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Cisco IOS Switching Commands

Cisco IOS Switching Commands

This chapter documents commands used to configure switching features in Cisco  IOS software. For guidelines on configuring switching features, refer to the Cisco IOS Switching Services Configuration Guide.


Note Beginning with Cisco IOS Release 11.3, all commands supported on the Cisco 7500 series routers are also supported on Cisco 7000 series routers.

clear ip flow stats

To clear the NetFlow switching statistics, use the clear ip flow stats EXEC command.

clear ip flow stats

Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1 CA.

The show ip cache flow command displays the NetFlow switching statistics. Use the clear ip flow stats command to clear the NetFlow switching statistics.

Example

The following example clears the NetFlow switching statistics on the router:

clear ip flow stats

Related Commands

You can use the master indexes or search online to find documentation of related commands.

show ip cache

encapsulation isl

Use the encapsulation isl subinterface configuration command to enable the Inter-Switch Link  (ISL). ISL is a Cisco protocol for interconnecting multiple switches and routers, and for defining VLAN topologies.

encapsulation isl vlan-identifier

Syntax Description

vlan-identifier

Virtual LAN identifier. The allowed range is 1 to 1000.

Default

Disabled

Command Mode

Subinterface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

ISL encapsulation is configurable on Fast Ethernet interfaces.

ISL encapsulation adds a 26-byte header to the beginning of the Ethernet frame. The header contains a 10-bit VLAN identifier that conveys VLAN membership identities between switches.

Example

The following example enables ISL on Fast Ethernet subinterface 2/1.20:

interface FastEthernet 2/1.20 
  encapsulation isl 400

Related Commands

You can use the master indexes or search online to find documentation of related commands.

bridge-group
debug vlan
show bridge vlan
show interfaces

show vlans

encapsulation sde

Use the encapsulation sde subinterface configuration command to enable IEEE 802.10 encapsulation of traffic on a specified subinterface in virtual LANs. IEEE 802.10 is a standard protocol for interconnecting multiple switches and routers, and for defining VLAN topologies.

encapsulation sde said

Syntax Description

said

Security association identifier. This value is used as the virtual LAN identifier. The valid range is 0 through 0xFFFFFFFE.

Default

Disabled

Command Mode

Subinterface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

SDE encapsulation is configurable only on the following interface types:

IEEE 802.10 Routing IEEE 802.10 Transparent Bridging

  • FDDI

  • Ethernet

  • FDDI

  • HDLC Serial

  • Transparent mode

  • Token Ring

Example

The following example enables SDE on FDDI subinterface 2/0.1 and assigns a VLAN identifier of 9999:

interface fddi 2/0.1
  encapsulation sde 9999

Related Commands

You can use the master indexes or search online to find documentation of related commands.

bridge-group
debug vlans
show bridge vlan
show interfaces
show vlans

encapsulation tr-isl

Use the encapsulation tr-isl subinterface configuration command to enable TRISL, a Cisco proprietary protocol for interconnecting multiple routers and switches and maintaining VLAN information as traffic goes between switches.

encapsulation tr-isl trbrf-vlan vlan-id bridge-num bridge-number

Syntax Description

vlan-id

Number identifying the VLAN.

bridge-number

Keyword that specifies the identification number of the bridge number on the ISL trunk. Possible values are 01 to 4095.

Command Mode

Subinterface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.3(4)T.

Examples

In the following example, TRISL is enabled on a Fast Ethernet interface:

interface FastEthernet4/0.2
 encapsulation tr-isl trbrf-vlan 999 bridge-num 14

Related Commands

You can use the master indexes or search online to find documentation of related commands.

clear drip counters
clear vlan statistics
multiring
multiring trcrf-vlan
show drip
show vlan
source-bridge trcrf-vlan

ip cache-invalidate-delay

To control the invalidation rate of the IP route cache, use the ip cache-invalidate-delay global configuration command. To allow the IP route cache to be immediately invalidated, use the no form of this command.

ip cache-invalidate-delay [minimum maximum quiet threshold]
no
ip cache-invalidate-delay

Syntax Description

minimum

(Optional) Minimum time (in seconds) between invalidation request and actual invalidation. The default is 2 seconds.

maximum

(Optional) Maximum time (in seconds) between invalidation request and actual invalidation. The default is 5 seconds.

quiet

(Optional) Length of quiet period (in seconds) before invalidation.

threshold

(Optional) Maximum number of invalidation requests considered to be quiet.

