escape sequence to abort.
Tracing route to group cbone-audio.cisco.com (224.0.255.1) to 171.69.4.139
Response from sj-eng-f2.cisco.com (171.69.4.139), 4 msec
   1 sj-eng-f2.cisco.com (171.69.4.139)<- sj-eng-cc2.cisco.com (171.69.4.135)
      Interface list: 171.69.60.128/26
Response from sj-eng-f2.cisco.com (171.69.121.2), 4 msec
   1 sj-eng-cc2.cisco.com (171.69.121.2)<- 0.0.0.0
      Interface list: 171.69.4.0/24
 

Table 31 describes the fields shown in the display.


Table 31: Mrbranch Field Descriptions
Field Description

Tracing route to group CBONE-WB (224.0.255.2) from 10.17.118.10

Route that is being traced.

68 msec

How long it took to receive the response.

Response from 10.17.118.10

Address of the router from which the response to the trace request packets came.

1

Order number of routers in the trace path.

10.17.118.10 <- 10.17.20.31

RPF (reverse path forwarding) neighbor information. The first response in this example indicates that a multicast packet sent from the router PIM2 will be received on interface 10.17.118.10. This multicast packet should have been forwarded from 10.17.20.31 because that is the address that this router would use as the next-hop router (found in the IP routing table) to send a unicast packet back to the original source (PIM2) of the multicast packet.

Interface list: 198.92.118.0/26 198.92.118.192/26

Interfaces out which a multicast packet from the router listed on the right side of the previous line (here, for the group 224.0.255.2 that had been forwarded by 10.17.20.31) will be forwarded. The list does not include interfaces that failed access list conditions or TTL threshold criteria.

Related Commands

mbranch
show ip mroute

mrinfo

To query what neighboring multicast routers are peering with the local router, use the mrinfo EXEC command.

mrinfo [hostname-or-address] [source-address-or-interface]
Syntax Description

hostname-or-address

(Optional) Queries the DNS name or IP address of the multicast router. If omitted, the router queries itself.

source-address-or-interface

(Optional) Source address used on mrinfo requests. If omitted, the source address is based on the outbound interface for the destination.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The mrinfo command is the MBONE's original tool to determine what neighboring multicast routers are peering with a multicast router. Cisco routers have supported responding to mrinfo requests since Cisco IOS Release 10.2.

Now you can query a multicast router using this command. The output format is identical to DVMRP's mrouted version. (The mrouted software is the UNIX software that implements DVMRP.)

Sample Display

The following is sample output of the mrinfo command:

Router # mrinfo
192.31.7.37 (barrnet-gw.cisco.com) [version cisco 11.1] [flags: PMSA]:
  192.31.7.37 -> 192.31.7.34 (sj-wall-2.cisco.com) [1/0/pim]
  192.31.7.37 -> 192.31.7.47 (dirtylab-gw-2.cisco.com) [1/0/pim]
  192.31.7.37 -> 192.31.7.44 (dirtylab-gw-1.cisco.com) [1/0/pim]
  131.119.26.10 -> 131.119.26.9 (su-pr2.bbnplanet.net) [1/32/pim]

mstat

To display IP multicast packet rate and loss information, use the mstat user EXEC command.

mstat source [destination] [group]
Syntax Description

source

DNS name or the IP address of the multicast-capable source.

destination

(Optional) DNS name or address of the destination. If omitted, the command uses the system at which the command is typed.

group

(Optional) DNS name or multicast address of the group to be displayed. Default address is 224.2.0.1 (the group used for MBONE Audio).

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

If no arguments are entered, the router will interactively prompt you for them.

This command is a form of UNIX mtrace that reports packet rate and loss information.

Sample Display

The following is sample output from the mstat command:

Router# mstat dino-ss2 dino-ss20 224.0.255.255  
Type escape sequence to abort.
Mtrace from 171.69.129.220 to 171.69.58.81 via group 224.0.255.255
>From source (dino-ss2.cisco.com) to destination (dino-ss20.cisco.com)
Waiting to accumulate statistics......
Results after 10 seconds:
 
  Source        Response Dest    Packet Statistics For     Only For Traffic
171.69.129.220    171.69.129.217    All Multicast Traffic     From 171.69.129.220
     |       __/  rtt 211  ms   Lost/Sent = Pct  Rate     To 224.0.255.255
     v      /     hop 131  ms   ---------------------     --------------------
171.69.129.217  DINO-CISCO-FR 
     |     ^      ttl   0   
     v     |      hop -6   ms    12/13 = 92%      1 pps    0/2 = --%  0 pps
171.69.121.35   eng-fr-2.cisco.com 
     |     ^      ttl   1   
     v     |      hop 3    ms    0/13 = --%      0 pps    0/2 = --%  0 pps
171.69.121.2    
171.69.5.26     sj-eng-cc4.cisco.com 
     |     ^      ttl   2   
     v     |      hop 0    ms    0/23 = --%      0 pps    -2/2 = --%  0 pps
171.69.5.21     
171.69.62.130   eng-ios-2.cisco.com 
     |     ^      ttl   3   
     v     |      hop 1    ms    0/903 = --%      0 pps    -18471/4 = --%  0 pps
 
Related Command

mtrace

mtrace

To trace the path from a source to a destination branch for a multicast distribution tree, use the mtrace user EXEC command.

mtrace source [destination] [group]
Syntax Description

source

DNS name or the IP address of the multicast-capable source. This is a unicast address of the beginning of the path to be traced.

destination

(Optional) DNS name or address of the unicast destination. If omitted, the mtrace starts from the system at which the command is typed.

group

(Optional) DNS name or multicast address of the group to be traced. Default address is 224.2.0.1 (the group used for MBONE Audio). When address 0.0.0.0 is used, the software invokes a weak mtrace. A weak mtrace is one that follows the RPF path to the source, regardless of whether any router along the path has multicast routing table state.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The trace request generated by the mtrace command is multicast to the multicast group to find the last hop router to the specified destination. The trace then follows the multicast path from destination to source by passing the mtrace request packet via unicast to each hop. Responses are unicast to the querying router by the first hop router to the source. This command allows you to isolate multicast routing failures.

If no arguments are entered, the router will interactively prompt you for them.

This command is identical in function to the UNIX version of mtrace.

Sample Display

The following is sample output from the mtrace command:

Router> mtrace 171.69.215.41 171.69.215.67 239.254.254.254
Type escape sequence to abort.
Mtrace from 171.69.215.41 to 171.69.215.67 via group 239.254.254.254
From source (?) to destination (?)
Querying full reverse path... 
 0  171.69.215.67
-1  171.69.215.67 PIM  thresh^ 0  0 ms  
-2  171.69.215.74 PIM  thresh^ 0  2 ms  
-3  171.69.215.57 PIM  thresh^ 0  894 ms  
-4  171.69.215.41 PIM  thresh^ 0  893 ms  
-5  171.69.215.12 PIM  thresh^ 0  894 ms  
-6  171.69.215.98 PIM  thresh^ 0  893 ms 
 

Table 32 describes the fields shown in the display.


Table 32: Mtrace Field Descriptions
Field Description

Mtrace from 171.69.215.41 to 171.69.215.67 via group 239.254.254.254

Name and address of source, destination, and group for which routes are being traced.

-3 171.69.215.57

Hops away from destination (-3) and address of intermediate router.

PIM thresh^ 0

Multicast protocol in use on this hop, and ttl threshold.

893 ms

Time taken for trace to be forwarded between hops.

Related Command

mstat

ping

To send an ICMP Echo Request to a multicast group, use the ping EXEC command.

ping [group-anme-or-address]
Syntax Description

group-name-or-address

(Optional) Sends an ICMP Echo Request to the specified multicast group.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.2.

If you use this command with no argument, the system prompts you.

neighbor (EGP, IGRP, RIP)

To define a neighboring router with which to exchange routing information, use this form of the neighbor router configuration command. To remove an entry, use the no form of this command.

neighbor ip-address
no neighbor ip-address
Syntax Description

ip-address

IP address of a peer router with which routing information will be exchanged.

Default

No neighboring routers are defined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

For exterior routing protocol EGP, this command specifies routing peers. For normally broadcast protocols such as IGRP or RIP, this command permits the point-to-point (nonbroadcast) exchange of routing information. When used in combination with the passive-interface router configuration command, routing information can be exchanged between a subset of routers and access servers on a LAN.

Multiple neighbor commands can be used to specify additional neighbors or peers.

OSPF has its own version of the neighbor command. See the neighbor (OSPF) command page in this chapter.

Examples

The following example establishes an EGP neighbor:

autonomous-system 109
router egp 110
neighbor 131.108.1.1

In the following example, IGRP updates are sent to all interfaces on network 131.108.0.0 except interface Ethernet 1. However, in this case a neighbor router configuration command is included. This command permits the sending of routing updates to specific neighbors. One copy of the routing update is generated per neighbor.

router igrp 109
network 131.108.0.0
passive-interface ethernet 1
neighbor 131.108.20.4
Related Command

passive-interface

neighbor (OSPF)

To configure OSPF routers and access servers interconnecting to nonbroadcast networks, use this form of the neighbor router configuration command. To remove a configuration, use the no form of this command.

neighbor ip-address [priority number] [poll-interval seconds]
no neighbor
ip-address [priority number] [poll-interval seconds]
Syntax Description

ip-address

Interface IP address of the neighbor.

number

(Optional) 8-bit number indicating the router priority value of the nonbroadcast neighbor associated with the IP address specified. The default is 0.

seconds

(Optional) Unsigned integer value reflecting the poll interval. RFC 1247 recommends that this value be much larger than the hello interval. The default is 2  minutes (120 seconds).

Default

No configuration is specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

X.25 and Frame Relay provide an optional broadcast capability that can be configured in the map to allow OSPF to run as a broadcast network. At the OSPF level you can configure the router as a broadcast network. See the x25 map and frame-relay map commands in "X.25 Commands" and "Frame Relay Commands" chapters, respectively, in the Wide-Area Networking Command Reference for more detail.

One neighbor entry must be included in the Cisco IOS software configuration for each known nonbroadcast network neighbor. The neighbor address has to be on the primary address of the interface.

If a neighboring router has become inactive (hello packets have not been seen for the Router Dead Interval period), it may still be necessary to send hello packets to the dead neighbor. These hello packets will be sent at a reduced rate called Poll Interval.

When the router first starts up, it sends only hello packets to those routers with non-zero priority, that is, routers which are eligible to become designated routers (DR) and backup designated routers (BDR). After DR and BDR are selected, DR and BDR will then start sending hello packets to all neighbors in order to form adjacencies.

Example

The following example declares a router at address 131.108.3.4 on a nonbroadcast network, with a priority of 1 and a poll-interval of 180:

router ospf
neighbor 131.108.3.4 priority 1 poll-interval 180
Related Command

ip ospf priority

neighbor advertisement-interval

To set the minimum interval between the sending of BGP routing updates, use the neighbor advertisement-interval router configuration command. To remove an entry, use the no form of this command.

neighbor {ip-address | peer-group-name} advertisement-interval seconds
no neighbor {ip-address | peer-group-name} advertisement-interval seconds
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

seconds

Time in seconds. Integer from 0 to 600.

Default

30 seconds for external peers and 5 seconds for internal peers.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

In the following example, the minimum time between sending BGP routing updates is set to 10  seconds:

router bgp 5
neighbor 4.4.4.4 advertisement-interval 10
Related Command

neighbor peer-group (creating)

neighbor any

To control how neighbor entries are added to the routing table for both EGP and BGP, use the neighbor any router configuration command. To remove a configuration, use the no form of this command.

neighbor any [access-list-number | name]
no neighbor any [
access-list-number | name]
Syntax Description

access-list-number | name

(Optional) Access list number or name that the neighbor must be accepted by to be allowed to peer with the EGP or BGP process. If no list is specified, any neighbor will be allowed to peer with the router.

Default

No configuration is specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, only neighbors permitted by access list 1 are allowed to peer with the local router:

access-list 1 permit 10.0.0.0 0.255.255.255
! global access list assignment
router egp 0
neighbor any 1
Related Commands

A dagger () indicates that the command is documented outside this chapter.

access-list (standard)
neighbor any third-party
router egp 0

neighbor any third-party

To configure an EGP process that determines which neighbors are treated as the next hop in EGP advertisements, use the neighbor any third-party router configuration command. To remove a configuration, use the no form of this command.

neighbor any third-party ip-address [internal | external]
no neighbor any third-party
ip-address [internal | external]
Syntax Description

ip-address

IP address of the third-party router that is to be the next hop in EGP advertisements.

internal

(Optional) Indicates that the third-party router should be listed in the internal section of the EGP update.

external

(Optional) Indicates that the third-party router should be listed in the external section of the EGP update.

Default

No EGP process is configured.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example specifies the particular neighbors that an EGP process will view as peers:

access-list 2 permit 10.0.0.0 0.255.255.255
! global access list assignment
router egp 0
neighbor any 2
neighbor any third-party 10.1.1.1
Related Commands

neighbor any
router egp 0

neighbor configure-neighbors

To have the Cisco IOS software treat temporary neighbors that have been accepted by a template as if they had been configured manually, use the neighbor configure-neighbors router configuration command. To restore the default, use the no form of this command.

neighbor template-name configure-neighbors
no neighbor
template-name configure-neighbors
Syntax Description

template-name

User-selectable designation that identifies a particular template. This can be an arbitrary word.

Default

New neighbors are treated as temporary.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Under normal circumstances, neighbors that are allowed to connect to the router because you had configured a template are treated as temporary. When a temporary neighbor disconnects, the local router will not try to actively re-establish a connection with it. In addition, information about temporary neighbors will not show up in the router configuration (show running-config).

When configure-neighbors is enabled on a particular template, any neighbor accepted by that template will be treated as if it had been manually configured. These neighbors will show up in show  running-config displays and will be written to the nonvolatile configuration if a copy  running-config startup-config command is issued.

Example

In the following example, any BGP speaker matching access list 7 can connect to the router and exchange information. Any neighbor that connects will be treated as if it had been manually configured.

access-list 7 permit 168.89.3.0 0.0.0.255
neighbor internal-ethernet neighbor-list 7
neighbor internal-ethernet configure-neighbors
Related Command

neighbor neighbor-list

neighbor default-originate

To allow a BGP speaker (the local router) to send the default route 0.0.0.0 to a neighbor for use as a default route, use the neighbor default-originate router configuration command. To remove the default route, use the no form of this command.

neighbor {ip-address | peer-group-name} default-originate [route-map map-name]
no neighbor {ip-address | peer-group-name} default-originate [route-map map-name]
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

route-map map-name

(Optional) Name of the route map. The route map allows route 0.0.0.0 to be injected conditionally.

Default

No default route is sent to the neighbor.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

This command does not require the presence of 0.0.0.0 in the local router. When used with a route map, the default route 0.0.0.0 is injected if the route map contains a match ip address clause and there is a route that matches the IP access list exactly. The route map can contain other match clauses also.

Examples

In the following example, the local router injects route 0.0.0.0 to the neighbor 160.89.2.3 unconditionally:

router bgp 109
network 160.89.0.0
neighbor 160.89.2.3 remote-as 200
neighbor 160.89.2.3 default-originate
 

In the following example, the local router injects route 0.0.0.0 to the neighbor 160.89.2.3 only if there is a route to 198.92.68.0:

router bgp 109
network 160.89.0.0
neighbor 160.89.2.3 remote-as 200
neighbor 160.89.2.3 default-originate route-map default-map
!
route-map default-map 10 permit
match ip address 1
!
access-list 1 permit 198.92.68.0

neighbor distribute-list

To distribute BGP neighbor information as specified in an access list, use the neighbor  distribute-list router configuration command. To remove an entry, use the no form of this command.

neighbor {ip-address | peer-group-name} distribute-list {access-list-number | name} {in | out}
no neighbor {ip-address | peer-group-name} distribute-list {access-list-number | name} {in |
out}
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

access-list-number | name

Number or name of a standard or extended access list. It can be an integer from 1 to 199.

in

Access list is applied to incoming advertisements to that neighbor.

out

Access list is applied to outgoing advertisements from that neighbor.

Default

No BGP neighbor is specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The peer-group-name argument first appeared in Cisco IOS Release 11.0. The access-list-name argument first appeared in Cisco IOS Release 11.2.

Using distribute lists is one of two ways to filter BGP advertisements. The other way is to use AS-path filters, as with the ip as-path access-list global configuration command and the neighbor filter-list command.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.

Example

The following example applies list 39 to incoming advertisements to neighbor 120.23.4.1:

router bgp 109
network 131.108.0.0
neighbor 120.23.4.1 distribute-list 39 in
Related Commands

ip as-path access-list
neighbor filter-list
neighbor peer-group (creating)

neighbor ebgp-multihop

To accept and attempt BGP connections to external peers residing on networks that are not directly connected, use the neighbor ebgp-multihop router configuration command. To return to the default, use the no form of this command.

neighbor {ip-address | peer-group-name} ebgp-multihop [ttl]
no neighbor {ip-address | peer-group-name} ebgp-multihop
Syntax Description

ip-address

IP address of the BGP-speaking neighbor.

peer-group-name

Name of a BGP peer group.

ttl

(Optional) Time-to-live in the range 1 to 255 hops.

Default

Only directly connected neighbors are allowed.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The peer-group-name argument first appeared in Cisco IOS Release 11.0.

This feature should only be used under the guidance of technical support staff.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

The following example allows connections to or from neighbor 131.108.1.1, which resides on a network that is not directly connected:

router bgp 109
neighbor 131.108.1.1 ebgp-multihop
Related Command

neighbor peer-group (creating)

neighbor filter-list

To set up a BGP filter, use the neighbor filter-list router configuration command. To disable this function, use the no form of this command.

neighbor {ip-address | peer-group-name} filter-list access-list-number {in | out |
weight weight}
no neighbor {ip-address | peer-group-name} filter-list access-list-number {in | out |
weight weight}
Syntax Description

ip-address

IP address of the neighbor.

peer-group-name

Name of a BGP peer group.

access-list-number

Number of an autonomous system path access list. You define this access list with the ip  as-path  access-list command.

in

Access list to incoming routes.

out

Access list to outgoing routes.

weight weight

Assigns a relative importance to incoming routes matching autonomous system paths. Acceptable values are 0 to 65535.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command establishes filters on both inbound and outbound BGP routes. Any number of weight filters are allowed on a per-neighbor basis, but only one in or out filter is allowed. The weight of a route affects BGP's route-selection rules.

The implemented weight is based on the first matched autonomous system path. Weights indicated when an autonomous system path is matched override the weights assigned by global neighbor commands. In other words, the weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.

See the "Regular Expressions" appendix in the Access Services Command Reference for information on forming regular expressions.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.

Example

In the following example, the BGP neighbor with IP address 128.125.1.1 is not sent advertisements about any path through or from the adjacent autonomous system 123:

ip as-path access-list 1 deny _123_
ip as-path access-list 1 deny ^123$
 
router bgp 109
network 131.108.0.0
neighbor 129.140.6.6 remote-as 123
neighbor 128.125.1.1 remote-as 47
neighbor 128.125.1.1 filter-list 1 out
Related Commands

ip as-path access-list
neighbor distribute-list
neighbor peer-group (creating)
neighbor weight

neighbor neighbor-list

To configure BGP to support anonymous neighbor peers by configuring a neighbor template, use the neighbor neighbor-list router configuration command. To delete a template, use the no form of this command.

neighbor template-name neighbor-list {access-list-number | name}
no neighbor template-name neighbor-list {access-list-number | name}
Syntax Description

template-name

User-selectable designation that identifies a particular template (an arbitrary word).

access-list-number | name

Number or name of an access list. It can be a number in the range 1 to 99 or an access list name.

Default

No configuration is defined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

To specify a group of anonymous neighbors, configure a neighbor template rather than specifically configure each neighbor. The template allows you to specify an IP access list, which defines remote systems that can establish a BGP connection to the router. External BGP peers must be on a directly connected Ethernet unless they are overridden by the neighbor ebgp-multihop command.

Once you specify a template, you configure the template as if it were a regular neighbor entry (such as setting the protocol version or filter lists) so that anonymous neighbors accepted by the template will receive the settings of the template.

These neighbors accepted by the template appear in the show ip bgp summary and show ip bgp neighbors displays, although they do not appear in the router configuration. When the session is disconnected, all knowledge about the neighbor is discarded and the Cisco IOS software will not attempt to actively re-establish a connection.

You can use the neighbor configure-neighbors command to request that the software treat peers learned through a template as if they were manually configured neighbors. These peers will then show up in write terminal displays and can be stored as part of the nonvolatile configuration.

The no neighbor neighbor-list command deletes the template and cause any temporary neighbors accepted by the template to be shut down and removed.

Examples

In the following example, any BGP speaker from 168.89.3.0 can connect to the router and exchange information:

access-list 7 permit 168.89.3.0 0.0.0.255
neighbor internal-ethernet neighbor-list 7
neighbor internal-ethernet configure-neighbors

In the following example, any BGP speaker in the connected internet can establish a BGP connection to the local router, and the local router will send them routing information. However, the distribute-list clause instructs the local router to ignore all information these remote BGP speakers send to it.

access-list 9 permit 0.0.0.0 255.255.255.255
access-list 10 deny 0.0.0.0 255.255.255.255
neighbor route-server-peers neighbor-list 9
neighbor route-server-peers distribute-list 10 in
Related Commands

A dagger () indicates that the command is documented outside this chapter.

access-list (standard)
neighbor configure-neighbors
neighbor ebgp-multihop

neighbor next-hop-self

To disable next-hop processing of BGP updates on the router, use the neighbor  next-hop-self router configuration command. To disable this feature, use the no form of this command.

neighbor {ip-address | peer-group-name} next-hop-self
no neighbor {ip-address | peer-group-name} next-hop-self
Syntax Description

ip-address

IP address of the BGP-speaking neighbor.

peer-group-name

Name of a BGP peer group.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The peer-group-name argument first appeared in Cisco IOS Release 11.0.

This command is useful in nonmeshed networks (such as Frame Relay or X.25) where BGP neighbors may not have direct access to all other neighbors on the same IP subnet.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.

Example

The following example forces all updates destined for 131.108.1.1 to advertise this router as the next hop:

router bgp 109
neighbor 131.108.1.1 next-hop-self
Related Command

neighbor peer-group (creating)

neighbor password

To enable MD5 authentication on a TCP connection between two BGP peers, use the neighbor password router configuration command. To disable this feature, use the no form of this command.

neighbor {ip-address | peer-group-name} password string
no neighbor {ip-address | peer-group-name} password
Syntax Description

ip-address

IP address of the BGP-speaking neighbor.

peer-group-name

Name of a BGP peer group.

string

Case-sensitive password of up to 80 characters. The first character cannot be a number. The string can contain any alphanumeric characters, including spaces. You cannot specify a password in the format number-space-anything. The space after the number causes problems.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

You can invoke authentication between two BGP peers, causing each segment sent on the TCP connection between them to be verified. This feature must be configured with the same password on both BGP peers; otherwise, the connection between them will not be made. The authentication feature uses the MD5 algorithm. Specifying this command causes the generation and checking of the MD5 digest on every segment sent on the TCP connection.

Configuring a password for a neighbor will cause an existing session to be torn down and a new one established.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

If a router has a password configured for a neighbor, but the neighbor router does not, a message such as the following will appear on the console while the routers attempt to establish a BGP session between them:

%TCP-6-BADAUTH: No MD5 digest from [peer's IP address]:11003 to [local router's IP address]:179
 

Similarly, if the two routers have different passwords configured, a message such as the following will appear on the console:

%TCP-6-BADAUTH: Invalid MD5 digest from [peer's IP address]:11004 to [local router's IP address]:179
Example

The following example enables the authentication feature between this router and the BGP neighbor at 131.102.1.1. The password that must also be configured for the neighbor is bla4u00=2nkq.

router bgp 109
neighbor 131.108.1.1 password bla4u00=2nkq
Related Command

neighbor peer-group (creating)

neighbor peer-group (assigning members)

To configure a BGP neighbor to be a member of a peer group, use the neighbor peer-group router configuration command. To remove the neighbor from the peer group, use the no form of this command.

neighbor ip-address peer-group peer-group-name
no neighbor ip-address peer-group peer-group-name
Syntax Description

ip-address

IP address of the BGP neighbor who belongs to the peer group specified by the tag.

peer-group-name

Name of the BGP peer group to which this neighbor belongs.

Default

There are no BGP neighbors in a peer group.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The neighbor at the IP address indicated inherits all the configured options of the peer group.

Example

In the following example, three neighbors are assigned to the peer group called "internal."

router bgp 100
neighbor internal peer-group
neighbor internal remote-as 100
neighbor internal update-source loopback 0
neighbor internal route-map set-med out
neighbor internal filter-list 1 out
neighbor internal filter-list 2 in
neighbor 171.69.232.53 peer-group internal
neighbor 171.69.232.54 peer-group internal
neighbor 171.69.232.55 peer-group internal
neighbor 171.69.232.55 filter-list 3 in
Related Commands

neighbor peer-group (creating)

neighbor peer-group (creating)

To create a BGP peer group, use the neighbor peer-group router configuration command. To remove the peer group and all of its members, use the no form of this command.

neighbor peer-group-name peer-group
no neighbor peer-group-name peer-group
Syntax Description

peer-group-name

Name of the BGP peer group.

Default

There is no BGP peer group.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Often in a BGP speaker, there are many neighbors configured with the same update policies (that is, same outbound route maps, distribute lists, filter lists, update source, and so on). Neighbors with the same update policies can be grouped into peer groups to simplify configuration and make update calculation more efficient.

Once a peer group is created with the neighbor peer-group command, it can be configured with the neighbor commands. By default, members of the peer group inherit all the configuration options of the peer group. Members can also be configured to override the options that do not affect outbound updates.

Peer group members will always inherit the following: remote-as (if configured), version, update-source, out-route-map, out-filter-list, out-dist-list, minimum-advertisement-interval, and next-hop-self. All the peer group members will inherit changes made to the peer group.

