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Table of Contents

Interface Commands

Interface Commands

This chapter contains the commands used to configure interface features that are not protocol-specific. For hardware technical descriptions, and for information about installing the router or access server interfaces, refer to the hardware installation and maintenance publication for your particular product.

For interface configuration tasks and examples, refer to the chapter entitled "Configuring Interfaces" in the Configuration Fundamentals Configuration Guide.

For information about the Channel Interface Processor (CIP), see the chapter entitled "IBM Channel Attach Commands" chapter in the Bridging and IBM Networking Command Reference. The CIP is described in a separate chapter because of the interrelationship of host system configuration values and device configuration values.


Note Some commands previously documented in this chapter have been replaced by new commands. Although they continue to perform their normal functions in the current release, support for these commands will cease in a future release.

access-list (standard)

Use the access-list global configuration command to establish MAC address access lists. Use the no form of this command to remove a single access list entry.

access-list access-list-number {permit | deny} address mask
no access-list access-list-number

Syntax Description
access-list-number Integer from 700 to 799 that you select for the list.
permit Permits the frame.
deny Denies the frame.
address mask 48-bit MAC addresses written in dotted triplet form. The ones bits in the mask argument are the bits to be ignored in the address value.
Default

No MAC address access lists are established.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Related Command

access-list (type-code)

access-list (type-code)

Use the access-list global configuration command to build type-code access lists. Use the no form of this command to remove a single access list entry.

access-list access-list-number {permit | deny} type-code wild-mask
no access-list access-list-number

Syntax Description
access-list-number User-selectable number between 200 and 299 that identifies the list.
permit Permits the frame.
deny Denies the frame.
type-code 16-bit hexadecimal number written with a leading "0x"; for example, 0x6000. You can specify either an Ethernet type code for Ethernet-encapsulated packets, or a DSAP/SSAP pair for 802.3 or 802.5-encapsulated packets. Ethernet type codes are listed in the appendix "Ethernet Type Codes."
wild-mask 16-bit hexadecimal number whose ones bits correspond to bits in the type-code argument that should be ignored when making a comparison. (A mask for a DSAP/SSAP pair should always be at least 0x0101. This is because these two bits are used for purposes other than identifying the SAP codes.)
Default

No type-code access lists are built.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Type-code access lists can have an impact on system performance; therefore, keep the lists as short as possible and use wildcard bit masks whenever possible.

Access lists are evaluated according to the following algorithm:

If the length/type field is greater than 1500, the packet is treated as an LSAP packet unless the DSAP and SSAP fields are AAAA. If the latter is true, the packet is treated using type-code filtering.

If you have both Ethernet Type II and LSAP packets on your network, you should set up access lists for both.

Use the last item of an access list to specify a default action; for example, permit everything else or deny everything else. If nothing else in the access list matches, the default action is normally to deny access; that is, filter out all other type codes.

Related Commands

access-list (extended)
access-list (standard)

async default ip address

The peer default ip address command replaces the async default ip address command. Refer to the description of the peer default ip address command for more information.

async default routing

To enable the router to pass routing updates to other routers over the AUX port configured as an asynchronous interface, use the async default routing interface configuration command.

async default routing
Syntax Description

This command has no keywords or arguments.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use the async default routing command to define the default behavior for router-to-router communication over connections to the AUX port configured as an asynchronous interface.

To require a remote user to manually configure routing over connections to the AUX port configured as an asynchronous interface, use the async dynamic routing command.

Example

The following example enables routing over asynchronous interface 0:

interface async 0
async default routing
Related Command

async dynamic routing

async dynamic address

To specify an address on an asynchronous interface (rather than using the default address), use the async dynamic address interface configuration command. Use the no form of this command to disable dynamic addressing.

async dynamic address
no async dynamic address

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 10.0.

Example

The following example shows dynamic addressing assigned to an interface:

interface async 1
async dynamic address
Related Commands

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

ppp +
slip

async dynamic routing

To enable manually configured routing on an asynchronous interface, use the async dynamic routing interface configuration command. Use the no form of this command to disable routing protocols; static routing is still used.

async dynamic routing
no async dynamic 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 10.0.

Example

The following example shows how to enable manually configured routing on asynchronous interface 1. The ip tcp header-compression passive command enables Van Jacobson TCP header compression and prevents transmission of compressed packets until a compressed packet arrives from the asynchronous link.

interface async 1
async dynamic routing
async dynamic address
async default ip address 1.1.1.2
ip tcp header-compression passive

A remote user who establishes a PPP or SLIP connection to this asynchronous interface can enable routing by using the /routing switch or the ppp/routing command.

However, if you want to establish routing by default on connections to an asynchronous interface, use the async default routing command when you configure the interface.

Related Commands

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

async default routing
async dynamic address
ip tcp header-compression
+

async mode dedicated

To place a line into network mode using SLIP or PPP encapsulation, use the async mode dedicated interface configuration command. Use the no form of this command to return the line to interactive mode.

async mode dedicated
no async 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 10.0.

With dedicated asynchronous mode, the interface will use either SLIP or PPP encapsulation, depending on which encapsulation method is configured for the interface. An EXEC prompt does not appear, and the line is not available for normal interactive use.

If you configure a line for dedicated mode, you will not be able to use async dynamic address, because there is no user prompt. You must configure either async default ip address and ip unnumbered or ip address.

Example

The following example assigns an Internet address to an asynchronous line and places the line into network mode. Setting the stop bits to 1 enhances performance.

interface async 1
async default ip address 182.32.7.51
async mode dedicated
encapsulation slip
Related Command

async mode interactive

async mode interactive

To enable the use of slip and ppp EXEC commands, use the async mode interactive line configuration command. Use the no form of this command to prevent users from enabling SLIP and PPP at the EXEC level.

async mode interactive
no async 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 10.0.

Example

The following example enables the ppp and slip EXEC commands:

interface async 1
async mode interactive
Related Commands

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

async mode dedicated
ppp
+
slip +

auto-polarity

To enable automatic receiver polarity reversal on a hub port connected to an Ethernet interface of a Cisco 2505 or Cisco 2507, use the auto-polarity hub configuration command. To disable this feature, use the no form of this command.

auto-polarity
no auto-polarity

Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Hub configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to a port on an Ethernet hub only.

Example

The following example enables automatic receiver polarity reversal on hub 0, ports 1 through 3:

hub ethernet 0 1 3
auto-polarity
Related Command

hub

backup delay

To define how much time should elapse before a secondary line status changes after a primary line status has changed, use the backup delay interface configuration command. To return to the default, so that as soon as the primary fails, the secondary is immediately brought up without delay, use the no form of this command.

backup delay {enable-delay | never} {disable-delay | never}
no backup delay {enable-delay | never} {disable-delay | never}

Syntax Description
enable-delay Integer that specifies the delay in seconds after the primary line goes down before the Cisco IOS software activates the secondary line.
disable-delay Integer that specifies the delay in seconds after the primary line comes up before the Cisco IOS software deactivates the secondary line.
never Prevents the secondary line from being activated or deactivated.
Default

0 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When a primary line goes down, the Cisco IOS software delays the amount of seconds defined by the enable-delay argument before enabling the secondary line. If, after the delay period, the primary line is still down, the secondary line is activated.

When a primary line comes back up, the software will delay the amount of seconds defined by the disable-delay argument.


Note In cases where spurious signal disruptions might appear as intermittent lost carrier signals, it is recommended that some delay be enabled before activating and deactivating a secondary.

The interval configured with the backup delay command does not affect the operation of the backup load command.
Examples

The following example sets a 10-second delay on deactivating the secondary line; however, the line is activated immediately:

interface serial 0
backup delay 0 10

The same example on the Cisco 7000 requires the following commands:

interface serial 1/1
backup delay 0 10

backup interface serial

To configure the serial interface as a secondary, or dial backup line, use the backup interface serial interface configuration command. Use the no form of this command to turn disable this feature.

backup interface serial number
backup interface serial slot/port  (for the Cisco 7000 series and 7200 series)
no backup interface serial number
no backup interface serial slot/port  (for the Cisco 7000 series and 7200 series)

Syntax Description
number Number of the serial port to be set as the secondary, or dial backup, interface line.
slot On the Cisco 7000 series and 7200 series, specifies the slot number.
port On the Cisco 7000 series and 7200 series, specifies the port number.
Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0. (An earlier command, backup interface, first appeared in Cisco IOS Release 10.0.)

Examples

The following example sets serial 1 as the backup line to serial 0:

interface serial 0
backup interface serial 1

The following example on the Cisco 7000 sets serial 2 as the backup line to serial 1:

interface serial 1/1
backup interface serial 2/2
Related Command

down-when-looped

backup load

To set the traffic load thresholds for dial backup service, use the backup load interface configuration command. Use the no form of this command to remove the setting.

backup load {enable-threshold | never} {disable-load | never}
no backup load {
enable-threshold | never} {disable-load | never}
Syntax Description
enable-threshold Integer that specifies a percentage of the primary line's available bandwidth.
never Specifies that the secondary line never be activated due to load.
disable-load Integer that specifies a percentage of the primary line's available bandwidth.
never Specifies that the secondary line never be deactivated due to load.
Default

Both arguments default to never.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When the transmitted or received load on the primary line is greater than the value assigned to the enable-threshold argument, the secondary line is enabled.

When the transmitted load on the primary line plus the transmitted load on the secondary line is less than the value entered for the disable-load argument, and the received load on the primary line plus the received load on the secondary line is less than the value entered for the disable-load argument, the secondary line is disabled.

If the never keyword is used instead of an enable-threshold value, the secondary line is never activated because of load. If the never keyword is used instead of a disable-load value, the secondary line is never deactivated because of load.

Examples

The following example sets the traffic load threshold to 60 percent on the primary line. When that load is exceeded, the secondary line is activated, and will not be deactivated until the combined load is less than 5 percent of the primary bandwidth.

interface serial 0
backup load 60 5

The same example on the Cisco 7000 requires the following commands:

interface serial 1/1
backup load 60 5

bandwidth

To set a bandwidth value for an interface, use the bandwidth interface configuration command. Use the no form of this command to restore the default values.

bandwidth kilobits
no bandwidth

Syntax Description
kilobits Intended bandwidth in kilobits per second. For a full bandwidth DS3, enter the value 44736.
Default

Default bandwidth values are set during startup and can be displayed with the EXEC command show interfaces.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The bandwidth command sets an informational parameter only; you cannot adjust the actual bandwidth of an interface with this command. For some media, such as Ethernet, the bandwidth is fixed; for other media, such as serial lines, you can change the actual bandwidth by adjusting hardware. For both classes of media, you can use the bandwidth configuration command to communicate the current bandwidth to the higher-level protocols.

Additionally, IGRP uses the minimum path bandwidth to determine a routing metric. The TCP protocol adjusts initial retransmission parameters based on the apparent bandwidth of the outgoing interface.

At higher bandwidths, the value you configure with the bandwidth command is not what is displayed by the show interface command. The value shown is that used in IGRP updates and also used in computing load.


Note This is a routing parameter only; it does not affect the physical interface.
Example

The following example sets the full bandwidth for DS3 transmissions:

interface serial 0
bandwidth 44736
Related Command

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

vines metric +

cablelength

To increase the pulse of a signal at the receiver and decrease the pulse from the transmitter using pulse equalization and line build-out for a T1 cable on a Cisco AS5200, use the cablelength controller configuration command. To return the pulse equalization and line build-out values to their default settings, use the no form of this command.

cablelength long dbgain-value dbloss-value
no cablelength long

Syntax Description
long Specifies a long cable length for channel service unit (CSU) connections.
dbgain-value Number of decibels by which the receiver signal is increased. Use the keyword gain26 or gain36 to specify this value. Default is gain36.
dbloss-value Number of decibels by which the receiver signal is decreased. Use one of the following keywords to specify this value:

  • 0db

  • -7.5db

  • -15db

  • -22.5db

Default is 0db.

Default

Long cable length, receiver gain of 36 dB, and transmitter loss of 0 dB

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command for configuring the T1 controller only if the Cisco AS5200's T1 line does not connect to an external CSU box. Ask your telephone service provider what decibel option to use when connecting the T1 line to a smart jack.

A pulse equalizer regenerates a signal that has been attenuated and filtered by a cable loss. Pulse equalization does not produce a simple gain, but it filters the signal to compensate for complex cable loss. A gain26 receiver gain compensates for a long cable length equivalent to 26 dB of loss, while a gain36 compensates for 36 dB of loss.

The lengthening or building out of a line is used to control far-end crosstalk. Building out attenuates the stronger signal from the customer installation transmitter so that the transmitting and receiving signals have similar amplitudes. A signal difference of less than 7.5 dB is ideal. Building out does not produce simple flat loss (also known as resistive flat loss). Instead, it simulates a cable loss of 7.5 dB, 15 dB, or 22.5 dB so that the resulting signal is handled properly by the receiving equalizer at the other end.

Example

The following example increases the receiver gain by 26 decibels and decreases the transmitting pulse by 7.5 decibels for a long cable:

cablelength long gain26 -7.5db

cas-group

To configure channelized T1 timeslots with channel associated signaling (also known as robbed bit signaling), which enables an integrated modem to receive and transmit analog calls, use the cas-group controller configuration command. Use the no form of this command to disable channel associated signaling for one or more timeslots.

cas-group channel-group [timeslots range]
no cas-group channel-group [timeslots range]

Syntax Description
channel-group Channel group number; the value can be between 0 and 23.
timeslots range (Optional) Specifies a range of timeslot values from 1 to 24. The default value configures all 24 timeslots with the channel associated signal called E&M (Ear and Mouth), which is the default signal type.
Default

Disabled

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command to enable an AS5200 modem to receive and send incoming and outgoing analog calls through each T1 controller that is configured for a channelized T1 line, which has 24 possible channels.

Switched 56 digital calls are not supported under this new feature.

Example

The following example shows you how to configure all 24 channels to support robbed bit signaling on a Cisco AS5200:

AS5200(config)# controller T1 0
AS5200(config-controller)# cas-group 1 timeslots 1-24
AS5200(config-controller)#
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 1 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 2 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 3 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 4 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 5 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 6 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 7 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 8 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 9 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 10 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 11 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 12 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 13 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 14 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 15 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 16 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 17 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 18 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 19 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 20 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 21 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 22 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 23 is up
%DSX0-5-RBSLINEUP: RBS of controller 1 timeslot 24 is up

channel-group

Use the channel-group controller configuration command to define the timeslots that belong to each T1 or E1 circuit.

channel-group number timeslots range [speed {48 | 56 | 64}]
Syntax Description
number Channel-group number. When configuring a T1 data line, channel-group numbers can be values from 0 to 23. When configuring an E1 data line, channel-group numbers can be values from 0 to 30.
timeslots range Timeslot or range of timeslots belonging to the channel group. The first timeslot is numbered 1. For a T1 controller, the timeslot range is from 1 to 24. For an E1 controller, the timeslot range is from 1 to 31.
speed {48 | 56 | 64} (Optional) Specifies the line speed (in kilobits per second) of the T1 or E1 link.
Default

The default line speed when configuring a T1 controller is 56 kbps.

The default line speed when configuring an E1 controller is 64 kbps.

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Use this command in configurations where the router or access server must communicate with a T1 or E1 fractional data line. The channel-group number may be arbitrarily assigned and must be unique for the controller. The timeslot range must match the timeslots assigned to the channel group. The service provider defines the timeslots that comprise a channel group.

Example

In the following example, three channel groups are defined. Channel-group 0 consists of a single timeslot, channel-group 8 consists of 7 timeslots and runs at a speed of 64 kbps per timeslot, and channel-group 12 consists of a single timeslot.

channel-group 0 timeslots 1
channel-group 8 timeslots 5,7,12-15,20 speed 64
channel-group 12 timeslots 2
Related Commands

framing
linecode

clear controller

Use the clear controller EXEC command to reset the T1 or E1 controller on the Cisco 7000 series, Cisco 7200 series, or Cisco 4000 series routers.

clear controller {t1 | e1} slot/port (Cisco 7000 series and Cisco 7200 series)
clear controller {t1 | e1} number (Cisco 4000 series)

Syntax Description
slot Backplane slot number; can be 0, 1, 2, 3, or 4. The slots are numbered from left to right.
port Port number of the interface. It can be 0 or 1 for the MIP (MultiChannel Interface Processor).

Ports on each interface processor are numbered from the top down.

number Network interface module (NIM) number, in the range 0 through 2.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 (for the Cisco 7000).
This command first appeared in Cisco IOS Release 11.0 (for the Cisco 4000).