Defaults

minimum = 2 seconds
maximum = 5 seconds, and 3 seconds with no more than zero invalidation requests

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

All cache invalidation requests are honored immediately.

This command should typically not be used except under the guidance of technical support personnel. Incorrect settings can seriously degrade network performance.

The IP fast-switching and autonomous-switching features maintain a cache of IP routes for rapid access. When a packet is to be forwarded and the corresponding route is not present in the cache, the packet is process-switched and a new cache entry is built. However, when routing table changes occur (such as when a link or an interface goes down), the route cache must be flushed so that it can be rebuilt with up-to-date routing information.

This command controls how the route cache is flushed. The intent is to delay invalidation of the cache until after routing has settled down. Because route table changes tend to be clustered in a short period of time, and the cache may be flushed repeatedly, a high CPU load might be placed on the router.

When this feature is enabled, and the system requests that the route cache be flushed, the request is held for at least minimum seconds. Then the system determines whether the cache has been "quiet" (that is, less than threshold invalidation requests in the last quiet seconds). If the cache has been quiet, the cache is then flushed. If the cache does not become quiet within maximum seconds after the first request, it is flushed unconditionally.

Manipulation of these parameters trades off CPU utilization versus route convergence time. Timing of the routing protocols is not affected, but removal of stale cache entries is affected.

Example

The following example sets a minimum delay of 5 seconds, a maximum delay of 30 seconds, and a quiet threshold of no more than 5 invalidation requests in the previous 10 seconds:

ip cache-invalidate-delay 5 30 10 5

Related Commands

You can use the master indexes or search online to find documentation of related commands.

ip route-cache
show ip cache

ip flow-cache entries

Use the ip flow-cache entries global configuration command to change the number of entries maintained in the NetFlow cache. Use the no form of this command to return to the default number of entries.

ip flow-cache entries number
no ip flow-cache entries

Syntax Description

number

Number of entries to maintain in the NetFlow cache. The valid range is 1024 to 524288 entries. The default is 65536 (64K).

Default

65536 entries (64K)

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1 CA.

Normally the default size of the NetFlow cache will meet your needs. However, you can increase or decrease the number of entries maintained in the cache to meet the needs of your flow traffic rates. For environments with a high amount of flow traffic (such as an internet core router), a larger value such as 131072 (128K) is recommended. To obtain information on your flow traffic, use the show ip cache flow command.

The default is 64K flow cache entries. Each cache entry is approximately 64 bytes of storage. Assuming a cache with the default number of entries, approximately 4MB of DRAM would be required. Each time a new flow is taken from the free flow queue, the number of free flows is checked. If there are only a few free flows remaining, NetFlow attempts to age 30 flows using an accelerated timeout. If there is only one free flow remaining, NetFlow automatically ages 30 flows regardless of their age. The intent is to ensure free flow entries are always available.

Caution Cisco recommends that you do not change the NetFlow cache entries. Improper use of this command could cause network problems. To return to the default NetFlow cache entries, use the no  ip  flow-cache entries global configuration command.

Example

The following example increases the number of entries in the NetFlow cache to 131072 (128K):

ip flow-cache entries 131072

Related Commands

You can use the master indexes or search online to find documentation of related commands.

show ip cache

ip flow-export

To enable the exporting of information in NetFlow cache entries, use the ip flow-export global configuration command. To disable the exporting of information, use the no form of this command.

ip flow-export ip-address udp-port [version 1 | version 5 [origin-as | peer-as]]
no ip flow-export

Syntax Description

ip-address

IP address of the workstation to which you want to send the NetFlow information.

udp-port

UDP protocol-specific port number.

version 1

(Optional) Specifies that the export packet uses the version 1 format. This is the default. The version field occupies the first two bytes of the export record. The number of records stored in the datagram is a variable between 1 and 24 for version 1.

version 5

(Optional) Specifies export packet uses the version 5 format. The number of records stored in the datagram is a variable between 1 and 30 for version 5.

origin-as

(Optional) Specifies that export statistics includes the origin autonomous system (AS) for the source and destination.

peer-as

(Optional) Specifies that export statistics includes the peer AS for the source and destination.