If a peer group is not configured with a remote-as, the members can be configured with the neighbor  {ip-address | peer-group-name} remote-as command. This allows you to create peer groups containing EBGP neighbors.

Example for an IBGP Peer Group

In the following example, the peer group named internal configures the members of the peer group to be IBGP neighbors. By definition, this is an IBGP peer group because the router bgp command and the neighbor remote-as command indicate the same autonomous system (in this case, AS  100). All the peer group members use loopback 0 as the update source and use set-med as the outbound route-map. The inbound filter-list command shows that except 171.69.232.55 all the neighbor has filter-list 2 as the inbound filter list.

router bgp 100
neighbor internal peer-group
neighbor internal remote-as 100
neighbor internal update-source loopback 0
neighbor internal route-map set-med out
neighbor internal filter-list 1 out
neighbor internal filter-list 2 in
neighbor 171.69.232.53 peer-group internal
neighbor 171.69.232.54 peer-group internal
neighbor 171.69.232.55 peer-group internal
neighbor 171.69.232.55 filter-list 3 in
Example for an EBGP Peer Group

In the following example, the peer group external-peers is defined without the neighbor remote-as command. This is what makes it an EBGP peer group. Each individual member of the peer group is configured with its respective AS-number separately. Thus the peer group consists of members from autonomous systems 200, 300 and 400. All the peer group members have set-metric route map as an outbound route map and filter-list 99 as an outbound filter list. Except for neighbor 171.69.232.110, all of them have 101 as the inbound filter list.

router bgp 100
neighbor external-peers peer-group
neighbor external-peers route-map set-metric out
neighbor external-peers filter-list 99 out
neighbor external-peers filter-list 101 in
neighbor 171.69.232.90 remote-as 200
neighbor 171.69.232.90 peer-group external-peers
neighbor 171.69.232.100 remote-as 300
neighbor 171.69.232.100 peer-group external-peers
neighbor 171.69.232.110 remote-as 400
neighbor 171.69.232.110 peer-group external-peers
neighbor 171.69.232.110 filter-list 400 in
Related Commands

clear ip bgp peer-group
neighbor peer-group (assigning members)
show ip bgp peer-group

neighbor remote-as

To add an entry to the BGP neighbor table, use the neighbor remote-as router configuration command. To remove an entry from the table, use the no form of this command.

neighbor {ip-address | peer-group-name} remote-as number
no neighbor {ip-address | peer-group-name} remote-as number
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

number

Autonomous system to which the neighbor belongs.

Default

There are no BGP neighbor peers.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The peer-group-name argument first appeared in Cisco IOS Release 11.0.

Specifying a neighbor with an autonomous system number that matches the autonomous system number specified in the router  bgp global configuration command identifies the neighbor as internal to the local autonomous system. Otherwise, the neighbor is considered external.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Examples

The following example specifies that a router at the address 131.108.1.2 is a neighbor in autonomous system number 109:

router bgp 110
network 131.108.0.0
neighbor 131.108.1.2 remote-as 109
 

In the following example, a BGP router is assigned to autonomous system 109, and two networks are listed as originating in the autonomous system. Then the addresses of three remote routers (and their autonomous systems) are listed. The router being configured will share information about networks 131.108.0.0 and 192.31.7.0 with the neighbor routers. The first router listed is in the same Class B network address space, but in a different autonomous system; the second neighbor command illustrates specification of an internal neighbor (with the same autonomous system number) at address 131.108.234.2; and the last neighbor command specifies a neighbor on a different network.

router bgp 109
network 131.108.0.0
network 192.31.7.0
neighbor 131.108.200.1  remote-as 167
neighbor 131.108.234.2  remote-as 109
neighbor 150.136.64.19  remote-as  99
Related Command

neighbor peer-group (creating)

neighbor route-map

To apply a route map to incoming or outgoing routes, use the neighbor route-map router configuration command. To remove a route map, use the no form of this command.

neighbor {ip-address | peer-group-name} route-map route-map-name {in | out}
no neighbor {ip-address | peer-group-name} route-map route-map-name {in | out}
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

route-map-name

Name of route map.

in

Apply to incoming routes.

out

Apply to outgoing routes.

Default

No route maps are applied to a peer.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If an outbound route map is specified, it is proper behavior to only advertise routes that match at least one section of the route map.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command. Specifying the command with an IP address will override the value inherited from the peer group.

Example

In the following example, route map "internal-map" is applied to incoming route from 198.92.70.24:

router bgp 5
neighbor 198.92.70.24 route-map internal-map in
!
route-map internal-map
match as-path 1
set local-preference 100
Related Command

neighbor peer-group (creating)

neighbor route-reflector-client

To configure the router as a BGP route reflector and configure the specified neighbor as its client, use the neighbor route-reflector-client router configuration command. To indicate that the neighbor is not a client, use the no form of this command. When all the clients are disabled, the local router is no longer a route reflector.

neighbor ip-address route-reflector-client
no neighbor
ip-address route-reflector-client
Syntax Description

ip-address

IP address of the BGP neighbor being identified as a client.

Default

There is no route reflector in the autonomous system.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

By default, all IBGP speakers in an autonomous system must be fully meshed, and neighbors do not readvertise IBGP learned routes to neighbors, thus preventing a routing information loop.

If you use route reflectors, all IBGP speakers need not be fully meshed. In the route reflector model, an internal BGP peer is configured to be a route  reflector responsible for passing IBGP learned routes to IBGP neighbors. This scheme eliminates the need for each router to talk to every other router.

Use the neighbor route-reflector-client command to configure the local router as the route reflector and the specified neighbor as one of its clients. All the neighbors configured with this command will be members of the client group and the remaining IBGP peers will be members of the nonclient group for the local route reflector.

If client-to-client reflection is enabled (by default it is enabled), clients of a route reflector cannot be members of a peer group. The bgp client-to-client reflection command controls client-to-client reflection.

Example

In the following example, the local router is a route reflector. It passes learned IBGP routes to the neighbor at 198.92.70.24.

router bgp 5
neighbor 198.92.70.24 route-reflector-client
Related Commands

bgp client-to-client reflection
bgp cluster-id
show ip bgp

neighbor send-community

To specify that a COMMUNITIES attribute should be sent to a BGP neighbor, use the neighbor send-community router configuration command. To remove the entry, use the no form of this command.

neighbor {ip-address | peer-group-name} send-community
no neighbor {ip-address | peer-group-name} send-community
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

Default

No COMMUNITIES attribute is sent to any neighbor.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3. The peer-group-name argment first appeared in Cisco IOS Release 11.0.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

In the following example, the router belongs to autonomous system 109 and is configured to send the COMMUNITIES attribute to its neighbor at IP address 198.92.70.23:

router bgp 109
neighbor 198.92.70.23 send-community
Related Commands

match community-list
neighbor peer-group (creating)
set community

neighbor soft-reconfiguration inbound

To configure the Cisco IOS software to start storing received updates, use the neighbor soft-reconfiguration inbound router configuration command. To not store received updates, use the no form of this command.

neighbor {ip-address | peer-group-name} soft-reconfiguration inbound
no neighbor {ip-address | peer-group-name} soft-reconfiguration inbound
Syntax Description

ip-address

IP address of the BGP-speaking neighbor.

peer-group-name

Name of a BGP peer group.

Default

None

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Entering this command starts the storage of received updates. This is required to do inbound soft reconfiguration. Outbound BGP soft-reconfiguration does not require inbound soft reconfiguration to be enabled.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

In the following example, inbound soft-reconfiguration is enabled for the neighbor 131.108.1.1. All the updates received from this neighbor will be stored unmodified, regardless of the inbound policy. When inbound soft reconfiguration is done later, the stored information will be used to generate a new set of inbound updates.

router bgp 100
neighbor 131.108.1.1 remote-as 200
neighbor 131.108.1.1 soft-reconfiguration inbound 
Related Command

neighbor peer-group (creating)

neighbor third-party

To send updates regarding Exterior Gateway Protocol (EGP) third-party routers, use the neighbor  third-party router configuration command. To disable these updates, use the no form of this command.

neighbor ip-address third-party third-party-ip-address [internal | external]
no neighbor ip-address third-party third-party-ip-address [internal | external]
Syntax Description

ip-address

IP address of the EGP peer.

third-party-ip-address

Address of the third-party router on the network shared by the Cisco router and the EGP peer specified by address.

internal

(Optional) Indicates that the third-party router should be listed in the internal section of the EGP update. This is the default.

external

(Optional) Indicates that the third-party router should be listed in the external section of the EGP update.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Using this third-party mechanism, EGP tells its peer that another router (the third party) on the shared network is the appropriate router for some set of destinations. If updates mentioning third-party routers are desired, use this command.

All networks reachable through the third-party router will be listed in the EGP updates as reachable by the router. The optional internal and external keywords indicate whether the third-party router should be listed in the internal or external section of the EGP update. Normally, all networks are mentioned in the internal section.

This command can be used multiple times to specify additional third-party routers.

Examples

In the following example, routes learned from router 131.108.6.99 will be advertised to 131.108.6.5 as third-party internal routes:

neighbor 131.108.6.5  third-party 131.108.6.99 internal
 

In the following example, routes learned from 131.108.6.100 will be advertised to 131.108.6.5 as third-party external routes:

neighbor 131.108.6.5 third-party 131.108.6.100 external

neighbor update-source

To have the Cisco IOS software allow internal BGP sessions to use any operational interface for TCP connections, use the neighbor update-source router configuration command. To restore the interface assignment to the closest interface, which is called the best local address, use the no form of this command

neighbor {ip-address | peer-group-name} update-source interface
no neighbor {ip-address | peer-group-name} update-source interface
Syntax Description

ip-address

IP address of the BGP-speaking neighbor.

peer-group-name

Name of a BGP peer group.

interface

Loopback interface.

Default

Best local address

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This feature works in conjunction with the loopback interface feature described in the "Configuring Interfaces" chapter of the Configuration Fundamentals Configuration Guide.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

In the following example, BGP TCP connections for the specified neighbor will be sourced with loopback interface's IP address rather than the best local address:

router bgp 110
network 160.89.0.0
neighbor 160.89.2.3 remote-as 110
neighbor 160.89.2.3 update-source Loopback0
Related Command

neighbor peer-group (creating)

neighbor version

To configure the Cisco IOS software to accept only a particular BGP version, use the neighbor  version router configuration command. To use the default version level of a neighbor, use the no form of this command.

neighbor {ip-address | peer-group-name} version value
no neighbor {ip-address | peer-group-name} version value
Syntax Description

ip-address

IP address of the BGP-speaking neighbor.

peer-group-name

Name of a BGP peer group.

value

BGP version number. The version can be set to 2 to force the software to only use Version 2 with the specified neighbor. The default is to use Version 4 and dynamically negotiate down to Version 2 if requested.

Default

BGP Version 4

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Entering this command disables dynamic version negotiation.

Our implementation of BGP supports BGP Versions 2, 3, and 4. If the neighbor does not accept default Version 4, dynamic version negotiation is implemented to negotiate down to Version 2.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

The following example locks down to Version 4 of the BGP protocol:

router bgp 109
neighbor 131.104.27.2 version 4
Related Command

neighbor peer-group (creating)

neighbor weight

To assign a weight to a neighbor connection, use the neighbor weight router configuration command. To remove a weight assignment, use the no form of this command.

neighbor {ip-address | peer-group-name} weight weight
no neighbor {ip-address | peer-group-name} weight weight
Syntax Description

ip-address

Neighbor's IP address.

peer-group-name

Name of a BGP peer group.

weight

Weight to assign. Acceptable values are 0 to 65535.

Default

Routes learned through another BGP peer have a default weight of 0 and routes sourced by the local router have a default weight of 32768.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

All routes learned from this neighbor will have the assigned weight initially. The route with the highest weight will be chosen as the preferred route when multiple routes are available to a particular network.

The weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.


Note For weight changes to take effect, it may be necessary to use clear ip bgp peer-group *.

If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group will inherit the characteristic configured with this command.

Example

The following example sets the weight of all routes learned via 151.23.12.1 to 50:

router bgp 109
neighbor 151.23.12.1 weight 50
Related Commands

neighbor distribute-list
neighbor filter-list
neighbor peer-group (creating)

net

To configure a network entity title (NET) for the routing process, use the net router configuration command. To remove a NET, use the no form of this command.

net network-entity-title
no net network-entity-title
Syntax Description

network-entity-title

NET that specifies the area address and the system ID for an IS-IS routing process. This argument can be either an address or a name.

Default

No NET is configured.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

For IS-IS, multiple NETs per router are allowed, with a maximum of three. There is no default value for this command.

Example

The following example specifies a single NET:

router isis Pieinthesky
net 47.0004.004d.0001.0000.0c11.1111.00

network (BGP)

To specify the list of networks for the BGP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.

network network-number [mask network-mask]
no network network-number [mask network-mask]
Syntax Description

network-number

Network that BGP will advertise.

mask

Network or subnetwork mask.

network-mask

(Optional) Network mask address.

Default

No networks are specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

These types of networks can be learned from connected routes, dynamic routing, and from static route sources.

A maximum of 200 network commands may be specified for a single BGP process.

Example

The following example sets up network 131.108.0.0 to be included in the BGP updates:

router bgp 120
network 131.108.0.0
Related Commands

A dagger () indicates that the command is documented outside this chapter.

network backdoor
network mask

network weight
router bgp

network (EGP)

To specify the list of networks for the EGP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.

network network-number
no network network-number
Syntax Description

network-number

IP address of a peer router with which routing information will be exchanged.

Default

No networks are specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The networks to be advertised to the EGP peers of an EGP routing process are advertised with a distance of zero. The restrictions on the network you specify are that it must appear in the routing table, and the network number must not contain any subnet information. The network can be connected, statically configured, or redistributed into EGP from other routing protocols. Multiple commands can be used to specify additional networks.

Example

The following example illustrates a typical configuration for an EGP router process. The router is in autonomous system 109 and is peering with routers in autonomous system 164. It will advertise the networks 131.108.0.0 and 192.31.7.0 to the router in autonomous system 164, 10.2.0.2. The information sent and received from peer routers can be filtered in various ways, including blocking information from certain routers and suppressing the advertisement of specific routes.

autonomous-system 109
router egp 164
network 131.108.0.0
network 192.31.7.0
neighbor 10.2.0.2
Related Command

router egp

network (IGRP and Enhanced IGRP)

To specify a list of networks for the Enhanced IGRP routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.

network network-number
no network network-number
Syntax Description

network-number

IP address of the directly connected networks.

Default

No networks are specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The network number specified must not contain any subnet information. You can specify multiple network commands.

IGRP or Enhanced IGRP sends updates to the interfaces in the specified network(s). Also, if an interface's network is not specified, it will not be advertised in any IGRP or Enhanced IGRP update.

Example

The following example configures a router for IGRP and assigns autonomous system 109. The network commands indicate the networks directly connected to the router.

router igrp 109
network 131.108.0.0
network 192.31.7.0
Related Commands

router igrp
router eigrp

network (RIP)

To specify a list of networks for the Routing Information Protocol (RIP) routing process, use this form of the network router configuration command. To remove an entry, use the no form of this command.

network network-number
no network network-number
Syntax Description

network-number

IP address of the network of directly connected networks.

Default

No networks are specified.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The network number specified must not contain any subnet information. You can specify multiple network commands. RIP routing updates will be sent and received only through interfaces on this network.

RIP sends updates to the interfaces in the specified networks. Also, if an interface's network is not specified, it will not be advertised in any RIP update.

Example

The following example defines RIP as the routing protocol to be used on all interfaces connected to networks 128.99.0.0 and 192.31.7.0:

router rip
network 128.99.0.0
network 192.31.7.0
Related Command

router rip

network area

To define the interfaces on which OSPF runs and to define the area ID for those interfaces, use the network area router configuration command. To disable OSPF routing for interfaces defined with the address wildcard-mask pair, use the no form of this command.

network address wildcard-mask area area-id
no network address wildcard-mask area area-id
Syntax Description

address

IP address.

wildcard-mask

IP-address-type mask that includes "don't care" bits.

area-id

Area that is to be associated with the OSPF address range. It can be specified as either a decimal value or as an IP address. If you intend to associate areas with IP subnets, you can specify a subnet address as the area-id.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The address and wildcard-mask arguments together allow you to define one or multiple interfaces to be associated with a specific OSPF area using a single command. Using the wildcard-mask allows you to define one or multiple interfaces to be associated with a specific OSPF area using a single command. If you intend to associate areas with IP subnets, you can specify a subnet address as the area-id.

For OSPF to operate on the interface, that interface's primary address must be covered by the network area command. If the network area command covers only the secondary address, it will not enable OSPF over that interface.

The Cisco IOS software sequentially evaluates the address/wildcard-mask pair for each interface as follows:

    1. The wildcard-mask is logically ORed with the interface IP address.

    2. The wildcard-mask is logically ORed with address in the network command.

    3. The software compares the two resulting values.

    4. If they match, OSPF is enabled on the associated interface and this interface is attached to the OSPF area specified.


Note Any individual interface can only be attached to a single area. If the address ranges specified for different areas overlap, the software will adopt the first area in the network command list and ignore the subsequent overlapping portions. In general, it is recommended that you devise address ranges that do not overlap in order to avoid inadvertent conflicts.
Example

In the following partial example, OSPF routing process 109 is initialized, and four OSPF areas are defined: 10.9.50.0, 2, 3, and 0. Areas 10.9.50.0, 2, and 3 mask specific address ranges, while area 0 enables OSPF for all other networks.

interface ethernet 0
ip address 131.108.20.1 255.255.255.0
router ospf 109
network 131.108.20.0  0.0.0.255 area 10.9.50.0
network 131.108.0.0  0.0.255.255 area 2
network 131.109.10.0  0.0.0.255 area 3
network 0.0.0.0  255.255.255.255 area 0
Related Command

router ospf

network backdoor

To specify a backdoor route to a BGP border router that will provide better information about the network, use the network backdoor router configuration command. To remove an address from the list, use the no form of this command.

network address backdoor
no network address backdoor
Syntax Description

address

IP address of the network to which you want a backdoor route.

Default

No network is advertised.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

A backdoor network is treated as a local network, except that it is not advertised.

Example

The following example configures network 131.108.0.0 as a local network and network 192.31.7.0 as a backdoor network:

router bgp 109
network 131.108.0.0
network 192.31.7.0 backdoor

network weight

To assign an absolute weight to a BGP network, use the network weight router configuration command. To delete an entry, use the no form of the command.

network address weight weight
no network address weight weight
Syntax Description

address

IP address of the network.

weight

Absolute weight, or importance. It can be an integer from 0 to  65535.

Default

Weight is unmodified. Weight is zero if the original default weight has not been modified by other router configuration commands.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The weight specified by this command overrides a weight assigned by the redistribute command.

Example

In the following example, the BGP network has a weight of 100:

router bgp 5
network 193.0.0.0 weight 100

offset-list

To add an offset to incoming and outgoing metrics to routes learned via RIP and IGRP, use the offset-list router configuration command. To remove an offset list, use the no form of this command.

offset-list {access-list-number | name} {in | out} offset [type number]
no offset-list {access-list-number | name} {in | out} offset [type number]
Syntax Description

access-list-number | name

Standard access list number or name to be applied. Access list number 0 indicates all access lists. If offset is 0, no action is taken. For IGRP, the offset is added to the delay component only.

in

Applies the access list to incoming metrics.

out

Applies the access list to outgoing metrics.

offset

Positive offset to be applied to metrics for networks matching the access list. If the offset is 0, no action is taken.

type

(Optional) Interface type to which the offset-list is applied.

number

(Optional) Interface number to which the offset-list is applied.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The type and number arguments first appeared in Cisco IOS Release 10.3. The name argument first appeared in Cisco IOS Release 11.2.

The offset value is added to the routing metric. An offset-list with an interface type and interface number is considered extended and takes precedence over an offset-list that is not extended. Therefore, if an entry passes the extended offset-list and the normal offset-list, the extended offset-list's offset is added to the metric.

Examples

In the following example, the router applies an offset of 10 to the router's delay component only to access list 21:

offset-list 21 out 10
 

In the following example, the router applies an offset of 10 to routes learned from Ethernet interface  0:

offset-list 21 in 10 ethernet 0

ospf auto-cost

To control how OSPF calculates default metrics for the interface, use the ospf auto-cost router configuration command. To assign cost based only on the interface type, use the no form of this command.

ospf auto-cost reference-bandwidth ref-bw
no ospf auto-cost reference-bandwidth
Syntax Description

ref-bw

Rate in megabits per second (bandwidth). The range is 1 to 4294967; the default is 100.

Default

100 Mbits

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

In Cisco IOS Release 10.3 and later, by default OSPF will calculate the OSPF metric for an interface according to the bandwidth of the interface. For example, a 64K link will get a metric of 1562, while a T1 link will have a metric of 64.

The OSPF metric is calculated as ref-bw divided by bandwidth, with ref-bw equal to 108 by default, and bandwidth determined by the bandwidth command. The calculation gives FDDI a metric of 1.

If you have multiple links with high bandwidth (such as FDDI or ATM), you might want to use a larger number to differentiate the cost on those links.

The value set by the ip ospf cost command overrides the cost resulting from the ospf auto-cost command.

Example

The following example changes the cost of the FDDI link to 10, while the gigabit Ethernet link remains at a cost of 1. Thus, the link costs are differentiated.

router ospf 1
 ospf auto-cost reference-bandwidth 1000
Related Command

ip ospf cost

ospf log-adj-changes

To configure the router to send a syslog message when the state of an OSPF neighbor changes, use the ospf  log-adj-changes router configuration command. To turn off this feature, use the no form of this command.

ospf log-adj-changes
no ospf log-adj-changes

Syntax Description

This command has no arguments or keywords.

Default

No such syslog message is sent.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Configure this command if you want to know about OSPF neighbor changes without turning on the debugging command debug ip ospf adjacency. The ospf log-adj-changes command provides a higher level view of changes to the state of the peer relationship with less output.

Example

The following example configures the router to send a syslog message for any neighbor state changes:

ospf log-adj-changes

output-delay

To change the interpacket delay for RIP updates sent, use the output-delay router configuration command. To remove the delay, use the no form of this command.

output-delay delay
no output-delay [delay]
Syntax Description

delay

Delay, in milliseconds, between packets in a multiple-packet RIP update. The range is 8 to 50 milliseconds. The default is no delay.

Default

0 milliseconds

Command Mode

Router configuration

Usage Guidelines

Consider using this command if you have a high-end router sending at high speed to a low-speed router that might not be able to receive at that fast a rate. Configuring this command will help prevent the routing table from losing information.

Example

In the following example, the interpacket delay is set to 10 milliseconds:

output-delay 10

passive-interface

To disable sending routing updates on an interface, use the passive-interface router configuration command. To reenable the sending of routing updates, use the no form of this command.

passive-interface type number
no passive-interface type number
Syntax Description

type

Interface type.

number

Interface number.

Default

Routing updates are sent on the interface.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you disable the sending of routing updates on an interface, the particular subnet will continue to be advertised to other interfaces, and updates from other routers on that interface continue to be received and processed.

For OSPF, OSPF routing information is neither sent nor received through the specified router interface. The specified interface address appears as a stub network in the OSPF domain.

For IS-IS, this command instructs IS-IS to advertise the IP addresses for the specified interface without actually running IS-IS on that interface. The no form of this command for IS-IS disables advertising IP addresses for the specified address.

Enhanced IGRP is disabled on an interface that is configured as passive although it advertises the route.

Examples

The following example sends IGRP updates to all interfaces on network 131.108.0.0 except Ethernet interface 1:

router igrp 109
network 131.108.0.0
passive-interface ethernet 1
 

The following configuration enables IS-IS on interfaces Ethernet 1 and serial 0 and advertises the IP addresses of Ethernet 0 in its Link State PDUs:

router isis Finance
passive-interface Ethernet 0
interface Ethernet 1
ip router isis Finance
interface serial 0
ip router isis Finance

redistribute

To redistribute routes from one routing domain into another routing domain, use the redistribute router configuration command. To disable redistribution, use the no form of this command.

redistribute protocol [process-id] {level-1 | level-1-2 | level-2} [metric metric-value]
[metric-type type-value] [match {internal | external 1 | external 2}]
[tag tag-value] [route-map map-tag] [weight weight] [subnets]
no redistribute protocol [process-id] {level-1 | level-1-2 | level-2} [metric metric-value]
[metric-type type-value] [match {internal | external 1 | external 2}]
[tag tag-value] [route-map map-tag] [weight weight] [subnets]

Syntax Description

protocol

Source protocol from which routes are being redistributed. It can be one of the following keywords: bgp, egp, igrp, isis, ospf, static [ip], connected, and rip.

The keyword static [ip] is used to redistribute IP static routes. The optional ip keyword is used when redistributing into IS-IS.

The keyword connected refers to routes which are established automatically by virtue of having enabled IP on an interface. For routing protocols such as OSPF and IS-IS, these routes will be redistributed as external to the autonomous system.

process-id

(Optional) For bgp, egp, or igrp, this is an autonomous system number, which is a 16-bit decimal number.
For isis, this is an optional tag that defines a meaningful name for a routing process. You can specify only one IS-IS process per router. Creating a name for a routing process means that you use names when configuring routing.
For ospf, this is an appropriate OSPF process ID from which routes are to be redistributed. This identifies the routing process. This value takes the form of a nonzero decimal number.
For rip, no process-id value is needed.

level-1

For IS-IS, Level 1 routes are redistributed into other IP routing protocols independently.

level-1-2

For IS-IS, both Level 1 and Level 2 routes are redistributed into other IP routing protocols.

level-2

For IS-IS, Level 2 routes are redistributed into other IP routing protocols independently.

metric metric-value

(Optional) Metric used for the redistributed route. If a value is not specified for this option, and no value is specified using the default-metric command, the default metric value is 0. Use a value consistent with the destination protocol.

metric-type type-value

(Optional) For OSPF, the external link type associated with the default route advertised into the OSPF routing domain. It can be one of two values:

1---Type 1 external route

2---Type 2 external route

If a metric-type is not specified, the Cisco IOS software adopts a Type 2 external route.