Examples

The following example resets the T1 controller at slot 4, port 0 on a Cisco 7000 series router:

clear controller t1 4/0

The following example resets the E1 controller at NIM 0 on a Cisco 4000 series router:

clear controller e1 0
Related Commands

controller e1
controller t1

clear controller lex

To reboot the LAN Extender chassis and restart its operating software, use the clear controller lex privileged EXEC command.

clear controller lex number [prom]
clear controller lex slot/port [prom]  (for the Cisco 7000 family)

Syntax Description
number Number of the LAN Extender interface corresponding to the LAN Extender to be rebooted.
prom (Optional) Forces a reload of the PROM image, regardless of any Flash image.
slot On the Cisco 7000 series, specifies the backplane slot number. On the Cisco 7000 and 7200, the value can be 0, 1, 2, 3, or 4. On the Cisco 7010, the value can be 0, 1, or 2.
port On the Cisco 7000 series, specifies the port number of the interface. The value can be 0, 1, 2, or 3 for the serial interface.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The clear controller lex command halts operation of the LAN Extender and performs a cold restart.

Without the prom keyword, if an image exists in Flash memory, and that image has a newer software version than the PROM image, and that image has a valid checksum, then this command runs the Flash image. If any one of these three conditions is not met, this command reloads the PROM image.

With the prom keyword, this command reloads the PROM image, regardless of any Flash image.

Examples

The following example halts operation of the LAN Extender bound to LAN Extender interface 2 and causes the LAN Extender to perform a cold restart from Flash memory:

Router# clear controller lex 2
reload remote lex controller? [confirm] yes

The following example halts operation of the LAN Extender bound to LAN Extender interface 2 and causes the LAN Extender to perform a cold restart from PROM:

Router# clear controller lex 2 prom
reload remote lex controller? [confirm] yes

clear counters

To clear the interface counters, use the clear counters EXEC command.

clear counters [type number]
clear counters
[type slot/port] [ethernet | serial] (for the Cisco 4000 series or Cisco 7000 series with a LAN Extender interface)
clear counters [type slot/port] (for the Cisco 7000 series and Cisco 7200 series, and for the Cisco 7500 with a Packet over SONET Interface Processor)
clear counters [type slot/port-adapter/port]  (for the Cisco 7000 series and the Cisco 7500 series with ports on VIP cards)

Syntax Description
type (Optional) Specifies the interface type; one of the keywords listed in Table 18.
number (Optional) Specifies the interface counter displayed with the show interfaces command.
ethernet (Optional) If the type is lex, you can clear the interface counters on the Ethernet interface.
serial (Optional) If the type is lex, you can clear the interface counters on the serial interface.
slot (Optional) Backplane slot number on the Cisco 7000 series and Cisco 7200 series. On the Cisco 7000 series and Cisco 7200 series, the value can be 0, 1, 2, 3, or 4. On the Cisco 7010, the value can be 0, 1, or 2.
port (Optional) Port number of the interface. On the Cisco 7000 series and Cisco 7200 series, the value can be 0, 1, 2, or 3 for the serial interface. For the Cisco 7500 if the interface type is posi, the value must be 0. For the VIP card, the port value can be the following:

· 0 for one-port Fast Ethernet interfaces

· 0, 1, 2, or 3 for four-port Ethernet interfaces

· 0, 1, 2, or 3 for four-port serial interfaces

· 0, 1, 2, or 3 for four-port Token Ring interfaces

· 0 for one-port FDDI interfaces

port-adapter (Optional) On the Cisco 7000 series and Cisco 7500 series, specifies the port adapter location on a VIP card. The value can be 0 or 1.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command clears all the current interface counters from the interface unless the optional arguments type and number are specified to clear only a specific interface type (serial, Ethernet, Token Ring, and so on).


Note This command will not clear counters retrieved using SNMP, but only those seen with the show interface EXEC command.


Table 18: Clear Counters Interface Type Keywords
Keyword Interface Type
async Asynchronous interface
bri Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI)
dialer Dialer interface
ethernet Ethernet interface
fast-ethernet Fast ethernet interface
fddi Fiber Distributed Data Interface (FDDI)
hssi High-Speed Serial Interface (HSSI)
lex LAN Extender interface
loopback Loopback interface
null Null interface
posi Packet OC-3 interface on the Packet over SONET Interface Processor
serial Synchronous serial interface
tokenring Token Ring interface
tunnel Tunnel interface
Examples

The following example illustrates how to clear all interface counters:

clear counters

The following example illustrates how to clear interface counters on the serial interface residing on a Cisco 1000 series LAN Extender:

clear counters lex 0 serial
Related Command

show interfaces

clear hub

To reset and reinitialize the hub hardware connected to an interface of a Cisco 2505 or Cisco 2507, use the clear hub ethernet EXEC command.

clear hub ethernet number
Syntax Description
ethernet Indicates the hub in front of an Ethernet interface.
number Hub number to clear, starting with 0. Since there is currently only one hub, this number is 0.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Example

The following example clears hub 0:

clear hub ethernet 0
Related Command

hub

clear hub counters

To set to zero the hub counters on an interface of a Cisco 2505 or Cisco 2507, use the clear hub counters EXEC command.

clear hub counters [ether number [port [end-port]]]
Syntax Description
ether (Optional) Indicates the hub in front of an Ethernet interface.
number (Optional) Hub number for which to clear counters. Since there is currently only one hub, this number is 0. If you specify the keyword ether, you must specify the number.
port (Optional) Port number on the hub. On the Cisco 2505, port numbers range from 1 through 8. On the Cisco 2507, port numbers range from 1 through 16. If a second port number follows, then this port number indicates the beginning of a port range. If you do not specify a port number, counters for all ports are cleared.
end-port (Optional) Ending port number of a range.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Example

The following example clears the counters displayed in a show hub command for all ports on hub 0:

clear hub counters ether 0
Related Command

show hub

clear interface

To reset the hardware logic on an interface, use the clear interface EXEC command.

clear interface type number
clear interface type slot/port (on a Cisco 7000 series and Cisco 7200 series, and for the Cisco 7500 with a Packet over SONET Interface Processor)
clear interface [type slot/port-adapter/port] (for ports on VIP cards in the Cisco 7000 series and the Cisco 7500 series routers)
clear interface type slot/port [:channel-group]  (on a Cisco 7000 MIP T1 interface)

Syntax Description
type Specifies the interface type; it is one of the keywords listed in Table 19.
number Specifies the port, connector, or interface card number.
slot On the Cisco 7000 series and Cisco 7200 series, specifies the backplane slot number. On the 7000 series, value can be 0, 1, 2, 3, or 4. On the 7010, value can be 0, 1, or 2. On the Cisco 7200 series, value can be 0, 1, 2, 3, 4, 5, or 6.
port Port number of the interface. For the Cisco 7500 if the interface type is posi, the value must be 0. On the Cisco 7000 series, this argument is required, and the value can be 0, 1, 2, 3, 4, or 5 depending on the type of interface, as follows:

(Optional) Port number of the interface. For the VIP card this argument is optional, and the value can be the following:

· 0 for one-port Fast Ethernet interfaces

· 0, 1, 2, or 3 for four-port Ethernet interfaces

· 0, 1, 2, or 3 for four-port serial interfaces

· 0, 1, 2, or 3 for four-port Token Ring interfaces

· 0 for one-port FDDI interfaces

port-adapter (Optional) On the Cisco 7000 and Cisco 7500 series, specifies the port-adapter location on a VIP card. The value can be 0 or 1.
:channel-group (Optional) On the Cisco 7000 series supporting channelized T1, specifies the channel from 0 to 23. This number is preceded by a colon.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Under normal circumstances, you do not need to clear the hardware logic on interfaces.


Table 19: Clear Interface Type Keywords
Keyword Interface Type
async Async interface
atm Asynchronous Transfer Mode (ATM) interface
bri Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI)
ethernet Ethernet interface
fddi Fiber Distributed Data Interface (FDDI)
hssi High-Speed Serial Interface (HSSI)
loopback Loopback interface
null Null interface
posi Packet OC-3 interface on the Packet over SONET Interface Processor
serial Synchronous serial interface
tokenring Token Ring interface
tunnel Tunnel interface
Example

The following example resets the interface logic on HSSI interface 1:

clear interface hssi 1

clear interface fastethernet

To reset the controller for a specified Fast Ethernet interface, use the clear interface fastethernet privileged EXEC command.

clear interface fastethernet number (Cisco 4500 series)
clear interface fastethernet
slot/port (Cisco 7000 series and Cisco 7200 series)
clear interface fastethernet slot/port-adapter/port (Cisco 7500 series)

Syntax Description
number Port, connector, or interface card number. On a Cisco 4500 or Cisco 4700 router, specifies the NPM number. The numbers are assigned at the factory at the time of installation or when added to a system.
slot On the Cisco 7000 series, slot location of the FEIP. On the Cisco 7200, slot 0 is the Fast Ethernet port on the I/O controller.
port On the Cisco 7000 series, port number on the interface.
port-adapter On the Cisco 7000 and 7500 series, specifies the port bay on a VIP card. The value can be 0 or 1.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Examples

The following example resets the controller for the Ethernet 0 interface on a Cisco 4500:

clear interface fastethernet 0

The following example resets the controller for the Ethernet interface located in slot 1 port 0 on a Cisco 7000 or Cisco 7200:

clear interface fastethernet 1/0

The following example resets the controller for the Ethernet interface located in slot 1 port adapter 0 port 0 on a Cisco 7500:

clear interface fastethernet 1/0/0

clear line

To return a line to its idle state, use the clear line privileged EXEC command at the system prompt.

clear line line-number
Syntax Description
line-number Asynchronous line port number assigned with the interface async command.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Normally, this command returns the line to its default as a terminal line, with the interface in a "down" state.

Example

The following example shows how to use the clear line command to return serial interface 5 to its idle state:

clear line 5

clear rif-cache

To clear entries from the Routing Information Field (RIF) cache, use the clear rif-cache EXEC command.

clear rif-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 illustrates how to clear the RIF cache:

clear rif-cache
Related Command

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

multiring +

clear service-module serial

To reset the integrated CSU/DSU on a Cisco 2524 or Cisco 2525 router, use the clear service-module serial privileged EXEC configuration command.

clear service-module serial number
Syntax Description
number Number of the serial interface.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command only in severe circumstances (for example, when the router is not responding to a CSU/DSU configuration command).

This command terminates all DTE and line loopbacks that are locally or remotely configured. It also interrupts data transmission through the router for up to 15 seconds. The software performs an automatic software reset in case of two consecutive configuration failures.

The CSU/DSU module is not reset with the clear interface command.

 
Caution If you experience technical difficulties with your router and intend to contact customer support, refrain from using this command. This command erases the router's past CSU/DSU performance statistics. To clear only the CSU/DSU performance statistics, issue the clear counters command.
Example

The following example resets the CSU/DSU on a Cisco 2524 or Cisco 2525 router:

clear service-module serial 0
Related Commands

clear counters
test service-module

clock rate

To configure the clock rate for the hardware connections on the serial interface appliques, network interface modules (NIMs), and interface processors to an acceptable bit rate, use the clock rate interface configuration command. Use the no clock rate command to remove the clock rate if you change the interface from a DCE to a DTE device.

clock rate bps
no clock rate

Syntax Description
bps Desired clock rate in bits per second: 1200, 2400, 4800, 9600, 19200, 38400, 56000, 64000, 72000, 125000, 148000, 500000, 800000, 1000000, 1300000, 2000000, or 4000000.
Default

No clock rate is configured.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Be aware that the fastest speeds might not work if your cable is too long, and that speeds faster than 148,000 bits per second are too fast for EIA/TIA-232 signaling. It is recommended that you only use the synchronous serial EIA/TIA-232 signal at speeds up to 64,000 bits per second. To permit a faster speed, use an EIA/TIA-449 or V.35 applique.

Example

The following example sets the clock rate on the first serial interface to 64,000 bits per second:

interface serial 0
clock rate 64000

clock source (Cisco AS5200)

To select the clock source for the time-division multiplexing (TDM) bus in a Cisco AS5200 access server, use the clock source interface configuration command. The no form of this command configures the clock source to its default setting.

clock source {line {primary | secondary} | internal}
no clock source line {primary | secondary}

Syntax Description
line Clock source on the active line.
primary Primary TDM clock source.
secondary Secondary TDM clock source.
internal Selects the free running clock (also known as internal clock) as the clock source.
Defaults

Primary TDM clock source from the T1 0 controller

Secondary TDM clock source from the T1 1 controller

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

To use the clocking coming in from a T1 line, configure the clock source line primary command on the T1 interface that has the most reliable clocking. Configure the clock source line secondary command on the T1 interface that has the next best known clocking. With this configuration, the primary line clocking is backed up to the secondary line if the primary clocking shuts down.

Example

The following example configures the Cisco AS5200 access server to use T1 controller 0 as the primary clock source and T1 controller 1 as the secondary clock source:

controller t1 0
clock source line primary
controller t1 1
clock source line secondary

clock source (controller)

Use the clock source controller configuration command to set the T1-line clock-source for the MIP in the Cisco 7000 series, Cisco 7200 series, and Cisco 7500 series or for the NPM in the Cisco 4000 series.

clock source {line | internal}
Syntax Description
line Specifies the T1 line as the clock source.
internal Specifies the MIP (Cisco 7000 series, Cisco 7200 series, and Cisco 7500 series) or the NPM (Cisco 4000) as the clock source.
Defaults

Primary TDM clock source from the T0 controller

Secondary TDM clock source from the T1 controller

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

To use the clocking coming in from a T1 line, configure the clock source line primary command on the controller that has the most reliable clocking. Configure the clock source line secondary command on the controller that has the next best known clocking. With this configuration, the primary line clocking is backed up to the secondary line if the primary clocking shuts down.

Example

The following example configures the Cisco AS5200 to use the T0 controller as the primary clocking source and the T1 controller as the secondary clocking source:

AS5200(config)# controller t1 0
AS5200(config-if)# clock source line primary
AS5200(config-if)# exit
AS5200(config)# controller t1 1
AS5200(config-if)# clock source line secondary
Related Commands

framing
linecode

clock source (interface)

To control which clock a G.703 E1 interface will use to clock its transmitted data from, use the clock source interface configuration command. The no form of this command restores the default value.

clock source {line | internal}
no clock source

Syntax Description
line Specifies that the interface will clock its transmitted data from a clock recovered from the line's receive data stream (default).
internal Specifies that the interface will clock its transmitted data from its internal clock.
Default

By default, the applique uses the line's receive data stream.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to a Cisco 4000 router or Cisco 7000 series and Cisco 7500 series router. A G.703-E1 interface can clock its transmitted data from either its internal clock or from a clock recovered from the line's receive data stream.

Example

The following example specifies the G.703-E1 interface to clock its transmitted data from its internal clock:

clock source internal

cmt connect

To start the processes that perform the connection management (CMT) function and allow the ring on one fiber to be started, use the cmt connect EXEC command.

cmt connect [interface-name [phy-a | phy-b]]
Syntax Description
interface-name (Optional) Specifies the FDDI interface.
phy-a (Optional) Selects Physical Sublayer A.
phy-b (Optional) Selects Physical Sublayer B.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

In normal operation, the FDDI interface is operational once the interface is connected and configured. The cmt connect command allows the operator to start the processes that perform the CMT function.

The cmt connect command is not needed in the normal operation of FDDI; this command is used mainly in interoperability tests.

Examples

The following examples demonstrate use of the cmt connect command for starting the CMT processes on the FDDI ring.

The following command starts all FDDI interfaces:

cmt connect

The following command starts both fibers on the FDDI interface unit 0:

cmt connect fddi 0

The following command on the Cisco 7000 series, the Cisco 7200 series, or Cisco 7500 series starts both fibers on the FDDI interface unit 0:

cmt connect fddi 1/0

The following command starts only Physical Sublayer A on the FDDI interface unit 0:

cmt connect fddi 0 phy-a

The following command on the Cisco 7000 starts only Physical Sublayer A on the FDDI interface unit 0:

cmt connect fddi 1/0 phy-a

cmt disconnect

To stop the processes that perform the connection management (CMT) function and allow the ring on one fiber to be stopped, use the cmt disconnect EXEC command.

cmt disconnect [interface-name [phy-a | phy-b]]
Syntax Description
interface-name (Optional) Specifies the FDDI interface.
phy-a (Optional) Selects Physical Sublayer A.
phy-b (Optional) Selects Physical Sublayer B.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

In normal operation, the FDDI interface is operational once the interface is connected and configured, and is turned off using the shutdown interface configuration command. The cmt disconnect command allows the operator to stop the processes that perform the CMT function and allow the ring on one fiber to be stopped.

The cmt disconnect command is not needed in the normal operation of FDDI; this command is used mainly in interoperability tests.

Examples

The following examples demonstrate use of the cmt disconnect command for stopping the CMT processes on the FDDI ring.