Default

Disabled

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

This command was modified to include the version keyword in Cisco IOS Release 11.1 CA.

There is a lot of information in a NetFlow cache entry. When flow switching is enabled with the ip  route-cache flow command, you can use the ip  flow-export command to configure the router to export the flow cache entry to a workstation when a flow expires. This feature can be useful for purposes of statistics, billing, and security.

Version 5 format includes the source and destination AS addresses, source and destination prefix masks, and a sequence number. Because this change may appear on your router as a maintenance release, support for version 1 format is maintained with the version 1 keyword.

For more information on version 1 and version 5 data format, refer to the "NetFlow Data Format" section in "Configuring NetFlow Switching" chapter of the Cisco IOS Switching Services Configuration Guide.

Examples

The following example configures the router to export the NetFlow cache entry to UDP port 125 on the workstation at 134.22.23.7 when the flow expires using version 1 format:

ip flow-export 134.22.23.7 125

The following example configures the router to export the NetFlow cache entry to UDP port 2048 on the workstation at 134.22.23.7 when the flow expires using version 5 format and including the peer AS information:

ip flow-export 134.22.23.7 2048 version 5 peer-as

Related Command

You can use the master indexes or search online to find documentation of related commands.

ip route-cache flow

ip route-cache

Use the ip route-cache interface configuration command to control the use of high-speed switching caches for IP routing. To disable any of these switching modes, use the no form of this command.

ip route-cache [cbus]
no ip route-cache [cbus]
ip route-cache same-interface
no ip route-cache same-interface

ip route-cache [flow]
no ip route-cache [flow]
ip route-cache distributed
no ip route-cache distributed

Syntax Description

cbus

(Optional) Enables both autonomous switching and fast switching.

same-interface

Enables fast-switching packets back out the interface on which they arrived.

flow

(Optional) Enables the RSP to perform flow switching on the interface.

distributed

Enables VIP distributed switching on the interface. This feature can be enabled on Cisco 7500 series routers with an RSP and Versatile Interface Processor (VIP) controllers. If both ip  route-cache flow and ip route-cache distributed are configured, the VIP does distributed flow switching. If only ip route-cache distributed is configured, the VIP does distribswitching.

Defaults

IP autonomous switching is disabled.
Fast switching varies by interface and media.
Distributed switching is disabled.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The distributed keyword first appeared in Cisco IOS Release 11.2.

Using the route cache is often called fast switching. The route cache allows outgoing packets to be load-balanced on a per-destination basis.

The ip route-cache command with no additional keywords enables fast switching.

Our routers generally offer better packet transfer performance when fast switching is enabled, with one exception. On networks using slow serial links (64K and below), disabling fast switching to enable the per-packet load sharing is usually the best choice.

You can enable IP fast switching when the input and output interfaces are the same interface, using the ip route-cache same-interface command. This normally is not recommended, though it is useful when you have partially meshed media, such as Frame Relay. You could use this feature on other interfaces, although it is not recommended because it would interfere with redirection.

When the Route Switch Processor (RSP) is flow switching, it uses a flow cache instead of a destination network cache to switch IP packets. The flow cache uses source and destination network address, protocol, and source and destination port numbers to distinguish entries.

The flow caching option can also be used to allow statistics to be gathered with a finer granularity. The statistics include IP subprotocols, well-known ports, total flows, average number of packets per flow, and average flow lifetime.