For IS-IS, it can be one of two values:

internal---IS-IS metric which is < 63.

external---IS-IS metric which is > 64 < 128.

The default is internal.

match {internal | external 1 | external 2}

(Optional) For OPSF, the criteria by which OSPF routes are redistributed into other routing domains. It an be one of the following:

internal---Routes that are internal to a specific autonomous system.

external 1---Routes that are external to the autonomous system, but are imported into OSPF as type 1 external route.

external 2---Routes that are external to the autonomous system, but are imported into OSPF as type 2 external route.

tag tag-value

(Optional) 32-bit decimal value attached to each external route. This is not used by the OSPF protocol itself. It may be used to communicate information between Autonomous System Boundary Routers. If none is specified, then the remote autonomous system number is used for routes from BGP and EGP; for other protocols, zero (0) is used.

route-map

(Optional) Route map should be interrogated to filter the importation of routes from this source routing protocol to the current routing protocol. If not specified, all routes are redistributed. If this keyword is specified, but no route map tags are listed, no routes will be imported.

map-tag

(Optional) Identifier of a configured route map.

weight weight

(Optional) Network weight when redistributing into BGP. An integer from 0 to 65535.

subnets

(Optional) For redistributing routes into OSPF, the scope of redistribution for the specified protocol.

Defaults

Route redistribution is disabled.

protocol---No source protocol is defined.
process-id---No process ID is defined.
metric metric-value---0
metric-type type-value---Type 2 external route
match internal | external---internal
external type-value---internal
tag tag-value---If no value is specified, the remote autonomous system number is used for routes
         from BGP and EGP; for other protocols, the default is 0.
route-map map-tag---If the route-map argument is not entered, all routes are redistributed; if no
         map-tag value is entered, no routes are imported.
weight weight---No network weight is defined.
subnets---No subnets are defined.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Changing or disabling any keyword will not affect the state of other keywords.

A router receiving a link-state protocol (LSP) with an internal metric will consider the cost of the route from itself to the redistributing router plus the advertised cost to reach the destination. An external metric only considers the advertised metric to reach the destination.

Routes learned from IP routing protocols can be redistributed at level-1 into an attached area or at level-2. The keyword level-1-2 allows both in a single command.

Redistributed routing information should always be filtered by the distribute-list out router configuration command. This ensures that only those routes intended by the administrator are passed along to the receiving routing protocol.

Whenever you use the redistribute or the default-information router configuration commands to redistribute routes into an OSPF routing domain, the router automatically becomes an Autonomous System Boundary Router (ASBR). However, an ASBR does not, by default, generate a default route into the OSPF routing domain.

When routes are redistributed between OSPF processes, no OSPF metrics are preserved.

When routes are redistributed into OSPF and no metric is specified in the metric keyword, the default metric that OSPF uses is 20 for routes from all protocols except BGP route, which gets a metric of 1.

When redistributing routes into OSPF, only routes that are not subnetted are redistributed if the subnets keyword is not specified.

The only connected routes affected by this redistribute command are the routes not specified by the network command.

You cannot use the default-metric command to affect the metric used to advertise connected routes.


Note The metric value specified in the redistribute command supersedes the metric value specified using the default-metric command.

Default redistribution of IGPs or EGP into BGP is not allowed unless default-information originate is specified.

When routes are redistributed into OSPF and no metric is specified in the metric keyword, the default metric that OSPF uses is 20 for routes from all protocols except BGP route, which gets a metric of 1.

Examples

The following are examples of the various configurations you would use to redistribute one routing protocol into another routing protocol.

The following example configuration causes OSPF routes to be redistributed into a BGP domain:

router bgp 109
redistribute ospf...
 

The following example configuration causes IGRP routes to be redistributed into an OSPF domain:

router ospf 110
redistribute igrp...
 

The following example causes the specified IGRP process routes to be redistributed into an OSPF domain. The IGRP-derived metric will be remapped to 100 and RIP routes to 200.

router ospf 109
redistribute igrp 108 metric 100 subnets
redistribute rip metric 200 subnets
 

In the following example, BGP routes are configured to be redistributed into IS-IS. The link-state cost is specified as 5, and the metric type will be set to external, indicating that it has lower priority than internal metrics.

router isis
redistribute bgp 120 metric 5 metric-type external
Related Commands

default-information originate (BGP)
default-information originate (EGP)
default-information originate (IS-IS)
default-information originate (OSPF)
distribute-list out
route-map
show route-map

route-map

To define the conditions for redistributing routes from one routing protocol into another, or to enable policy routing, use the route-map global configuration command and the match and set route-map configuration commands. To delete an entry, use the no route-map command.

route-map map-tag [permit | deny] [sequence-number]
no route-map map-tag [permit | deny] [sequence-number]
Syntax Description

map-tag

Defines a meaningful name for the route map. The redistribute router configuration command uses this name to reference this route map. Multiple route maps may share the same map tag name.

permit

(Optional) If the match criteria are met for this route map, and permit is specified, the route is redistributed as controlled by the set actions. In the case of policy routing, the packet is policy routed.

If the match criteria are not met, and permit is specified, the next route map with the same map tag is tested. If a route passes none of the match criteria for the set of route maps sharing the same name, it is not redistributed by that set.

The permit keyword is the default.

deny

(Optional) If the match criteria are met for the route map, and deny is specified, the route is not redistributed or in the case of policy routing, the packet is not policy routed, and no further route maps sharing the same map tag name will be examined. If the packet is not policy-routed, it reverts to the normal forwarding algorithm.

sequence-number

(Optional) Number that indicates the position a new route map is to have in the list of route maps already configured with the same name. If given with the no form of this command, it specifies the position of the route map that should be deleted.

Default

No default is available.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use route maps to redistribute routes or to subject packets to policy routing. Both purposes are described in this section.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.
The match route-map configuration command has multiple formats. The related match commands are listed in the section "Related Commands for Redistribution." The match commands can be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.
Use route maps when you want detailed control over how routes are redistributed between routing processes. The destination routing protocol is the one you specify with the router global configuration command. The source routing protocol is the one you specify with the redistribute router configuration command. See the following example as an illustration of how route maps are configured.
When you are passing routes through a route map, a route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route-map section with an explicit match specified.
Another purpose of route maps is to enable policy-routing. Use the ip policy route-map command, in addition to the route-map command, and the match and set commands to define the conditions for policy-routing packets. The related match and set commands are listed in the section "Related Commands for Policy Routing." The match commands specify the conditions under which policy routing occurs. The set commands specify the routing actions to perform if the criteria enforced by the match commands are met. You might want to policy-route packets some way other than the obvious shortest path.

The sequence-number works as follows:

    1. If no entry is defined with the supplied tag, an entry is created with sequence-number set to 10.

    2. If only one entry is defined with the supplied tag, that entry becomes the default entry for the following route-map command. The sequence-number of this entry is unchanged.

    3. If more than one entry is defined with the supplied tag, an error message is printed to indicate that sequence-number is required.

If no route-map map-tag is specified (with no sequence-number), the whole route-map is deleted.

Examples

The following example redistributes all OSPF routes into IGRP:

router igrp 109
redistribute ospf 110
default metric 1000 100 255 1 1500
 

The following example redistributes RIP routes with a hop count equal to 1 into OSPF. These routes will be redistributed into OSPF as external link state advertisements with a metric of 5, metric type of Type 1 and a tag equal to 1.

router ospf 109
redistribute rip route-map rip-to-ospf
 
route-map rip-to-ospf permit
match metric 1
set metric 5
set metric-type type1
set tag 1
Related Commands for Redistribution

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight
show route-map

Related Commands for Policy Routing

ip policy route-map
match ip address
match length
set default interface
set interface
set ip default next-hop
set ip next-hop

router bgp

To configure the Border Gateway Protocol (BGP) routing process, use the router bgp global configuration command. To remove a routing process, use the no form of this command.

router bgp autonomous-system
no router bgp autonomous-system
Syntax Description

autonomous-system

Number of an autonomous system that identifies the router to other BGP routers and tags the routing information passed along.

Default

No BGP routing process is enabled by default.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command allows you to set up a distributed routing core that automatically guarantees the loop-free exchange of routing information between autonomous systems.

Example

The following example configures a BGP process for autonomous system 120:

router bgp 120
Related Commands

neighbor (EGP, IGRP, RIP)
network (BGP)
timers bgp

router egp

To configure the Exterior Gateway Protocol (EGP) routing process, use the router egp global configuration command. To turn off an EGP routing process, use the no router egp command.

router egp remote-as
no router egp remote-as
Syntax Description

remote-as

Autonomous system number the router expects its peers to be advertising in their EGP messages.

Default

No EGP routing process is defined.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You must specify the autonomous system number before starting EGP. The local autonomous system number will be included in EGP messages sent by the Cisco IOS software. The software does not insist that the actual remote autonomous system number match the configured autonomous system numbers. The output from the debug ip-egp EXEC command will advise of any discrepancies.

Example

The following example assigns a router to autonomous system 109 and is peering with routers in autonomous system 164:

autonomous-system 109
router egp 164
Related Commands

autonomous-system (EGP)
neighbor (EGP, IGRP, RIP)
network (EGP)
timers egp

router egp 0

To specify that a router should be considered a core gateway, use the router egp 0 global configuration command. To disable this function, use the no form of this command.

router egp 0
no router egp 0

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Core gateways are central clearinghouses of routing information. Only one core gateway process can be configured in a router.

The router egp 0 global configuration command allows a specific router to have an EGP process that will enable it to act as a peer with any reachable autonomous system and information is exchanged freely between autonomous systems.

Normally, an EGP process expects to communicate with neighbors from a single autonomous system. Because all neighbors are in the same autonomous system, the EGP process assumes that these neighbors all have consistent internal information. Therefore, if the EGP process is informed about a route from one of its neighbors, it will not send it out to other neighbors.

With core EGP, the assumption is that all neighbors are from different autonomous systems, and all have inconsistent information. In this case, the EGP process distributes routes from one neighbor to all others (but not back to the originator). This allows the EGP process to be a central clearinghouse for information.

To control how an EGP process determines which neighbors will be treated as peers, use the neighbor any router configuration command with the router egp 0 global configuration command.

Example

The following example illustrates how an EGP core gateway can be configured:

access-list 1 permit 10.0.0.0 0.255.255.255
! global access list assignment
router egp 0
neighbor any 1
network 131.108.0.0
Related Commands

neighbor any
neighbor any third-party

router eigrp

To configure the Enhanced IGRP routing process, use the router eigrp global configuration command. To shut down a routing process, use the no form of this command.

router eigrp autonomous-system
no router eigrp autonomous-system

Syntax Description

autonomous-system

Autonomous system number that identifies the routes to the other Enhanced IGRP routers. It is also used to tag the routing information.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example shows how to configure an Enhanced IGRP routing process and assign process number 109:

router eigrp 109
Related Command

network (IGRP and Enhanced IGRP)

router igrp

To configure the Interior Gateway Routing Protocol (IGRP) routing process, use the router igrp global configuration command. To shut down an IGRP routing process, use the no form of this command.

router igrp autonomous-system
no router igrpautonomous-system
Syntax Description

autonomous-system

Autonomous system number that identifies the routes to the other IGRP routers. It is also used to tag the routing information.

Default

No IGRP routing process is defined.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

It is not necessary to have a registered autonomous system number to use IGRP. If you do not have a registered number, you are free to create your own. We recommend that if you do have a registered number, you use it to identify the IGRP process.

Example

The following example shows how to configure an IGRP routing process and assign process number  109:

router igrp 109
Related Command

network (IGRP and Enhanced IGRP)

router isis

To enable the IS-IS routing protocol and to specify an IS-IS process for IP, use the router isis global configuration command. To disable IS-IS routing, use the no form of this command.

router isis [tag]
no router isis [tag]
Syntax Description

tag

(Optional) Meaningful name for a routing process. If it is not specified, a null tag is assumed and the process is referenced with a null tag. This name must be unique among all IP router processes for a given router.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You can specify only one IS-IS process per router. Only one IS-IS process is allowed whether you run it in integrated mode, ISO CLNS only, or IP only.

Example

The following example configures the router for IP routing and enables the IS-IS routing protocol:

ip routing
router isis
Related Commands

ip router isis
net

router odr

To configure a router to accept on demand routing (ODR) routes from stub routers, use the router odr global configuration command. To disable stub routing, use the no form of this command.

router odr process-id
no router odr process-id
Syntax Description

process-id

Number of a process that identifies the routes to the other ODR routers.

Default

The router ignores any received ODR information.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command on hub routers to enable ODR to update the routing table with information learned via ODR stub routers.

Example

The following examples sets up the routers in the distribution list to accept on demand routing routes from the specified access list.

router odr
distribute-list 101 in
access-list 101 permit ip host 10.0.0.1 198.92.110.0 255.255.255.0
access-list 101 permit ip 11.1.1.1 255.0.0.0 198.92.111.0 255.255.255.0
router ospf 1
redistribute odr subnets
Related Commands

distribute-list in
distribute-list out
distance
maximum-paths
timers odr

router ospf

To configure an OSPF routing process, use the router ospf global configuration command. To terminate an OSPF routing process, use the no form of this command.

router ospf process-id
no router ospf process-id
Syntax Description

process-id

Internally used identification parameter for an OSPF routing process. It is locally assigned and can be any positive integer. A unique value is assigned for each OSPF routing process.

Default

No OSPF routing process is defined.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You can specify multiple OSPF routing processes in each router.

Example

The following example shows how to configure an OSPF routing process and assign a process number of 109:

router ospf 109
Related Command

network area

router rip

To configure the Routing Information Protocol (RIP) routing process, use the router rip global configuration command. To turn off the RIP routing process, use the no form of this command.

router rip
no router rip

Syntax Description

This command has no arguments or keywords.

Default

No RIP routing process is defined.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example shows how to begin the RIP routing process:

router rip
Related Command

network (RIP)

send-lifetime

To set the time period during which an authentication key on a key chain is valid to be sent, use the send-lifetime key chain key configuration command. To revert to the default value, use the no form of this command.

send-lifetime start-time {infinite | end-time | duration seconds}
no send-lifetime [start-time {infinite | end-time | duration seconds}]
Syntax Description

start-time

Beginning time that the key specified by the key command is valid to be sent. The syntax can be either of the following:

               hh:mm:ss Month date year

               hh:mm:ss date Month year

hh---hours

mm---minutes

ss---seconds

date---date (1-31)

Month---first three letters of the month

year---year (four digits)

The default start time and the earliest acceptable date is January 1, 1993.

infinite

Key is valid to be sent from the start-time on.

end-time

Key is valid to be sent from the start-time until end-time. The syntax is the same as that for start-time. The end-time must be after the start-time. The default end time is an infinite time period.

duration seconds

Length of time in seconds that the key is valid to be sent.

Default

Forever (The starting time is January 1, 1993, and the ending time is infinite.)

Command Mode

Key chain key configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Currently only RIP Version 2 uses key chains.

Specify a start-time and one of the following: infinite, end-time, or duration seconds.

We recommend running NTP or some other time synchronization method if you intend to set lifetimes on keys.

If the last key expires, authentication will continue and an error message will be generated. To disable authentication, you must manually delete the last valid key.

Example

The following example configures a key chain called trees. The key chestnut will be accepted from 1:30 p.m. to 3:30 p.m. and be sent from 2:00 p.m. to 3:00 p.m. The key birch will be accepted from 2:30 p.m. to 4:40 p.m. and be sent from 3:00 p.m. to 4:00 p.m. The overlap allows for migration of keys or a discrepancy in the router's set time. There is a half  hour leeway on each side to handle time-of-day differences.

interface ethernet 0
  ip rip authentication key-chain trees
  ip rip authentication mode md5
!
router rip
  network 172.19.0.0
  version 2
!
key chain trees
    key 1
     key-string chestnut
     accept-lifetime 13:30:00 Jan 25 1996 duration 7200
     send-lifetime 14:00:00 Jan 25 1996 duration 3600
  key 2
     key-string birch
     accept-lifetime 14:30:00 Jan 25 1996 duration 7200
     send-lifetime 15:00:00 Jan 25 1996 duration 3600
Related Commands

accept-lifetime
key
key chain
key-string
show key chain

set as-path

To modify an autonomous system path for BGP routes, use the set as-path route map configuration command. To not modify the autonomous system path, use the no form of this command.

set as-path {tag | prepend as-path-string}
no set as-path {tag | prepend as-path-string}
Syntax Description

tag

Converts the tag of a route into an autonomous system path. Applies only when redistributing routes into BGP.

prepend as-path-string

Appends the string following the keyword prepend to the as-path of the route that is matched by the route map. Applies to inbound and outbound BGP route maps.

Default

Autonomous system path is not modified.

Command Mode

Route map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The only global BGP metric available to influence the best path selection is the AS-PATH length. By varying the length of the AS-PATH, a BGP speaker can influence the best path selection by a peer further away.

By allowing you to convert the tag into an autonomous system path, the set as-path tag variation of this command modifies the autonomous system length. The set as-path prepend variation allows you to "prepend" an arbitrary autonomous system path string to BGP routes. Usually the local autonomous system number is prepended multiple times. This increases the autonomous system path length.

Examples

The following example converts the tag of a redistributed route into an autonomous system path:

route-map set-as-path-from-tag
match as-path 2
set as-path prepend 100 100 100
!
router bgp 100
redistribute ospf 109 route-map se	t-as-path-from-tag
 

The following example prepends 100 100 100 to all the routes advertised to 131.108.1.1:

route-map set-as-path
match as-path 1
set as-path prepend 100 100 100
!
router bgp 100
neighbor 131.108.1.1 route-map set-as-path out
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

set automatic-tag

To automatically compute the tag value, use the set automatic-tag route-map configuration command. To disable this function, use the no form of this command.

set automatic-tag
no set automatic-tag

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, the Cisco IOS software is configured to automatically compute the tag value for the BGP learned routes:

route-map tag
match as path 10
set automatic-tag 
!
router bgp 100
table-map tag
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

set community

To set the BGP COMMUNITIES attribute, use the set community route-map configuration command. To delete the entry, use the no form of this command.

set community {community-number [additive]} | none
no set community community-number [additive]
Syntax Description

community-number

Valid values are 1 to 4294967200, no-export, or no-advertise.

additive

(Optional) Adds the community to the already existing communities.

none

Removes the COMMUNITY attribute from the prefixes that pass the route-map.

Default

No BGP COMMUNITIES attributes exist.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, routes that pass the autonomous system path access list 1 have the community set to 109. Routes that pass the autonomous system path access list 2 have the community set to no-export (these routes will not be advertised to any EBGP peers).

route-map set_community 10 permit
match as-path 1
set community 109
 
route-map set_community 20 permit
match as-path 2
set community no-export
Related Commands

match community-list
route-map

set default interface

To indicate where to output packets that pass a match clause of a route map for policy routing and have no explicit route to the destination, use the set default interface route-map configuration command. To delete an entry, use the no form of this command.

set default interface type number [... type number]
no set default interface type number [... type number]
Syntax Description

type

Interface type, used with the interface number, to which packets are output.

number

Interface number, used with the interface type, to which packets are output.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use this command to provide certain users a different default route. If the Cisco IOS software has no explicit route for the destination, then it routes the packet to this interface. The first interface specified with the set default interface command that is up is used. The optionally specified interfaces are tried in turn.

Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which policy routing occurs. The set commands specify the set actions---the particular routing actions to perform if the criteria enforced by the match commands are met.

The set clauses can be used in conjunction with one another. They are evaluated in the following order:

set ip next-hop
set interface
set ip default next-hop
set default interface

Example

In the following example, packets that have a Level 3 length of 3 to 50 bytes and for which the software has no explicit route to the destination are output to Ethernet interface 0:

interface serial 0
ip policy route-map brighton
!
route-map brighton
match length 3 50
set default interface ethernet 0
Related Commands

ip policy route-map
match ip address
match length
route-map
set interface
set ip default next-hop
set ip next-hop

set interface

To indicate where to output packets that pass a match clause of route map for policy routing, use the set interface route-map configuration command. To delete an entry, use the no form of this command.

set interface type number [... type number]
no set interface type number [... type number]
Syntax Description

type

Interface type, used with the interface number, to which packets are output.

number

Interface number, used with the interface type, to which packets are output.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which policy routing occurs. The set commands specify the set actions---the particular routing actions to perform if the criteria enforced by the match commands are met.

If the first interface specified with the set interface command is down, the optionally specified interfaces are tried in turn.

The set clauses can be used in conjunction with one another. They are evaluated in the following order:

set ip next-hop
set interface
set ip default next-hop
set default interface

A useful next hop implies an interface. As soon as a next hop and an interface are found, the packet is routed.

Specifying set interface null 0 is a way to write a policy that the packet be dropped and an "unreachable" message be generated.

Example

In the following example, packets with a Level 3 length of 3 to 50 bytes are output to Ethernet interface 0:

interface serial 0
ip policy route-map testing
!
route-map testing
match length 3 50
set interface ethernet 0
Related Commands

ip policy route-map
match ip address
match length
route-map
set default interface
set ip default next-hop
set ip next-hop

set ip default next-hop

To indicate where to output packets that pass a match clause of a route map for policy routing and for which the Cisco IOS software has no explicit route to a destination, use the set ip default next-hop route-map configuration command. To delete an entry, use the no form of this command.

set ip default next-hop ip-address [... ip-address]
no set ip default next-hop ip-address [... ip-address]
Syntax Description

ip-address

IP address of the next hop to which packets are output. It must be an adjacent router.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use this command to provide certain users a different default route. If the software has no explicit route for the destination in the packet, then it routes the packet to this next hop. The first next hop specified with the set ip default next-hop command that appears to be adjacent to the router is used. The optional specified IP addresses are tried in turn.

Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which policy routing occurs. The set commands specify the set actions---the particular routing actions to perform if the criteria enforced by the match commands are met.

The set clauses can be used in conjunction with one another. They are evaluated in the following order:

set ip next-hop
set interface
set ip default next-hop
set default interface

Example

The following example provides two sources with equal access to two different service providers. Packets arriving on async interface 1 from the source 1.1.1.1 are sent to the router at 6.6.6.6 if the software has no explicit route for the packet's destination. Packets arriving from the source 2.2.2.2 are sent to the router at 7.7.7.7 if the software has no explicit route for the packet's destination. All other packets for which the software has no explicit route to the destination are discarded.

access-list 1 permit ip 1.1.1.1 0.0.0.0
access-list 2 permit ip 2.2.2.2 0.0.0.0
!
interface async 1
ip policy route-map equal-access
!
route-map equal-access permit 10
match ip address 1
set ip default next-hop 6.6.6.6
route-map equal-access permit 20
match ip address 2
set ip default next-hop 7.7.7.7
route-map equal-access permit 30
set default interface null0
Related Commands

ip policy route-map
match ip address
match length
route-map
set default interface
set interface
set ip next-hop

set ip next-hop

To indicate where to output packets that pass a match clause of a route map for policy routing, use the set ip next-hop route-map configuration command. To delete an entry, use the no form of this command.

set ip next-hop ip-address [... ip-address]
no set ip next-hop ip-address [... ip-address]
Syntax Description

ip-address

IP address of the next hop to which packets are output. It must be the address of an adjacent router.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use the ip policy route-map interface configuration command, the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for policy routing packets. The ip policy route-map command identifies a route map by name. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which policy routing occurs. The set commands specify the set actions---the particular routing actions to perform if the criteria enforced by the match commands are met.

If the interface associated with the first next hop specified with the set ip next-hop command is down, the optionally specified IP addresses are tried in turn.

The set clauses can be used in conjunction with one another. They are evaluated in the following order:

set ip next-hop
set interface
set ip default next-hop
set default interface

Example

In the following example, packets with a Level 3 length of 3 to 50 bytes are output to the router at IP address 161.14.2.2:

interface serial 0
ip policy route-map thataway
!
route-map thataway
match length 3 50
set ip next-hop 161.14.2.2
Related Commands

ip policy route-map
match ip address
match length
route-map
set default interface
set interface
set ip default next-hop

set ip precedence

To set the precedence value in the IP header, use the set ip precedence route-map configuration command. To instruct the router to leave the precedence value alone, use the no form of this command.

set ip precedence value
no set ip precedence

Syntax Description

value

Number or name that sets the precedence bits in the IP header. The number and its corresponding name are as follows, from least important to most important:

Number        Name

0                            routine
1                            priority
2                            immediate
3                            flash
4                            flash-override
5                            critical
6                            internet
7                            network

Default

The software leaves the value that was there.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

You can set the precedence using either a number or the corresponding name.


Note Setting the precedence bit affects weighted fair queuing (WFQ). It acts as a multipler on the WFQ weighting, using a formula of 4096 divided by the IP precedence value plus 1. For more information, see the fair-queue command in the "Performance Management Commands" chapter in the Configuration Fundamentals Command Reference.

The way the network gives priority (or some type of expedited handling) to the marked traffic is through the application of WFQ or WRED at points downstream in the network. Typically, you would set IP precedence at the edge of the network (or administrative domain) and have queuing act on it thereafter. WFQ can speed up handling for high precedence traffic at congestion points. WRED ensures high precedence traffic has lower loss rates than other traffic during times of congestion.

The mapping from keywords such as routine and priority to a precedence value is useful only in some instances. That is, the use of the precedence bit is evolving. The customer can define the meaning of a precedence value by enabling other features that use the value. In the case of our high- end Internet QoS, IP precedences can be used to establish classes of service that do not necessarily correspond numerically to better or worse handling in the network. For example, IP precedence 2 can be given 90% of the bandwidth on output links in the network, and IP precedence 6 can be given 5% using the DWFQ implementation on the VIPs.

Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another, or for policy routing. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution or policy routing is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution or policy routing actions to perform if the criteria enforced by the match commands are met. The no  route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

The following example sets the IP precedence to 5 (critical) for packets that pass the route-map match:

interface serial 0
 ip policy route-map texas
!
route-map texas
 match length 68 128
 set ip precedence 5
Related Commands

You can use the master indexes or search online to find documentation of related commands.

fair-queue
ip policy route-map
route-map

set level

To indicate where to import routes, use the set level route-map configuration command. To delete an entry, use the no form of this command.

set level {level-1 | level-2 | level-1-2 | stub-area | backbone}
no set level {level-1 | level-2 | level-1-2 | stub-area | backbone}

Syntax Description

level-1

Imports routes into a Level-1 area.

level-2

Imports routes into Level-2 subdomain.

level-1-2

Imports routes into Level-1 and Level-2.

stub-area

Imports routes into OSPF NSSA area.

backbone

Imports routes into OSPF backbone area.

Defaults

Disabled

For IS-IS destinations, the default value is level-2. For OSPF destinations, the default value is backbone.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, routes will be imported into the Level 1 area:

route-map name
set level level-l
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag
set weight

set local-preference

To specify a preference value for the autonomous system path, use the set local-preference route-map configuration command. To delete an entry, use the no form of this command.

set local-preference value
no set local-preference value
Syntax Description

value

Preference value. An integer from 0 to 4294967295.

Default

Preference value of 100

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The preference is sent only to all routers in the local autonomous system.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

You can change the default preference value with the bgp default local-preference command.

Example

In the following example, the local preference is set to 100 for all routes that are included in access list 1:

route-map map-preference
match as-path 1
set local-preference 100
Related Commands

bgp default local-preference
match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set metric
set metric-type
set next-hop
set origin
set tag
set weight

set metric

To set the metric value for a routing protocol other than IGRP or IP Enhanced IGRP, use the set metric route-map configuration command. To return to the default metric value, use the no form of this command.

set metric metric-value
no set metric metric-value
Syntax Description

metric-value

Metric value in kilobits per second. It can be an integer from -294967295 to 294967295.

Default

Default metric value.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, the metric value for the routing protocol is set to 100:

route-map set-metric
set metric 100
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric-type
set next-hop
set origin
set tag
set weight

set metric

To set the metric value for IGRP or IP Enhanced IGRP in a route-map, use the set metric route-map configuration command. To return to the default metric value, use the no form of this command.

set metric bandwidth delay reliability loading mtu
no set metric bandwidth delay reliability loading mtu
Syntax Description

bandwidth

Metric value or IGRP bandwidth of the route in kilobits per second. It can be in the range 0 to 4294967295.

delay

Route delay in tens of microseconds. It can be in the range 0 to 4294967295.

reliability

Likelihood of successful packet transmission expressed as a number between 0 and 255. The value 255 means 100 percent reliability; 0 means no reliability.

loading

Effective bandwidth of the route expressed as a number from 0 to 255 (255 is 100 percent loading).

mtu

Minimum maximum transmission unit (MTU) size of the route in bytes. It can be in the range 0 to 4294967295.

Default

No metric will be set in the route-map.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.


Note We recommend you consult your Cisco technical support representative before changing the default value.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, the bandwidth is set to 10,000, the delay is set to 10, the reliability is set to 255, the loading is set to 1, and the MTU is set to 1500:

set metric 10000 10 255 1 1500

set metric-type

To set the metric type for the destination routing protocol, use the set metric-type route-map configuration command. To return to the default, use the no form of this command.

set metric-type {internal | external | type-1 | type-2}
no set metric-type {internal | external | type-1 | type-2}

Syntax Description

internal

IS-IS internal metric.

external

IS-IS external metric.

type-1

OSPF external type 1 metric.

type-2

OSPF external type 2 metric.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, the metric type of the destination protocol is set to OSPF external type 1:

route-map map-type
set metric-type type-1
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set next-hop
set origin
set tag
set weight

set metric-type internal

To set the MED value on prefixes advertised to EBGP neighbors to match the IGP metric of the next hop, use the set metric internal route-map configuration command. To return to the default, use the no form of this command.

set metric-type internal
no set metric-type internal

Syntax Description

This command has not arguments or keywords.

Default

Disabled

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command will cause BGP to advertise a MED that corresponds to the IGP metric associated with the NEXT HOP of the route. This command applies to generated, iBGP-, and eBGP-derived routes.

If this command is used, multiple BGP speakers in a common AS can advertise different MEDs for a particular prefix. Also, note that if the IGP metric changes, BGP will not readvertise the route.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

Use the route-map global configuration command, and the match and set route-map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, the MED for all the advertised routes to neighbor 160.89.2.3 is set to the corresponding IGP metric of the nexthop:

router bgp 109
 network 160.89.0.0
 neighbor 160.89.2.3 remote-as 200
 neighbor 160.89.2.3 route-map setMED out
!
route-map setMED permit 10
 match as-path 1
 set metric-type internal
!
 ip as-path access-list 1 permit .*
Related Command

route-map

set next-hop

To specify the address of the next hop, use the set next-hop route-map configuration command. To delete an entry, use the no form of this command.

set next-hop next-hop
no set next-hop next-hop
Syntax Description

next-hop

IP address of the next hop router.

Default

Default next-hop address.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, routes that pass the access list have the next hop set to 198.92.70.24:

route-map map_hop
match address 5
set next-hop 198.92.70.24
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set origin
set tag
set weight

set origin

To set the BGP origin code, use the set origin route-map configuration command. To delete an entry, use the no form of this command.

set origin {igp | egp autonomous-system | incomplete}
Syntax Description

igp

Remote IGP.

egp

Local EGP.

autonomous-system

Remote autonomous system. This is an integer from 0 to 65535.

incomplete

Unknown heritage.

Default

Default origin, based on route in main IP routing table.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, routes that pass the route map have the origin set to IGP:

route-map set_origin
match as-path 10
set origin igp
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set tag
set weight

set-overload-bit

To configure the router to signal other routers not to use it as intermediate hop in their SPF calculations, use the set-overload-bit router configuration command. To remove the designation, use the no form of this command.

set-overload-bit
no set-overload-bit

Syntax Description

This command has no arguments or keywords.

Default

The overload bit is not set.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command forces the router to set the overload bit (also known as the hippity bit) in its non-pseudonode LSPs. Normally the setting of the overload bit is allowed only when a router runs into problems. For example, when a router is experiencing a memory shortage, it might be that the Link State database is not complete, resulting in an incomplete or inaccurate routing table. By setting the overload bit in its LSPs, other routers can ignore the unreliable router in their SPF calculations until the router has recovered from its problems.

The result will be that no paths through this router are seen by other routers in the IS-IS area. However, IP and CLNS prefixes directly connected to this router will be still be reachable.

This command can be useful when you want to connect a router to an ISIS network, but don't want real traffic flowing through it under any circumstances. Examples are:

Example

The following example configures the set-over-load bit:

router isis
 set-overload-bit

set tag

To set a tag value of the destination routing protocol, use the set tag route-map configuration command. To delete the entry, use the no form of this command.

set tag tag-value
no set tag tag-value
Syntax Description

tag-value

Name for the tag. Integer from 0 to 4294967295.

Default

If not specified, the default action is to forward the tag in the source routing protocol onto the new destination protocol.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria---the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The set route-map configuration commands specify the redistribution set actions to be performed when all of a route map's match criteria are met. When all match criteria are met, all set actions are performed.

Example

In the following example, the tag value of the destination routing protocol is set to 5:

route-map tag
set tag 5
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set weight

set weight

To specify the BGP weight for the routing table, use the set weight route-map configuration command. To delete an entry, use the no form of this command.

set weight weight
no set weight weight
Syntax Description

weight

Weight value. It can be an integer from 0 to 65535.

Default

The weight is not changed by the specified route map.

Command Mode

Route-map configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You must have a match clause (even if it points to a "permit everything" list) if you want to set tags.

The implemented weight is based on the first matched autonomous system path. Weights indicated when an autonomous system path is matched override the weights assigned by global neighbor commands. In other words, the weights assigned with the match as-path and set weight route-map commands override the weights assigned using the neighbor weight and neighbor filter-list commands.

Example

In the following example, the BGP weight for the routes matching the autonomous system path access list is set to  200:

route-map set-weight
match as-path 10
set weight 200
Related Commands

match as-path
match community-list
match interface
match ip address
match ip next-hop
match ip route-source
match metric
match route-type
match tag
route-map
set as-path
set automatic-tag
set community
set level
set local-preference
set metric
set metric-type
set next-hop
set origin
set tag

show ip bgp

To display entries in the BGP routing table, use the show ip bgp EXEC command.

show ip bgp [network] [network-mask] [longer-prefixes]
Syntax Description

network

(Optional) Network number, entered to display a particular network in the BGP routing table.

network-mask

(Optional) Displays all BGP routes matching the address/mask pair.

longer-prefixes

(Optional) Displays route and more specific routes.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip bgp command:

Router# show ip bgp
 
BGP table version is 716977, local router ID is 193.0.32.1
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
* i3.0.0.0          193.0.22.1             0    100      0 1800 1239 ?
*>i                 193.0.16.1             0    100      0 1800 1239 ?
* i6.0.0.0          193.0.22.1             0    100      0 1800 690 568 ?
*>i                 193.0.16.1             0    100      0 1800 690 568 ?
* i7.0.0.0          193.0.22.1             0    100      0 1800 701 35 ?
*>i                 193.0.16.1             0    100      0 1800 701 35 ?
*                   198.92.72.24                         0 1878 704 701 35 ?
* i8.0.0.0          193.0.22.1             0    100      0 1800 690 560 ?
*>i                 193.0.16.1             0    100      0 1800 690 560 ?
*                   198.92.72.24                         0 1878 704 701 560 ?
* i13.0.0.0         193.0.22.1             0    100      0 1800 690 200 ?
*>i                 193.0.16.1             0    100      0 1800 690 200 ?
*                   198.92.72.24                         0 1878 704 701 200 ?
* i15.0.0.0         193.0.22.1             0    100      0 1800 174 ?
*>i                 193.0.16.1             0    100      0 1800 174 ?
* i16.0.0.0         193.0.22.1             0    100      0 1800 701 i
*>i                 193.0.16.1             0    100      0 1800 701 i
*                   198.92.72.24                         0 1878 704 701 i
 

Table 33 describes significant fields shown in the display.


Table 33: Show IP BGP Field Descriptions
Field Description

BGP table version

Internal version number of the table. This number is incremented whenever the table changes.

local router ID

IP address of the router.

Status codes

Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values:

s suppressed

Entry is suppressed.

* valid

Entry is valid.

> best

Entry is the best to use for that network.

i -internal

Entry learned via an internal BGP session.

Origin codes

Indicates the origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values:

i - IGP

Entry originated from IGP and was advertised with a network router configuration command.

e - EGP

Entry originated from EGP.

? - incomplete

Origin of the path is not clear Usually, this is a router that is redistributed into BGP from an IGP.

Network

IP address of a network entity.

Next Hop

IP address of the next system that is used when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the router has some non-BGP routes to this network.

Metric

If shown, this is the value of the interautonomous system metric. This is frequently not used.

LocPrf

Local preference value as set with the set local-preference route-map configuration command. The default value is 100.

Weight

Weight of the route as set via autonomous system filters.

Path

Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path.

The following is sample output from the show ip bgp command when you specify longer-prefixes:

Router# show ip bgp 198.92.0.0 255.255.0.0 longer-prefixes
 
BGP table version is 1738, local router ID is 198.92.72.24
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
*> 198.92.0.0       198.92.72.30        8896         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.1.0       198.92.72.30        8796         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.11.0      198.92.72.30       42482         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.14.0      198.92.72.30        8796         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.15.0      198.92.72.30        8696         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.16.0      198.92.72.30        1400         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.17.0      198.92.72.30        1400         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.18.0      198.92.72.30        8876         32768 ?
*                   198.92.72.30                         0 109 108 ?
*> 198.92.19.0      198.92.72.30        8876         32768 ?
*                   198.92.72.30                         0 109 108 ?

show ip bgp cidr-only

To display routes with nonnatural network masks (that is, classless interdomain routing, or CIDR), use the show ip bgp cidr-only privileged EXEC command.

show ip bgp cidr-only
Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip bgp cidr-only command:

Router# show ip bgp cidr-only 
 
BGP table version is 220, local router ID is 198.92.73.131
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
*> 192.0.0.0/8      198.92.72.24                         0 1878 ?
*> 198.92.0.0/16    198.92.72.30                         0 108 ?
 

Table 34 describes significant fields shown in the display.


Table 34: Show IP BGP CIDR-Only Field Descriptions
Field Description

BGP table version is 220

Internal version number for the table. This is incremented any time the table changes.

local access server ID

An Internet address of the access server.

Status codes

s---The table entry is suppressed.

*---The table entry is valid.

>---The table entry is the best entry to use for that network.

i---The table entry was learned via an internal BGP session.

Network

Internet address of the network the entry describes.

Next Hop

IP address of the next system to use when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the access server has some non-BGP route to this network.

LocPrf

Local preference value. Default is 100.

Metric

If shown, this is the value of the interautonomous system metric. This is frequently not used.

Weight

Set through the use of autonomous system filters.

Path

Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path. At the end of the path is the origin code for the path.

i---The entry was originated with the IGP and advertised with a
           network router configuration command.

e---The route originated with EGP.

?---The origin of the path is not clear. Usually this is a path that is
           redistributed into BGP from an IGP.


show ip bgp community

To display routes that belong to specified BGP communities, use the show ip bgp community EXEC command.

show ip bgp community community-number [exact]
Syntax Description

community-number

Valid value is community number in the range 1 to 4294967200, internet, no-export, or no-advertise.

exact

(Optional) Displays only routes that have exactly the same specified communities.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Sample Display

The following is sample output from the show ip bgp community command:

Router# show ip bgp community 10
 
BGP table version is 716977, local router ID is 193.0.32.1
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
* i3.0.0.0          193.0.22.1             0    100      0 1800 1239 ?
*>i                 193.0.16.1             0    100      0 1800 1239 ?
* i6.0.0.0          193.0.22.1             0    100      0 1800 690 568 ?
*>i                 193.0.16.1             0    100      0 1800 690 568 ?
* i7.0.0.0          193.0.22.1             0    100      0 1800 701 35 ?
*>i                 193.0.16.1             0    100      0 1800 701 35 ?
*                   198.92.72.24                         0 1878 704 701 35 ?
* i8.0.0.0          193.0.22.1             0    100      0 1800 690 560 ?
*>i                 193.0.16.1             0    100      0 1800 690 560 ?
*                   198.92.72.24                         0 1878 704 701 560 ?
* i13.0.0.0         193.0.22.1             0    100      0 1800 690 200 ?
*>i                 193.0.16.1             0    100      0 1800 690 200 ?
*                   198.92.72.24                         0 1878 704 701 200 ?
* i15.0.0.0         193.0.22.1             0    100      0 1800 174 ?
*>i                 193.0.16.1             0    100      0 1800 174 ?
* i16.0.0.0         193.0.22.1             0    100      0 1800 701 i
*>i                 193.0.16.1             0    100      0 1800 701 i
*                   198.92.72.24                         0 1878 704 701 i
 

Table 35 describes significant fields shown in the display.


Table 35: Show IP BGP Community Field Descriptions
Field Description

BGP table version

Internal version number of the table. This number is incremented whenever the table changes.

local router ID

IP address of the router.

Status codes

Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values:

s suppressed

Entry is suppressed.

* valid

Entry is valid.

> best

Entry is the best to use for that network.

i -internal

Entry learned via an internal BGP session.

Origin codes

Indicates the origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values:

i - IGP

Entry originated from IGP and was advertised with a network router configuration command.

e - EGP

Entry originated from EGP.

? - incomplete

Origin of the path is not clear Usually, this is a router that is redistributed into BGP from an IGP.

Network

IP address of a network entity.

Next Hop

IP address of the next system that is used when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the router has some non-BGP routes to this network.

Metric

If shown, this is the value of the interautonomous system metric. This is frequently not used.

LocPrf

Local preference value as set with the set local-preference route-map configuration command. The default value is 100.

Weight

Weight of the route as set via autonomous system filters.

Path

Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path.

show ip bgp community-list

To display routes that are permitted by the BGP community list, use the show ip bgp community-list EXEC command.

show ip bgp community-list community-list-number [exact]
Syntax Description

community-list-number

Community list number in the range 1 to 99.

exact

(Optional) Displays only routes that have an exact match.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Sample Display

The following is sample output of the show ip bgp community-list command:

Router# show ip bgp community-list 20
 
BGP table version is 716977, local router ID is 193.0.32.1
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
* i3.0.0.0          193.0.22.1             0    100      0 1800 1239 ?
*>i                 193.0.16.1             0    100      0 1800 1239 ?
* i6.0.0.0          193.0.22.1             0    100      0 1800 690 568 ?
*>i                 193.0.16.1             0    100      0 1800 690 568 ?
* i7.0.0.0          193.0.22.1             0    100      0 1800 701 35 ?
*>i                 193.0.16.1             0    100      0 1800 701 35 ?
*                   198.92.72.24                         0 1878 704 701 35 ?
* i8.0.0.0          193.0.22.1             0    100      0 1800 690 560 ?
*>i                 193.0.16.1             0    100      0 1800 690 560 ?
*                   198.92.72.24                         0 1878 704 701 560 ?
* i13.0.0.0         193.0.22.1             0    100      0 1800 690 200 ?
*>i                 193.0.16.1             0    100      0 1800 690 200 ?
*                   198.92.72.24                         0 1878 704 701 200 ?
* i15.0.0.0         193.0.22.1             0    100      0 1800 174 ?
*>i                 193.0.16.1             0    100      0 1800 174 ?
* i16.0.0.0         193.0.22.1             0    100      0 1800 701 i
*>i                 193.0.16.1             0    100      0 1800 701 i
*                   198.92.72.24                         0 1878 704 701 i
 

Table 36 describes significant fields shown in the display.


Table 36: Show IP BGP Community List Field Descriptions
Field Description

BGP table version

Internal version number of the table. This number is incremented whenever the table changes.

local router ID

IP address of the router.

Status codes

Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values:

s suppressed

Entry is suppressed.

* valid

Entry is valid.

> best

Entry is the best to use for that network.

i -internal

Entry learned via an internal BGP session.

Origin codes

Indicates the origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values:

i - IGP

Entry originated from IGP and was advertised with a network router configuration command.

e - EGP

Entry originated from EGP.

? - incomplete

Origin of the path is not clear. Usually, this is a router that is redistributed into BGP from an IGP.

Network

IP address of a network entity.

Next Hop

IP address of the next system that is used when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the router has some non-BGP routes to this network.

Metric

If shown, this is the value of the interautonomous system metric. This is frequently not used.

LocPrf

Local preference value as set with the set local-preference route-map configuration command. The default value is 100.

Weight

Weight of the route as set via autonomous system filters.

Path

Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path.

show ip bgp filter-list

To display routes that conform to a specified filter list, use the show ip bgp filter-list privileged EXEC command.

show ip bgp filter-list access-list-number
Syntax Description

access-list-number

Number of an autonomous system path access list. It can be a number from 1 to  199.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip bgp filter-list command:

Router# show ip bgp filter-list 2
 
BGP table version is 1738, local router ID is 198.92.72.24
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
*  198.92.0.0       198.92.72.30                         0 109 108 ?
*  198.92.1.0       198.92.72.30                         0 109 108 ?
*  198.92.11.0      198.92.72.30                         0 109 108 ?
*  198.92.14.0      198.92.72.30                         0 109 108 ?
*  198.92.15.0      198.92.72.30                         0 109 108 ?
*  198.92.16.0      198.92.72.30                         0 109 108 ?
*  198.92.17.0      198.92.72.30                         0 109 108 ?
*  198.92.18.0      198.92.72.30                         0 109 108 ?
*  198.92.19.0      198.92.72.30                         0 109 108 ?
*  198.92.24.0      198.92.72.30                         0 109 108 ?
*  198.92.29.0      198.92.72.30                         0 109 108 ?
*  198.92.30.0      198.92.72.30                         0 109 108 ?
*  198.92.33.0      198.92.72.30                         0 109 108 ?
*  198.92.35.0      198.92.72.30                         0 109 108 ?
*  198.92.36.0      198.92.72.30                         0 109 108 ?
*  198.92.37.0      198.92.72.30                         0 109 108 ?
*  198.92.38.0      198.92.72.30                         0 109 108 ?
*  198.92.39.0      198.92.72.30                         0 109 108 ?
 

Table 37 describes significant fields shown in the display.


Table 37: Show IP BGP Filter-List Field Descriptions
Field Description

BGP table version is 1738

Internal version number for the table. This is incremented any time the table changes.

local access server ID

An Internet address of the access server.

Status codes

s---The table entry is suppressed.

*---The table entry is valid.

>---The table entry is the best entry to use for that network.

i---The table entry was learned via an internal BGP session.

Network

Internet address of the network the entry describes.

Next Hop

IP address of the next system to use when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the access server has some non-BGP route to this network.

LocPrf

Local preference value. Default is 100.

Metric

If shown, this is the value of the interautonomous system metric. This is frequently not used.

Weight

Set through the use of autonomous system filters.

Path

Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path. At the end of the path is the origin code for the path.

i---The entry was originated with the IGP and advertised with a
         network router configuration command.

e---The route originated with EGP.

?---The origin of the path is not clear. Usually this is a path that is
           redistributed into BGP from an IGP.


show ip bgp inconsistent-as

To display routes with inconsistent originating autonomous systems, use the show ip bgp inconsistent-as privileged EXEC command.

show ip bgp inconsistent-as
Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Sample Display

The following is sample output from the show ip bgp inconsistent-as command:

Router# show ip bgp inconsistent-as
BGP table version is 87, local router ID is 172.19.82.53
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
*  11.0.0.0         171.69.232.55          0             0 300 88 90 99 ?
*>                  171.69.232.52       2222             0 400 ?
*  171.69.0.0       171.69.232.55          0             0 300 90 99 88 200 ?
*>                  171.69.232.52       2222             0 400 ?
*  200.200.199.0    171.69.232.55          0             0 300 88 90 99 ?
*>                  171.69.232.52       2222             0 400 ?
 

show ip bgp neighbors

To display information about the TCP and BGP connections to neighbors, use the show ip bgp neighbors EXEC command.

show ip bgp neighbors address received routes
Syntax Description

address

(Optional) Address of the neighbor whose routes you have learned from.

received routes

(Optional) If you specify an address, displays all received updates from the specified neighbor.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The received routes keyword first appeared in Cisco IOS Release 11.2.

Sample Displays

The following is sample output from the show ip bgp neighbors command:

Router# show ip bgp neighbors
 
#sh ip bg nei 171.69.232.149 received-routes BGP table version is 61, local router ID is 1.1.1.1 Status codes: s suppressed, d damped, h history, * valid, > best, i - internal Origin codes: i - IGP, e - EGP, ? - incomplete 
 
Network	Next Hop	Metric LocPrf Weight Path
*> 172.19.1.0/24 171.69.232.149	1200	0 200 ?
*> 172.19.9.0/24 171.69.232.149	1300	0 200 ?
*> 172.19.14.0/24 171.69.232.149	0	0 200 ?
*> 172.19.15.0/24 171.69.232.149	0	0 200 ?
*> 172.19.16.0/24 171.69.232.149	0	0 200 ?
*> 172.19.17.0/24 171.69.232.149	1110	0 200 ?
*> 172.19.19.0/24 171.69.232.149	0	0 200 ?
*> 172.19.20.0/24 171.69.232.149	1163	0 200 ?
*> 172.19.29.0/24 171.69.232.149	1210	0 200 ?
*> 172.19.32.0/24 171.69.232.149	1200	0 200 ?
*> 172.19.40.0/24 171.69.232.149	1200	0 200 ?
*> 172.19.48.0/24 171.69.232.149	1200	0 200 ?
*> 172.19.56.0/24 171.69.232.149	1200	0 200 ?
 

Table 38 describes the fields shown in the display.


Table 38: Show IP BGP Neighbors Field Descriptions
Field Description

BGP neighbor

Lists the IP address of the BGP neighbor and its autonomous system number. If the neighbor is in the same autonomous system as the router, then the link between them is internal; otherwise, it is considered external.

BGP version

Specifies that the BGP version being used to communicate with the remote router is BGP version 3; the neighbor's router ID (an IP address) is also specified.

BGP state

Indicates the internal state of this BGP connection.

   table version

Indicates that the neighbor has been updated with this version of the primary BGP routing table.

   up time

Indicates the amount of time that the underlying TCP connection has been in existence.

Last read

Time that BGP last read a message from this neighbor.

   hold time

Maximum amount of time that can elapse between messages from the peer.

   keepalive interval

Time period between sending keepalive packets, which help ensure that the TCP connection is up.

Received

Number of received messages indicates the number of total BGP messages received from this peer, including keepalives. The number of notifications is the number of error messages received from the peer.

Sent

The number of sent messages indicates the total number of BGP messages that have been sent to this peer, including keepalives. The number of notifications is the number of error messages that we have sent to this peer.

Connections established

The number of connections established is a count of the number of times that we have established a TCP connection and the two peers have agreed speak BGP with each other. The number of dropped connections is the number of times that a good connection has failed or been taken down.

The remainder of the display describes the status of the underlying TCP connection.

The following is sample output from the show ip bgp neighbors command when you specify the routes keyword:

Router# show ip bgp neighbors 198.41.177.210 routes
 
BGP table version is 212136, local router ID is 131.108.5.225
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop         Metric LocPrf Weight Path
*> 163.179.0.0      192.41.177.210                    100 2551 i
*  192.203.50.0     192.41.177.210                    100 2551 ?
*> 199.183.0.0/16   192.41.177.210                    100 2551 i
 

Table 39 describes the fields shown in the display.


Table 39: Show IP BGP Neighbors Routes Field Descriptions
Field Description

BGP table version

Internal version number of the table. This number is incremented whenever the table changes.

local router ID

IP address of the router.

Status codes

Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values:

s suppressed

Entry is suppressed.

* valid

Entry is valid.