The following command stops all FDDI interfaces:

cmt disconnect

The following command stops both fibers on the FDDI interface unit 0:

cmt disconnect fddi 0

The following command on the Cisco 7000 series, the Cisco 7200 series, or Cisco 7500 series stops both fibers on the FDDI interface unit zero:

cmt disconnect fddi 1/0

The following command stops only Physical Sublayer A on the FDDI interface unit 0. This command causes the FDDI media to go into a wrapped state so that the ring will be broken.

cmt disconnect fddi 0 phy-a

The following command on the Cisco 7000 series or Cisco 7500 series stops only Physical Sublayer A on the FDDI interface unit 0 in slot 1. This command causes the FDDI media to go into a wrapped state so that the ring will be broken.

cmt disconnect fddi 1/0 phy-a

compress

To configure software compression for Link Access Procedure, Balanced (LAPB), and High-Level Data Link Control (HDLC) encapsulations, use the compress interface configuration command. To disable compression, use the no form of this command.

compress [predictor | stac]
no compress
[predictor | stac]

Syntax Description
predictor (Optional) Specifies that a predictor compression algorithm will be used.
stac (Optional) Specifies that a Stacker (LZS) compression algorithm will be used.
Default

Compression is disabled.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 (as compress predictor). The command, compress predictor stac first appeared in Cisco IOS Release 10.3.

You can configure point-to-point software compression for all LAPB, PPP, and HDLC encapsulations. Compression reduces the size of frames via lossless data compression. The compression algorithm used is a predictor algorithm (the RAND compression algorithm), which uses a compression dictionary to predict what the next character in the frame will be.

For HDLC encapsulations, you can specify a Stacker compression algorithm by using the stac keyword. PPP and LAPB encapsulations support both predictor and Stacker compression algorithms.

Compression is performed in software and may significantly affect system performance. We recommend that you disable compression if CPU load exceeds 65 percent. To display the CPU load, use the show process cpu EXEC command.

Compression requires that both ends of the serial link be configured to use compression. You should never enable compression for connections to a public data network.


Note The best performance
data compression algorithms adjust their compression methodology as they identify patterns in the data. To prevent data loss and support this adjustment process, the compression algorithm is run over LAPB to ensure that everything is sent in order, with no missing data and no duplicate data.

If the majority of your traffic is already compressed files, we recommend that you not use compression. If the files are already compressed, the additional processing time spent in attempting unsuccessfully to compress them again will slow system performance.

Table 20 provides general guidelines for deciding which compression type to select for LAPB encapsulations.


Table 20: Compression Guidelines for LAPB Encapsulations
Compression Type to Use Situation
Predictor The bottleneck is caused by the load on the router or access server.
Stacker The bottleneck is the result of line bandwidth.
None Most files are already compressed.

Stacker compression for LAPB encapsulations reaches its performance ceiling on T1 lines; it is not recommended for faster lines because the added processing slows their performance. Stacker compression processing might be slower on other systems than on the Cisco 4500 routers.

When using predictor compression, you can adjust the MTU for the serial interface and the LAPB maximum bits per frame (N1) parameter, as shown in the first example, to avoid informational diagnostics regarding excessive MTU or N1 sizes. However, you should not change those parameters when you use Stacker compression.

Examples

The following example enables predictor compression on serial interface 0 for a LAPB link:

interface serial 0
encapsulation lapb
compress predictor
mtu 1509
lapb n1 12072

The following example enables Stacker compression on serial interface 0 for a LAPB link. This example does not set the MTU size and the maximum bits per frame (N1); we recommend that you do not change those LAPB parameters for Stacker compression:

interface serial 0
encapsulation lapb
compress predictor
Related Commands

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

encapsulation lapb
encapsulation x25
show compress
show processes
+

controller

To configure a T1 or E1 controller and enter controller configuration mode, use the controller global configuration command.

controller {t1 | e1} slot/port (on the Cisco 7000 and the Cisco 7500 series)
controller {t1 | e1} number (on the Cisco 4000 series)
Syntax Description
t1 T1 controller.
e1 E1 controller.
slot

  • On the Cisco 7000, the slot numbers are 0, 1, 2, 3, or 4 from left to right.

  • On the Cisco 7010, the slot number can be 0, 1, or 2 from bottom to top.

  • On the Cisco 7505, the slot number can be 0. 1, 2, or 3 from bottom to top.

  • On the Cisco 7507, the slot number can be 0 and 1 (CyBus0) and 4 through 6 (Cybus1), from left to right.

  • On the Cisco 7513, the slot numbers are 0 through 5 (CyBus 0) and 8 through 12 (CyBus 1), from left to right.

port

Port number of the interface. It can be 0 or 1 for the MIP (MultiChannel Interface Processor). Ports on each interface processor are numbered from the top down.
number Network processor module (NPM) number, in the range 0 through 2.
Default

No T1 or E1 controller is configured.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 (for the Cisco 7000 and 7500 series).
This command first appeared in Cisco IOS Release 11.0 (for the Cisco 4000).

This command is used in configurations where the router or access server is intended to communicate with a T1 or E1 fractional data line. Additional parameters for the T1 or E1 line must be configured for the controller before the T1 or E1 circuits can be configured by means of the interface global configuration command.

This command is used only on a Cisco 7000 series and Cisco 7500 series or Cisco 4000 series router.

This command does not apply to the Cisco 7200 series.

Examples

In the following example, the MIP in slot 4, port 0 of a Cisco 7000 is configured as a T1 controller:

controller t1 4/0

In the following example, NIM 0 of a Cisco 4000 is configured as a T1 controller:

controller t1 0
Related Commands

channel-group
clear controller lex
clear controller t1
clock source (controller)
framing
linecode
show controllers e1
show controller t1

copy flash lex

To download an executable image from Flash memory on the core router to the LAN Extender chassis, use the copy flash lex privileged EXEC command.

copy flash lex number
Syntax Description
number Number of the LAN Extender interface to which to download an image from Flash memory.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

If you attempt to download a version of the software older than what is currently running on the LAN Extender, a warning message is displayed.

Example

The following example illustrates how to copy the executable image namexx to the LAN Extender interface 0:

Router# copy flash lex 0
Name of file to copy? namexx
Address of remote host [255.255.255.255] <cr>
writing namexx !!!!!!!!!!!!!!!!!!!!!!!!!copy complete
Related Command

copy tftp lex

copy tftp lex

To download an executable image from a TFTP server to the LAN Extender, use the copy tftp lex privileged EXEC command.

copy tftp lex number
Syntax Description
number Number of the LAN Extender interface to which to download an image.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

If you attempt to download a version of the software older than what is currently running on the LAN Extender, a warning message is displayed.

Example

The following example illustrates how to copy the file namexx from the TFTP server:

Router# copy tftp lex 0
Address or name of remote host (255.255.255.255]? 131.108.1.111
Name of file to copy? namexx
OK to overwrite software version 1.0 with 1.1 ?[confirm]
Loading namexx from 131.108.13.111!!!!!!!!!!!!!!!!!!!!!!!!!
[OK - 127825/131072 bytes]
Successful download to LAN Extender

crc

To set the length of the cyclic redundancy check (CRC) on a Fast Serial Interface Processor (FSIP) or HSSI Interface Processor (HIP) of the Cisco 7000 series and Cisco 7500 series or on a 4-port serial adapter of the Cisco 7200 series, use the crc interface configuration command. To set the CRC length to 16 bits, use the no form of this command.

crc size
no crc

Syntax Description
size CRC size (16 or 32 bits).
Default

16 bits

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

All interfaces use a 16-bit cyclic redundancy check (CRC) by default, but also support a 32-bit CRC. CRC is an error-checking technique that uses a calculated numeric value to detect errors in transmitted data. The designators 16 and 32 indicate the length (in bits) of the frame check sequence (FCS). A CRC of 32 bits provides more powerful error detection, but adds overhead. Both the sender and receiver must use the same setting.

CRC-16, the most widely used throughout the United States and Europe, is used extensively with wide-area networks (WANs). CRC-32 is specified by IEEE 802 and as an option by some point-to-point transmission standards. It is often used on SMDS networks and LANs.

Example

In the following example, the 32-bit CRC is enabled on serial interface 3/0:

interface serial 3/0
crc 32

crc4

To enable generation of CRC4 on the G.703 E1 port adapter on the FSIP, use the crc4 interface configuration command. To disable this feature, use the no form of this command.

crc4
no crc4

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.

This command applies to a Cisco 4000 router or Cisco 7000 series and Cisco 7500 series router. It is useful for checking data integrity while operating in framed mode. CRC4 provides additional protection for a frame alignment signal under noisy conditions. Refer to CCITT Recommendation G.704 for a definition of CRC4.

This command does not apply to the Cisco 7200 series.

Example

The following example enables CRC4 generation on the G.703 E1 port adapter on the FSIP:

crc4

dce-terminal-timing enable

When running the line at high speeds and long distances, use the dce-terminal-timing enable interface configuration command to prevent phase shifting of the data with respect to the clock. If SCTE is not available from the DTE, use no form of this command, which causes the DCE to use its own clock instead of SCTE from the DTE.

dce-terminal-timing enable
no dce-terminal-timing enable

Syntax Description

This command has no keywords or arguments.

Default

DCE uses its own clock.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

On the Cisco 4000 platform, you can specify the serial Network Interface Module timing signal configuration. When the board is operating as a DCE and the DTE provides terminal timing (SCTE or TT), the dce-terminal-timing enable command causes the DCE to use SCTE from the DTE.

Example

The following example prevents phase shifting of the data with respect to the clock:

interface serial 0
dce-terminal-timing enable

delay

To set a delay value for an interface, use the delay interface configuration command. Use the no form of this command to restore the default delay value.

delay tens-of-microseconds
no delay

Syntax Description
tens-of-microseconds Integer that specifies the delay in tens of microseconds for an interface or network segment.
Default

Default delay values may be displayed with the EXEC command show interfaces.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example sets a 30,000-microsecond delay on serial interface 3:

interface serial 3
delay 30000
Related Command

show interfaces

description (controller)

To add a description to an E1 or T1 controller on a Cisco 7000 series and Cisco 7500 series router, use the description controller configuration command. Use the no form of this command to remove the description.

description string
no description

Syntax Description
string Comment or a description to help you remember what is attached to the controller.
Default

No description is added.

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The description command is meant solely as a comment to be put in the configuration to help you remember what certain E1 or T1 controllers are used for. The description affects the MIP interfaces only and appears in the output of the show controllers e1, show controllers t1, and show running-config EXEC commands.

Example

The following example describes a 3174 controller:

controller t1
description 3174 Controller for test lab
Related Commands

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

show controllers e1
show controller t1
show running-config
+

description (interface)

To add a description to an interface configuration, use the description interface configuration command. Use the no form of this command to remove the description.

description string
no description

Syntax Description
string Comment or a description to help you remember what is attached to this interface.
Default

No description is added.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The description command is meant solely as a comment to be put in the configuration to help you remember what certain interfaces are used for. The description appears in the output of the following EXEC commands: show startup-config, show interfaces, and show running-config.

Example

The following example shows how to add a description for a T1 interface:

interface serial 0
description Fractional T1 line to Mountain View -- 128 Kb/s
Related Commands

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

show interfaces
show running-config
+
show startup-config +

down-when-looped

To configure an interface to inform the system it is down when loopback is detected, use the down-when-looped interface configuration command.

down-when-looped
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 10.0.

This command is valid for HDLC or PPP encapsulation on serial and HSSI interfaces.

When an interface has a backup interface configured, it is often desirable that the backup interface be enabled when the primary interface is either down or in loopback. By default, the backup is only enabled if the primary interface is down. By using the down-when-looped command, the backup interface will also be enabled if the primary interface is in loopback.

If testing an interface with the loopback command, or by placing the DCE into loopback, down-when-looped should not be configured; otherwise, packets will not be transmitted out the interface that is being tested.

Example

In the following example, interface serial 0 is configured for HDLC encapsulation. It is then configured to let the system know that it is down when in loopback mode.

interface serial0
encapsulation hdlc
down-when-looped
Related Commands

backup interface serial
loopback (interface)

dte-invert-txc

On the Cisco 4000 series, you can specify the serial Network Processor Module timing signal configuration. When the board is operating as a DTE, the dte-invert-txc command inverts the TXC clock signal it gets from the DCE that the DTE uses to transmit data. Use the no form of this command if the DCE accepts SCTE from the DTE.

dte-invert-txc
no dte-invert-txc

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 10.0.

Use this command if the DCE cannot receive SCTE from the DTE, the data is running at high speeds, and the transmission line is long. This prevents phase shifting of the data with respect to the clock.

If the DCE accepts SCTE from the DTE, use no dte-invert-txc.

Example

The following example inverts the TXC on serial interface 0:

interface serial 0
dte-invert-txc

early-token-release

To enable early token release on Token Ring interfaces, use the early-token-release interface configuration command. Once enabled, use the no form of this command to disable this feature.

early-token-release
no early-token-release

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 10.0.

Early token release is a method whereby the Token Ring interfaces can release the token back onto the ring immediately after transmitting, rather than waiting for the frame to return. This feature helps increase the total bandwidth of the Token Ring.

The Token Ring Interface Processor (TRIP) on the Cisco 7000 series and Cisco 7500 series and the Token Ring adapters on the Cisco 7200 series all support early token release.

Examples

The following example enables the use of early token release on Token Ring interface 1:

interface tokenring 1
early-token-release

On the Cisco 7000 series, to enable the use of early token release on your Token Ring interface processor in slot 4 on port 1, issue the following configuration commands:

interface tokenring 4/1
early-token-release

encapsulation

To set the encapsulation method used by the interface, use the encapsulation interface configuration command.

encapsulation encapsulation-type
Syntax Description
encapsulation-type Encapsulation type; one of the following keywords:
Default

The default depends on the type of interface. For example, a synchronous serial interface defaults to HDLC.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

To use SLIP or PPP, the router or access server must be configured with an IP routing protocol or with the ip host-routing command. This configuration is done automatically if you are using old-style slip address commands. However, you must configure it manually if you configure SLIP or PPP via the interface async command.

Examples

The following example resets HDLC serial encapsulation on serial interface 1:

interface serial 1
encapsulation hdlc

The following example enables PPP encapsulation on serial interface 0:

interface serial 0
encapsulation ppp
Related Commands

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

keepalive
ppp
+
ppp authentication +
slip +

encapsulation atm-dxi

Use the encapsulation atm-dxi interface configuration command to enable ATM-DXI encapsulation. The no form of this command disables ATM-DXI.

encapsulation atm-dxi
no encapsulation atm-dxi

Syntax Description

This command has no arguments or keywords.

Default

HDLC

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example configures ATM-DXI encapsulation on serial interface 1:

interface serial 1
encapsulation atm-dxi
Related Command

atm-dxi map

encapsulation lapb

To set the LAPB encapsulation method used by the interface, use the encapsulation lapb interface configuration command.

encapsulation lapb [dte | dce] [multi | protocol]
Syntax Description
dte (Optional) DDN X.25 DTE operation (for serial interface).
dce (Optional) DDN X.25 DCE operation (for serial interface).
multi (Optional) Multiprotocol support.
protocol (Optional) Protocol type. Use any of the keywords in the following list:
apollo--Apollo domain
appletalk--AppleTalk
clns--ISO CLNS
decnet--DECnet
ip--IP
ipx--Novell IPX
multi--Multiprotocol operation
qllc--QLLC protocol
snapshot--Snapshot routing support
vines--Banyan VINES
xns--Xerox Network Services
Default

DTE is the default operational type.

IP is the default protocol type.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. (The options first appeared in Cisco IOS Release 10.3.)

To use a particular encapsulation, you must configure the router or access server with that protocol type.

Example

The following example enables LAPB encapsulation on serial interface 0, using a default IP routing protocol:

interface serial 0
encapsulation lapb

encapsulation x25

To specify an serial interface's operation as an X.25 device, use the encapsulation x25 interface configuration command.

encapsulation x25 [dte | dce] [ddn | bfe | ietf]
Syntax Description
dte (Optional) Specifies operation as a DTE. This is the default X.25 mode.
dce (Optional) Specifies operation as a DCE.
ddn (Optional) Specifies DDN encapsulation on an interface using DDN X.25 standard service
bfe (Optional) Specifies BFE encapsulation on an interface attached to a Blacker Front End device. Available for BFE operation only.
ietf (Optional) Specifies that the interface's datagram encapsulation should default to use of the IETF standard method, as defined by RFC 1356.
Defaults

The default serial encapsulation is HDLC. You must explicitly configure an X.25 encapsulation method.

DTE operation is the default X.25 mode. Cisco's traditional X.25 encapsulation method is the default.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 (with the dce option). The remaining options first apeared in Cisco IOS Release 10.3.

One end of an X.25 link must be a logical DCE and the other end a logical DTE. (This assignment is independent of the interface's hardware DTE/DCE identity.) Typically, when connecting to a public data network (PDN), the customer equipment acts as the DTE and the PDN attachment acts as the DCE.

Cisco has supported the encapsulation of a number of datagram protocols for quite some time, using a standard means when available and proprietary means when necessary. More recently the IETF adopted a standard, RFC 1356, for encapsulating most types of datagram traffic over X.25. X.25 interfaces use Cisco's traditional method unless explicitly configured for IETF operation; if the ietf keyword is specified, that standard will be used unless Cisco's traditional method is explicitly configured. For details see the x25 map command.