On Cisco 7500 series routers with RSP and Versatile Interface Processor (VIP) controllers, the VIP hardware can be configured to switch packets received by the VIP with no per-packet intervention on the part of the RSP. When VIP distributed switching is enabled, the input VIP interface tries to switch IP packets instead of forwarding them to the RSP for switching. Distributed switching helps decrease the demand on the RSP.

Not all switching methods are available on all platforms. Refer to the Cisco Product Catalog for information about features available on the platform you are using.

Examples

The following example enables both fast switching and autonomous switching:

ip route-cache cbus

The following example disables both fast switching and autonomous switching:

no ip route-cache

The following example turns off autonomous switching only:

no ip route-cache cbus

The following example enables VIP distributed flow switching on the interface:

interface ethernet 0/5/0
  ip address 17.252.245.2 255.255.255.0
  ip route-cache distributed
  ip route-cache flow

The following example returns the system to its defaults (fast switching enabled; autonomous switching disabled):

ip route-cache

Related Commands

You can use the master indexes or search online to find documentation of related commands.

ip cache-invalidate-delay
show ip cache

ip route-cache flow

To enable NetFlow switching for IP routing, use the ip route-cache flow interface configuration command. To disable NetFlow switching, use the no form of this command.

ip route-cache flow
no ip route-cache flow

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.

NetFlow switching is a high-performance, network-layer switching path that captures as part of its switching function a rich set of traffic statistics. These traffic statistics include user, protocol, port, and type of service information that can be used for a wide variety of purposes such as network analysis and planning, accounting, and billing. To export NetFlow data, use the ip flow-export global configuration command.

NetFlow switching is supported on IP and IP encapsulated traffic over all interface types and encapsulations except for ISL/VLAN, ATM and Frame Relay interfaces when more than one input access control list is used on the interface, and ATM LANE.

In conventional switching at the network layer, each incoming packet is handled on an individual basis with a series of functions to perform access list checks, capture accounting data, and switch the packet. With NetFlow switching, after a flow has been identified and access list processing of the first packet in the flow has been performed, all subsequent packets are handled on a "connection-oriented" basis as part of the flow, where access list checks are bypassed and packet switching and statistics capture are performed in tandem.

A network flow is identified as a unidirectional stream of packets between a source and destination---both defined by a network-layer IP address and transport-layer port number. Specifically, a flow is identified as the combination of the following fields:

  • source IP address

  • destination IP address

  • source port number

  • destination port number

  • protocol type

  • type of service

  • input interface

NetFlow switching operates by creating a flow cache that contains the information needed to switch and perform access list check for all active flows. The NetFlow cache is built by processing the first packet of a flow through the standard fast switching path. As a result, each flow is associated with an incoming and outgoing interface port number and with a specific security access permission and encryption policy. The cache also includes entries for traffic statistics that are updated in tandem with the switching of subsequent packets. After the NetFlow cache is created, packets identified as belonging to an existing flow can be switched based on the cached information and security access list checks bypassed. Flow information is maintained within the NetFlow cache for all active flows.

NetFlow switching is one of the available switching modes. When you configure NetFlow on an interface, the other switching modes are not used on that interface. Also, with NetFlow switching you can export data (traffic statistics) to a remote workstation for further processing.

NetFlow switching is based on identifying packet flows and performing switching and access list processing within a router. It does not involve any connection-setup protocol either between routers or to any other networking device or end station and does not require any change externally---either to the traffic or packets themselves or to any other networking device. Thus, NetFlow switching is completely transparent to the existing network, including end stations and application software and network devices like LAN switches. Also, because NetFlow switching is performed independently on each internetworking device, it does not need to be operational on each router in the network. Network planners can selectively invoke NetFlow switching (and NetFlow data export) on a router/interface basis to gain traffic performance, control, or accounting benefits in specific network locations.


Note NetFlow does consume additional memory and CPU resources compared to other switching modes; therefore, it is important to understand the resources required on your router before enabling NetFlow.