> best

Entry is the best to use for that network.

i -internal

Entry learned via an internal BGP session.

Origin codes

Indicates the origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values:

i - IGP

Entry originated from IGP and was advertised with a network router configuration command.

e - EGP

Entry originated from EGP.

? - incomplete

Origin of the path is not clear. Usually, this is a router that is redistributed into BGP from an IGP.

Network

IP address of a network entity.

Next Hop

IP address of the next system that is used when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the router has some non-BGP routes to this network.

Metric

If shown, this is the value of the interautonomous system metric. This is frequently not used.

LocPrf

Local preference value as set with the set local-preference route-map configuration command. The default value is 100.

Weight

Weight of the route as set via autonomous system filters.

Path

Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path.

show ip bgp paths

To display all the BGP paths in the database, use the show ip bgp paths EXEC command.

show ip bgp paths
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip bgp paths command:

Router# show ip bgp paths
 
Address    Hash Refcount Metric Path
0x297A9C      0        2      0 i
0x30BF84      1        0      0 702 701 ?
0x2F7BC8      2      235      0 ?
0x2FA1D8      3        0      0 702 701 i
 

Table 40 describes significant fields shown in the display.


Table 40: Show IP BGP Paths Field Descriptions
Field Description

Address

Internal address where the path is stored.

Hash

Hash bucket where path is stored.

Refcount

Number of routes using that path.

Metric

The multiple exit discriminator (MED) metric for the path. (The name of this metric for BGP versions 2 and 3 is INTER_AS.)

Path

The AS_PATH for that route, followed by the origin code for that route.

show ip bgp peer-group

To display information about BGP peer groups, use the show ip bgp peer-group EXEC command.

show ip bgp peer-group [tag] [summary]
Syntax Description

tag

(Optional) Displays information about that specific peer group.

summary

(Optional) Displays a summary of the status of all the members of a peer group.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Sample Display

The following is sample output from the show ip bgp peer-group command:

Router# show ip bgp peer-group0 internal
BGP neighbor is internal, peer-group leader
  BGP version 4
  Minimum time between advertisement runs is 5 seconds
  Incoming update AS path filter list is 2
  Outgoing update AS path filter list is 1
  Route map for outgoing advertisements is set-med
 

show ip bgp regexp

To display routes matching the regular expression, use the show ip bgp regexp privileged EXEC command.

show ip bgp regexp regular-expression
Syntax Description

regular-expression

Regular expression to match the BGP autonomous system paths.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display
Router# show ip bgp regexp 108$
 
BGP table version is 1738, local router ID is 198.92.72.24
Status codes: s suppressed, * valid, > best, i - internal
Origin codes: i - IGP, e - EGP, ? - incomplete
 
   Network          Next Hop          Metric LocPrf Weight Path
*  198.92.0.0       198.92.72.30                         0 109 108 ?
*  198.92.1.0       198.92.72.30                         0 109 108 ?
*  198.92.11.0      198.92.72.30                         0 109 108 ?
*  198.92.14.0      198.92.72.30                         0 109 108 ?
*  198.92.15.0      198.92.72.30                         0 109 108 ?
*  198.92.16.0      198.92.72.30                         0 109 108 ?
*  198.92.17.0      198.92.72.30                         0 109 108 ?
*  198.92.18.0      198.92.72.30                         0 109 108 ?
*  198.92.19.0      198.92.72.30                         0 109 108 ?
*  198.92.24.0      198.92.72.30                         0 109 108 ?
*  198.92.29.0      198.92.72.30                         0 109 108 ?
*  198.92.30.0      198.92.72.30                         0 109 108 ?
*  198.92.33.0      198.92.72.30                         0 109 108 ?
*  198.92.35.0      198.92.72.30                         0 109 108 ?
*  198.92.36.0      198.92.72.30                         0 109 108 ?
*  198.92.37.0      198.92.72.30                         0 109 108 ?
*  198.92.38.0      198.92.72.30                         0 109 108 ?
*  198.92.39.0      198.92.72.30                         0 109 108 ?
 

show ip bgp summary

To display the status of all BGP connections, use the show ip bgp summary EXEC command.

show ip bgp summary
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip bgp summary command:

Router# show ip bgp summary
 
BGP table version is 717029, main routing table version 717029
19073 network entries (37544 paths) using 3542756 bytes of memory
691 BGP path attribute entries using 57200 bytes of memory
 
Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State
193.0.16.1      4  1755   32642    2973   717029    0    0 1:27:11  
193.0.17.1      4  1755    4790    2973   717029    0    0 1:27:51  
193.0.18.1      4  1755    7722    3024   717029    0    0 1:28:13  
193.0.19.1      4  1755       0       0        0    0    0 2d02     Active
193.0.20.1      4  1755    3673    3049   717029    0    0 2:50:10  
193.0.21.1      4  1755    3741    3048   717029    0    0 12:24:43 
193.0.22.1      4  1755   33129    3051   717029    0    0 12:24:48 
193.0.23.1      4  1755       0       0        0    0    0 2d02     Active
193.0.24.1      4  1755       0       0        0    0    0 2d02     Active
193.0.25.1      4  1755       0       0        0    0    0 2d02     Active
193.0.26.1      4  1755       0       0        0    0    0 2d02     Active
193.0.27.1      4  1755    4269    3049   717029    0    0 12:39:33 
193.0.28.1      4  1755    3037    3050   717029    0    0 2:08:15  
198.92.72.24    4  1878   11635   13300   717028    0    0 0:50:39  
 

Table 41 describes significant fields shown in the display.


Table 41: Show IP BGP Summary Field Descriptions
Field Description

BGP table version

Internal version number of BGP database.

main routing table version

Indicates last version of BGP database that was injected into main routing table.

Neighbor

IP address of a neighbor.

V

Indicates BGP version number spoken to that neighbor.

MsgRcvd

BGP messages received from that neighbor.

MsgSent

BGP messages sent to that neighbor.

TblVer

Last version of the BGP database that was sent to that neighbor.

InQ

Number of messages from that neighbor waiting to be processed.

OutQ

Number of messages waiting to be sent to that neighbor.

Update/State

The length of time that the BGP session has been in state Established, or the current state if it is not Established.

show ip dvmrp route

To display the contents of the DVMRP routing table, use the show ip dvmrp route EXEC command.

show ip dvmrp route [name | ip-address]
Syntax Description

name | ip-address

(Optional) Name or IP address of an entry in the DVMRP routing table.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Sample Display

The following is sample output of the show ip dvmrp route command:

Router# show ip dvmrp route
 
DVMRP Routing Table - 1 entry
171.68.0.0/16 [100/11] uptime 07:55:50, expires 00:02:52
    via 137.39.3.93, Tunnel3
 

Table 42 describes the fields shown in the display


Table 42: Show IP DVMRP Route Field Descriptions
Field Description

1 entry

Number of entries in the DMVRP routing table.

171.68.0.0/16

Source network.

[100/11]

Administrative distance/metric.

uptime

How long in hours, minutes, and seconds that the route has been in the DVMRP routing table.

expires

How long in hours, minutes, and seconds until the entry is removed from the DVMRP routing table.

via 137.39.3.93

Next-hop router to the source network.

Tunnel3

Interface to the source network.

Related Command

ip dvmrp accept-filter

show ip egp

To display statistics about EGP connections and neighbors, use the show ip egp EXEC command.

show ip egp
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip egp command:

Router# show ip egp
 
Local autonomous system is 109
  EGP Neighbor FAS/LAS State   SndSeq RcvSeq Hello Poll j/k Flags
  10.3.0.27      1/109 IDLE       625  61323    60  180   0 Perm, Act
* 10.2.0.37      1/109 UP 12:29   250  14992    60  180   3 Perm, Act
* 10.7.0.63      1/109 UP  1d19   876  10188    60  180   4 Perm, Pass
 

Table 43 describes the fields shown in the display.


Table 43: Show IP EGP Field Descriptions
Field Description

EGP Neighbor

Address of the EGP neighbor.

FAS

Foreign autonomous system number.

LAS

Local autonomous system number.

State

State of the connection between peers.

SndSeq

Send sequence number.

RcvSeq

Receive sequence number.

Hello

Interval between Hello/I-Heard-You packets.

Poll

Interval between Poll/Update packets.

j/k

Measure of reachability; 4 is perfect.

Flags

Perm---Permanent.

Temp---Temporary (neighbor will be removed).

Act---Active, controlling the connection.

Pass---Passive, neighbor controls the connection.

show ip eigrp interfaces

To display information about interfaces configured for Enhanced IGRP, use the show ip eigrp interfaces EXEC command.

show  ip eigrp interfaces [type number] [as-number]
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

as-number

(Optional) Autonomous system number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use the show ip eigrp interfaces command to determine on which interfaces Enhanced IGRP is active, and to find out information about Enhanced IGRP relating to those interfaces.

If an interface is specified, only that interface is displayed. Otherwise, all interfaces on which Enhanced IGRP is running are displayed.

If an autonomous system is specified, only the routing process for the specified autonomous system is displayed. Otherwise, all Enhanced IGRP processes are displayed.

Sample Display

The following is sample output from the show ip eigrp interfaces command:

Router> show ip eigrp interfaces
IP EIGRP interfaces for process 109
 
                    Xmit Queue    Mean   Pacing Time   Multicast   Pending
Interface   Peers   Un/Reliable   SRTT   Un/Reliable   Flow Timer  Routes
Di0           0         0/0          0      11/434          0          0
Et0           1         0/0        337       0/10           0          0
SE0:1.16      1         0/0         10       1/63         103          0
Tu0           1         0/0        330       0/16           0          0
 
Related Command

show ip eigrp neighbors

show ip eigrp neighbors

To display the neighbors discovered by Enhanced IGRP, use the show ip eigrp neighbors EXEC command.

show ip eigrp neighbors [type number]
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Use the show ip eigrp neighbors command to determine when neighbors become active and inactive. It is also useful for debugging certain types of transport problems.

Sample Display

The following is sample output from the show ip eigrp neighbors command:

Router# show ip eigrp neighbors
 
IP-EIGRP Neighbors for process 77
Address                 Interface     Holdtime Uptime   Q      Seq  SRTT  RTO
                                      (secs)   (h:m:s)  Count  Num  (ms)  (ms)
160.89.81.28            Ethernet1     13       0:00:41  0      11   4     20
160.89.80.28            Ethernet0     14       0:02:01  0      10   12    24
160.89.80.31            Ethernet0     12       0:02:02  0      4    5     20
 

Table 44 explains the fields in the output.


Table 44: Show IP Enhanced IGRP Neighbors Field Descriptions
Field Description

process 77

Autonomous system number specified in the router configuration command.

Address

IP address of the enhanced IGRP peer.

Interface

Interface on which the router is receiving hello packets from the peer.

Holdtime

Length of time, in seconds, that the Cisco IOS software will wait to hear from the peer before declaring it down. If the peer is using the default hold time, this number will be less than 15. If the peer configures a nondefault hold time, it will be reflected here.

Uptime

Elapsed time, in hours, minutes, and seconds, since the local router first heard from this neighbor.

Q Count

Number of Enhanced IGRP packets (Update, Query, and Reply) that the software is waiting to send.

Seq Num

Sequence number of the last update, query, or reply packet that was received from this neighbor.

SRTT

Smooth round-trip time. This is the number of milliseconds it takes for an Enhanced IGRP packet to be sent to this neighbor and for the local router to receive an acknowledgment of that packet.

RTO

Retransmission timeout, in milliseconds. This is the amount of time the software waits before retransmitting a packet from the retransmission queue to a neighbor.

show ip eigrp topology

To display the Enhanced IGRP topology table, use the show ip eigrp topology EXEC command.

show ip eigrp topology [autonomous-system-number | [[ip-address] mask]]
Syntax Description

autonomous-system-number

(Optional) Autonomous system number.

ip-address

(Optional) IP address. When specified with a mask, a detailed description of the entry is provided.

mask

(Optional) Subnet mask.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the show ip eigrp topology command to determine Diffusing Update Algorithm (DUAL) states and to debug possible DUAL problems.

Sample Display

The following is sample output from the show ip eigrp topology command:

Router# show ip eigrp topology
 
IP-EIGRP Topology Table for process 77
 
Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
       r - Reply status
 
P 160.89.90.0 255.255.255.0, 2 successors, FD is 0
          via 160.89.80.28 (46251776/46226176), Ethernet0
          via 160.89.81.28 (46251776/46226176), Ethernet1
          via 160.89.80.31 (46277376/46251776), Ethernet0
P 160.89.81.0 255.255.255.0, 1 successors, FD is 307200
          via Connected, Ethernet1
          via 160.89.81.28 (307200/281600), Ethernet1
          via 160.89.80.28 (307200/281600), Ethernet0
          via 160.89.80.31 (332800/307200), Ethernet0
 

Table 45 explains the fields in the output.


Table 45: Show IP Enhanced IGRP Topology Field Descriptions
Field Description

Codes

State of this topology table entry. Passive and Active refer to the Enhanced IGRP state with respect to this destination; Update, Query, and Reply refer to the type of packet that is being sent.

P - Passive

No Enhanced IGRP computations are being performed for this destination.

A - Active

Enhanced IGRP computations are being performed for this destination.

U - Update

Indicates that an update packet was sent to this destination.

Q - Query

Indicates that a query packet was sent to this destination.

R - Reply

Indicates that a reply packet was sent to this destination.

r - Reply status

Flag that is set when after the software has sent a query and is waiting for a reply.

160.89.90.0 and so on

Destination IP network number.

255.255.255.0

Destination subnet mask.

successors

Number of successors. This number corresponds to the number of next hops in the IP routing table.

FD

Feasible distance. This value is used in the feasibility condition check. If the neighbor's reported distance (the metric after the slash) is less than the feasible distance, the feasibility condition is met and that path is a feasible successor. Once the software determines it has a feasible successor, it does not have to send a query for that destination.

replies

Number of replies that are still outstanding (have not been received) with respect to this destination. This information appears only when the destination is in Active state.

state

Exact Enhanced IGRP state that this destination is in. It can be the number 0, 1, 2, or 3. This information appears only when the destination is Active.

via

IP address of the peer who told the software about this destination. The first N of these entries, where N is the number of successors, are the current successors. The remaining entries on the list are feasible successors.

(46251776/46226176)

The first number is the Enhanced IGRP metric that represents the cost to the destination. The second number is the Enhanced IGRP metric that this peer advertised.

Ethernet0

Interface from which this information was learned.

show ip eigrp traffic

To display the number of Enhanced IGRP packets sent and received, use the show ip eigrp traffic EXEC command.

show ip eigrp traffic [autonomous-system-number]
Syntax Description

autonomous-system-number

(Optional) Autonomous system number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip eigrp traffic command:

Router# show ip eigrp traffic
 
IP-EIGRP Traffic Statistics for process 77
  Hellos sent/received: 218/205
  Updates sent/received: 7/23
  Queries sent/received: 2/0
  Replies sent/received: 0/2
  Acks sent/received: 21/14
 

Table 46 describes the fields that might be shown in the display.


Table 46: Show IP Enhanced IGRP Traffic Field Descriptions
Field Description

process 77

Autonomous system number specified in the ip router command.

Hellos sent/received

Number of hello packets that were sent and received.

Updates sent/received

Number of update packets that were sent and received.

Queries sent/received

Number of query packets that were sent and received.

Replies sent/received

Number of reply packets that were sent and received.

Acks sent/received

Number of acknowledgment packets that were sent and received.

show ip igmp groups

To display the multicast groups that are directly connected to the router and that were learned via IGMP, use the show ip igmp groups EXEC command.

show ip igmp groups [group-name | group-address | type number]
Syntax Description

group-name

(Optional) Name of the multicast group, as defined in the DNS hosts table.

group-address

(Optional) Address of the multicast group. This is a multicast IP address in four-part, dotted notation.

type

(Optional) Interface type.

number

(Optional) Interface number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you omit all optional arguments, the show ip igmp groups command displays by group address and interface type and number all directly connected multicast groups.

Sample Display

The following is sample output from the show ip igmp groups command:

Router# show ip igmp groups
 
IGMP Connected Group Membership
Group Address    Interface       Uptime    Expires   Last Reporter
224.0.255.1      Ethernet0       18:51:41  0:02:15   198.92.37.192
224.2.226.60     Ethernet0       1:51:31   0:02:17   198.92.37.192
224.2.127.255    Ethernet0       18:51:45  0:02:17   198.92.37.192
226.2.2.2        Ethernet1       18:51:47  never     0.0.0.0
224.2.0.1        Ethernet0       18:51:43  0:02:14   198.92.37.192
225.2.2.2        Ethernet0       18:51:43  0:02:21   198.92.37.33
225.2.2.2        Ethernet1       18:51:47  never     0.0.0.0
225.2.2.4        Ethernet0       18:18:02  0:02:20   198.92.37.192
225.2.2.4        Ethernet1       18:23:32  0:02:55   198.92.36.128
 

Table 47 describes the fields shown in the display.


Table 47: Show IP IGMP Groups Field Descriptions
Field Description

Group address

Address of the multicast group.

Interface

Interface through which the group is reachable.

Uptime

How long in hours, minutes, and seconds this multicast group has been known.

Expires

How long in hours, minutes, and seconds until the entry is removed from the IGMP groups table.

Last Reporter

Last host to report being a member of the multicast group.

Related Command

ip igmp query-interval

show ip igmp interface

To display multicast-related information about an interface, use the show ip igmp interface EXEC command.

show ip igmp interface [type number]
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you omit the optional arguments, the show ip igmp interface command displays information about all interfaces.

This command also displays information about dynamically learned DVMRP routers on the interface.

Sample Display

The following is sample output from the show ip igmp interface command:

Router# show ip igmp interface
 
Ethernet0 is up, line protocol is up
  Internet address is 198.92.37.6, subnet mask is 255.255.255.0
  IGMP is enabled on interface
  IGMP query interval is 60 seconds
  Inbound IGMP access group is not set
  Multicast routing is enabled on interface
  Multicast TTL threshold is 0
  Multicast designated router (DR) is 198.92.37.33
  No multicast groups joined
Ethernet1 is up, line protocol is up
  Internet address is 198.92.36.129, subnet mask is 255.255.255.0
  IGMP is enabled on interface
  IGMP query interval is 60 seconds
  Inbound IGMP access group is not set
  Multicast routing is enabled on interface
  Multicast TTL threshold is 0
  Multicast designated router (DR) is 198.92.36.131
  Multicast groups joined: 225.2.2.2 226.2.2.2
Tunnel0 is up, line protocol is up
  Internet address is 10.1.37.2, subnet mask is 255.255.0.0
  IGMP is enabled on interface
  IGMP query interval is 60 seconds
  Inbound IGMP access group is not set
  Multicast routing is enabled on interface
  Multicast TTL threshold is 0
  No multicast groups joined
 

Table 48 describes the fields shown in the display.


Table 48: Show IP IGMP Interface Field Descriptions
Field Description

Ethernet0 is up, line protocol is up

Interface type, number, and status.

Internet address is...
subnet mask is...

Internet address of the interface and subnet mask being applied to the interface, as specified with the ip address command.

IGMP is enabled on interface

Indicates whether IGMP has been enabled on the interface with the ip pim command.

IGMP query interval is 60 seconds

Interval at which the Cisco IOS software sends PIM router-query messages, as specified with the ip igmp query-interval command.

Inbound IGMP access group is not set

Indicates whether an IGMP access group has been configured with the ip igmp access-group command.

Multicast routing is enabled on interface

Indicates whether multicast routing has been enabled on the interface with the ip pim command.

Multicast TTL threshold is 0

Packet time-to-threshold, as specified with the ip multicast ttl-threshold command.

Multicast designated router (DR) is...

IP address of the designated router for this LAN segment (subnet).

Multicast groups joined:
No multicast groups joined

Indicates whether this interface is a member of any multicast groups and, if so, lists the IP addresses of the groups.

Related Commands

ip address
ip igmp access-group
ip igmp query-interval
ip multicast ttl-threshold
ip pim

show ip irdp

To display IRDP values, use the show ip irdp EXEC command.

show ip irdp
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip irdp command:

Router# show ip irdp
 
Ethernet 0 has router discovery enabled
 
Advertisements will occur between every 450 and 600 seconds.
Advertisements are valid for 1800 seconds.
Default preference will be 100.
 --More--
Serial 0 has router discovery disabled
 --More--
Ethernet 1 has router discovery disabled
 

As the display shows, show ip irdp output indicates whether router discovery has been configured for each router interface, and lists the values of router discovery configurables for those interfaces on which router discovery has been enabled. Explanations for the less self-evident lines of output in the display are as follows:

Advertisements will occur between every 450 and 600 seconds.
 

This indicates the configured minimum and maximum advertising interval for the interface.

Advertisements are valid for 1800 seconds.
 

This indicates the configured holdtime values for the interface.

Default preference will be 100.
 

This indicates the configured (or in this case default) preference value for the interface.

show ip local policy

To display the route map used for local policy routing, if any, use the show ip local policy EXEC command.

show ip local policy
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Sample Display

The following is sample output from the show ip local policy command:

Router# show ip local policy
Local policy routing is enabled, using route map equal
route-map equal, permit, sequence 10
  Match clauses:
    length 150 200
  Set clauses:
    ip next-hop 10.10.11.254
  Policy routing matches: 0 packets, 0 bytes
route-map equal, permit, sequence 20
  Match clauses:
    ip address (access-lists): 101 
  Set clauses:
    ip next-hop 10.10.11.14
  Policy routing matches: 2 packets, 172 bytes
Related Commands

ip local policy route-map
match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop

show ip mcache

To display the contents of the IP fast-switching cache, use the show ip mcache EXEC command.

show ip mcache [group [source]]
Syntax Description

group

(Optional) Displays the fast-switching cache for the single group. The group argument can be either a Class D IP address or a DNS name.

source

(Optional) If source is also specified, displays a single multicast cache entry. The source argument can be either a unicast IP address or a DNS name.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Sample Display

The following is sample output from the show ip mcache command. This entry shows a specific source (wrn-source 204.62.246.73) sending to the World Radio Network group (224.2.143.24).

Router> show ip mcache wrn wrn-source
 
IP Multicast Fast-Switching Cache 
(204.62.246.73/32, 224.2.143.24), Fddi0, Last used: 00:00:00  
  Ethernet0       MAC Header: 01005E028F1800000C1883D30800 
  Ethernet1       MAC Header: 01005E028F1800000C1883D60800 
  Ethernet2       MAC Header: 01005E028F1800000C1883D40800 
  Ethernet3       MAC Header: 01005E028F1800000C1883D70800
 

Table 49 describes the significant fields in the display.


Table 49: Show IP Mcache Field Descriptions
Field Description

204.62.246.73

Source address.

224.2.143.24

Destination address.

Fddi0

Incoming or expected interface on which the packet should be received.

Last used:

Latest time the entry was accessed for a packet that was successfully fast- switched. The word "Semi-fast" indicates that the first part of the outgoing interface list is fast switched and the rest of the list is process level switched.

Ethernet0

MAC Header:

Outgoing interface list and respective MAC header that is used when rewriting the packet for output. If the interface is a tunnel, the MAC header will show the real next hop MAC header and then, in parentheses, the real interface name.

show ip mroute

To display the contents of the IP multicast routing table, use the show ip mroute EXEC command.

show ip mroute [group-name | group-address] [source] [summary] [count] [active kbps]
Syntax Description

group-name | group-address

(Optional) IP address, name, or interface of the multicast group as defined in the DNS hosts table.

source

(Optional) IP address or name of a multicast source.

summary

(Optional) Displays a one-line, abbreviated summary of each entry in the IP multicast routing table.

count

(Optional) Displays statistics about the group and source, including number of packets, packets per second, average packet size, and bits per second.

active kbps

(Optional) Displays the rate that active sources are sending to multicast groups. Active sources are those sending at a rate of kbps or higher. The kbps argument defaults to 4 kbps.

Default

The show ip mroute command displays all groups and sources.
The show ip mroute active command displays all sources sending at a rate greater than or equal to 4  kbps.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you omit all optional arguments and keywords, the show ip mroute command displays all entries in the IP multicast routing table.

The Cisco IOS software populates the multicast routing table by creating source, group (S,G) entries from star, group (*,G) entries. The star refers to all source addresses, the "S" refers to a single source address, and the "G" is the destination multicast group address. In creating (S,G) entries, the software uses the best path to that destination group found in the unicast routing table (that is, via Reverse Path Forwarding [RPF]).

Sample Displays

The following is sample output from the show ip mroute command for a router operating is dense mode. This command displays the contents of the IP multicast routing table for the multicast group named cbone-audio.

Router> show ip mroute cbone-audio
 
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, C - Connected, L - Local, P - Pruned
       R - RP-bit set, F - Register flag, T - SPT-bit set
Timers: Uptime/Expires
Interface state: Interface, Next-Hop, State/Mode
 
(*, 224.0.255.1), uptime 0:57:31, expires 0:02:59, RP is 0.0.0.0, flags: DC
  Incoming interface: Null, RPF neighbor 0.0.0.0, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Dense, 0:57:31/0:02:52
    Tunnel0, Forward/Dense, 0:56:55/0:01:28
 
(198.92.37.100/32, 224.0.255.1), uptime 20:20:00, expires 0:02:55, flags: C
  Incoming interface: Tunnel0, RPF neighbor 10.20.37.33, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Dense, 20:20:00/0:02:52
 

The following is sample output from the show ip mroute command for a router operating in sparse mode:

Router# show ip mroute
 
IP Multicast Routing Table
Flags: D - Dense, S - Sparse, C - Connected, L - Local, P - Pruned
       R - RP-bit set, F - Register flag, T - SPT-bit set
Timers: Uptime/Expires
Interface state: Interface, Next-Hop, State/Mode
 
(*, 224.0.255.3), uptime 5:29:15, RP is 198.92.37.2, flags: SC
  Incoming interface: Tunnel0, RPF neighbor 10.3.35.1, Dvmrp
  Outgoing interface list:
    Ethernet0, Forward/Sparse, 5:29:15/0:02:57
 
(198.92.46.0/24, 224.0.255.3), uptime 5:29:15, expires 0:02:59, flags: C
  Incoming interface: Tunnel0, RPF neighbor 10.3.35.1
  Outgoing interface list:
    Ethernet0, Forward/Sparse, 5:29:15/0:02:57
 

Table 50 explains the fields shown in the displays.