When an X.25 interface is reconfigured, all of the interface's X.25 parameters are initialized except the x25 map commands. The x25 map statements that are configured for an interface are not deleted when the encapsulation is changed, so they will be retained if the interface is later reconfigured for X.25 operation.

A router or access server attaching to the Defense Data Network (DDN) or to a Blacker Front End (BFE) device can be configured to use their respective algorithms to convert between IP and X.121 addresses by using the ddn or bfe options, respectively. An IP address should be assigned to the interface, from which the algorithm will generate the interface's X.121 address; for proper operation, this X.121 address should not be modified.

A router or access server DDN attachment can operate as either a DTE or a DCE device. A BFE attachment can operate only as a DTE device. The ietf option is not available if either the ddn or bfe option is selected.

Example

The following example configures the interface for connection to a Blacker Front End device:

interface serial 0
encapsulation x25 bfe

error-threshold

To set the mechanism that protects against packet overload and resulting recount errors on the MCI interface cards, use the error-threshold interface configuration command.

error-threshold milliseconds
Syntax Description
milliseconds Frequency at which the error recount will be set in milliseconds. Default is 1000 ms.
Default

1000 ms

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following commands set the error recount threshold on Ethernet interface 2 to 10,000 ms:

interface ethernet 2
error-threshold 10000

fddi burst-count

To allow the FCI card to preallocate buffers to handle bursty FDDI traffic (for example, NFS bursty traffic), use the fddi burst-count interface configuration command. Use the no form of this command to revert to the default value.

fddi burst-count number
no fddi burst-count

Syntax Description
number Number of preallocated buffers in the range from 1 to 10. Default is 3 buffers.
Default

3 buffers

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command applies to the FCI card only. The microcode software version should not be 128.45 or 128.43.

Example

The following example sets the number of buffers to 5:

interface fddi 0
fddi burst-count 5

fddi c-min

To set the C-Min timer on the PCM, use the fddi c-min interface configuration command. Use the no form of this command to revert to the default value.

fddi c-min microseconds
no fddi c-min

Syntax Description
microseconds Sets the timer value in microseconds. Default is 1600 microseconds.
Default

1600 microseconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command applies to the processor CMT only. You need extensive knowledge of the PCM state machine to tune this timer. Use this command when you run into PCM interoperability problems.

Example

The following example sets the C-Min timer to 2000 microseconds:

interface fddi 0
fddi c-min 2000
Related Commands

fddi tb-min
fddi tl-min-time
fddi t-out

fddi cmt-signal-bits

To control the information transmitted during the connection management (CMT) signaling phase, use the fddi cmt-signal-bits interface configuration command.

fddi cmt-signal-bits signal-bits [phy-a | phy-b]
Syntax Description
signal-bits A hexadecimal number preceded by 0x; for example, 0x208. The FDDI standard defines ten bits of signaling information that must be transmitted, as follows:

· bit 0--Escape bit. Reserved for future assignment by the FDDI standards committee.

· bits 1 and 2--Physical type, as defined in Table 21.

· bit 3--Physical compatibility. Set if topology rules include the connection of a physical-to-physical type at the end of the connection.

· bits 4 and 5--Link confidence test duration; set as defined in Table 22.

· bit 6--Media Access Control (MAC) available for link confidence test.

· bit 7--Link confidence test failed. The setting of bit 7 indicates that the link confidence was failed by the Cisco end of the connection.

· bit 8--MAC for local loop.

· bit 9--MAC on physical output.

phy-a (Optional) Selects Physical Sublayer A.
phy-b (Optional) Selects Physical Sublayer B.
Defaults

The default signal bits for the phy-a and phy-b keywords are as follows:

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If neither the phy-a nor phy-b keyword is specified, the signal bits apply to both physical connections.


Note Use of the fddi cmt-signal-bits configuration command is not recommended under normal operations. This command is used when debugging specific CMT implementation issues.

Use Table 21 and Table 22 to set the physical type and duration bits.


Table 21: FDDI Physical Type Bit Specifications
Bit 2 Bit 1 Physical Type
0 0 Physical A
1 0 Physical B
0 1 Physical S
1 1 Physical M


Table 22: FDDI Link Confidence Test Duration Bit Specification
Bit 5 Bit 4 Test Duration
0 0 Short test (default 50 ms)
1 0 Medium test (default 500 ms)
0 1 Long test (default 5 seconds)
1 1 Extended test (default 50 seconds)
Example

The following example sets the CMT signaling phase to signal bits 0x208 on both physical connections:

interface fddi 0
fddi cmt-signal-bits 208

fddi duplicate-address-check

To turn on the duplicate address detection capability on the FDDI, use the fddi duplicate-address-check interface configuration command. Use the no form of this command to disable this feature.

fddi duplicate-address-check
no fddi duplicate-address-check

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 10.0.

If you use this command, the Cisco IOS software will detect a duplicate address if multiple stations are sharing the same MAC address. If the software finds a duplicate address, it will shut down the interface.

Example

The following example enables duplicate address checking on the FDDI:

interface fddi 0
fddi duplicate-address-check

fddi encapsulate

To specify encapsulating bridge mode on the CSC-C2/FCIT interface card, use the fddi encapsulate interface configuration command. Use the no form of this command to turn off encapsulation bridging and return the FCIT interface to its translational, nonencapsulating mode.

fddi encapsulate
no fddi encapsulate

Syntax Description

This command has no arguments or keywords.

Default

The FDDI interface by default uses the SNAP encapsulation format defined in RFC 1042. It is not necessary to define an encapsulation method for this interface when using the CSC-FCI interface card.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The no fddi encapsulate command applies only to CSC-C2/FCIT interfaces, because the CSC-FCI interfaces are always in encapsulating bridge mode. The CSC-C2/FCIT interface card fully supports transparent and translational bridging for the following configurations:

The command fddi encapsulate puts the CSC-C2/FCIT interface into encapsulation mode when doing bridging. In transparent mode, the FCIT interface interoperates with earlier versions of the CSC-FCI encapsulating interfaces when performing bridging functions on the same ring.

 
Caution Bridging between dissimilar media presents several problems that can prevent communications from occurring. These problems include bit-order translation (or usage of MAC addresses as data), maximum transfer unit (MTU) differences, frame status differences, and multicast address usage. Some or all of these problems might be present in a multimedia bridged LAN and might prevent communication from taking place. These problems are most prevalent when bridging between Token Rings and Ethernets or between Token Rings and FDDI nets. This is because of the different way Token Ring is implemented by the end nodes.

The following protocols have problems when bridged between Token Ring and other media: Novell IPX, DECnet Phase IV, AppleTalk, VINES, XNS, and IP. Further, the following protocols may have problems when bridged between FDDI and other media: Novell IPX and XNS. We recommend that these protocols be routed whenever possible.

Example

The following example sets FDDI interface 1 on the CSC-C2/FCIT interface card to encapsulating bridge mode:

interface fddi 1
fddi encapsulate

fddi smt-frames

To enable the SMT frame processing capability on the FDDI, use the fddi smt-frames interface configuration command. Use the no form of this command to disable this feature and prevent the Cisco IOS software from generating or responding to SMT frames.

fddi smt-frames
no fddi smt-frames

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 10.0.

Use the no form of this command to turn off SMT frame processing for diagnosing purposes. Use the fddi smt-frames command to reenable the feature.

Example

The following example disables SMT frame processing:

interface fddi 0
no fddi smt-frames

fddi tb-min

To set the TB-Min timer in the physical connection management (PCM), use the fddi tb-min interface configuration command. Use the no form of this command to revert to the default value.

fddi tb-min milliseconds
no fddi tb-min

Syntax Description
milliseconds Sets the TB-Min timer value in milliseconds.
Default

100 ms

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to the processor CMT only. You need extensive knowledge of the PCM state machine to tune this timer. Use this command when you run into PCM interoperability problems.

Example

The following example sets the TB-Min timer to 200 ms:

interface fddi 0
fddi tb-min 200
Related Commands

fddi c-min
fddi tl-min-time
fddi t-out

fddi tl-min-time

To control the TL-Min time (the minimum time to transmit a Physical Sublayer, or PHY line state, before advancing to the next physical connection management (PCM) state, as defined by the X3T9.5 specification), use the fddi tl-min-time interface configuration command.

fddi tl-min-time microseconds
Syntax Description
microseconds Integer that specifies the time used during the connection management (CMT) phase to ensure that signals are maintained for at least the value of TL-Min so the remote station can acquire the signal.
Default

30 microseconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Interoperability tests have shown that some implementations of the FDDI standard need more than 30 microseconds to sense a signal.

Examples

The following example changes the TL-Min time from 30 microseconds to 100 microseconds:

interface fddi 0
fddi tl-min-time 100

The following example changes the TL-Min time from 30 microseconds to 100 microseconds on a Cisco 7000:

interface fddi 3/0
fddi tl-min-time 100
Related Commands

fddi c-min
fddi tl-min-time
fddi t-out

fddi token-rotation-time

To control ring scheduling during normal operation and to detect and recover from serious ring error situations, use the fddi token-rotation-time interface configuration command.

fddi token-rotation-time microseconds
Syntax Description
microseconds Integer that specifies the token rotation time (TRT).
Default

5000 microseconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The FDDI standard restricts the allowed time to be greater than 4000 microseconds and less than 165,000 microseconds. As defined in the X3T9.5 specification, the value remaining in the TRT is loaded into the token holding timer (THT). Combining the values of these two timers provides the means to determine the amount of bandwidth available for subsequent transmissions.

Examples

The following example sets the rotation time to 24,000 microseconds:

interface fddi 0
fddi token-rotation-time 24000

The following example sets the rotation time to 24,000 microseconds on a Cisco 7000:

interface fddi 3/0
fddi token-rotation-time 24000

fddi t-out

To set the t-out timer in the physical connection management (PCM), use the fddi t-out interface configuration command. Use the no form of this command to revert to the default value.

fddi t-out milliseconds
no fddi t-out

Syntax Description
milliseconds Sets the timeout timer.
Default

100 ms

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command applies to the processor CMT only. You need extensive knowledge of the PCM state machine to tune this timer. Use this command when you run into PCM interoperability problems.

Example

The following example sets the timeout timer to 200 ms:

interface fddi 0
fddi t-out 200
Related Commands

fddi c-min
fddi tb-min
fddi tl-min-time

fddi valid-transmission-time

To recover from a transient ring error, use the fddi valid-transmission-time interface configuration command.

fddi valid-transmission-time microseconds
Syntax Description
microseconds Integer that specifies the transmission valid timer (TVX) interval.
Default

2500 microseconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Examples

The following example changes the transmission timer interval to 3000 microseconds:

interface fddi 0
fddi valid-transmission-time 3000

The following example changes the transmission timer interval to 3000 microseconds on a Cisco 7000 or Cisco 7200:

interface fddi 3/0
fddi valid-transmission-time 3000

fdl

To set the facilities data-link exchange standard for the CSU on the T1 controllers on the Cisco AS5200, enter the fdl controller configuration command. To disable facilities data-link support, use the no form of this command.

fdl {att | ansi}
no fdl
{att | ansi}
Syntax Description
att Selects AT&T technical reference 54016 for Extended Super Frame facilities data-link exchange support.
ansi Selects ANSI T1.403 for Extended Super Frame facilities data-link exchange support.
Default

Disabled

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

You must configure this command on both T1 controllers if you want to support the CSU function on each T1 line. However, you must use the same facilities data-link exchange standard as your service provider. You can have a different standard configured on each T1 interface.

Example

The following example configures the ANSI T1.403 standard for T1 controller 0:

controller t1 0
fdl ansi

framing

Use the framing controller configuration command to select the frame type for the T1 or E1 data line.

framing {sf | esf} (for T1 lines)
framing {crc4 | no-crc4} [australia] (for E1 lines)

Syntax Description
sf Specifies Super Frame as the T1 frame type.
esf Specifies Extended Super Frame as the T1 frame type.
crc4 Specifies CRC4 frame as the E1 frame type.
no-crc4 Specifies no CRC4 frame as the E1 frame type.
australia (Optional) Specifies the E1 frame type used in Australia.
Defaults

Super Frame is the default on a T1 line.

CRC4 frame is the default on an E1 line.

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 as framing {sf | esf}.

Use this command in configurations where the router or access server is intended to communicate with T1 or E1 fractional data line. The service provider determines which framing type, either sf, esf, or crc4, is required for your T1/E1 circuit.

Example

The following example selects Extended Super Frame as the T1 frame type:

framing esf
Related Commands

channel-group
linecode

group-range

To create a list of member asynchronous interfaces (associated with a group interface), use the group-range interface configuration command. Use the no form of the command to remove an interface from the member list.

group-range low-end-of-range high-end-of-range
no group-number interface

Syntax Description
low-end-of-range Beginning interface number to be made a member of the group interface.
high-end-of-range Ending interface number to be made a member of the group interface.
interface Interface number to add to the group.
Default

No interfaces are designated as members of a group.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Using the group-range command, you create a group of asynchronous interfaces that are associated with a group asynchronous interface on the same device. This group interface is configured by using the interface group-async command. This one-to-many structure allows you to configure all associated member interfaces by entering one command on the group interface, rather than entering this command on each interface. You can customize the configuration on a specific interface by using the member command.

Examples

The following example defines interfaces 2, 3, 4, 5, 6, and 7 as members of asynchronous group interface 0:

interface group-async 0
group range 2 7 
Related Commands

interface group-async
member

half-duplex

Use the half-duplex interface configuration command to configure an SDLC interface for half-duplex mode. Use the no form of this command to reset the interface for full-duplex mode.

half-duplex
no half-duplex

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 11.2.

The half-duplex command is used to configure an SDLC interface for half-duplex mode.

The half-duplex command deprecates the both the sdlc hdx and media-type half-duplex commands.


Note The media-type half-duplex command exists in Cisco IOS Release 11.0(5). As of Release 11.0(6), the keyword half-duplex was removed from the media-type command. In Release 11.0(6), the functionality for specifying half duplex mode is provided by the half-duplex command.
Example

In the following example, an SDLC interface has been configured for half-duplex mode:

encapsulation sdlc-primary
half-duplex
Related Command

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

half-duplex timer +

half-duplex controlled-carrier

To place a low-speed serial interface in controlled-carrier mode, instead of constant-carrier mode, use the half-duplex controlled-carrier interface configuration command. Use the no form of this command to return the interface to constant-carrier mode.

half-duplex controlled-carrier
no half-duplex controlled-carrier

Syntax Description

This command has no arguments or keywords.

Default

Constant-carrier mode, where DCD is held constant and asserted by the DCE half-duplex interface.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies only to low-speed serial DCE interfaces in half-duplex mode. Configure a serial interface for half-duplex mode by using the media-type half-duplex command. These interfaces are available on Cisco 2520 through 2523 routers.

Controlled-carrier operation means that the DCE interface will have DCD deasserted in the quiescent state. When the interface has something to transmit, it will assert DCD, wait a user-configured amount of time, then start the transmission. When the interface has finished transmitting, it will again wait a user-configured amount of time, then deassert DCD.

An interface placed in controlled-carrier mode can be returned to constant-carrier mode by using the no form of the command.

Examples

The following examples show how to place the interface in controlled-carrier mode and back into constant-carrier operation.

Changing to controlled-carrier mode from the default of constant-carrier operation:

interface serial 2
half-duplex controlled-carrier

Changing to constant-carrier operation from controlled-carrier mode:

interface serial 2
no half-duplex controlled-carrier
Related Commands

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

half-duplex timer +
physical-layer +

hold-queue

To specify the hold-queue limit of an interface, use the hold-queue interface configuration command. Use the no form of this command with the appropriate keyword to restore the default values for an interface.

hold-queue length {in | out}
no hold-queue {in | out}

Syntax Description
length Integer that specifies the maximum number of packets in the queue.
in Specifies the input queue.
out Specifies the output queue.
Default

The default input hold-queue limit is 75 packets. The default output hold-queue limit is 40 packets. These limits prevent a malfunctioning interface from consuming an excessive amount of memory. There is no fixed upper limit to a queue size.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The input hold queue prevents a single interface from flooding the network server with too many input packets. Further input packets are discarded if the interface has too many input packets outstanding in the system.

If priority output queueing is being used, the length of the four output queues is set using the priority-list global configuration command. The hold-queue command cannot be used to set an output hold queue length in this situation.

For slow links, use a small output hold-queue limit. This approach prevents storing packets at a rate that exceeds the transmission capability of the link. For fast links, use a large output hold-queue limit. A fast link may be busy for a short time (and thus require the hold queue), but can empty the output hold queue quickly when capacity returns.

To display the current hold queue setting and the number of packets discarded because of hold queue overflows, use the EXEC command show interfaces.