Examples

The following example enables NetFlow switching on the interface:

interface ethernet 0/5/0
  ip address 17.252.245.2 255.255.255.0
  ip route-cache flow

The following example returns the interface to its defaults (fast switching enabled; autonomous switching disabled):

interface ethernet 0/5/0
  ip route-cache

Related Commands

You can use the master indexes or search online to find documentation of related commands.

ip flow-export
show ip cache

show ip cache

To display the routing table cache used to fast switch IP traffic, use the show ip cache EXEC command.

show ip cache [prefix mask] [type number]

Syntax Description

prefix

(Optional) Display only the entries in the cache that match the prefix and mask combination.

mask

(Optional) Display only the entries in the cache that match the prefix and mask combination.

type

(Optional) Display only the entries in the cache that match the interface type and number combination.

number

(Optional) Display only the entries in the cache that match the interface type and number combination.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. The arguments prefix, mask, type, and number first appeared in Cisco IOS Release 10.0. The show ip cache display shows MAC headers up to 92 bytes.

Sample Displays

The following is sample output from the show ip cache command:

Router# show ip cache
IP routing cache version 4490, 141 entries, 20772 bytes, 0 hash overflows
Minimum invalidation interval 2 seconds, maximum interval 5 seconds,
   quiet interval 3 seconds, threshold 0 requests
Invalidation rate 0 in last 7 seconds, 0 in last 3 seconds
Last full cache invalidation occurred 0:06:31 ago
Prefix/Length       Age       Interface       MAC Header
131.108.1.1/32      0:01:09   Ethernet0/0     AA000400013400000C0357430800
131.108.1.7/32      0:04:32   Ethernet0/0     00000C01281200000C0357430800
131.108.1.12/32     0:02:53   Ethernet0/0     00000C029FD000000C0357430800
131.108.2.13/32     0:06:22   Fddi2/0         00000C05A3E000000C035753AAAA0300
                                              00000800
131.108.2.160/32    0:06:12   Fddi2/0         00000C05A3E000000C035753AAAA0300
                                              00000800
131.108.3.0/24      0:00:21   Ethernet1/2     00000C026BC600000C03574D0800
131.108.4.0/24      0:02:00   Ethernet1/2     00000C026BC600000C03574D0800
131.108.5.0/24      0:00:00   Ethernet1/2     00000C04520800000C03574D0800
131.108.10.15/32    0:05:17   Ethernet0/2     00000C025FF500000C0357450800
131.108.11.7/32     0:04:08   Ethernet1/2     00000C010E3A00000C03574D0800
131.108.11.12/32    0:05:10   Ethernet0/0     00000C01281200000C0357430800
131.108.11.57/32    0:06:29   Ethernet0/0     00000C01281200000C0357430800

Table 3 describes significant fields shown in the display.


Table 3:
Field Description

IP routing cache version

Version number of this table. This number is incremented any time the table is flushed.

entries

Number of valid entries.

bytes

Number of bytes of processor memory for valid entries.

hash overflows

Number of times autonomous switching cache overflowed.

Minimum invalidation interval

Minimum time delay between cache invalidation request and actual invalidation.

maximum interval

Maximum time delay between cache invalidation request and actual invalidation.

quiet interval

Length of time between cache flush requests before the cache will be flushed.

threshold n requests

Maximum number of requests that can occur while the cache is considered quiet.

Invalidation rate n in last m seconds

Number of cache invalidations during the last m seconds.

0 in last 3 seconds

Number of cache invalidation requests during the last quiet interval.

Last full cache invalidation occurred hh:mm:ss ago

Time since last full cache invalidation was performed.

Prefix/Length

Network reachability information for cache entry.

Age

Age of cache entry.

Interface

Output interface type and number.

MAC Header

Layer 2 encapsulation information for cache entry.