Table 50: Show IP Mroute Field Descriptions
Field Description

Flags:

Provides information about the entry.

D - Dense

Entry is operating in dense mode.

S - Sparse

Entry is operating in sparse mode.

C - Connected

A member of the multicast group is present on the directly connected interface.

L - Local

The router itself is a member of the multicast group.

P - Pruned

Route has been pruned. The Cisco IOS software keeps this information in case a downstream member wants to join the source.

     R - Rp-bit set

Indicates that the (S,G) entry is pointing towards the RP. This is typically prune state along the shared tree for a particular source.

     F - Register flag

Indicates that the software is Registering for a multicast source.

     T - SPT-bit set

Indicates that packets have been received on the shortest path source tree.

(*, 224.0.255.1)
(198.92.37.100/32, 224.0.255.1)

Entry in the IP multicast routing table. The entry consists of the IP address of the source router followed by IP address of the multicast group. An asterisk (*) in place of the source router indicates all sources.

Entries in the first format are referred to as (*,G,) or "star comma G," entries. Entries in the second format are referred to as (S,G) or ("S  comma  G") entries. (*,G) entries are used to build (S,G) entries.

uptime

How long in hours, minutes, and seconds the entry has been in the IP multicast routing table.

expires

How long in hours, minutes, and seconds until the entry will be removed from the IP multicast routing table on the outgoing interface.

RP

Address of the rendezvous point (RP) router. For routers and access servers operating in sparse mode, this address is always 0.0.0.0.

flags:

Information about the entry.

Incoming interface:

Expected interface for a multicast packet from the source. If the packet is not received on this interface, it is discarded.

RPF neighbor

IP address of the upstream router to the source. "Tunneling" indicates that this router is sending data to the RP encapsulated in Register packets. The hexadecimal number in parentheses indicates to which RP we are registering. Each bit indicates a different RP if multiple RPs per group are used.

Dvmrp or Mroute

Indicates if the RPF information is obtained from the DVMRP routing table or the static mroutes configuration.

Outgoing interface list:

Interfaces through which packets will be forwarded. When the interface has ip pim nbma-mode, the IP address of the PIM neighbor is also displayed.

Ethernet0

Name and number of the outgoing interface.

Forward/Dense

Indicates that packets will be forwarded on the interface if there are no restrictions due to access lists or TTL threshold. Following the slash, mode in which the interface is operating (dense or sparse).

time/time

How long in hours, minutes, and seconds the entry has been in the IP multicast routing table. Following the slash, how long in hours, minutes, and seconds until the entry will be removed from the IP multicast routing table.

Related Command

ip igmp query-interval

show ip ospf

To display general information about OSPF routing processes, use the show ip ospf EXEC command.

show ip ospf [process-id]
Syntax Description

process-id

(Optional) Process ID. If this argument is included, only information for the specified routing process is included.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip ospf command when entered without a specific OSPF process ID:

Router# show ip ospf
 
Routing Process "ospf 201" with ID 192.42.110.200
Supports only single TOS(TOS0) route
It is an area border and autonomous system boundary router
Summary Link update interval is 0:30:00 and the update due in 0:16:26
External Link update interval is 0:30:00 and the update due in 0:16:27
Redistributing External Routes from,
   	igrp 200 with metric mapped to 2, includes subnets in redistribution
   	rip with metric mapped to 2
   	igrp 2 with metric mapped to 100
   	igrp 32 with metric mapped to 1
Number of areas in this router is 3
Area 192.42.110.0
   	Number of interfaces in this area is 1
   	Area has simple password authentication
   	SPF algorithm executed 6 times
   	Area ranges are
   	Link State Update Interval is 0:30:00 and due in 0:16:55
   	Link State Age Interval is 0:20:00 and due in 0:06:55
 

Table 51 describes significant fields shown in the display.


Table 51: Show IP OSPF Field Descriptions
Field Description

Routing process "ospf 201" with ID 192.42.110.200

Process ID and OSPF router ID.

Type of service

Number of Types of service supported (Type 0 only).

Type of OSPF Router

Possible types are internal, area border, or autonomous system boundary.

Summary Link update interval

Specify summary update interval in hours:minutes:seconds, and time to next update.

External Link update interval

Specify external update interval in hours:minutes:seconds, and time to next update.

Redistributing External Routes from

Lists of redistributed routes, by protocol.

Number of areas

Number of areas in router, area addresses, and so on.

Link State Update Interval

Specify router and network link state update interval in hours:minutes:seconds, and time to next update.

Link State Age Interval

Specify max-aged update deletion interval and time until next database cleanup in hours:minutes:seconds.

show ip ospf border-routers

To display the internal OSPF routing table entries to an area border router (ABR) and autonomous system boundary router (ASBR), use the show ip ospf border-routers privileged EXEC command.

show ip ospf border-routers
Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip ospf border-routers command:

Router# show ip ospf border-routers
 
OSPF Process 109 internal Routing Table
 
Destination      Next Hop        Cost   Type     Rte Type Area           SPF No
 
160.89.97.53     144.144.1.53    10     ABR      INTRA    0.0.0.3        3
160.89.103.51    160.89.96.51    10     ABR      INTRA    0.0.0.3        3
160.89.103.52    160.89.96.51    20     ASBR     INTER    0.0.0.3        3
160.89.103.52    144.144.1.53    22     ASBR     INTER    0.0.0.3        3
 

Table 52 describes the fields shown in the display.


Table 52: Show IP OSPF Border-Routers Field Descriptions
Field Description

Destination

Destination's router ID.

Next Hop

Next hop toward the destination.

Cost

Cost of using this route.

Type

The router type of the destination; it is either an area border router (ABR) or autonomous system boundary router (ASBR) or both.

Rte Type

The type of this route, it is either an intra-area or interarea route.

Area

The area ID of the area that this route is learned from.

SPF No

The internal number of SPF calculation that installs this route.

show ip ospf database

Use the show ip ospf database EXEC command to display lists of information related to the OSPF database for a specific router. The various forms of this command deliver information about different OSPF link state advertisements.

show ip ospf [process-id area-id] database
show ip ospf [
process-id area-id] database [router] [link-state-id]
show ip ospf [
process-id area-id] database [network] [link-state-id]
show ip ospf [
process-id area-id] database [summary] [link-state-id]
show ip ospf [
process-id area-id] database [asb-summary] [link-state-id]
show ip ospf [
process-id area-id] database [nssa-external] [link-state-id]
show ip ospf [
process-id] database [external] [link-state-id]
show ip ospf [
process-id area-id] database [database-summary]
Syntax Description

process-id

(Optional) Internally used identification parameter. It is locally assigned and can be any positive integer number. The number used here is the number assigned administratively when enabling the OSPF routing process.

area-id

(Optional) Area number associated with the OSPF address range defined in the network router configuration command used to define the particular area.

link-state-id

(Optional) Identifies the portion of the Internet environment that is being described by the advertisement. The value entered depends on the advertisement's LS type. It must be entered in the form of an IP address.

When the link state advertisement is describing a network, the link-state-id can take one of two forms:

---The network's IP address (as in type 3 summary link advertisements and in autonomous system external link advertisements).

---A derived address obtained from the link state ID. (Note that masking a network links advertisement's link state ID with the network's subnet mask yields the network's IP address.)

When the link state advertisement is describing a router, the link state ID is always the described router's OSPF router ID.

When an autonomous system external advertisement (LS  Type = 5) is describing a default route, its link state ID is set to Default Destination (0.0.0.0).

When entered with the optional keyword router, network, summary, asb-summary, external, or database-summary, different displays result. Examples and brief descriptions of each form follow.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The following form of the command first appeared in Cisco IOS Release 11.0:

show ip ospf [process-id area-id] database  [database-summary].

Sample Display of Show IP OSPF Database with No Arguments or Keywords

The following is sample output from the show ip ospf database command when no arguments or keywords are used:

Router# show ip ospf database
 
OSPF Router with id(190.20.239.66) (Process ID 300)
 
                 Displaying Router Link States(Area 0.0.0.0)
 
  Link ID       ADV Router      Age        Seq#     Checksum  Link count
155.187.21.6   155.187.21.6    1731    0x80002CFB    0x69BC       8
155.187.21.5   155.187.21.5    1112    0x800009D2    0xA2B8       5
155.187.1.2    155.187.1.2     1662    0x80000A98    0x4CB6       9
155.187.1.1    155.187.1.1     1115    0x800009B6    0x5F2C       1
155.187.1.5    155.187.1.5     1691    0x80002BC     0x2A1A       5
155.187.65.6   155.187.65.6    1395    0x80001947    0xEEE1       4
155.187.241.5  155.187.241.5   1161    0x8000007C    0x7C70       1
155.187.27.6   155.187.27.6    1723    0x80000548    0x8641       4
155.187.70.6   155.187.70.6    1485    0x80000B97    0xEB84       6
 
                Displaying Net Link States(Area 0.0.0.0)
 
  Link ID       ADV Router      Age        Seq#        Checksum
155.187.1.3  192.20.239.66     1245    0x800000EC      0x82E
 
                Displaying Summary Net Link States(Area 0.0.0.0)
 
  Link ID       ADV Router       Age        Seq#        Checksum
155.187.240.0   155.187.241.5    1152      0x80000077      0x7A05
155.187.241.0   155.187.241.5    1152      0x80000070      0xAEB7
155.187.244.0   155.187.241.5    1152      0x80000071      0x95CB
 

Table 53 describes significant fields shown in the display.


Table 53: Show IP OSPF Database Field Descriptions
Field Description

Link ID

Router ID number.

ADV Router

Advertising router's ID.

Age

Link state age.

Seq#

Link state sequence number (detects old or duplicate link state advertisements).

Checksum

Fletcher checksum of the complete contents of the link state advertisement.

Link count

Number of interfaces detected for router.

Sample Display Using Show IP OSPF Database ASB-Summary

The following is sample output from the show ip ospf database asb-summary command when no optional arguments are specified:

Router# show ip ospf database asb-summary
 
OSPF Router with id(190.20.239.66) (Process ID 300)
 
                Displaying Summary ASB Link States(Area 0.0.0.0)
 
	LS age: 1463
	Options: (No TOS-capability)
	LS Type: Summary Links(AS Boundary Router)
	Link State ID: 155.187.245.1 (AS Boundary Router address)
	Advertising Router: 155.187.241.5
	LS Seq Number: 80000072
	Checksum: 0x3548
	Length: 28
	Network Mask: 0.0.0.0 TOS: 0  Metric: 1
 

Table 54 describes significant fields shown in the display.


Table 54: Show IP OSPF Database ASB-Summary Field Descriptions
Field Description

Router ID

Router ID number.

Process ID

OSPF process ID.

LS age

Link state age.

Options

Type of service options (Type 0 only).

LS Type

Link state type.

Link State ID

Link state ID (autonomous system boundary router).

Advertising Router

Advertising router's ID.

LS Seq Number

Link state sequence (detects old or duplicate link state advertisements).

Checksum

LS checksum (Fletcher checksum of the complete contents of the link state advertisement).

Length

Length in bytes of the link state advertisement.

Network Mask

Network mask implemented.

TOS

Type of service.

Metric

Link state metric.

Sample Display Using Show IP OSPF Database External

The following is sample output from the show ip ospf database external command when no optional arguments are specified:

Router# show ip ospf database external
 
OSPF Router with id(190.20.239.66) (Process ID 300)
 
                   Displaying AS External Link States
 
LS age: 280
Options: (No TOS-capability)
LS Type: AS External Link
Link State ID: 143.105.0.0 (External Network Number)
Advertising Router: 155.187.70.6
LS Seq Number: 80000AFD
Checksum: 0xC3A
Length: 36
Network Mask: 255.255.0.0
     		Metric Type: 2 (Larger than any link state path)
     		TOS: 0
     		Metric: 1
     		Forward Address: 0.0.0.0
     		External Route Tag: 0
 

Table 55 describes significant fields shown in the display.


Table 55: Show IP OSPF Database External Field Descriptions
Field Description

Router ID

Router ID number.

Process ID

OSPF process ID.

LS age

Link state age.

Options

Type of service options (Type 0 only).

LS Type

Link state type.

Link State ID

Link state ID (External Network Number).

Advertising Router

Advertising router's ID.

LS Seq Number

Link state sequence number (detects old or duplicate link state advertisements).

Checksum

LS checksum (Fletcher checksum of the complete contents of the link state advertisement).

Length

Length in bytes of the link state advertisement.

Network Mask

Network mask implemented.

   Metric Type

External Type.

   TOS

Type of service.

   Metric

Link state metric.

   Forward Address

Forwarding address. Data traffic for the advertised destination will be forwarded to this address. If the forwarding address is set to 0.0.0.0, data traffic will be forwarded instead to the advertisement's originator.

   External Route Tag

External route tag, a 32-bit field attached to each external route. This is not used by the OSPF protocol itself.

Sample Display Using Show IP OSPF Database Network

The following is sample output from the show ip ospf database network command when no optional arguments are specified:

Router# show ip ospf database network
 OSPF Router with id(190.20.239.66) (Process ID 300)
 
                Displaying Net Link States(Area 0.0.0.0)
 
LS age: 1367
Options: (No TOS-capability)
LS Type: Network Links
Link State ID: 155.187.1.3 (address of Designated Router)
Advertising Router: 190.20.239.66
LS Seq Number: 800000E7
Checksum: 0x1229
Length: 52
Network Mask: 255.255.255.0
        Attached Router: 190.20.239.66
        Attached Router: 155.187.241.5
        Attached Router: 155.187.1.1
        Attached Router: 155.187.54.5
        Attached Router: 155.187.1.5
 

Table 56 describes significant fields shown in the display.


Table 56: Show IP OSPF Database Network Field Descriptions
Field Description

OSPF Router with ID

Router ID number.

Process ID

OSPF process ID.

LS age:

Link state age.

Options:

Type of service options (Type 0 only).

LS Type:

Link state type.

Link State ID

Link state ID of designated router.

Advertising Router

Advertising router's ID.

LS Seq Number

Link state sequence (detects old or duplicate link state advertisements).

Checksum

LS checksum (Fletcher checksum of the complete contents of the link state advertisement).

Network Mask

Network mask implemented.

AS Boundary Router

Definition of router type.

Attached Router

List of routers attached to the network, by IP address.

Sample Display Using Show IP OSPF Database Router

The following is sample output from the show ip ospf database router command when no optional arguments are specified:

Router# show ip ospf database router
 
OSPF Router with id(190.20.239.66) (Process ID 300)
 
 
                Displaying Router Link States(Area 0.0.0.0)
 
LS age: 1176
Options: (No TOS-capability)
LS Type: Router Links
Link State ID: 155.187.21.6
Advertising Router: 155.187.21.6
LS Seq Number: 80002CF6
Checksum: 0x73B7
Length: 120
AS Boundary Router
155   Number of Links: 8
 
Link connected to: another Router (point-to-point)
(link ID) Neighboring Router ID: 155.187.21.5
(Link Data) Router Interface address: 155.187.21.6
Number of TOS metrics: 0
TOS 0 Metrics: 2
 

Table 57 describes significant fields shown in the display.


Table 57: Show IP OSPF Database Router Field Descriptions
Field Description

OSPF Router with ID

Router ID number.

Process ID

OSPF process ID.

LS age

Link state age.

Options

Type of service options (Type 0 only).

LS Type

Link state type.

Link State ID

Link state ID.

Advertising Router

Advertising router's ID.

LS Seq Number

Link state sequence (detects old or duplicate link state advertisements).

Checksum

LS checksum (Fletcher checksum of the complete contents of the link state advertisement).

Length

Length in bytes of the link state advertisement.

AS Boundary Router

Definition of router type.

Number of Links

Number of active links.

link ID

Link type.

Link Data

Router interface address.

TOS

Type of service metric (Type 0 only).

Sample Display Using Show IP OSPF Database Summary

The following is sample output from show ip ospf database summary command when no optional arguments are specified:

Router# show ip ospf database summary
 
       OSPF Router with id(190.20.239.66) (Process ID 300)
 
                Displaying Summary Net Link States(Area 0.0.0.0)
 
LS age: 1401
Options: (No TOS-capability)
LS Type: Summary Links(Network)
Link State ID: 155.187.240.0 (summary Network Number)
Advertising Router: 155.187.241.5
LS Seq Number: 80000072
Checksum: 0x84FF
Length: 28
Network Mask: 255.255.255.0   TOS: 0  Metric: 1
 

Table 58 describes significant fields shown in the display.


Table 58: Show IP OSPF Database Summary Field Descriptions
Field Description

OSPF Router with ID

Router ID number.

Process ID

OSPF process ID.

LS age

Link state age.

Options

Type of service options (Type 0 only).

LS Type

Link state type.

Link State ID

Link state ID (summary network number).

Advertising Router

Advertising router's ID.

LS Seq Number

Link state sequence (detects old or duplicate link state advertisements).

Checksum

LS checksum (Fletcher checksum of the complete contents of the link state advertisement).

Length

Length in bytes of the link state advertisement.

Network Mask

Network mask implemented.

TOS

Type of service.

Metric

Link state metric.

Sample Display Using Show IP OSPF Database Database-Summary

The following is sample output from show ip ospf database database-summary command when no optional arguments are specified:

Router# show ip ospf database database-summary
 
          OSPF Router with ID (172.19.65.21) (Process ID 1)
 
Area ID     Router    Network    Sum-Net    Sum-ASBR    Subtotal    Delete    Maxage
202         1         0          0          0           1           0         0
AS External                                             0           0         0
Total       1         0          0          0           1
 

Table 59 describes significant fields shown in the display.


Table 59: Show IP OSPF Database Database-Summary Field Descriptions
Field Description

Area ID

Area number.

Router

Number of router link state advertisements in that area.

Network

Number of network link state advertisements in that area.

Sum-Net

Number of summary link state advertisements in that area.

Sum-ASBR

Number of summary autonomous system boundary router (ASBR) link state advertisements in that area.

Subtotal

Sum of Router, Network, Sum-Net, and Sum-ASBR for that area.

Delete

Number of link state advertisements that are marked "Deleted" in that area.

Maxage

Number of link state advertisements that are marked "Maxaged" in that area.

AS External

Number of external link state advertisements.

show ip ospf interface

To display OSPF-related interface information, use the show ip ospf interface EXEC command.

show ip ospf interface [type number]
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip ospf interface command when Ethernet 0 is specified:

Router# show ip ospf interface ethernet 0
 
Ethernet 0 is up, line protocol is up
	Internet Address 131.119.254.202, Mask 255.255.255.0, Area 0.0.0.0
	AS 201, Router ID 192.77.99.1, Network Type BROADCAST, Cost: 10
	Transmit Delay is 1 sec, State OTHER, Priority 1
	Designated Router id 131.119.254.10, Interface address 131.119.254.10
	Backup Designated router id 131.119.254.28, Interface addr 131.119.254.28
	Timer intervals configured, Hello 10, Dead 60, Wait 40, Retransmit 5
	Hello due in 0:00:05
	Neighbor Count is 8, Adjacent neighbor count is 2
  	Adjacent with neighbor 131.119.254.28  (Backup Designated Router)
  	Adjacent with neighbor 131.119.254.10  (Designated Router)
 

Table 60 describes significant fields shown in the display.


Table 60: Show IP OSPF Interface Ethernet 0 Field Descriptions
Field Description

Ethernet

Status of physical link and operational status of protocol.

Internet Address

Interface IP address, subnet mask, and area address.

AS

Autonomous system number (OSPF process ID), router ID, network type, link state cost.

Transmit Delay

Transmit delay, interface state, and router priority.

Designated Router

Designated router ID and respective interface IP address.

Backup Designated router

Backup designated router ID and respective interface IP address.

Timer intervals configured

Configuration of timer intervals.

Hello

Number of seconds until next hello packet is sent out this interface.

Neighbor Count

Count of network neighbors and list of adjacent neighbors.

show ip ospf neighbor

To display OSPF-neighbor information on a per-interface basis, use the show ip ospf neighbor EXEC command.

show ip ospf neighbor [type number] [neighbor-id] detail
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

neighbor-id

(Optional) Neighbor ID.

detail

Displays all neighbors given in detail (list all neighbors).

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Displays

The following is sample output from the show ip ospf neighbor command showing a single line of summary information for each neighbor:

Router# show ip ospf neighbor
 
   ID          Pri   State        Dead Time     Address         Interface
199.199.199.137 1    FULL/DR       0:00:31    160.89.80.37      Ethernet0
192.31.48.1     1    FULL/DROTHER  0:00:33    192.31.48.1       Fddi0
192.31.48.200   1    FULL/DROTHER  0:00:33    192.31.48.200     Fddi0
199.199.199.137 5    FULL/DR       0:00:33    192.31.48.189     Fddi0
 

The following is sample output showing summary information about the neighbor that matches the neighbor ID:

Router# show ip ospf neighbor 199.199.199.137
 
Neighbor 199.199.199.137, interface address 160.89.80.37
    In the area 0.0.0.0 via interface Ethernet0
    Neighbor priority is 1, State is FULL
    Options 2
    Dead timer due in 0:00:32
    Link State retransmission due in 0:00:04
 Neighbor 199.199.199.137, interface address 192.31.48.189
    In the area 0.0.0.0 via interface Fddi0
    Neighbor priority is 5, State is FULL
    Options 2
    Dead timer due in 0:00:32
    Link State retransmission due in 0:00:03
 

If you specify the interface along with the Neighbor ID, the Cisco IOS software displays the neighbors that match the neighbor ID on the interface, as in the following sample display:

Router# show ip ospf neighbor e 0 199.199.199.137
 
Neighbor 199.199.199.137, interface address 160.89.80.37
    In the area 0.0.0.0 via interface Ethernet0
    Neighbor priority is 1, State is FULL
    Options 2
    Dead timer due in 0:00:37
    Link State retransmission due in 0:00:04
 

You can also specify the interface without the neighbor ID to show all neighbors on the specified interface, as in the following sample display:

Router# show ip ospf neighbor f 0
 
   ID          Pri   State        Dead Time     Address         Interface
192.31.48.1     1    FULL/DROTHER  0:00:33    192.31.48.1       Fddi0
192.31.48.200   1    FULL/DROTHER  0:00:32    192.31.48.200     Fddi0
199.199.199.137 5    FULL/DR       0:00:32    192.31.48.189     Fddi0
 

The following is sample output from the show ip ospf neighbor detail command:

Router# show ip ospf neighbor detail
 
Neighbor 160.89.96.54, interface address 160.89.96.54
    In the area 0.0.0.3 via interface Ethernet0
    Neighbor priority is 1, State is FULL
    Options 2
    Dead timer due in 0:00:38
 Neighbor 160.89.103.52, interface address 160.89.103.52
    In the area 0.0.0.0 via interface Serial0
    Neighbor priority is 1, State is FULL
    Options 2
    Dead timer due in 0:00:31
 

Table 61 describes the fields shown in the displays.


Table 61: Show IP OSPF Neighbor Field Descriptions
Field Description

Neighbor x.x.x.x

Neighbor router ID.

interface address x.x.x.x

IP address of the interface.

In the area

Area and interface through which OSPF neighbor is known.

Neighbor priority

Router priority of neighbor, neighbor state.

State

OSPF state.

Options

Hello packet options field contents (E-bit only; possible values are 0 and 2; 2 indicates area is not a stub; 0 indicates area is a stub.

Dead timer

Expected time before Cisco IOS software will declare neighbor dead.

show ip ospf virtual-links

To display parameters about and the current state of OSPF virtual links, use the show ip ospf virtual-links EXEC command.

show ip ospf virtual-links
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The information displayed by show ip ospf virtual-links is useful in debugging OSPF routing operations.

Sample Display

The following is sample output from the show ip ospf virtual-links command:

Router# show ip ospf virtual-links
 
Virtual Link to router 160.89.101.2 is up
Transit area 0.0.0.1, via interface Ethernet0, Cost of using 10
Transmit Delay is 1 sec, State POINT_TO_POINT
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 0:00:08
Adjacency State FULL
 

Table 62 describes significant fields shown in the display.


Table 62: Show IP OSPF Virtual-Links Field Descriptions
Field Description

Virtual Link to router 160.89.101.2 is Up

Specifies the OSPF neighbor, and if the link to that neighbor is Up or Down.

Transit area 0.0.0.1

The transit area through which the virtual link is formed.

via interface Ethernet0

The interface through which the virtual link is formed.

Cost of using 10

The cost of reaching the OSPF neighbor through the virtual link.

Transmit Delay is 1 sec

The transmit delay on the virtual link.

State POINT_TO_POINT

The state of the OSPF neighbor.

Timer intervals...

The various timer intervals configured for the link.

Hello due in 0:00:08

When the next hello is expected from the neighbor.

Adjacency State FULL

The adjacency state between the neighbors.

show ip pim interface

To display information about interfaces configured for PIM, use the show ip pim interface EXEC command.

show ip pim interface [type number] [count]
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

count

(Optional) Displays the number of IP multicast packets received and sent on the interface.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The count keyword was added in Release  11.0.

This command works only on interfaces that are configured for PIM.

Sample Display

The following is sample output from the show ip pim interface command:

Router# show ip pim interface
 
Address          Interface          Mode    Neighbor  Query     DR
                                            Count     Interval
198.92.37.6      Ethernet0          Dense   2         30        198.92.37.33
198.92.36.129    Ethernet1          Dense   2         30        198.92.36.131
10.1.37.2        Tunnel0            Dense   1         30        0.0.0.0
 

The following is sample output from the show ip pim interface command with a count:

Router# show ip pim interface count
 
Address          Interface          FS  Mpackets In/Out
171.69.121.35    Ethernet0          *   548305239/13744856
171.69.121.35    Serial0.33         *   8256/67052912
198.92.12.73     Serial0.1719       *   219444/862191
 

Table 63 describes the fields shown in the display.