Note Increasing the hold queue can have detrimental effects on network routing and response times. For protocols that use seq/ack packets to determine round trip times, do not increase the output queue. Dropping packets instead informs hosts to slow down transmissions to match available bandwidth. This is generally better than having duplicate copies of the same packet within the network (which can happen with large hold queues).
Example

The following example illustrates how to set a small input queue on a slow serial line:

interface serial 0
hold-queue 30 in
Related Command

show interfaces

hssi external-loop-request

To allow the router to support a CSU/DSU that uses the LC signal to request a loopback from the router, use the hssi external-loop-request interface configuration command. Use the no form of this command to disable the feature.

hssi external-loop-request
no hssi external-loop-request

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 10.0.

The HSA applique (on the HSSI) contains an LED that indicates the LA, LB, and LC signals transiting through the devices. The CSU/DSU uses the LC signal to request a loopback from the router. The CSU/DSU may want to do this so that its own network management diagnostics can independently check the integrity of the connection between the CSU/DSU and the router.

Use this command to enable a two-way, internal, and external loopback request on HSSI from the CSU/DSU.


Note If your CSU/DSU does not support this feature, it should not be enabled in the router. Not enabling this feature prevents spurious line noise from accidentally tripping the external loopback request line, which would interrupt the normal data flow.
Example

The following example enables a CSU/DSU to use the LC signal to request a loopback from the router:

hssi external-loop-request

hssi internal-clock

To convert the HSSI interface into a 45 MHz clock master, use the hssi internal-clock interface configuration command. Use the no form of this command to disable the clock master mode.

hssi internal-clock
no hssi internal-clock

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 10.0.

Use this command in conjunction with the HSSI null-modem cable to connect two Cisco routers together with HSSI. You must configure this command at both ends of the link, not just one.

Example

The following example converts the HSSI interface into a 45 MHz clock master:

hssi internal-clock

hub

To enable and configure a port on an Ethernet hub of a Cisco 2505 or Cisco 2507, use the hub global configuration command.

hub ethernet number port [end-port]
Syntax Description
ethernet Indicates that the hub is in front of an Ethernet interface.
number Hub number, starting with 0. Since there is currently only one hub, this number is 0.
port Port number on the hub. On the Cisco 2505, port numbers range from 1 through 8. On the Cisco 2507, port numbers range from 1 through 16. If a second port number follows, then the first port number indicates the beginning of a port range.
end-port (Optional) Last port number of a range.
Default

No hub ports are configured.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Examples

The following example enables port 1 on hub 0:

hub ethernet 0 1
no shutdown

The following example enables ports 1 through 8 on hub 0:

hub ethernet 0 1 8
no shutdown
Related Command

shutdown

ignore-dcd

Use the ignore-dcd interface configuration command to configure the serial interface to monitor the DSR signal (instead of the DCD signal) as the line up/down indicator. Use the no form of this command to restore the default behavior.

ignore-dcd
no ignore-dcd

Syntax Description

This command has no arguments or keywords.

Default

The serial interface, operating in DTE mode, monitors the DCD signal as the line up/down indicator.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

This command applies to Quad Serial NIM interfaces on the Cisco 4000 series and Hitachi-based serial interfaces on the Cisco 2500 series and Cisco 3000 series.

When the serial interface is operating in DTE mode, it monitors the Data Carrier Detect (DCD) signal as the line up/down indicator. By default, the attached DCE device sends the DCD signal. When the DTE interface detects the DCD signal, it changes the state of the interface to up.

In some configurations, such as an SDLC multidrop environment, the DCE device sends the Data Set Ready (DSR) signal instead of the DCD signal, which prevents the interface from coming up. Use this command to tell the interface to monitor the DSR signal instead of the DCD signal as the line up/down indicator.

Example

The following example configures serial interface 0 to monitor the DSR signal as the line up/down indicator:

interface serial 0
ignore-dcd

interface

To configure an interface type and enter interface configuration mode, use the interface global configuration command.

interface type number
interface
type slot/port  (for the Cisco 7000 series and Cisco 7200 series, and for the Cisco 7500 series with a Packet over SONET Interface Processor)
interface [type slot/port-adapter/port] [ethernet | serial]  (for ports on VIP cards in the Cisco 7000 and the 7500 series routers)
interface serial slot/port:channel-group  (for channelized T1 or E1 on the Cisco 7000 series)
interface serial number:channel-group  (for channelized T1 or E1 on the Cisco 4000 series)

To configure a subinterface, use the interface global configuration command.

interface type slot/port-adapter/port.subinterface-number {multipoint | point-to-point} (for ports on VIP cards in the Cisco 7000 and the 7500 series routers)
interface type slot/port.subinterface-number {multipoint | point-to-point} (for the Cisco 7000 series and Cisco 7200 series)
interface type slot/port-adapter.subinterface-number {multipoint | point-to-point}  (for the Cisco 7500 series)

Syntax Description
type Type of interface to be configured. See Table 23.
number Port, connector, or interface card number. On a Cisco 4000 series router, specifies the NPM number. The numbers are assigned at the factory at the time of installation or when added to a system, and can be displayed with the show interfaces command.
slot On the Cisco 7000 series and Cisco 7200 series, specifies the backplane slot number. On the 7000, value can be 0, 1, 2, 3, or 4. On the Cisco 7010, value can be 0, 1, or 2. The slots are numbered from left to right. On the Cisco 7505, the slot number can be 0. 1, 2, or 3 from bottom to top. On the Cisco 7507, the slot number can be 0 and 1 (CyBus0) and 4 through 6 (Cybus1), from left to right. On the Cisco 7513, the slot numbers are 0 through 5 (CyBus 0) and 8 through 12 (CyBus 1), from left to right.
port Port number on the interface. On the Cisco 7000 series and Cisco 7200 series this argument is required, and the value can be 0, 1, 2, 3, 4, 5, 6, or 7 depending on the type of interface, as follows:

· AIP (ATM Interface Processor) 0

· EIP (Ethernet Interface Processor) 0, 1, 2, 3, 4, or 5

· FEIP (Fast Ethernet Interface Processor) 0, 1

· FIP (FDDI Interface Processor) 0

· FSIP (Fast Serial Interface Processor) 0, 1, 2, 3, 4, 5, 6, or 7

· HIP (HSSI Interface Processor) 0

· MIP (MultiChannel Interface Processor) 0 or 1

· TRIP (Token Ring Interface Processor) 0, 1, 2, or 3

On the Cisco 7000 series and 7200 series, ports on each interface processor are numbered from the top down.

(Optional) Port number of the interface. For the VIP card this argument is optional, and the value can be the following:

· 0 for one-port Fast Ethernet interfaces

· 0, 1, 2, or 3 for four-port Ethernet interfaces

· 0, 1, 2, or 3 for four-port serial interfaces

· 0, 1, 2, or 3 for four-port Token Ring interfaces

· 0 for one-port FDDI interfaces

port-adapter (Optional) On the Cisco 7000 and Cisco 7500 series, specifies the ports on a VIP card. The value can be 0 or 1.
:channel-group On the Cisco 4000 series or Cisco 7000 series, specifies the T1 channel group number in the range of 0 to 23 defined with the channel-group controller configuration command. On a dual port card, it is possible to run channelized on one port and primary rate on the other port.
.subinterface-number Subinterface number in the range 1 to 4294967293. The number that precedes the period (.) must match the number this subinterface belongs to.
multipoint | point-to-point Specifies a multipoint or point-to-point subinterface. There is no default.
Default

None

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 for the Cisco 7000 series.
This command first appeared in Cisco IOS Release 11.0 for the Cisco 4000 series.

Subinterfaces can be configured to support partially meshed Frame Relay networks (refer to the chapter entitled "Configuring Interfaces" in the Configuration Fundamentals Configuration Guide).

There is no correlation between the number of the physical serial interface and the number of the logical LAN Extender interface. These interfaces can have the same or different numbers.


Table 23: Interface Type Keywords
Keyword Interface Type
async Port line used as an asynchronous interface.
atm ATM interface.
bri Integrated Services Digital Network (ISDN) Basic Rate Interface (BRI). This interface configuration is propagated to each of the B channels. B channels cannot be individually configured. The interface must be configured with dial-on-demand commands in order for calls to be placed on that interface.
dialer Dialer interface.
ethernet Ethernet IEEE 802.3 interface.
fastethernet 100-Mbps Ethernet interface on the Cisco 4500, Cisco 4700, Cisco 7000 series and Cisco 7500 series.
fddi Fiber Distributed Data Interface (FDDI).
group-async Master asynchronous interface.
hssi High-Speed Serial Interface (HSSI).
lex LAN Extender (LEX) interface.
loopback Software-only loopback interface that emulates an interface that is always up. It is a virtual interface supported on all platforms. The interface-number is the number of the loopback interface that you want to create or configure. There is no limit on the number of loopback interfaces you can create.
null Null interface.
posi Packet OC-3 interface on the Packet over SONET Interface Processor
serial Serial interface.
tokenring Token Ring interface.
tunnel Tunnel interface; a virtual interface. The number is the number of the tunnel interface that you want to create or configure. There is no limit on the number of tunnel interfaces you can create.
Examples

In the following example, serial interface 0 is configured with PPP encapsulation:

interface serial 0
encapsulation ppp

The following example enables loopback mode and assigns an IP network address and network mask to the interface. The loopback interface established here will always appear to be up:

interface loopback 0
ip address 131.108.1.1 255.255.255.0

The following example for the Cisco 7000 shows the interface configuration command for Ethernet port 4 on the EIP that is installed in (or recently removed from) slot 2:

interface ethernet 2/4

The following example begins configuration on the Token Ring interface processor in slot 1 on
port 0 of a Cisco 7000:

interface tokenring 1/0

The following example shows how a partially meshed Frame Relay network can be configured. In this example, subinterface serial 0.1 is configured as a multipoint subinterface with three frame relay PVCs associated, and subinterface serial 0.2 is configured as a point-to-point subinterface.

interface serial 0
encapsulation frame-relay
interface serial 0.1 multipoint
ip address 131.108.10.1 255.255.255.0
frame-relay interface-dlci 42 broadcast
frame-relay interface-dlci 53 broadcast
interface serial 0.2 point-to-point
ip address 131.108.11.1 255.255.0
frame-relay interface-dlci 59 broadcast

The following example configures circuit 0 of a T1 link for Point-to-Point Protocol (PPP) encapsulation:

controller t1 4/1
circuit 0 1
interface serial 4/1:0
ip address 131.108.13.1 255.255.255.0
encapsulation ppp

The following example configures LAN Extender interface 0:

interface lex 0
Related Commands

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

circuit
controller
mac-address
+
ppp +
show interfaces
slip
+

interface dialer

To designate a dialer rotary group leader, use the interface dialer global configuration command.

interface dialer interface-number
Syntax Description
interface-number Integer in the range 0 to 9 that you select to indicate a dialer rotary group.
Default

None

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Dialer rotary groups allow you to apply a single interface configuration to a set of interfaces. Once the interface configuration is propagated to a set of interfaces, those interfaces can be used to place calls using the standard dial-on-demand criteria. When many destinations are configured, any of these interfaces can be used for outgoing calls.

Dialer rotary groups are useful in environments that require many calling destinations. Only the rotary group needs to be configured with all of the dialer map commands. The only configuration required for the interfaces is the dialer rotary-group command that indicates which interface is part of a dialer rotary group.

Although a dialer rotary group is configured as an interface, it is not a physical interface. Instead it represents a group of interfaces. Any number of dialer groups can be defined.

Interface configuration commands entered after the interface dialer command will be applied to all physical interfaces assigned to specified rotary group.

Example

The following example identifies dialer interface 1 as the dialer rotary group leader. Dialer interface 1 is not a physical interface, but represents a group of interfaces. The interface configuration commands that follow apply to all interfaces included in this group.

interface dialer 1
encapsulation ppp
dialer in-band
dialer map ip 172.30.2.5 username YYY 14155553434
dialer map ip 172.30.4.5 username ZZZ
Related Command

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

dialer rotary-group +

interface fastethernet

To select a particular Fast Ethernet interface for configuration, use the interface fastethernet global configuration command.

interface fastethernet number (Cisco 4500 series and Cisco 4700 series)
interface fastethernet
slot/port (Cisco 7000 series and Cisco 7200 series)
interface fastethernet slot/port-adapter/port (Cisco 7500 series)

Syntax Description
number Port, connector, or interface card number. On a Cisco 4500 or Cisco 4700 router, specifies the NIM or NPM number. The numbers are assigned at the factory at the time of installation or when added to a system.
slot On the Cisco 7000 series, slot location of the FEIP. On the Cisco 7200, slot 0 is the Fast Ethernet port on the I/O controller.
port On the Cisco 7000 series, port number on the interface.
port-adapter On the Cisco 7000 and 7500 series, specifies the port bay on a VIP card. The value can be 0 or 1.
Default

None

Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Examples

The following example configures Fast Ethernet interface 0 for standard Advanced Research Projects Agency (ARPA) encapsulation (the default setting) on a Cisco 4500 or Cisco 4700 router:

interface fastethernet 0
Related Command

show interfaces fastethernet

interface group-async

To create a group interface that will serve as master, to which asynchronous interfaces can be associated as members, use the interface group-async command. Use the no form of the command to restore the default.

interface group-async number
no interface group-async number

Syntax Description
number Number of the asynchronous group interface being created.
Default

No interfaces are designated as group masters.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Using the interface group-async command, you create a single asynchronous interface to which other interfaces are associated as members using the group-range command. This one-to-many configuration allows you to configure all associated member interfaces by entering one command on the group master interface, rather than entering this command on each individual interface. You can create multiple group masters on a device; however, each member interface can only be associated with one group.

Examples

The following example defines asynchronous group master interface 0:

interface group-async 0
Related Commands

group-range
member

invert-transmit-clock

Delays between the SCTE clock and data transmission indicate that the transmit clock signal might not be appropriate for the interface rate and length of cable being used. Different ends of the wire may have variances that differ slightly. To invert the clock signal to compensate for these factors, use the invert-transmit-clock interface configuration command. This command applies only to the Cisco 7000 series and Cisco 7500 series. To return to the transmit clock signal to its initial state, use the no form of this command.

invert-transmit-clock
no invert-transmit-clock

Syntax Description

This command has no arguments or keywords.

Default

Not inverted

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, the clock signal on serial interface 3/0 is inverted.

interface serial 3/0
invert-transmit-clock

ip address-pool

To enable an address pooling mechanism used to supply IP addresses to dial-in asynchronous, synchronous, or ISDN point-to-point interfaces, use the ip address-pool global configuration command. To disable IP address pooling globally on all interfaces with the default configuration, use the no form of the command.

ip address-pool [dhcp-proxy-client | local]
no ip address-pool

Syntax Description
dhcp-proxy-client (Optional) Uses the router as the proxy-client between a third-party Dynamic Host Configuration Protocol (DHCP) server and peers connecting to the router.
local (Optional) Uses the local address pool named default.
Default

IP address pooling is disabled.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The global default mechanism applies to all interfaces that have been left in the default setting of the peer default ip address pool command.

If any peer default ip address command other than peer default ip address pool (the default) is configured, then the interface uses that mechanism and not the global default mechanism. Thus all interfaces can be independently configured or left unconfigured so that the global default mechanism setting apply. This flexibility minimizes the configuration effort on the part of the administrator.

Examples

The following example specifies the DHCP proxy client mechanism as the global default mechanism for assigning peer IP addresses:

ip address-pool dhcp-proxy-client

The following example specifies a local IP address pool called default as the global default mechanism for all interfaces that have been left in their default setting:

ip address-pool local
Related Commands

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

encapsulation ppp +
encapsulation slip +
ip dhcp-server
ip local pool
member peer default ip address
peer default ip address

peer default ip address pool
ppp
+
show dhcp
show ip local pool
slip
+

ip dhcp-server

To specify which Dynamic Host Configuration Protocol (DHCP) servers to use on your network, specify the IP address of one or more DHCP servers available on the network, use the ip dhcp-server global configuration command. Use the no form of the command to remove a DHCP server's IP address.

ip dhcp-server [ip-address | name]
no ip dhcp-server [ip-address | name]

Syntax Description
ip-address (Optional) IP address of a DHCP server.
name (Optional) Name of a DHCP server.
Default

The IP limited broadcast address of 255.255.255.255 is used for transactions if no DHCP server is specified. This allows automatic detection of DHCP servers.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

A DHCP server temporarily allocates network addresses to clients through the access server on an as-needed basis. While the client is active, the address is automatically renewed in a minimum of 20-minute increments. When the user terminates the session, the interface connection is terminated so that network resources can be quickly reused. You can specify up to ten servers on the network.

In normal situations, if a user's SLIP/PPP session fails (for example if a modem line disconnects), the allocated address will be reserved temporarily to preserve the same IP address for the client when dialed back into the server. This way, the session that was accidentally terminated can often be resumed.