Show IP Cache Field Descriptions

The following is sample output from the show ip cache command with a prefix and mask specified:

Router# show ip cache 131.108.5.0 255.255.255.0
IP routing cache version 4490, 119 entries, 17464 bytes, 0 hash overflows
Minimum invalidation interval 2 seconds, maximum interval 5 seconds,
   quiet interval 3 seconds, threshold 0 requests
Invalidation rate 0 in last second, 0 in last 3 seconds
Last full cache invalidation occurred 0:11:56 ago
Prefix/Length       Age       Interface       MAC Header
131.108.5.0/24      0:00:34   Ethernet1/2     00000C04520800000C03574D0800

The following is sample output from the show ip cache command with an interface specified:

Router# show ip cache e0/2
IP routing cache version 4490, 141 entries, 20772 bytes, 0 hash overflows
Minimum invalidation interval 2 seconds, maximum interval 5 seconds,
   quiet interval 3 seconds, threshold 0 requests
Invalidation rate 0 in last second, 0 in last 3 seconds
Last full cache invalidation occurred 0:06:31 ago
Prefix/Length       Age       Interface       MAC Header
131.108.10.15/32    0:05:17   Ethernet0/2     00000C025FF500000C0357450800

show ip cache flow

To display a summary of the NetFlow switching statistics, use the show ip cache flow EXEC command.

show ip cache flow

Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

This command was modified to update the display with the latest information in Cisco IOS Release  11.1 CA.

Sample Display

The following is a sample output from the show ip cache flow command.

Router# show ip cache flow
IP packet size distribution (12718M total packets):
   1-32   64   96  128  160  192  224  256  288  320  352  384  416  448  480
     .000  .554  .042  .017  .015  .009  .009  .009  .013  .030  .006  .007  .005  .004  .004
    512  544  576 1024 1536 2048 2560 3072 3584 4096 4608
      .003  .007  .139  .019  .098  .000  .000  .000  .000  .000  .000
IP Flow Switching Cache, 4456448 bytes
  65509 active, 27 inactive, 820628747 added
  955454490 ager polls, 0 flow alloc failures
  Exporting flows to 1.1.15.1 (2057)
  820563238 flows exported in 34485239 udp datagrams, 0 failed
  last clearing of statistics 00:00:03
Protocol         Total  Flows   Packets Bytes  Packets Active(Sec) Idle(Sec)
--------         Flows   /Sec     /Flow  /Pkt     /Sec     /Flow     /Flow
TCP-Telnet     2656855    4.3        86    78    372.3      49.6      27.6
TCP-FTP        5900082    9.5         9    71     86.8      11.4      33.1
TCP-FTPD       3200453    5.1       193   461   1006.3      45.8      33.4
TCP-WWW      546778274  887.3        12   325  11170.8       8.0      32.3
TCP-SMTP      25536863   41.4        21   283    876.5      10.9      31.3
TCP-X           116391    0.1       231   269     43.8      68.2      27.3
TCP-BGP          24520    0.0        28   216      1.1      26.2      39.0
TCP-Frag         56847    0.0        24   952      2.2      13.1      33.2
TCP-other     49148540   79.7        47   338   3752.6      30.7      32.2
UDP-DNS      117240379  190.2         3   112    570.8       7.5      34.7
UDP-NTP        9378269   15.2         1    76     16.2       2.2      38.7
UDP-TFTP          8077    0.0         3    62      0.0       9.7      33.2
UDP-Frag         51161    0.0        14   322      1.2      11.0      39.4
UDP-other     45502422   73.8        30   174   2272.7       8.5      37.8
ICMP          14837957   24.0         5   224    125.8      12.1      34.3
IGMP             40916    0.0       170   207     11.3     197.3      13.5
IPINIP            3988    0.0     48713   393    315.2     644.2      19.6
GRE               3838    0.0        79   101      0.4      47.3      25.9
IP-other         77406    0.1        47   259      5.9      52.4      27.0
Total:       820563238 1331.7        15   304  20633.0       9.8      33.0
SrcIf    SrcIPaddress    DstIf    DstIPaddress    Pr SrcP DstP Pkts B/Pk Active
Fd0/0        80.0.0.3                Hs1/0        200.1.9.1              06 0621 0052        7      87        5.9
Fd0/0        80.0.0.3                Hs1/0        200.1.8.1              06 0620 0052        7      87        1.8
Hs1/0        200.0.0.3              Fd0/0        80.1.10.1              06 0052 0621        6      58        1.8
Hs1/0        200.0.0.3              Fd0/0        80.1.1.1                06 0052 0620        5      62        5.9
Fd0/0        80.0.0.3                Hs1/0        200.1.3.1              06 0723 0052      16      68        0.3
HS1/0        200.0.0.3              Fd0/0        80.1.2.1                06 0052 0726        6      58      11.8
Fd0/0        80.0.0.3                Hs1/0        200.1.5.1              06 0726 0052        6      96        0.3
Hs1/0        200.0.0.3              Fd0/0        80.1.4.1                06 0052 0442        3      76        0.3
Hs1/0        200.0.0.3              Fd0/0        80.1.7.1                06 0052 D381      11  1171        0.6