Table 63: Show IP PIM Interface Field Descriptions
Field Description

Address

IP address of the next-hop router.

Interface

Interface type and number that is configured to run PIM.

Mode

Multicast mode in which the Cisco IOS software is operating. This can be dense mode or sparse mode. DVMRP indicates a DVMRP tunnel is configured.

Neighbor Count

Number of PIM neighbors that have been discovered through this interface. If the Neighbor Count is 1 for a DVMRP tunnel, the neighbor is active (receiving probes and reports).

Query Interval

Frequency, in seconds, of PIM router-query messages, as set by the ip pim query-interval interface configuration command. The default is 30 seconds.

DR

IP address of the designated router on the LAN. Note that serial lines do not have designated routers, so the IP address is shown as 0.0.0.0.

FS

An asterisk (*) in this column indicates fast switching is enabled.

Mpackets In/Out

Number of packets into and out of the interface since the box has been up.

Related Commands

ip pim
show ip pim neighbor

show ip pim neighbor

To list the PIM neighbors discovered by the Cisco IOS software, use the show ip pim neighbor EXEC command.

show ip pim neighbor [type number]
Syntax Description

type

(Optional) Interface type.

number

(Optional) Interface number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use this command to determine which routers on the LAN are configured for PIM.

Sample Display

The following is sample output from the show ip pim neighbor command:

Router# show ip pim neighbor
 
PIM Neighbor Table
Neighbor Address  Interface          Uptime    Expires   Mode
198.92.37.2       Ethernet0          17:38:16  0:01:25   Dense
198.92.37.33      Ethernet0          17:33:20  0:01:05   Dense (DR)
198.92.36.131     Ethernet1          17:33:20  0:01:08   Dense (DR)
198.92.36.130     Ethernet1          18:56:06  0:01:04   Dense
10.1.22.9         Tunnel0            19:14:59  0:01:09   Dense
 

Table 64 describes the fields shown in the display.


Table 64: Show IP PIM Neighbor Field Descriptions
Field Description

Neighbor Address

IP address of the PIM neighbor.

Interface

Interface type and number on which the neighbor is reachable.

Uptime

How long in hours, minutes, and seconds the entry has been in the PIM neighbor table.

Expires

How long in hours, minutes, and seconds until the entry will be removed from the IP multicast routing table.

Mode

Mode in which the interface is operating.

(DR)

Indicates that this neighbor is a designated router on the LAN.

Related Command

show ip pim interface

show ip pim rp

To display the rendezvous point (RP) routers associated with a sparse-mode multicast group, use the show ip pim rp EXEC command.

show ip pim rp [group-name | group-address]
Syntax Description

group-name

(Optional) Name of the multicast group, as defined in the DNS hosts table.

group-address

(Optional) Address of the multicast group. This is a multicast IP address in four-part, dotted notation.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Displays

The following is sample output from the show ip pim rp command from a router that is not an RP:

Router1# show ip pim rp
 
Group: 224.2.127.255, number of RPs: 1
  RP address: 198.92.37.2, state: Up, uptime 0:01:25, expires in 0:03:04
 

The following is sample output from the show ip pim rp command from a router that is an RP:

Router2# show ip pim rp
 
Group: 224.2.127.255, number of RPs: 1
  RP address: 198.92.37.2, state: Up, next RP-reachable in 0:01:01
 

Table 65 describes the fields shown in the displays.


Table 65: Show IP PIM RP Field Descriptions
Field Description

Group:

Address of the multicast group.

number of RPs:

Number of RPs in the multicast group.

RP address:

Address of the RP.

state:

State of the RP router; it can be Up or Down.

uptime

How long in hours, minutes, and seconds the RP has been up.

expires

How long in hours, minutes, and seconds until the entry for this RP expires.

next RP-reachable in

How long in hours, minutes, and seconds until the RP will send its next RP-reachable message.

Related Command

show ip mroute

show ip policy

To display the route map used for policy routing, use the show ip policy EXEC command.

show ip policy
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Sample Displays

The following is sample output from the show ip policy command:

Router# show ip policy
Interface      Route map
local          equal
Ethernet0      equal
 

The following is sample output from the show route-map command, which relates to the preceding sample display:

Router# show route-map
route-map equal, permit, sequence 10
  Match clauses:
    length 150 200
  Set clauses:
    ip next-hop 10.10.11.254
  Policy routing matches: 0 packets, 0 bytes
route-map equal, permit, sequence 20
  Match clauses:
    ip address (access-lists): 101 
  Set clauses:
    ip next-hop 10.10.11.14
  Policy routing matches: 144 packets, 15190 bytes
Related Commands

match ip address
match length
route-map
set default interface
set interface
set ip default next-hop
set ip next-hop

show ip protocols

To display the parameters and current state of the active routing protocol process, use the show ip protocols EXEC command.

show ip protocols
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The information displayed by show ip protocols is useful in debugging routing operations. Information in the Routing Information Sources field of the show ip protocols output can help you identify a router suspected of delivering bad routing information.

Sample Displays

The following is sample output from the show ip protocols command, showing IGRP processes:

Router# show ip protocols
 
Routing Protocol is "igrp 109"
  Sending updates every 90 seconds, next due in 44 seconds
  Invalid after 270 seconds, hold down 280, flushed after 630
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Default networks flagged in outgoing updates
  Default networks accepted from incoming updates
  IGRP metric weight K1=1, K2=0, K3=1, K4=0, K5=0
  IGRP maximum hopcount 100
  IGRP maximum metric variance 1
  Redistributing: igrp 109
  Routing for Networks:
    198.92.72.0
  Routing Information Sources:
    Gateway         Distance      Last Update
    198.92.72.18         100      0:56:41
    198.92.72.19         100      6d19
    198.92.72.22         100      0:55:41
    198.92.72.20         100      0:01:04
    198.92.72.30         100      0:01:29
  Distance: (default is 100)
 
Routing Protocol is "bgp 1878"
  Sending updates every 60 seconds, next due in 0 seconds
  Outgoing update filter list for all interfaces is 1
  Incoming update filter list for all interfaces is not set
  Redistributing: igrp 109
  IGP synchronization is disabled
  Automatic route summarization is enabled
  Neighbor(s):
    Address          FiltIn FiltOut DistIn DistOut Weight RouteMap
    192.108.211.17                1                      
    192.108.213.89                1                      
    198.6.255.13                  1                      
    198.92.72.18                  1                      
    198.92.72.19                                         
    198.92.84.17                  1                      
  Routing for Networks:
    192.108.209.0
    192.108.211.0
    198.6.254.0
  Routing Information Sources:
    Gateway         Distance      Last Update
    198.92.72.19          20      0:05:28
  Distance: external 20 internal 200 local 200
 

Table 66 describes significant fields shown in the display.


Table 66: Show IP Protocols Field Descriptions for IGRP Processes
Field Description

Routing Protocol is "igrp 109"

Specifies the routing protocol used.

Sending updates every 90 seconds

Specifies the time between sending updates.

next due in 88 seconds

Precisely when the next update is due to be sent.

Invalid after 270 seconds

Specifies the value of the invalid parameter.

hold down for 280

Specifies the current value of the hold-down parameter.

flushed after 630

Specifies the time in seconds after which the individual routing information will be thrown (flushed) out.

Outgoing update ...

Specifies whether the outgoing filtering list has been set.

Incoming update ...

Specifies whether the incoming filtering list has been set.

Default networks

Specifies how these networks will be handled in both incoming and outgoing updates.

IGRP metric

Specifies the value of the K0-K5 metrics, as well as the maximum hopcount.

Redistributing

Lists the protocol that is being redistributed.

Routing

Specifies the networks for which the routing process is currently injecting routes.

Routing Information Sources

Lists all the routing sources the Cisco IOS software is using to build its routing table. For each source, you will see the following displayed:

  • IP address

  • Administrative distance

  • Time the last update was received from this source.

The following is sample output from the show ip protocols command, showing Enhanced IGRP processes:

Router# show ip protocols
 
Routing Protocol is "eigrp 77"
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Redistributing: eigrp 77
  Automatic network summarization is in effect
  Routing for Networks:
    160.89.0.0
  Routing Information Sources:
    Gateway         Distance      Last Update
    160.89.81.28          90      0:02:36
    160.89.80.28          90      0:03:04
    160.89.80.31          90      0:03:04
  Distance: internal 90 external 170
 

Table 67 describes the fields that might be shown in the display.


Table 67: Show IP Protocols Field Descriptions for Enhanced IGRP Processes
Field Description

Routing Protocol is "eigrp 77"

Name and autonomous system number of the currently running routing protocol.

Outgoing update filter list for all interfaces...

Indicates whether a filter for outgoing routing updates has been specified with the distribute-list out command.

Outgoing update filter list for all interfaces...

Indicates whether a filter for outgoing routing updates has been specified with the distribute-list in command.

Redistributing: eigrp 77

Indicates whether route redistribution has been enabled with the redistribute command.

Automatic network summarization...

Indicates whether route summarization has been enabled with the auto-summary command.

Routing for Networks:

Networks for which the routing process is currently injecting routes.

Routing Information Sources:

Lists all the routing sources that the Cisco IOS software is using to build its routing table. The following is displayed for each source: IP address, administrative distance, and time the last update was received from this source.

Distance: internal 90 external 170

Internal and external distances of the router. Internal distance is the degree of preference given to Enhanced IGRP internal routes. External distance is the degree of preference given to Enhanced IGRP external routes.

The following is sample output from the show ip protocols command, showing IS-IS processes:

Router# show ip protocols
 
Routing Protocol is "isis"
  Sending updates every 0 seconds
  Invalid after 0 seconds, hold down 0, flushed after 0
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Redistributing: isis
  Address Summarization:
    None
  Routing for Networks:
    Serial0
  Routing Information Sources:
  Distance: (default is 115)
 

The following is sample output from the show ip protocols command, showing RIP processes:

Router# show ip protocols
 
Routing Protocol is "rip"
  Sending updates every 30 seconds, next due in 2 seconds
  Invalid after 180 seconds, hold down 180, flushed after 240
  Outgoing update filter list for all interfaces is not set
  Incoming update filter list for all interfaces is not set
  Redistributing: rip
  Default version control: send version 2, receive version 2
    Interface        Send  Recv   Key-chain
    Ethernet0        2     2      trees 
    Fddi0            2     2                      
  Routing for Networks:
    172.19.0.0
    2.0.0.0
    3.0.0.0
  Routing Information Sources:
    Gateway         Distance      Last Update
  Distance: (default is 120)

show ip route

Use the show ip route EXEC command to display the current state of the routing table.

show ip route [address [mask] [longer-prefixes]] | [protocol [process-id]]
Syntax Description

address

(Optional) Address about which routing information should be displayed.

mask

(Optional) Argument for a subnet mask.

longer-prefixes

(Optional) The address and mask pair becomes a prefix and any routes that match that prefix are displayed.

protocol

(Optional) Name of a routing protocol; or the keyword connected, static, or summary. If you specify a routing protocol, use one of the following keywords: bgp, egp, eigrp, hello, igrp, isis, ospf, or rip.

process-id

(Optional) Number used to identify a process of the specified protocol.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The longer-prefixes keyword first appeared in IOS Release 11.0. The process-id argument first appeared in IOS Release 10.3.

Sample Displays

The following is sample output from the show ip route command when entered without an address:

Router# show ip route
 
Codes: I - IGRP derived, R - RIP derived, O - OSPF derived
       C - connected, S - static, E - EGP derived, B - BGP derived
       * - candidate default route, IA - OSPF inter area route
       E1 - OSPF external type 1 route, E2 - OSPF external type 2 route
 
Gateway of last resort is 131.119.254.240 to network 129.140.0.0
 
O E2 150.150.0.0 [160/5] via 131.119.254.6, 0:01:00, Ethernet2
E    192.67.131.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2
O E2 192.68.132.0 [160/5] via 131.119.254.6, 0:00:59, Ethernet2
O E2 130.130.0.0 [160/5] via 131.119.254.6, 0:00:59, Ethernet2
E    128.128.0.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2
E    129.129.0.0 [200/129] via 131.119.254.240, 0:02:22, Ethernet2
E    192.65.129.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2
E    131.131.0.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2
E    192.75.139.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2
E    192.16.208.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2
E    192.84.148.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2
E    192.31.223.0 [200/128] via 131.119.254.244, 0:02:22, Ethernet2
E    192.44.236.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2
E    140.141.0.0 [200/129] via 131.119.254.240, 0:02:22, Ethernet2
E    141.140.0.0 [200/129] via 131.119.254.240, 0:02:23, Ethernet2
 

The following is sample output that includes some IS-IS Level 2 routes learned:

Router# show ip route
 
Codes: I - IGRP derived, R - RIP derived, O - OSPF derived
       C - connected, S - static, E - EGP derived, B - BGP derived
       i - IS-IS derived
       * - candidate default route, IA - OSPF inter area route
	E1 - OSPF external type 1 route, E2 - OSPF external type 2 route
       L1 - IS-IS level-1 route, L2 - IS-IS level-2 route
 
Gateway of last resort is not set
 
     160.89.0.0 is subnetted (mask is 255.255.255.0), 3 subnets
C       160.89.64.0 255.255.255.0 is possibly down,
          routing via 0.0.0.0, Ethernet0
i L2    160.89.67.0 [115/20] via 160.89.64.240, 0:00:12, Ethernet0
i L2    160.89.66.0 [115/20] via 160.89.64.240, 0:00:12, Ethernet0
 

Table 68 describes significant fields shown in these two displays.


Table 68: Show IP Route Field Descriptions
Field Description

O

Indicates protocol that derived the route. Possible values include the following:

  • I---IGRP derived

  • R---RIP derived

  • O---OSPF derived

  • C---connected

  • S---static

  • E---EGP derived

  • B---BGP derived

  • i---IS-IS derived

E2

Type of route. Possible values include the following:

  • *---Indicates the last path used when a packet was forwarded. It pertains only to the non-fast-switched packets. However, it does not indicate what path will be used next when forwarding a non-fast-switched packet, except when the paths are equal cost.

  • IA---OSPF interarea route.

  • E1---OSPF external type 1 route.

  • E2---OSPF external type 2 route.

  • L1---IS-IS Level 1 route.

  • L2---IS-IS Level 2 route.

150.150.0.0

Indicates the address of the remote network.

[160/5]

The first number in the brackets is the administrative distance of the information source; the second number is the metric for the route.

via 131.119.254.6

Specifies the address of the next router to the remote network.

0:01:00

Specifies the last time the route was updated in hours:minutes:seconds.

Ethernet 2

Specifies the interface through which the specified network can be reached.

When you specify that you want information about a specific network displayed, more detailed statistics are shown. The following is sample output from the show ip route command when entered with the address 131.119.0.0.

Router# show ip route 131.119.0.0
 
Routing entry for 131.119.0.0 (mask 255.255.0.0)
   	Known via "igrp 109", distance 100, metric 10989
   	Tag 0
   	Redistributing via igrp 109
   	Last update from 131.108.35.13 on TokenRing0, 0:00:58 ago
   	Routing Descriptor Blocks:
   	* 131.108.35.13, from 131.108.35.13, 0:00:58 ago, via TokenRing0
      		Route metric is 10989, traffic share count is 1
      		Total delay is 45130 microseconds, minimum bandwidth is 1544 Kbit
      		Reliability 255/255, minimum MTU 1500 bytes
      		Loading 2/255, Hops 4
 

Table 69 describes significant fields shown in the display.


Table 69: Show IP Route with Address Field Descriptions
Field Description

Routing entry for 131.119.0.0 (mask 255.255.0.0)

Network number and mask.

Known via "igrp 109"

Indicates how the route was derived.

distance 100

Administrative distance of the information source.

Tag 0

Integer that is used to implement the route.

Redistributing via igrp 109

Indicates redistribution protocol.

Last update from 131.108.35.13 on TokenRing0

Indicates the IP address of a router that is the next hop to the remote network and the router interface on which the last update arrived.

0:00:58 ago

Specifies the last time the route was updated in hours:minutes:seconds.

131.108.35.13, from 131.108.35.13, 0:00:58 ago

Indicates the next hop address, the address of the gateway that sent the update, and the time that has elapsed since this update was received in hours:minutes:seconds.

via TokenRing0

Interface for this route.

Route metric is 10989

This value is the best metric for this routing descriptor block.

traffic share count is 1

Number of uses for this routing descriptor block.

Total delay is 45130 microseconds

Total propagation delay in microseconds.

minimum bandwidth is 1544 Kbit

Minimum bandwidth encountered when transmitting data along this route.

Reliability 255/255

Likelihood of successful packet transmission expressed as a number between 0 and 255 (255 is 100 percent reliability).

minimum MTU 1500 bytes

Smallest MTU along the path.

Loading 2/255

Effective bandwidth of the route in kilobits per second/255 is saturation.

Hops 4

Hops to the destination or to the router where the route first enters IGRP.

The following is sample output using the longer-prefixes keyword. When the longer-prefixes keyword is included, the address and mask pair becomes the prefix, and any address that matches that prefix is displayed. Therefore, multiple addresses are displayed.

In the following example, the logical AND operation is performed on the source address 128.0.0.0 and the mask 128.0.0.0, resulting in 128.0.0.0. Each destination in the routing table is also logically ANDed with the mask and compared to that result of 128.0.0.0. Any destinations that fall into that range are displayed in the output.

Router# show ip route 128.0.0.0 128.0.0.0 longer-prefixes 
 
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default
 
Gateway of last resort is not set
 
S    134.134.0.0 is directly connected, Ethernet0
S    131.131.0.0 is directly connected, Ethernet0
S    129.129.0.0 is directly connected, Ethernet0
S    128.128.0.0 is directly connected, Ethernet0
S    198.49.246.0 is directly connected, Ethernet0
S    192.160.97.0 is directly connected, Ethernet0
S    192.153.88.0 is directly connected, Ethernet0
S    192.76.141.0 is directly connected, Ethernet0
S    192.75.138.0 is directly connected, Ethernet0
S    192.44.237.0 is directly connected, Ethernet0
S    192.31.222.0 is directly connected, Ethernet0
S    192.16.209.0 is directly connected, Ethernet0
S    144.145.0.0 is directly connected, Ethernet0
S    140.141.0.0 is directly connected, Ethernet0
S    139.138.0.0 is directly connected, Ethernet0
S    129.128.0.0 is directly connected, Ethernet0
     172.19.0.0 255.255.255.0 is subnetted, 1 subnets
C       172.19.64.0 is directly connected, Ethernet0
     171.69.0.0 is variably subnetted, 2 subnets, 2 masks
C       171.69.232.32 255.255.255.240 is directly connected, Ethernet0
S       171.69.0.0 255.255.0.0 is directly connected, Ethernet0
Router#
Related Commands

A dagger () indicates that the command is documented outside this chapter.

show interfaces tunnel
show ip route summary

show ip route summary

To display the current state of the routing table, use the show ip route summary EXEC command.

show ip route summary
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip route summary command:

Router# show ip route summary
 
Route Source    Networks    Subnets     Overhead    Memory (bytes)
connected       0           3           126         360
static          1           2           126         360
igrp 109        747         12          31878       91080
internal        3                                   360
Total           751         17          32130       92160
Router#
 

Table 70 describes the fields shown in the display:


Table 70: Show IP Route Summary Field Descriptions
Field Description

Route Source

Routing protocol name, or the keyword connected, static or internal. Internal indicates those routes that are in the routing table that are not owned by any routing protocol.

Networks

Number of prefixes that are present in the routing table for each route source.

Subnets

Number of subnets that are present in the routing table for each route source, including host routes.

Overhead

Any additional memory involved in allocating the routes for the particular route source other than the memory specified in the Memory field.

Memory

Number of bytes allocated to maintain all the routes for the particular route source.

Related Command

show ip route

show ip route supernets-only

To display information about supernets, use the show ip route supernets-only privileged EXEC command.

show ip route supernets-only
Syntax Description

This command has no arguments or keywords.

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show ip route supernets-only command:

Router# show ip route supernets-only
 
Codes: I - IGRP derived, R - RIP derived, O - OSPF derived
       C - connected, S - static, E - EGP derived, B - BGP derived
       i - IS-IS derived, D - EIGRP derived
       * - candidate default route, IA - OSPF inter area route
       E1 - OSPF external type 1 route, E2 - OSPF external type 2 route
       L1 - IS-IS level-1 route, L2 - IS-IS level-2 route
       EX - EIGRP external route
 
Gateway of last resort is not set
 
B    198.92.0.0 (mask is 255.255.0.0) [20/0] via 198.92.72.30, 0:00:50
B    192.0.0.0 (mask is 255.0.0.0) [20/0] via 198.92.72.24, 0:02:50
Router#
 

This display shows supernets only; it does not show subnets.

show ip rpf

To display how IP multicast routing does Reverse-Path Forwarding (RPF), use the show ip  rpf EXEC command.

show ip rpf source-address-or-name
Syntax Description

source-address-or-name

Source name or address of the host for which the RPF information is displayed.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The router can Reverse-Path Forward from multiple routing tables (that is, the unicast routing table, DVMRP routing table, or static mroutes). This command tells you where the information is retrieved from.

Sample Display

The following is sample output of the show ip rpf command:

Router # show ip rpf 171.69.10.13
RPF information for sj-eng-mbone.cisco.com (171.69.10.13)
  RPF interface: BRI0
  RPF neighbor: eng-isdn-pri3.cisco.com (171.69.121.10)
  RPF route/mask: 171.69.0.0/255.255.0.0
  RPF type: unicast

Table 71 describes the significant fields in the display.


Table 71: Show IP RPF Field Descriptions
Field Description

RPF information for name (address)

Host name and address that this information concerns.

RPF interface

For the given source, interface from which router expects to get packets.

RPF neighbor

For given source, neighbor from which router expects to get packets.

RPF route/mask

Route number and mask that matched against this source.

RPF type:

Routing table from which this route was obtained, either unicast, DVMRP, or static mroute.

show ip rsvp interface

To display RSVP-related interface information, use the show ip rsvp interface EXEC command.

show ip rsvp interface [interface]
Syntax Description

interface

(Optional) Interface type.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to show the current allocation budget and maximum allocatable bandwidth.

Sample Display

The following is sample output from the show ip rsvp interface command when Ethernet 1 is specified:

	Router# show ip rsvp interface
 interface allocated maximum    flow max   percent UDP IP UDP+IP UDP M/C
 Et1        0          7500       7500       0 /255 0   2 0      no     
 Se0        1150       1158       1158       253/255 0   1 0      no)
 

Table 72 describes significant fields shown in the display.


Table 72: Show IP RSVP Interface Field Descriptions
Field Description

Interface

Interface name.

Allocated

Current allocation budget.

Maximum

Maximum allocatable bandwidth.

Flow Max

Maximum flow possible on this interface.

Percent

Percent of bandwidth utilized.

UDP

Number of neighbors sending UDP-encapsulated RSVP.

IP

Number of neighbors sending IP-encapsulated RSVP.

UDP+IP

Number of neighbors sending both.

UDP /MC

Is router configured for UDP on this interface?

show ip rsvp interface installed

To display RSVP-related installed filters and corresponding bandwidth information, use the show ip rsvp interface EXEC command.

show ip rsvp interface installed [interface]
Syntax Description

interface

(Optional) Interface type.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to show the current installed RSVP filters and the corresponding bandwidth information for a specified interface or all interfaces.

Sample Display

The following is sample output from the show ip rsvp interface installed command:

Router# show ip rsvp interface installed
RSVP: 
RSVP: Ethernet1: has no installed reservations
RSVP: Serial0:
     kbps   To              From       Protocol DPort Sport Weight Conversation
     0      224.250.250.1   132.240.2.28     UDP 20    30    128   270
     150    224.250.250.1   132.240.2.1      UDP 20    30    128   268
     100    224.250.250.1   132.240.1.1      UDP 20    30    128   267
     200    224.250.250.1   132.240.1.25     UDP 20    30    256   265
     200    224.250.250.2   132.240.1.25     UDP 20    30    128   271
     0      224.250.250.2   132.240.2.28     UDP 20    30    128   269
     150    224.250.250.2   132.240.2.1      UDP 20    30    128   266
     350    224.250.250.3   0.0.0.0          UDP 20    0     128   26
 

Table 73 describes significant fields shown in the display.


Table 73: Show IP RSVP Interface Installed Field Descriptions
Field Description

kbps

Interface name.

To

IP address of source device.

From

IP address of destination device.

Protocol DPort

Protocol type of destination UDP/TCP port (not usually the protocol any more).

Sport

Source UDP/TCP port.

Weight

Weight used in Weighted Fair Queuing (WFQ).

Conversation

WFQ conversation number. If the WFQ is not configured on the interface, weight and conversation will be zero.

show ip rsvp neighbor

To display current RSVP neighbors, use the show ip rsvp neighbor EXEC command.

show ip rsvp neighbor [interface]
Syntax Description

interface

(Optional) Interface type.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to show the current RSVP neighbors and identify if the neighbor is using IP or UDP encapsulation for a specified interface or all interfaces.

Sample Display

The following is sample output from the show ip rsvp neighbor command:

	Router# show ip rsvp neighbor
 
RSVP: Et1 neighbors:
 IP   132.240.3.25   
 IP   132.240.3.28   
RSVP: Se0 neighbors:
 IP   132.240.4.30 
 

show ip rsvp sender

To display RSVP-related sender information currently in the database, use the show ip rsvp sender EXEC command.

show ip rsvp sender [interface]
Syntax Description

interface

(Optional) Interface type.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to show the current RSVP sender (PATH) information currently in the database for a specified interface or all interfaces.