To use the DHCP proxy-client feature, enable your access server to be a proxy-client on asynchronous interfaces by using the ip address-pool dhcp-proxy-client command. If you wish to specify which DHCP servers are used on your network, use the ip dhcp-server command to define up to ten specific DHCP servers.


Note To facilitate transmission, configure intermediary routers (or access servers with router functionality) to use an ip helper address whenever the DHCP server is not on the local LAN and the access server is using broadcasts to interact with the DHCP server. See "Configuring IP" in this publication.

The ip address-pool dhcp-proxy-client command initializes proxy-client status to all interfaces defined as asynchronous on the access server. To selectively disable proxy-client status on a single asynchronous interface, use the no peer default ip address interface command.


Note To facilitate transmission, configure intermediary routers to use an ip helper address whenever the DHCP server is not on the local LAN and the router is using broadcasts to interact with the DHCP server. See "Configuring IP" in the Configuration Fundamentals Configuration Guide.
Example

The following command specifies a DHCP server with the IP address of 129.12.13.81:

ip dhcp-server 129.12.13.81
Related Commands

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

ip address-pool dhcp-proxy-client
ip helper address
+
peer default ip address pool
show dhcp
+

ip local pool

To configure a local pool of IP addresses to be used when a remote peer connects to a point-to-point interface, use the ip local pool global configuration command. To delete an address pool, use the no form of this command.

ip local pool {default | pool-name low-ip-address [high-ip-address]}
no ip local pool
{default | poolname}
Syntax Description
default Default local address pool that is used if no other pool is named.
pool-name Name of a specific local address pool.
low-ip-address Lowest IP address in the pool.
high-ip-address (Optional) Highest IP address in the pool. If this value is omitted only the low-ip-address IP address is included in the local pool. The maximum number of IP addresses per pool is 256.
Default

No address pools are configured.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

Use the ip local pool command to create one or more local address pools from which IP addresses are assigned when a peer connects. The default address pool is then used on all point-to-point interfaces after the ip address-pool local global configuration command is issued. To use a specific, named address pool on an interface, use the peer default ip address pool interface configuration command.

These pools can also be used with the translate command for one-step vty-async connections and in certain AAA/TACACS+ authorization functions. Refer to the "Protocol Translation" chapter in the Access Services Configuration Guide and the "System Management" chapter of the Configuration Fundamentals Configuration Guide for more information. Pools can be displayed with the show ip local pool command.

Example

The following command creates a local IP address pool by the name of quark, which contains all local IP addresses from 172.16.23.0 to 172.16.23.255:

ip local pool quark 172.16.23.0 172.16.23.255 
Related Commands

ip address-pool
show ip local pool

isdn incoming-voice modem

To enable incoming ISDN voice calls to access the AS5200 call switch module and integrated modems, use the isdn incoming-voice modem interface configuration command. The no form of this command stops all incoming ISDN analog calls from routing to the modems.

isdn incoming-voice modem
no isdn incoming-voice modem

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 11.2.

Incoming ISDN digital calls are unaffected by this command. ISDN digital calls directly connect to network resources even when the no isdn incoming-voice modem command is configured.

Example

The following example enables incoming and outgoing ISDN calls to route to the modems using the D channel serial interface:

interface serial 0:23 
isdn incoming-voice modem

keepalive

To set the keepalive timer for a specific interface, use the keepalive interface configuration command. To turn off keepalives entirely, use the no form of this command.

keepalive [seconds]
no keepalive
[seconds]
Syntax Description
seconds (Optional) Unsigned integer value greater than 0. The default is 10 seconds.
Default

Enabled and set to 10 seconds on most interfaces; disabled on asynchronous interfaces.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Asynchrounous interfaces do not send and do not expect keepalives from the remote end of a point-to-point connection. To enable keepalives on asynchrounous interfaces, use the keepalive command and set a specific interval.

You can configure the keepalive interval, which is the frequency at which the Cisco IOS software sends messages to itself (Ethernet and Token Ring) or to the other end (serial), to ensure a network interface is alive. The interval in previous software versions was 10 seconds; it is now adjustable in 1-second increments down to 1 second. An interface is declared down after three update intervals have passed without receiving a keepalive packet.

Setting the keepalive timer to a low value is very useful for rapidly detecting Ethernet interface failures (transceiver cable disconnecting, cable unterminated, and so on).

A typical serial line failure involves losing Carrier Detect (CD) signal. Because this sort of failure is typically noticed within a few milliseconds, adjusting the keepalive timer for quicker routing recovery is generally not useful.


Note When adjusting the keepalive timer for a very low bandwidth serial interface, large datagrams can delay the smaller keepalive packets long enough to cause the line protocol to go down. You may need to experiment to determine the best value.
Example

The following example sets the keepalive interval to 3 seconds:

interface ethernet 0
keepalive 3

lex burned-in-address

To set the burned-in MAC address for a LAN Extender interface, use the lex burned-in-address interface configuration command. To clear the burned-in MAC address, use the no form of this command.

lex burned-in-address ieee-address
no lex burned-in-address

Syntax Description
ieee-address 48-bit IEEE MAC address written as a dotted triplet of four-digit hexadecimal numbers.
Default

No burned-in MAC address is set

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Use this command only on a LAN Extender interface that is not currently active (not bound to a serial interface).

Example

The following example sets the burned-in MAC address on LAN Extender interface 0:

interface serial 4
encapsulation ppp
interface lex 0
lex burned-in-address 0000.0c00.0001
ip address 131.108.172.21 255.255.255.0

lex input-address-list

To assign an access list that filters on MAC addresses, use the lex input-address-list interface configuration command. To remove an access list from the interface, use the no form of this command.

lex input-address-list access-list-number
no lex input-address-list

Syntax Description
access-list-number Number of the access list you assigned with the access-list global configuration command. It can be a number from 700 to 799.
Default

No access lists are preassigned to a LAN Extender interface.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3 (The no 1ex input-address-list command first appeared in Cisco IOS Release 10.0.)

Use the lex input-address-list command to filter the packets that are allowed to pass from the LAN Extender to the core router. The access list filters packets based on the source MAC address.

The LAN Extender interface does not process MAC-address masks. Therefore, you should omit the mask from the access-list commands.

For LAN Extender interfaces, an implicit permit everything entry is automatically defined at the end of an access list. Note that this default differs from other access lists, which have an implicit deny everything entry at the end of each access list.

Example

The following example applies access list 710 to LAN Extender interface 0. This access list denies all packets from MAC address 0800.0214.2776 and permits all other packets.

access-list 710 deny 0800.0214.2776 
interface lex 0
lex input-address-list 710
Related Command

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

access-list +

lex input-type-list

To assign an access list that filters Ethernet packets by type code, use the lex input-type-list interface configuration command. To remove an access list from the interface, use the no form of this command.

lex input-type-list access-list-number
no lex input-type-list

Syntax Description
access-list-number Number of the access list you assigned with the access-list global configuration command. It can be a number in the range 200 to 299.
Default

No access lists are preassigned to a LAN Extender interface.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Filtering is done on the LAN Extender chassis.

The LAN Extender interface does not process masks. Therefore, you should omit the mask from the access-list commands.

For LAN Extender interfaces, an implicit permit everything entry is automatically defined at the end of an access list. Note that this default differs from other access lists, which have an implicit deny everything entry at the end of each access list.

Example

The following example applies access list 220 to LAN Extender interface 0. This access list denies all AppleTalk packets (packets with a type field of 0x809B) and permits all other packets.

access-list 220 deny 0x809B 0x0000
interface lex 0
lex input-type-list 220
Related Command

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

access-list +

lex priority-group

To activate priority output queuing on the LAN Extender, use the lex priority-group interface configuration command. To disable priority output queuing, use the no form of this command.

lex priority-group group
no lex priority-group

Syntax Description
group Number of the priority group. It can be a number in the range 1 to 10.
Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

To define queuing priorities, use the priority-list protocol global configuration command. Note that you can use only the following forms of this command:

priority-list list protocol protocol {high | medium | normal | low}
priority-list list protocol bridge {high | medium | normal | low} list list-number

If you specify a protocol that does not have an assigned Ethernet type code, such as x25, stun, or pad, it is ignored and will not participate in priority output queuing.

Example

The following example activates priority output queuing on LAN Extender interface 0:

priority-list 5 protocol bridge medium list 701
lex interface 0
lex priority-group 5
Related Command

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

priority-list protocol +

lex retry-count

To define the number of times to resend commands to the LAN Extender chassis, use the lex retry-count interface configuration command. To return to the default value, use the no form of this command.

lex retry-count number
no lex retry-count
[number]

Syntax Description
number Number of times to retry sending commands to the LAN Extender. It can be a number in the range 0 to 100. The default is 10 times.
Default

10

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

After the core router has sent a command the specified number of times without receiving an acknowledgment from the LAN Extender, it stops sending the command altogether.

Example

The following example resends commands 20 times to the LAN Extender:

lex interface 0
lex retry-count 20
Related Command

lex timeout

lex timeout

To define the amount of time to wait for a response from the LAN Extender, use the lex timeout interface configuration command. To return to the default time, use the no form of this command.

lex timeout milliseconds
no lex timeout
[milliseconds]

Syntax Description
milliseconds Time, in milliseconds, to wait for a response from the LAN Extender before resending the command. It can be a number in the range 500 to 60000. The default is 2000 ms (2 seconds).
Default

2000 ms (2 seconds)

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The lex timeout command defines the amount of time that the core router will wait to receive an acknowledgment after having sent a command to the LAN Extender.

Example

The following example causes unacknowledged packets to be resent at 4-second intervals:

lex interface 0
lex timeout 4000
Related Command

lex retry-count

linecode

Use the linecode controller configuration command to select the line-code type for the T1 or E1 line.

linecode {ami | b8zs | hdb3}
Syntax Description
ami Specifies alternate mark inversion (AMI) as the line-code type. Valid for T1 or E1 controllers; the default for T1 lines.
b8zs Specifies B8ZS as the line-code type. Valid for T1 controller only.
hdb3 Specifies high-density bipolar 3 (hdb3) as the line-code type. Valid for E1 controller only; the default for E1 lines.
Defaults

AMI is the default for T1 lines.

High-density bipolar 3 is the default for E1 lines.

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. (The option hdb3 first appeared in Cisco IOS Release 10.3.)

Use this command in configurations where the router or access server must communicate with T1 fractional data lines. The T1 service provider determines which line-code type, either ami or b8zs, is required for your T1 circuit. Likewise, the E1 service provider determines which line-code type, either ami or hdb3, is required for your E1 circuit.

Example

The following example specifies B8ZS as the line-code type:

linecode b8zs

link-test

To reenable the link-test function on a port on an Ethernet hub of a Cisco 2505 or Cisco 2507, use the link-test hub configuration command. Use the no form of this command to disable this feature if a pre-10BaseT twisted-pair device not implementing link test is connected to the hub port.

link-test
no link-test

Syntax Description

This command has no arguments or keywords.

Default

Enabled

Command Mode

Hub configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to a port on an Ethernet hub only. Disable this feature if a 10BaseT twisted-pair device at the other end of the hub does not implement the link test function.

Example

The following example disables the link test function on hub 0, ports 1 through 3:

hub ethernet 0 1 3
no link-test
Related Command

hub

local-lnm

To enable Lanoptics Hub Networking Management of a PCbus Token Ring interface, use the local-lnm interface configuration command. Use the no form of this command to disable Lanoptics Hub Networking Management.

local-lnm
no local-lnm

Syntax Description

This command has no arguments or keywords.

Default

Management is not enabled.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

The Token Ring interface on the AccessPro PC card can be managed by a remote LAN manager over the PCbus interface. At present, the Lanoptics Hub Networking Management software running on an IBM compatible PC is supported.

Example

The following example enables Lanoptics Hub Networking Management:

local-lnm

loopback (E1 controller)

To loop an entire E1 line (including all channel-groups defined on the controller) toward the line and back toward the router or access server, use the loopback controller configuration command. To remove the loop, use the no form of this command.

loopback
no loopback

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command is useful for testing the DCE device (CSU/DSU) itself.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on the E1 line:

controller e1 0
loopback 

loopback (interface)

To diagnose equipment malfunctions between interface and device, use the loopback interface configuration command. The no loopback command disables the test.

loopback
no loopback

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 10.0.

On HSSI serial interface cards, the loopback function configures a two-way internal and external loop on the HSA applique of the specific interface.

On MCI and SCI serial interface cards, the loopback functions when a CSU/DSU or equivalent device is attached to the router or access server. The loopback command loops the packets through the CSU/DSU to configure a CSU loop, when the device supports this feature.

On the MCI and MEC Ethernet cards, the interface receives back every packet it sends when the loopback command is enabled. Loopback operation has the additional effect of disconnecting network server functionality from the network.

On the CSC-FCI FDDI card, the interface receives back every packet it sends when the loopback command is enabled. Loopback operation has the additional effect of disconnecting network server functionality from the network.

On all Token Ring interface cards (except the 4-megabit CSC-R card), the interface receives back every packet it sends when the loopback command is enabled. Loopback operation has the additional effect of disconnecting network server functionality from the network.


Note Loopback does not work on an X.21 DTE because the X.21 interface definition does not include a loopback definition.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on Ethernet interface 4:

interface ethernet 4
loopback
Related Commands

down-when-looped
show interfaces loopback

loopback applique

To configure an internal loop on the HSSI applique, use the loopback interface configuration command. To remove the loop, use the no form of this command.

loopback applique
no loopback applique

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 10.0.

This command loops the packets within the applique, to provide a way to test communication within the router or access server. It is useful for sending pings to yourself to check functionality of the applique.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on the HSSI applique:

interface serial 1
loopback applique
Related Command

show interfaces loopback

loopback dte

To loop packets back to the DTE from the CSU/DSU, when the device supports this feature, use the loopback interface configuration command. To remove the loop, use the no form of this command.

loopback dte
no loopback dte

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 10.0.

This command is useful for testing the DTE-to-DCE cable.

For the Cisco 2524 and Cisco 2525 routers, this command is used to test the performance of the integrated CSU/DSU. Packets are looped from within the CSU/DSU back to the serial interface of the router. Send a test ping to see if the packets successfully looped back. To cancel the loopback test, use the no loopback dte command.

When using the 4-wire 56/64-kbps CSU/DSU module, an out-of-service signal is transmitted to the remote CSU/DSU.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on the DTE interface:

interface serial 1
loopback dte
Related Command

show interfaces loopback

loopback line

To loop packets completely through the CSU/DSU to configure the CSU loop, when the device supports this feature, use the loopback line interface configuration command. To remove the loop, use the no form of this command.

loopback line [payload]
no loopback line
[payload]
Syntax Description
payload (Optional) Configures a loopback point at the DSU and loops back data to the network on an integrated CSU/DSU for a Cisco 2524 and Cisco 2525.
Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command is useful for testing the DCE device (CSU/DSU) itself. When the loopback line command is configured on the 2-wire 56-kbps CSU/DSU module or the 4-wire 56/64-kbps CSU/DSU modules installed on a Cisco 2524 or Cisco 2525 router, the network data loops back at the CSU and the router data loops back at the DSU. If the CSU/DSU is configured for switched mode, you must have an established connection to perform a payload-line loopback. To loop the received data through the minimum amount of CSU/DSU circuitry, issue the loopback line command.

When you issue the loopback line payload command on an integrated CSU/DSU module, the router cannot transmit data through the serial interface for the duration of the loopback. Choosing the DSU as a loopback point loops the received-network data through the maximum amount of CSU/DSU circuitry. Data is not looped back to the serial interface. An active connection is required when operating in switched mode for payload loopbacks.

If you enable the loopback line command on the fractional T1/T1 module, the CSU/DSU performs a full-bandwidth loopback through the CSU portion of the module and data transmission through the serial interface is interrupted for the duration of the loopback. No reframing or corrections of bipolar violation errors or cyclic redundancy check (CRC) errors are performed. When you configure the loopback line payload command on the FT1/T1 module, the CSU/DSU performs a loopback through the DSU portion of the module. The loopback line payload command reframes the data link, regenerates the signal, and corrects bipolar violations and Extended Super Frame CRC errors.

When performing a T1-line loopback with Extended Super Frame on a Cisco 2524 or Cisco 2525 router, communication over the facilities data link is interrupted, but performance statistics are still updated. To show interfaces currently in loopback operation on a Cisco 2524 or Cisco 2525 router, use the show service-module EXEC command.