Table 4 describes the fields in the packet size distribution lines of the output.


Table 4:
Field Description

IP packet size distribution

The two lines below this banner show the percentage distribution of packets by size range. In this display, 55.4% of the packets fall in the size range 33 to 64 bytes.

Packet Size Distribution Field Descriptions

Table 5 describes the fields in the flow switching cache lines of the output.


Table 5:
Field Description

bytes

Number of of bytes of memory the NetFlow cache uses,

active

Number of active flows in the NetFlow cache at the time this command was entered.

inactive

Number of flow buffers allocated in the NetFlow cache, but are not currently assigned to a specific flow at the time this command was entered.

added

Number of flows created since the start of the summary period.

ager polls

Number of times the NetFlow code looked at the cache to expire entries (used by Cisco for diagnostics only).

flow alloc failures

Number of times the NetFlow code tried to allocate a flow but could not.

Exporting flows

IP address and UDP port number of the workstation to which flows are exported.

flows exported in udp datagrams

Total number of flows exported and the total number of UDP datagrams used to export the flows to the workstation.

failed

Number of flows that could not be exported by the router because of output interface limitations.

last clearing of statistics

Standard time output (hh:mm:ss) since the clear ip flow stats command was executed. This time output changes to hours and days after the time exceed 24  hours

Flow Switching Cache Display Field Descriptions

Table 6 describes the fields in the activity-by-protocol lines of the output.


Table 6:
Field Description

Protocol

IP protocol and the "well known" port number as described in RFC 1340.

Total Flows

Number of flows for this protocol since the last time statistics were cleared.

Flows/Sec

Average number of flows for this protocol seen per second; equal to total flows/number of seconds for this summary period.

Packets/Flow

Average number of packets observed for the flows seen for this protocol. Equal to Total Packets for this protocol or number of flows for this protocol for this summary period.

Bytes/Pkt

Average number of bytes observed for the packets seen for this protocol (total bytes for this protocol or the total number of packet for this protocol for this summary period).

Packets/Sec

Average number of packets for this protocol per second (total packets for this protocol) or the total number of seconds for this summary period).

Active(Sec)/Flow

Sum of all the seconds from the first packet to the last packet of an expired flow (for example, TCP FIN, time-out, and so forth) in seconds or total flows for this protocol for this summary period.

Idle(Sec)/Flow

Sum of all the seconds from the last packet seen in each nonexpired flow for this protocol until the time this command was entered, in seconds or total flows for this protocol for this summary period.

Activity-By-Protocol Display Field Descriptions

Table 7 describes the fields in the current flow lines of the output.


Table 7:
Field Description

SrcIf

Internal port name for the source interface.

SrcIPaddress

Source IP address for this flow.

DstIf

Router's internal port name for the destination interface.

DstIPaddress

Destination IP address for this flow.

Pr

IP protocol; for example, 6=TCP, 17=UDP, . as defined in RFC 1340.

SrcP

Source port address, TCP/UDP "well known" port number, as defined in RFC  1340.

DstP

Destination port address, TCP/UDP "well known" port number, as defined in RFC  1340.

Pkts

Number of packets observed for this flow.

B/Pkt

Average observed number of bytes per packet for this flow.

Active

Number of seconds between first and last packet of a flow.

Current Flow Display Field Descriptions

Related Commands

You can use the master indexes or search online to find documentation of related commands.

ip route-cache
clear ip flow stats


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