Sample Display

The following is sample output from the show ip rsvp sender command:

	Router# show ip rsvp sender
To              From        Protocol DPort Sport Previous Hop    If Kbps
 224.250.250.1   132.240.1.1     UDP 20    30    132.240.3.25    Lo1 50 5
 224.250.250.2   132.240.1.1     UDP 20    30    132.240.3.25    Lo1 50 5
 224.250.250.2   132.240.1.25    UDP 20    30    132.240.3.25    Lo1 50 5
 224.250.250.2   132.240.2.1     UDP 20    30    132.240.3.28    Lo1 50 5
 224.250.250.2   132.240.2.28    UDP 20    30    132.240.3.28    Lo1 50 5
 224.250.250.3   132.240.1.1     UDP 20    30    132.240.3.25    Lo1 50 5
 224.250.250.3   132.240.1.25    UDP 20    30    132.240.3.25    Lo1 50 5
 224.250.250.3   132.240.2.1     UDP 20    30    132.240.3.28    Lo1 50 5
 224.250.250.3   132.240.2.28    UDP 20    30    132.240.3.28    Lo1 50 5
 

show ip rsvp request

To display RSVP-related request information being requested upstream, use the show ip rsvp request EXEC command.

show ip rsvp request [interface]
Syntax Description

interface

(Optional) Interface type.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to show the RSVP reservations currently being requested upstream for a specified interface or all interfaces. The received reservations may differ from requests because of aggregated or refused reservations.

Sample Display

The following is sample output from the show ip rsvp request command:

Router# show ip rsvp request
To         From       Protocol DPort Sport Next Hop   If Filter Service B/W Burst
224.250.250.1 132.240.1.1  UDP 20    30    132.240.3.25 Et1 FF DELY 1 100  60
224.250.250.1 132.240.1.25 UDP 20    30    132.240.3.25 Et1 FF DELY 2 200  60
224.250.250.1 132.240.2.1  UDP 20    30    132.240.3.28 Et1 FF DELY 1 150  65
224.250.250.2 132.240.1.25 UDP 20    30    132.240.3.25 Et1 SE RATE   200  60
224.250.250.2 132.240.2.1  UDP 20    30    132.240.3.28 Et1 SE LOAD   150  65
224.250.250.3 0.0.0.0      UDP 20    0     132.240.3.25 Et1 WF LOAD   300  60

show ip rsvp reservation

To display RSVP-related receiver information currently in the database, use the show ip rsvp reservation EXEC command.

show ip rsvp reservation [interface]
Syntax Description

interface

(Optional) Interface type.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to show the current receiver (RESV) information currently in the database for a specified interface or all interfaces. This information includes reservations aggregated and forwarded from other RSVP routers.

Sample Display

The following is sample output from the show ip rsvp reservation command:

	Router# show ip rsvp res
To         From       Protocol DPort Sport Next Hop   If Filter Service B/W Burst
224.250.250.1 132.240.1.1  UDP 20    30    132.240.4.30 Se0 FF DELY 1 100  60
224.250.250.1 132.240.1.25 UDP 20    30    132.240.4.30 Se0 FF DELY 2 200  60
224.250.250.1 132.240.2.1  UDP 20    30    132.240.4.30 Se0 FF DELY 1 150  65
224.250.250.2 132.240.1.25 UDP 20    30    132.240.4.30 Se0 SE RATE   200  60
224.250.250.2 132.240.2.1  UDP 20    30    132.240.4.30 Se0 SE LOAD   150  65
224.250.250.3 0.0.0.0      UDP 20    0     132.240.4.30 Se0 WF LOAD   350  65
 

show ip sdr

To display the session directory cache, use the show ip  sdr EXEC command.

show ip sdr [group | "session-name" | detail]
Syntax Description

group

(Optional) Displays the sessions defining the multicast group in detail format.

"session-name"

(Optional) Displays the single session in detail format.

detail

(Optional) Displays all sessions in detail format.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

If the router is configured to be a member of 224.2.127.254 (the default sd group), it will cache sdr announcements.

If no arguments or keywords are used with this command, the system displays a sorted list of session names.

Sample Display

The following is sample output of the show ip sdr command:

Router # show ip sdr 
SDR Cache - 198 entries
!Cannes Film Festival
Alan Kay: Georgia Tech Distinguished Lecture
ANL TelePresence Microscopy Collaboratory
ASC MSRC Ribbon Cutting Ceremony
audio test
Basler Fasnacht 1997 !
BayLISA meeting
Bellcore testing
Bellcore testing2
Bielsko-Biala
calren2 - private
Cannes Testing
Cbay session
CERN ATLAS
CERN LEPC meeting
CERN LHCC
CILEA pre-test for Archaeonet
cisco Beta
cisco PIM users
CMU
CMU-UKA
CRAY T3E (Course)

Table 74 describes the fields in the display.


Table 74: Show IP SDR Field Descriptions
Field Description

SDR Cache - x entries

Number of entries (sessions) in the cache.

!Cannes Film Festsival

Name of session.

Related Commands

clear ip sdr
ip sdr cache-timeout
ip sdr listen

show isis database

To display the IS-IS link state database, use the show isis database EXEC command.

show isis database [level-1] [level-2] [l1] [l2] [detail] [lspid]
Syntax Description

level-1

(Optional) Displays the IS-IS link state database for Level  1.

level-2

(Optional) Displays the IS-IS link state database for Level  2.

l1

(Optional) Abbreviation for the option level-1.

l2

(Optional) Abbreviation for the option level-2.

detail

(Optional) When specified, the contents of each LSP is displayed. Otherwise, a summary display is provided.

lspid

(Optional) Link-state protocol ID. When specified, the contents of a single LSP is displayed by its ID number.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Each of the options shown in brackets for this command can be entered in an arbitrary string within the same command entry. For example, the following are both valid command specifications and provide the same output: show  isis  database  detail  l2 and show  isis  database  l2  detail.

Sample Display

The following is sample output from the show isis database command when it is specified with no options or as show  isis  database  l1  l2:

Router# show isis database
 
	IS-IS Level-1 Link State Database
	LSPID                 	LSP Seq Num	    LSP Checksum	  LSP Holdtime	  ATT/P/OL
	0000.0C00.0C35.00-00  	0x0000000C	     0x5696        	792	           0/0/0
	0000.0C00.40AF.00-00* 	0x00000009	     0x8452        	1077	          1/0/0
	0000.0C00.62E6.00-00  	0x0000000A	     0x38E7	        383	           0/0/0
	0000.0C00.62E6.03-00  	0x00000006     	0x82BC        	384	           0/0/0
	0800.2B16.24EA.00-00  	0x00001D9F	     0x8864	        1188	          1/0/0
	0800.2B16.24EA.01-00  	0x00001E36     	0x0935        	1198          	1/0/0
 
IS-IS Level-2 Link State Database
	LSPID	                 LSP Seq Num    	LSP Checksum	  LSP Holdtime	  ATT/P/OL
	0000.0C00.0C35.03-00  	0x00000005	     0x04C8	        792           	0/0/0
	0000.0C00.3E51.00-00	  0x00000007     	0xAF96        	758           	0/0/0
	0000.0C00.40AF.00-00* 	0x0000000A     	0x3AA9	        1077          	0/0/0
 

Table 75 describes significant fields shown in the display.


Table 75: Show IS-IS Database Field Descriptions
Field Description

LSPID

The link state PDU ID. The first six octets form the System ID. The next octet is the pseudo ID. When this value is zero, the LSP describes links from the system. When it is nonzero, the LSP is a pseudonode LSP. The designated router for an interface is the only system that originates pseudonode LSPs. The last octet is the LSP number. If there is more data than can fit in a single LSP, additional LSPs are sent with increasing LSP numbers. An asterisk (*) indicates that the LSP was originated by the local system.

LSP Seq Num

Sequence number for the LSP that allows other systems to determine if they have received the latest information from the source.

LSP Checksum

Checksum of the entire LSP packet.

LSP Holdtime

Amount of time the LSP remains valid, in seconds.

ATT

The Attach bit. This indicates that the router is also a Level 2 router, and it can reach other areas.

 P

The P bit. Detects if the IS is area partition repair capable.

 OL

The Overload bit. Determines if the IS is congested.

Sample Display Using Show IS-IS Database Detail

The following is sample output from the show isis database detail command.

Router# show isis database detail
 
IS-IS Level-1 Link State Database
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime  ATT/P/OL
0000.0C00.0C35.00-00  0x0000000C   0x5696        325           0/0/0
  Area Address: 47.0004.004D.0001
  Area Address: 39.0001
  Metric: 10   IS 0000.0C00.62E6.03
  Metric: 0    ES 0000.0C00.0C35
 --More--
0000.0C00.40AF.00-00* 0x00000009   0x8452        608           1/0/0
  Area Address: 47.0004.004D.0001
  Metric: 10   IS 0800.2B16.24EA.01
  Metric: 10   IS 0000.0C00.62E6.03
  Metric: 0    ES 0000.0C00.40AF
 
IS-IS Level-2 Link State Database
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime  ATT/P/OL
0000.0C00.0C35.03-00  0x00000005   0x04C8        317           0/0/0
  Metric: 0    IS 0000.0C00.0C35.00
 --More--
0000.0C00.3E51.00-00  0x00000009   0xAB98        1182          0/0/0
  Area Address: 39.0004
  Metric: 10   IS 0000.0C00.40AF.00
  Metric: 10   IS 0000.0C00.3E51.05
 

As the output shows, in addition to the information displayed with show isis database, the show isis database detail command displays the contents of each LSP.

Table 76 describes the fields shown in the display.


Table 76: Show IS-IS Database Detail Field Descriptions
Field Description

LSPID

The link state PDU ID. The first six octets form the System ID. The next octet is the pseudo ID. When this value is zero, the LSP describes links from the system. When it is nonzero, the LSP is a pseudonode LSP. The designated router for an interface is the only system that originates pseudonode LSPs. The last octet is the LSP number. If there is more data than can fit in a single LSP, additional LSPs are sent with increasing LSP numbers. An asterisk (*) indicates that the LSP was originated by the local system.

LSP Seq Num

Sequence number for the LSP that allows other systems to determine if they have received the latest information from the source.

LSP Checksum

Checksum of the entire LSP packet.

LSP Holdtime

Amount of time the LSP remains valid, in seconds.

ATT

The attach bit. This indicates that the router is also a Level 2 router, and it can reach other areas.

 P

The P bit. Detects if the IS is area partition-repair-capable.

 OL

The Overload bit. Determines if the IS is congested.

Area Address:

Reachable area addresses from the router.

Metric:

IS-IS metric for the route.

Sample Display Using Show IS-IS Database Detail Displaying IP Addresses

The following is additional sample output from the show isis database detail command.This is a Level 2 LSP. The area address 39.0001 is the address of the area in which the router resides.

Router# show isis database detail l2
 
IS-IS Level-2 Link State Database
LSPID                 LSP Seq Num  LSP Checksum  LSP Holdtime  ATT/P/OL
0000.0C00.1111.00-00* 0x00000006   0x4DB3        1194          0/0/0
  Area Address: 39.0001
  NLPID:       0x81 0xCC
  IP Address:  160.89.64.17
  Metric: 10   IS 0000.0C00.1111.09
  Metric: 10   IS 0000.0C00.1111.08
  Metric: 10   IP 160.89.65.0 255.255.255.0
  Metric: 10   IP 160.89.64.0 255.255.255.0
  Metric: 0    IP-External 10.0.0.0 255.0.0.0
 

Table 77 describes the fields shown in the display.


Table 77: Show IS-IS Database Detail Field Descriptions Displaying IP Addresses
Field Description

LSPID

The link state PDU ID. The first six octets form the System ID. The next octet is the pseudo ID. When this value is zero, the LSP describes links from the system. When it is nonzero, the LSP is a pseudonode LSP. The designated router for an interface is the only system that originates pseudonode LSPs. The last octet is the LSP number. If there is more data than can fit in a single LSP, additional LSPs are sent with increasing LSP numbers. An asterisk (*) indicates that the LSP was originated by the local system.

LSP Seq Num

Sequence number for the LSP that allows other systems to determine if they have received the latest information from the source.

LSP Checksum

Checksum of the entire LSP packet.

LSP Holdtime

Amount of time the LSP remains valid, in seconds.

ATT

The attach bit. This indicates that the router is also a Level 2 router, and it can reach other areas.

 P

The P bit. Detects if the IS is area partition repair capable.

 OL

The Overload bit. Determines if the IS is congested.

Area Address:

Reachable area addresses from the router.

NLPID

Indicates that both IP and OSI (0x0cc and 0x081 respectively) are supported in IS-IS for this router.

IP Address:

The IP address for the router is advertised in the LSP.

Metric:

IS-IS metric for the route.

   Various addresses

The "IP" entries are the directly connected IP subnets the router is advertising (with associated metrics). The "IP-External" is a redistribute route.

show key chain

To display authentication key information, use the show key chain EXEC command.

show key chain [name-of-chain]
Syntax Description

name-of-chain

(Optional) Name of the key chain to display, as named in the key chain command.

Default

Information about all key chains is displayed.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Sample Display

The following is sample output from the show key chain command:

Router# show key chain
Key-chain flintstone:
    key 1 -- text "fred"
        accept lifetime (always valid) - (always valid) [valid now]
        send lifetime (always valid) - (always valid) [valid now]
    key 2 -- text "barney"
        accept lifetime (00:00:00 Dec 5 1995) - (23:59:59 Dec 5 1995)
        send lifetime (06:00:00 Dec 5 1995) - (18:00:00 Dec 5 1995)
Related Commands

accept-lifetime
key
key chain
key-string
send-lifetime

show route-map

To display configured route-maps, use the show route-map EXEC command.

show route-map [map-name]
Syntax Description

map-name

(Optional) Name of a specific route-map.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Display

The following is sample output from the show route-map command:

Router# show route-map
 
route-map foo, permit, sequence 10
  Match clauses:
    tag 1 2
  Set clauses:
    metric 5
route-map foo, permit, sequence 20
  Match clauses:
    tag 3 4
  Set clauses:
    metric 6
 

Table 78 describes the fields shown in the display:


Table 78: Show Route-Map Field Descriptions
Field Description

route-map

Name of the route map.

permit

Indicates that the route is redistributed as controlled by the set actions.

sequence

Number that indicates the position a new route map is to have in the list of route maps already configured with the same name.

Match clauses
   tag

Match criteria---conditions under which redistribution is allowed for the current route map.

Set clauses
   metric

Set actions---the particular redistribution actions to perform if the criteria enforced by the match commands are met.

Related Commands

redistribute
route-map

summary-address

Use the summary-address router configuration command to create aggregate addresses for IS-IS or OSPF. The no summary-address command restores the default.

summary-address address mask {level-1 | level-1-2 | level-2} prefix mask [not-advertise]
[tag
tag]
no summary-address address mask {level-1 | level-1-2 | level-2}
Syntax Description

address

Summary address designated for a range of addresses.

mask

IP subnet mask used for the summary route.

level-1

Only routes redistributed into Level 1 are summarized with the configured address/mask value. This keyword applies to IS-IS only.

level-1-2

The summary router is injected into both a Level 1 area and a Level 2 subdomain. This keyword applies to IS-IS only.

level-2

Routes learned by Level 1 routing will be summarized into the Level 2 backbone with the configured address/mask value. This keyword applies to IS-IS only.

prefix

IP route prefix for the destination.

mask

IP subnet mask used for the summary route.

not-advertise

Used to suppress routes that match the prefix/mask pair. This keyword applies to OSPF only.

tag tag

(Optional) Tag value that can be used as a "match" value for controlling redistribution via route maps. This keyword applies to OSPF only.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Multiple groups of addresses can be summarized for a given level. Routes learned from other routing protocols can also be summarized. The metric used to advertise the summary is the smallest metric of all the more specific routes. This command helps reduce the size of the routing table.

Using this command for OSPF causes an OSPF autonomous system boundary router (ASBR) to advertise one external route as an aggregate for all redistributed routes that are covered by the address. For OSPF, this command summarizes only routes from other routing protocols that are being redistributed into OSPF. Use the area range command for route summarization between OSPF areas.

Example for IS-IS

In the following example, summary address 10.1.0.0 includes address 10.1.1, 10.1.2, 10.1.3, 10.1.4, and so forth. Only the address 10.1.0.0 is advertised in an IS-IS Level 1 Link State PDU.

summary-address 10.1.0.0 255.255.0.0 level-1
Example for OSPF

In the following example, summary address 10.1.0.0 includes address 10.1.1.0, 10.1.2.0, 10.1.3.0, and so forth. Only the address 10.1.0.0 is advertised in an external link state advertisement.

summary-address 10.1.0.0 255.255.0.0
Related Commands

area range
ip ospf authentication-key
ip ospf message-digest-key

synchronization

To enable the synchronization between BGP and your IGP, use the synchronization router configuration command. To enable the Cisco IOS software to advertise a network route without waiting for the IGP, use the no form of this command.

synchronization
no synchronization

Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Usually, a BGP speaker does not advertise a route to an external neighbor unless that route is local or exists in the IGP. The no synchronization command allows the Cisco IOS software to advertise a network route without waiting for the IGP. This feature allows routers and access servers within an autonomous system to have the route before BGP makes it available to other autonomous systems.

Use synchronization if there are routers in the autonomous system that do not speak BGP.

Example

The following example enables a router to advertise a network route without waiting for the IGP:

router bgp 120
no synchronization

table-map

To modify metric and tag values when the IP routing table is updated with BGP learned routes, use the table-map router configuration command. To disable this function, use the no form of the command.

table-map route-map-name
no table-map route-map-name
Syntax Description

route-map-name

Route-map name, from the route-map command.

Default

Disabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command adds the route-map name defined by the route-map command to the IP routing table. This command is used to set the tag name and the route metric to implement redistribution.

You can use match clauses of route maps in the table-map command. IP access list, autonomous system paths, and next-hop match clauses are supported.

Example

In the following example, the Cisco IOS software is configured to automatically compute the tag value for the BGP learned routes and to update the IP routing table.

route-map tag
match as path 10
set automatic-tag 
!
router bgp 100
table-map tag
Related Commands

match as-path
match ip address
match ip next-hop
route-map

timers basic (EGP, RIP, IGRP)

To adjust EGP, RIP, or IGRP network timers, use the timers basic router configuration command. To restore the default timers, use the no form of this command.

timers basic update invalid holddown flush [sleeptime]
no timers basic
Syntax Description

update

Rate in seconds at which updates are sent. This is the fundamental timing parameter of the routing protocol.

invalid

Interval of time in seconds after which a route is declared invalid; it should be at least three times the value of update. A route becomes invalid when there is an absence of updates that refresh the route. The route then enters holddown. The route is marked inaccessible and advertised as unreachable. However, the route is still used for forwarding packets.

holddown

Interval in seconds during which routing information regarding better paths is suppressed. It should be at least three times the value of update. A route enters into a holddown state when an update packet is received that indicates the route is unreachable. The route is marked inaccessible and advertised as unreachable. However, the route is still used for forwarding packets. When holddown expires, routes advertised by other sources are accepted and the route is no longer inaccessible.

flush

Amount of time in seconds that must pass before the route is removed from the routing table; the interval specified must be at least the sum of invalid and holddown. If it is less than this sum, the proper holddown interval cannot elapse, which results in a new route being accepted before the holddown interval expires.

sleeptime

(Optional) For IGRP only, interval in milliseconds for postponing routing updates in the event of a flash update. The sleeptime value should be less than the update time. If the sleeptime is greater than the update time, routing tables will become unsynchronized.

Defaults
Protocol update invalid holddown flush sleeptime

EGP

N/A

1080

N/A

1200

N/A

RIP

30

180

180

240

N/A

IGRP

90

270

280

630

0

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The basic timing parameters for IGRP, EGP, and RIP are adjustable. Since these routing protocols are executing a distributed, asynchronous routing algorithm, it is important that these timers be the same for all routers and access servers in the network.


Note The current and default timer values can be seen by inspecting the output of the show ip protocols EXEC command. The relationships of the various timers should be preserved as described previously.
Examples

In the following example, updates are broadcast every 5 seconds. If a router is not heard from in 15  seconds, the route is declared unusable. Further information is suppressed for an additional 15  seconds. At the end of the suppression period, the route is flushed from the routing table.

router igrp 109
 timers basic 5  15  15  30
 

Note that by setting a short update period, you run the risk of congesting slow-speed serial lines; however, this is not a big concern on faster-speed Ethernets and T1-rate serial lines. Also, if you have many routes in your updates, you can cause the routers to spend an excessive amount of time processing updates.

When the timers basic command is used with EGP, the update time and holddown time are ignored. For example, the commands that follow will set the invalid time for EGP to 100 seconds and the flush time to 200 seconds.

router egp 47
 timers basic 0 100 0 200

timers bgp

To adjust BGP network timers, use the timers bgp router configuration command. To reset the BGP timing defaults, use the no form of this command.

timers bgp keepalive holdtime
no timers bgp
Syntax Description

keepalive

Frequency, in seconds, with which the Cisco IOS software sends keepalive messages to its peer. The default is 60 seconds.

holdtime

Interval, in seconds, after not receiving a keepalive message that the software declares a peer dead. The default is 180  seconds.

Defaults

keepalive: 60 seconds
holdtime: 180 seconds

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example changes the keepalive timer to 70 seconds and the holdtime timer to 210  seconds:

timers bgp 70 210
Related Commands

clear ip bgp peer-group
router bgp
show ip bgp

timers egp

To adjust EGP hello and polltime network timers, use the timers egp router configuration command. The no form of this command resets the EGP timing defaults.

timers egp hello polltime
no timers egp
Syntax Description

hello

Frequency, in seconds, with which the software sends Hello messages to its peer. The default is 60 seconds.

polltime

Interval, in seconds, for how frequently to exchange updates. The default is 180 seconds.

Defaults

hello: 60 seconds
polltime: 180 seconds

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

To change the invalid time or flush time for EGP routes, use the timers basic router configuration command.

Example

The following example changes the EGP timers to 2 minutes and 5 minutes, respectively:

timers egp 120 300
Related Commands

router egp
show ip egp
timers basic (EGP, RIP, IGRP)

timers spf

To configure the delay time between when OSPF receives a topology change and when it starts a shortest path first (SPF) calculation, and the hold time between two consecutive SPF calculations, use the timers spf router configuration command. To return to the default timer values, use the no form of this command.

timers spf spf-delay spf-holdtime
no timers spf
spf-delay spf-holdtime

Syntax Description

spf-delay

Delay time, in seconds, between when OSPF receives a topology change and when it starts a SPF. calculation. It can be an integer from 0 to 65535. The default time is 5 seconds. A value of 0 means that there is no delay; that is, the SPF calculation is started immediately.

spf-holdtime

Minimum time, in seconds, between two consecutive SPF calculations. It can be an integer from 0 to 65535. The default time is 10 seconds. A value of 0 means that there is no delay; that is, two consecutive SPF calculations can be done one immediately after the other.

Defaults

spf-delay: 5 seconds
spf-holdtime: 10 seconds

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Setting the delay and hold time low causes routing to switch to the alternate path more quickly in the event of a failure. However, it consumes more CPU processing time.

Example

The following example changes the delay to 10 seconds and the hold time to 20 seconds:

timers spf 10 20

traffic-share

To control how traffic is distributed among routes when there are multiple routes for the same destination network that have different costs, use the traffic-share router configuration command. To disable this function, use the no form of the command.

traffic-share {balanced | min}
[no] traffic share {balanced | min}
Syntax Description

balanced

Distributes traffic proportionately to the ratios of the metrics.

min

Uses routes that have minimum costs.

Default

Traffic is distributed proportionately to the ratios of the metrics.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command applies to IGRP and Enhanced IGRP routing protocols only. With the default setting, routes that have higher metrics represent less-preferable routes and get less traffic. Configuring traffic-share min causes the Cisco IOS software to only divide traffic among the routes with the best metric. Other routes will remain in the routing table, but will receive no traffic.

Example

In the following example, only routes of minimum cost will be used:

router igrp 5
traffic-share min

validate-update-source

To have the Cisco IOS software validate the source IP address of incoming routing updates for RIP and IGRP routing protocols, use the validate-update-source router configuration command. To disable this function, use the no form of this command.

validate-update-source
no validate-update-source

Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command is only applicable to RIP and IGRP. The software ensures that the source IP address of incoming routing updates is on the same IP network as one of the addresses defined for the receiving interface.

Disabling split horizon on the incoming interface will also cause the system to perform this validation check.

For unnumbered IP interfaces (interfaces configured as ip unnumbered), no checking is performed.

Example

In the following example, a router is configured to not perform validation checks on the source IP address of incoming RIP updates:

router rip
network 128.105.0.0
no validate-update-source

variance

To control load balancing in an Enhanced IGRP-based internetwork, use the variance router configuration command. To reset the variance to the default value, use the no form of this command.

variance multiplier
no variance
Syntax Description

multiplier

Metric value used for load balancing. It can be a value from 1 to 128. The default is 1, which means equal-cost load balancing.

Default

1 (equal-cost load balancing)

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Setting a variance value lets the Cisco IOS software determine the feasibility of a potential route. A route is feasible if the next router in the path is closer to the destination than the current router and if the metric for the entire path is within the variance. Only paths that are feasible can be used for load balancing and included in the routing table.

If the following two conditions are met, the route is deemed feasible and can be added to the routing table:

    1. The local best metric must be greater than the metric learned from the next router.

    2. The multiplier times the local best metric for the destination must be greater than or equal to the metric through the next router.

Example

The following example sets a variance value of 4:

router igrp 109
variance 4

version

To specify a RIP version used globally by the router, use the version router configuration command. Use the no form of this command to restore the default value.

version {1 | 2}
no version
Syntax Description

1

Specifies RIP Version 1.

2

Specifies RIP Version 2.

Default

The software receives RIP Version 1 and Version 2 packets, but sends only Version 1 packets.

Command Mode

Router configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

To specify RIP versions used on an interface basis, use the ip rip receive version and ip rip send version commands.

Example

The following example enables the software to send and receive RIP Version 2 packets:

version 2
Related Commands

ip rip receive version
ip rip send version
show ip protocols


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Posted: Mon Feb 1 10:05:59 PST 1999
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