To show interfaces currently in loopback operation on other routers, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on the DCE device:

interface serial 1
loopback line

The following example shows how to configure a payload loopback on a Cisco 2524 or 2525 router:

Router1(config-if)#loopback line payload
Loopback in progress
Router1(config-if)#no loopback line

The following example shows the output on a Cisco 2524 or 2525 router when you loop a packet in switched mode without an active connection:

Router1(config-if)#service-module 56k network-type switched
Router1(config-if)#loopback line payload
Need active connection for this type of loopback
% Service module configuration command failed: WRONG FORMAT.
Related Command

show interfaces loopback

loopback local (T1 controller)

To loop an entire T1 line (including all channel-groups defined on the controller) toward the line and the router or access server, use the loopback local controller configuration command. To remove the loop, use the no form of this command.

loopback local
no loopback local

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command is useful for testing the DCE device (CSU/DSU) itself.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on the T1 line:

controller t1 0
loopback local

loopback local (interface)

To loop a channelized T1 or channelized E1 channel-group, use the loopback local interface configuration command. To remove the loop, use the no form of this command.

loopback local
no loopback local

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.

This command is useful for looping a single channel-group in a channelized environment without disrupting the other channel-groups.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures the loopback test on the T1 line:

interface serial 1/0:22
loopback local
Related Command

show interfaces loopback

loopback remote (T1 controller)

To loop packets from a MIP through the CSU/DSU, over a dedicated T1 link, to the remote CSU at the single destination for this T1 link and back, use the loopback remote controller configuration command. To remove the loop, use the no form of this command.

loopback remote
no loopback remote

Syntax Description

This command has no arguments or keywords.

Default

Disabled

Command Mode

Controller configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command applies only when the device supports the remote function. It is used for testing the data communication channels.

For MIP cards, this controller configuration command applies if only one destination exists at the remote end of the cloud, the entire T1 line is dedicated to it, and the device at the remote end is a CSU (not a CSU/DSU). This is an uncommon case; MIPs are not usually used in this way.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures a remote loopback test:

interface serial 0
loopback remote
Related Command

show interfaces loopback

loopback remote (interface)

To loop packets through a CSU/DSU, over a DS-3 link or a channelized T1 link, to the remote CSU/DSU and back, use the loopback remote interface configuration command. To remove the loop, use the no form of this command.

loopback remote
no loopback remote

loopback remote {full | payload | smart-jack} [0in1 | 1in1 | 1in2 | 1in5 | 1in8 | 3in24 | qrw | user-pattern value]  (Cisco 2524 or Cisco 2525 only)
no loopback remote
{full | payload | smart-jack}
loopback remote [2047 | 511 | stress-pattern pattern number] (Cisco 2524 or Cisco 2525 only)
no loopback remote


Note The keywords full, payload, smart-jack, 0in1 through 3in24, qrw, and user-pattern 24bit-binary value apply to the fractional T1/T1 CSU/DSU module installed on a Cisco 2524 or Cisco 2525 router. The keywords 2047, 511, and stress-pattern apply to the 2- and 4-wire 56/64-kbps CSU/DSU modules installed on a Cisco 2524 or Cisco 2525 router. The features for each module are grouped and described in the following two syntax descriptions.
Syntax Description for the FT1/T1 CSU/DSU Module
full Transmits a full-bandwidth line loopback request to a remote device, which is used for testing the line and remote CSU.
payload Transmits a payload line loopback request to a remote device, which is used for testing the line and remote DSU.
smart-jack Transmits a loopback request to the remote smart-jack, which some service providers attach on the line before the customer premises equipment (CPE). You cannot put the local smart-jack into loopback.
0in1 (Optional) Transmits an all-zeros test pattern used for verifying B8ZS line encoding. The remote end my report a loss of signal when using alternate mark inversion (AMI) line coding.
1in1 (Optional) Transmits an all-ones test pattern used for signal power measurements.
1in2 (Optional) Transmits an alternating ones and zeroes test pattern used for testing bridge taps.
1in5 (Optional) Transmits the industry standard test-pattern loopback request.
1in8 (Optional) Transmits a test pattern used for stressing timing recovery of repeaters.
3in24 (Optional) Transmits a test pattern used for testing the ones density tolerance on AMI lines.
qrw (Optional) Transmits a quasi-random word test pattern, which is a random signal that simulates user data.
user-pattern
value
(Optional) Transmits a test pattern that you define. Enter a binary string up to 24 bits long. For the fixed patterns such 0in1 and 1in1, the T1 framing bits are jammed on top of the test pattern; for the user-pattern, the pattern is simply repeated in the timeslots.
Syntax Description for the 2- and 4-Wire 56/64-kbps CSU/DSU Modules
2047 Transmits a pseudo-random test pattern that repeats after 2047 bits.
511 Transmits a pseudo-random test pattern that repeats after 511 bits.
stress-pattern
pattern number
Transmits a DDS stress pattern available only on the 4-wire 56/64-kbps CSU/DSU module. You may enter a stress pattern from 1 to 4. A 1 pattern sends 100 bytes of all 1s and then 100 bytes of all 0s to test the stress clocking of the network. A 2 pattern sends 100 bytes of a 0x7e pattern and then 100 bytes of all 0s. A 3 pattern sends continuous bytes of a 0x46 pattern. A 4 pattern sends continuous bytes of a 0x02 pattern.
Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command applies only when the remote CSU/DSU device supports the function. It is used for testing the data communication channels. The loopback usually is performed at the line port, rather than the DTE port, of the remote CSU/DSU.

For a multiport interface processor (MIP) connected to a network via a channelized T1 link, the loopback remote interface configuration command applies if the remote interface is served by a DDS line (56 kbps or 64 kbps) and the device at the remote end is a CSU/DSU. In addition, the CSU/DSU at the remote end must react to latched DDS CSU loopback codes. Destinations that are served by other types of lines or that have CSU/DSUs that do not react to latched DDS CSU codes cannot participate in an interface remote loopback. Latched DDS CSU loopback code requirements are described in AT&T specification TR-TSY-000476, "OTGR Network Maintenance Access and Testing."

On the integrated FT1/T1 CSU/DSU module installed on a Cisco 2524 and Cisco 2525 router, the loopback remote full command sends the loopup code to the remote CSU/DSU. The remote CSU/DSU performs a full-bandwidth loopback through the CSU portion of the module. The loopback remote payload command sends the loopup code on the configured timeslots, while maintaining the D4-extended super framing. The remote CSU/DSU performs the equivalent of a loopback line payload request. The remote CSU/DSU loops back only those timeslots that are configured at the remote end. This loopback reframes the data link, regenerates the signal, and corrects bipolar violations and Extended Super Frame CRC errors. The loopback remote smart-jack command sends a loopup code to the remote smart jack. You cannot put the local smart jack into loopback.

Failure to loopup or initiate a remote loopback request could be caused by enabling the no service-module t1 remote-loopback command or having an alternate remote-loopback code configured on the remote end. When the loopback is terminated, the result of the pattern test is displayed.

On the 2- and 4-wire 56/64-kbps CSU/DSU modules installed on a Cisco 2524 or Cisco 2525 router, an active connection is required before a loopup can be initiated while in switched mode. When transmitting V.54 loopbacks, the remote device is commanded into loopback using V.54 messages. Failure to loopup or initiate a remote loopback request could be caused by enabling the no service-module 56k remote-loopback command.

To show interfaces currently in loopback operation, use the show interfaces loopback EXEC command.

Example

The following example configures a remote loopback test:

interface serial 0
loopback remote
Related Command

show interfaces loopback

media-type

To specify the physical connection for one of the following configurations, use the media type command:

Use the no form of this command to restore the default value.

media-type {aui | 10baset | 100baset | mii}
no media-type {aui | 10baset | 100baset | mii}

Syntax Description
aui Selects a 15-pin physical connection.
10baset Selects an RJ45 10BaseT physical connection.
100baset Specifies an RJ45 100BaseT physical connection.
mii Specifies a media-independent interface.
Default

AUI 15-pin physical connection is the default setting on the Cisco 4000 series.

100BaseT physical connection is the default setting on the Cisco 7000 series and 7200 series.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Examples

The following example selects an RJ45 10BaseT physical connection on Ethernet interface 1:

interface ethernet 1
media-type 10baset

The following example specifies a media-independent interface physical connection to Fast Ethernet slot 0, port 1 on the Cisco 7000 or 7200 series:

interface fastethernet 0/1
media-type mii

The following example specifies a media-independent interface physical connection to Fast Ethernet slot 0, port-adapter 1, port 1 on the Cisco 7500 series:

interface fastethernet 0/1/1
media-type mii

member

To alter the configuration of an asynchronous interface that is a member of a group, use the member interface configuration command. Use the no form of the command to restore defaults set at the group master interface.

member number interface-command
no member number interface-command

Syntax Description
number Number of the asynchronous interface to be altered.
interface-command One or more of the following commands entered for this specific interface:

· peer default ip address

· description

Default

No individual configurations are set for member interfaces.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

You can customize a member interface by using the member command. (Interfaces are designated as members of a group by using the interface group-async and group-range commands.) To restore the defaults set at the group master interface, use the no form of this command.

Example

The following example defines interface 3 with a description of line 3, attached to a Hayes Optima modem:

interface group-async 0
member 3 description line #3 Hayes Optima
Related Commands

group-range
interface group-async

mop enabled

To enable an interface to support the Maintenance Operation Protocol (MOP), use the mop enabled interface configuration command. To disable MOP on an interface, use the no mop enabled command.

mop enabled
no mop enabled

Syntax Description

This command has no arguments or keywords.

Default

Enabled on Ethernet interfaces and disabled on all other interfaces.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, MOP is enabled for serial interface 0:

interface serial 0
mop enabled
Related Commands

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

mop retransmit-timer +
mop retries +
mop sysid

mop sysid

To enable an interface to send out periodic Maintenance Operation Protocol (MOP) system identification messages, use the mop sysid interface configuration command. To disable MOP message support on an interface, use the no form of this command.

mop sysid
no mop sysid

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 10.0.

You can still run MOP without having the background system ID messages sent. This lets you use the MOP remote console, but does not generate messages used by the configurator.

Example

In the following example, serial interface 0 is enabled to send MOP system identification messages:

interface serial 0
mop sysid
Related Commands

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

mop device-code +
mop enabled

mtu

To adjust the maximum packet size or maximum transmission unit (MTU) size, use the mtu interface configuration command. Use the no form of this command to restore the MTU value to its original default value.

mtu bytes
no mtu

Syntax Description
bytes Desired size in bytes.
Defaults

Table 24 lists default MTU values according to media type.


Table 24: Default Media MTU Values
Media Type Default MTU
Ethernet 1500
Serial 1500
Token Ring 4464
ATM 4470
FDDI 4470
HSSI (HSA) 4470
Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Each interface has a default maximum packet size or maximum transmission unit (MTU) size. This number generally defaults to the largest size possible for that type interface. On serial interfaces, the MTU size varies, but cannot be set smaller than 64 bytes.

 
Caution Changing an MTU size on a Cisco 7500 router will result in recarving of buffers and resetting of all interfaces. The following message is displayed:

%RSP-3-Restart:cbus complex

Note Changing the MTU value with the mtu interface configuration command can affect values for the protocol-specific versions of the command (ip mtu for example). If the values specified with the ip mtu interface configuration command is the same as the value specified with the mtu interface configuration command, and you change the value for the mtu interface configuration command, the ip mtu value automatically matches the new mtu interface configuration command value. However, changing the values for the ip mtu configuration commands has no effect on the value for the mtu interface configuration command.
Example

The following example specifies an MTU of 1000 bytes:

interface serial 1
mtu 1000
Related Commands

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

encapsulation smds +
ip mtu +

nrzi-encoding

To enable non-return to zero inverted (NRZI) line coding format, use the nrzi-encoding interface configuration command. Use the no form of this command to disable this capability.

nrzi-encoding
no nrzi-encoding

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 10.0.

All FSIP interface types support nonreturn to zero (NRZ) and nonreturn to zero inverted (NRZI) format. This is a line coding format that is required for serial connections in some environments. NRZ encoding is most common. NRZI encoding is used primarily with RS-232 connections in IBM environments.

Example

In the following example, serial interface 1 is configured for NRZI encoding:

interface serial 1
nrzi-encoding

peer default ip address

Use the peer default ip address interface configuration command to specify an IP address, an address from a specific IP address pool, or an address from the DHCP mechanism to be returned to a remote peer connecting to this interface. Use the no form of the command to disable a prior peer IP address pooling configuration on an interface.

peer default ip address {ip-address | dhcp | pool [pool-name]}
no peer default ip address

Syntax Description
ip-address Specific IP address to be assigned to a remote peer dialing in to the interface. To prevent duplicate IP addresses from being assigned on more than one interface, this command argument cannot be applied to a dialer rotary group nor to an ISDN interface.
dhcp Retrieve an IP address from the DHCP server.
pool Use the global default mechanism as defined by the ip address-pool command unless the optional poolname argument is supplied. This is the default.
pool-name (Optional) Name of a local address pool created using the ip local pool command. Retrieve an address from this pool regardless of the global default mechanism setting.
Default

pool

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to point-to-point interfaces that support the PPP or SLIP encapsulation.

This command allows an administrator to configure all possible address pooling mechanisms on a interface-by-interface basis.

The peer default ip address command can override the global default mechanism defined by the ip address-pool command on an interface-by-interface basis.

Examples

The following command specifies that this interface will use a local IP address pool called pool3:

peer default ip address pool pool3

The following command specifies that this interface will use the IP address 172.140.34.21:

peer default ip address 172.140.34.21

The following command reenables the global default mechanism to be used on this interface:

peer default ip address pool
Related Commands

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

encapsulation ppp
encapsulation slip
ip address-pool
ip dhcp-server
ip local pool
ppp
+
slip +
show dhcp

physical-layer

To specify the mode of a slow-speed serial interface on a router as either synchronous or asynchronous, use the physical-layer interface configuration command. Use the no form of this command to return the interface to its default mode, which is synchronous.

physical-layer {sync | async}
no physical-layer

Syntax Description
sync Place the interface in synchronous mode.
async Place the interface in asynchronous mode.
Default

Synchronous mode

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies only to low-speed serial interfaces available on Cisco 2520 through Cisco 2523 routers.

If you specify the no physical-layer command, you return the interface to its default mode (synchronous).

In synchronous mode, low-speed serial interfaces support all interface configuration commands available for high-speed serial interfaces, except the following two commands:

When placed in asynchronous mode, low-speed serial interfaces support all commands available for standard asynchronous interfaces.

When you enter this command, it does not appear in the output of show running config and show startup config commands, because the command is a physical layer command.

Examples

The following examples show different uses of this command.

The following example shows how to change a low-speed serial interface from synchronous to asynchronous mode:

interface serial 2
physical-layer async

posi framing-sdh

To select SDH STM-1 framing on a Packet OC-3 interface in a Cisco RSP/7000 or Cisco 7500 router, which has a Route Switch Processor, use the posi framing-sdh interface configuration command. To revert to the default SONET STS-3c framing, use the no form of this command.

posi framing-sdh
no posi framing-sdh

Syntax Description

This command has no keywords or arguments.

Default

SONET STS-3c framing

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Example

In the following example, the interface is configured for SDH STM-1 framing:

interface posi 3/0
posi framing-sdh
no shutdown
Related Commands

interface posi
posi internal-clock

posi internal-clock

To set the internal clock as the transmission clock source, use the posi internal-clock interface configuration command. To revert to the default recovered receive clock as the transmission clock source, use the no form of this command.

posi internal-clock
no posi internal-clock

Syntax Description

This command has no keywords or arguments.

Default

The recovered receive clock

Command mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Example

The following command reverts to the default recovered receive clock:

interface posi 3/0
no posi internal-clock
Related Commands

interface posi
posi framing-sdh

pulse-time

To enable pulsing DTR signal intervals on the serial interfaces, use the pulse-time interface configuration command. Use the no form of this command to restore the default interval.

pulse-time seconds
no pulse-time

Syntax Description
seconds Integer that specifies the DTR signal interval in seconds.
Default

0 seconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

When the serial line protocol goes down (for example, because of loss of synchronization) the interface hardware is reset and the DTR signal is held inactive for at least the specified interval. This function is useful for handling encrypting or other similar devices that use the toggling of the DTR signal to resynchronize.

Example

The following example enables DTR pulse signals for three seconds on serial interface 2:

interface serial 2
pulse-time 3

ring-speed

To set the ring speed for the CSC-1R and CSC-2R Token Ring interfaces, use the ring-speed interface configuration command.

ring-speed speed
Syntax Description
speed Integer that specifies the ring speed, either 4 for 4-Mbps or 16 for 16-Mbps operation.
Default

16-Mbps operation

 
Caution Configuring a ring speed that is wrong or incompatible with the connected Token Ring will cause the ring to beacon, which effectively takes the ring down and makes it nonoperational.
Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example sets a Token Ring interface ring speed to 4 Mbps:

interface tokenring 0
ring-speed 4

service-module 56k clock rate

To configure the network line speed for a 4-wire 56/64-kbps CSU/DSU module, use the service-module 56k clock rate interface configuration command. Use the no form of this command to enable a network line speed of 56 kbps.

service-module 56k clock rate line-speed
no service-module 56k clock rate line-speed

Syntax Description
line-speed Network line speed in kbps; one of the following keywords 2.4, 4.8, 9.6, 19.2, 38.4, 56, 64, and auto. Default is 56 kbps.
Default

56 kbps

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

The 64-kbps line speed cannot be used with back-to-back digital data service (DDS) lines. The subrate line speeds are determined by the service provider.

Only the 56-kbps line speed is available in switched mode, which is enabled using the service-module 56k network-type interface configuration command on the 4-wire CSU/DSU. The 2-wire CSU/DSU default is set to switched mode.

The keyword auto enables the CSU/DSU to decipher current line speed from the sealing current running on the network. Use auto only when transmitting over telco DDS lines and the clocking source is taken from the line.

Example

The following example displays two routers connected in back-to-back DDS mode. However, the configuration fails because the auto rate is used.

Router1(config-if)#service-module 56k clock source internal
Router1(config-if)#service-module 56k clock rate 38.4
Router2(config-if)#service-module 56k clock rate auto
a1#ping 10.1.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds:
.....		
Success rate is 0 percent (0/5)
Router2(config-if)#service-module 56k clock rate 38.4 
Router1#ping 10.1.1.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 52/54/56 ms

When transferring from DDS mode to switched mode, you must set the correct clock rate, as shown in the following example:

Router2(config-if)#service-module 56k network-type dds
Router2(config-if)#service-module 56k clock rate 38.4
Router2(config-if)#service-module 56k network-type switched
% Have to use 56k or auto clock rate for switched mode
% Service module configuration command failed: WRONG FORMAT.
Router2(config-if)#service-module 56k clock rate auto
% WARNING - auto rate will not work in back-to-back DDS.
Router2(config-if)#service-module 56k network-type switched
Related Commands

service-module 56k clock source
service-module 56k network-type

service-module 56k clock source

To configure the clock source for the 4-wire 56/64-kbps CSU/DSU module, use the service-module 56k clock source interface configuration command. Use the no form of this command to enable the line clock.

service-module 56k clock source {line | internal}
no service-module 56k clock source {line | internal}

Syntax Description
line Uses the clocking provided by the active line.
internal Uses internal clocking provided by the module.
Default

Line clock

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

In most applications, the CSU/DSU should be configured with the clock source line command. For back-to-back configurations, configure one CSU/DSU with the clock source internal command and the other with clock source line command.

Example

The following example configures internal clocking and transmission at 38.4 kbps.

service-module 56k clock source internal
service-module 56k clock rate 38.4
Related Command

service-module 56k clock rate

service-module 56k data-coding

To prevent application data from replicating loopback codes when operating at 64 kbps on a 4-wire CSU/DSU, use the service-module 56k data-coding interface configuration command. Use the no form of this command to enable normal transmission.

service-module 56k data-coding {normal | scrambled}
no service-module 56k data-coding {normal | scrambled}

Syntax Description
normal Specifies normal transmission of data.
scrambled Scrambles bit codes or user data before transmission. All control codes such as out of service and out of frame are avoided.
Default

Normal data transmission

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies only to the Cisco 2524 or Cisco 2525 router.

Enable the scrambled configuration only in 64-kbps digital data service (DDS) mode. If the network type is set to switched, the configuration is refused.

If you transmit scrambled bit codes, both CSU/DSUs must have this command configured for successful communication.

Example

The following example scrambles bit codes or user data before transmission:

service-module 56k clock rate 64
service-module 56k data-coding scrambled
Related Command

service-module 56k clock rate

service-module 56k network-type

To transmit packets in switched dial-up mode or digital data service (DDS) mode using the 4-wire 56/64-kbps CSU/DSU module, use the service-module 56k network-type interface configuration command. Use the no form of this command to transmit from a dedicated leased line in DDS mode.

service-module 56k network-type {dds | switched}
no service-module 56k network-type {dds | switched}

Syntax Description
dds Transmits packets in DDS mode or through a dedicated leased line.
switched Transmits packets in switched dial-up mode, which is the only setting on the 2-wire switched 56-kbps CSU/DSU module.
Default

DDS is enabled for the 4-wire CSU/DSU.

Switched is enabled for the 2-wire CSU/DSU.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies to the Cisco 2524 and Cisco 2525 routers.

In switched mode, you need additional dialer configuration commands to configure dial-out numbers. Before you enable the service-module 56k network-type switched command, both CSU/DSUs must use a clock source coming from the line and the clock rate configured to auto or 56 kbps. If the clock rate is not set correctly, this command will not be accepted.

The 2-wire and 4-wire 56/64-kbps CSU/DSU modules use V.25 bis dial commands to interface with the router. Therefore, the interface must be configured using the dialer in-band command. DTR dial is not supported.


Note Any loopbacks in progress are terminated when switching between modes.
Example

The following example configures transmission in switched dial-up mode:

service-module 56k clock rate auto
service-module 56k network-type switched
dialer in-band
dialer string 2576666
dialer-group 1
Related Commands

A dagger (+) indicates that the command is documented in another chapter.

dialer in-band +
service-module 56k clock rate
service-module 56k clock source
service-module 56k switched-carrier

service-module 56k remote-loopback

To enable the acceptance of a remote loopback request on a 2- or 4-wire 56/64-kbps CSU/DSU module, use the service-module 56k remote-loopback interface configuration command. Use the no form of this command to disable the module from entering loopback.

service-module 56k remote-loopback
no service-module
56k remote-loopback

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.

This command applies to the Cisco 2524 and Cisco 2525 routers.

The no service-module 56k remote-loopback command prevents the local CSU/DSU from being placed into loopback by remote devices on the line. The line provider is still able to put the module into loopback by reversing sealing current. Unlike the T1 module, the 2- or 4-wire 56/64-kbps CSU/DSU module can still initiate remote loopbacks with the no form of this command configured.

Examples

The following example enables transmitting and receiving remote loopbacks:

service-module 56k remote-loopback
Related Command

loopback remote (interface)

service-module 56k switched-carrier

To select a service provider to use with a 2- or 4-wire 56/64 kbps dial-up line, use the service-module 56k switched-carrier interface configuration command. Use the no form of this command to enable the default service provider.

service-module 56k switched-carrier {att | sprint | other}
no service-module 56k switched-carrier {att | sprint | other}

Syntax Description
att AT&T or other digital network service provider.
sprint Sprint or other service provider whose network requires echo cancelers.
other Service provider besides AT&T or Sprint.
Default

ATT is enabled on the 4-wire 56/64-kbps CSU/DSU module.

Sprint is enabled on the 2-wire switched 56-kbps CSU/DSU module.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command only on the 2- or 4-wire 56/64-kbps CSU/DSU modules installed on a Cisco 2524 or Cisco 2525 router.

On a Sprint network, echo-canceler tones are sent during call setup to prevent the echo cancelers from damaging digital data. The transmission of echo-canceler tones may increase call setup times by 8 seconds on the 4-wire module. Having echo cancellation enabled does not affect data traffic.

This configuration command is ignored if the network type is DDS.

Example

The following example configures AT&T as a service provider:

service-module 56k network-type switched
service-module 56k switched-carrier att
Related Command

service-module 56k network-type

service-module t1 clock source

To specify the clock source for the fractional T1/T1 CSU/DSU module installed in a Cisco 2524 or Cisco 2525 router, use the service-module t1 clock source interface configuration command. Use the no form of this command to enable the line clock.

service-module t1 clock source {internal | line}
no service-module t1 clock source {internal | line}

Syntax Description
internal Specifies the CSU/DSU internal clock.
line Specifies the line clock.
Default

Line clock

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Example

The following example sets an internal clock source on serial line 0:

interface serial 0
service-module t1 clock source line
Related Command

service-module 56k clock source

service-module t1 data-coding

To guarantee the ones density requirement on an AMI line using the fractional T1/T1 module, use the service-module t1 data-coding inverted interface configuration command. Use the no form of this command to enable normal data transmission.

service-module t1 data-coding {inverted | normal}
no service-module t1 data-coding {inverted | normal}

Syntax Description
inverted Inverts bit codes by changing all 1 bits into 0 bits and all 0 bits into 1 bits.
normal Requests that no bit codes be inverted before transmission.
Default

Normal transmission

Command Mode

Interface configuration

Usage Guidelines
Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies to the Cisco 2524 and Cisco 2525 routers.

Data inversion is used to guarantee the ones density requirement on an AMI line when using bit-oriented protocols such as High-Level Data Link Control (HDLC), Point-to-Point Protocol (PPP), X.25, and Frame Relay. If the timeslot speed is set to 56 kbps, this command is rejected because line density is guaranteed when transmitting at 56 kbps. Use this command with the 64-kbps line speed.

If you transmit inverted bit codes, both CSU/DSUs must have this command configured for successful communication.

Example

The following example inverts bit codes using a timeslot speed of 64 kbps:

service-module t1 timeslots all speed 64
service-module t1 data-coding inverted
Related Commands

service-module t1 linecode
service-module t1 timeslots

service-module t1 framing

To select the frame type for a line using the fractional T1/T1 (FT1/T1) module from a Cisco 2524 or Cisco 2525 router, use the service-module t1 framing interface configuration command. Use the no form of this command to select the default, which is Extended Super Frame as the T1 frame type.

service-module t1 framing {esf | sf}
no service-module t1 framing {esf | sf}

Syntax Description
esf Specifies Extended Super Frame as the T1 frame type.
sf Specifies D4 Super Frame as the T1 frame type.
Default

esf

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Use this command in configurations where the router communicates with FT1/T1 data lines. The service provider determines which framing type, either esf or sf, is required for your circuit.

Example

The following example enables Super Frame as the FT1/T1 frame type:

service-module t1 framing sf

service-module t1 lbo

To configure the CSU line build out (LBO) on a fractional T1/T1 CSU/DSU module, use the service-module t1 lbo interface configuration command. Use the no form of this command to disable line build out.

service-module t1 lbo {-15 db | -7.5 db | none}
no service-module t1 lbo {-15 db | -7.5 db | none}

Syntax Description
-15 db Decreases outgoing signal strength by 15 dB.
-7.5 db Decreases outgoing signal strength by 7.5 dB.
none Transmits packets without decreasing outgoing signal strength.
Default

No line build out

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies to the Cisco 2524 and Cisco 2525 routers.

Use this command to decrease the outgoing signal strength to an optimum value for a fractional T1 line receiver. The ideal signal strength should be -15 dB to -22 dB, which is calculated by adding the phone company loss + cable length loss + line build out.

You may use this command in back-to-back configurations, but it is not needed on most actual T1 lines.

Example

The following example shows an lbo setting of -7.5 dB:

service-module t1 lbo -7.5db

service-module t1 linecode

To select the line code for the fractional T1/T1 module installed on a Cisco 2524 or Cisco 2525 router, use the service-module t1 linecode interface configuration command. Use the no form of this command to select the default, which is the B8ZS line code.

service-module t1 linecode {ami | b8zs}
no service-module t1 linecode {ami | b8zs}

Syntax Description
ami Specifies alternate mark inversion (AMI) as the line code.
b8zs Specifies binary 8 zero substitution (B8ZS) as the line code.
Default

b8zs

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Configuring B8ZS is a method of ensuring the ones density requirement on a T1 line by substituting intentional bipolar violations in bit positions four and seven for a sequence of eight zero bits. When the CSU/DSU is configured for AMI, you must guarantee the ones density requirement in your router configuration using the service-module t1 data-coding inverted command or the service-module t1 timeslots speed 56 command.

Your T1 service provider determines which line code, either ami or b8zs, is required for your T1 circuit.

Example

The following example specifies AMI as the line code:

service-module t1 linecode ami
Related Commands

service-module t1 data-coding
service-module t1 timeslots

service-module t1 remote-alarm-enable

To generate remote alarms (yellow alarms) at the local CSU/DSU or detect remote alarms sent from the remote CSU/DSU, use the service-module t1 remote-alarm-enable interface configuration command. Use the no form of this command to disable remote alarms.

service-module t1 remote-alarm-enable
no service-module t1 remote-alarm-enable

Syntax Description

This command has no arguments or keywords.

Default

Remote alarms disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies to the fractional T1/T1 CSU/DSU module installed on Cisco 2524 and Cisco 2525 routers.

Remote alarms are transmitted by the CSU/DSU when it detects an alarm condition, such as a red alarm (loss of frame) or blue alarm (unframed ones). The receiving CSU/DSU then knows there is an error condition on the line.

With D4 Super Frame configured, a remote alarm condition is transmitted by setting the bit 2 of each time slot to zero. For received user data that has the bit 2 of each time slot set to zero, the CSU/DSU interprets the data as a remote alarm and interrupts data transmission, which explains why remote alarms are disabled by default. With Extended Super Frame configured, the remote alarm condition is signalled out of band in the facilities data link.

You can see if the FT1/T1 CSU/DSU is receiving a remote alarm (yellow alarm) by issuing the show service-module command.

Example

The following example enables remote alarm generation and detection:

service-module t1 remote-alarm-enable
Related Command

service-module t1 framing

service-module t1 remote-loopback

To specify if the fractional T1/T1 CSU/DSU module enters loopback mode when it receives a loopback code on the line, use the service-module t1 remote-loopback interface configuration command. Use the no form of this command to disable remote loopbacks.

service-module t1 remote-loopback {full | payload} [alternate | v54]
no service-module t1 remote-loopback {full | payload}

Syntax Description
full Configures the remote loopback code used to transmit or accept CSU loopback requests.
payload Configures the loopback code used by the local CSU/DSU to generate or detect payload-loopback commands.
alternate (Optional) Transmits a remote CSU/DSU loopback request using a 4-in-5 pattern for loopup and 2-in-3 pattern for loopdown. This is an inverted version of the standard loopcode request.
v54 (Optional) Industry standard loopback code. Use this configuration for CSU/DSUs that may not support the Accunet loopup standards. This keyword is used only with a payload request, not a full request.

Note By entering the service-module t1 remote-loopback command without specifying any keywords, you enable the standard-loopup codes, which use a 1-in-5 pattern for loopup and a 1-in-3 pattern for loopdown.
Default

Full and payload loopbacks with standard-loopup codes

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies only to the Cisco 2524 and Cisco 2525 routers.

You can simultaneously configure the full and payload loopback points. However, only one loopback code can be configured at a time. For example, if you configure the service-module t1 remote-loopback payload alternate command, a payload v54 request cannot be transmitted or accepted.

The no form of this command disables loopback requests. For example, the no service-module t1 remote-loopback full command ignores all full-bandwidth loopback transmissions and requests. Configuring the no form of the command may not prevent telco line providers from looping your router in esf mode, because fractional T1/T1 lines use facilities data link messages to initiate loopbacks.

If you enable the service-module t1 remote-loopback command, the loopback remote commands on the FT1/T1 CSU/DSU module will not be successful.

Example

The following example displays two routers connected back-to-back through a fractional T1/T1 line:

no service-module t1 remote-loopback full
service-module t1 remote-loopback payload alternate
loopback remote full
%SERVICE_MODULE-5-LOOPUPFAILED: Unit 0 - Loopup of remote unit failed
service-module t1 remote-loopback payload v54
loopback remote payload
%SERVICE_MODULE-5-LOOPUPFAILED: Unit 0 - Loopup of remote unit failed
service-module t1 remote-loopback payload alternate
loopback remote payload
%SERVICE_MODULE-5-LOOPUPREMOTE: Unit 0 - Remote unit placed in loopback
Related Command

loopback remote (interface)

service-module t1 timeslots

To define timeslots that constitute a fractional T1/T1 (FT1/T1) channel in a Cisco 2524 or Cisco 2525 router, use the service-module t1 timeslots interface configuration command. Use the no form of this command to resume the default setting (all FT1/T1 timeslots transmit at 64 kbps).

service-module t1 timeslots {range | all} [speed {56 | 64}]
no service-module t1 timeslots {range | all}

Syntax Description
range The DS0 timeslots that constitute the FT1/T1 channel. The range is from 1 to 24, where the first timeslot is numbered 1 and the last timeslot is numbered 24. Specify this field by using a series of subranges separated by commas.
all Selects all FT1/T1 timeslots.
speed (Optional) Specifies the timeslot speed.
56 56 kbps.
64 64 kbps. This is the default for all timeslots.
Default

64 kbps

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command specifies which timeslots are used in fractional T1 operation and determines the amount of bandwidth available to the router in each FT1/T1 channel.

The timeslot range must match the timeslots assigned to the channel group. Your service provider defines the timeslots that comprise a channel group.

To use the entire T1 line, enable the service-module t1 timeslots all command.

Example

The following example displays a series of timeslot ranges and a speed of 64 kbps:

service-module t1 timeslots 1-10,15-20,22 speed 64
Related Commands

service-module t1 data-coding
service-module t1 linecode

show async status

To display the status of the asynchronous interfaces (which on routers is interface 1, the auxiliary port), use the show async status user EXEC command:

show async status
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Shows all asynchronous sessions, whether they are using SLIP or PPP encapsulation.

Sample Display

The following is sample output from the show async status command:

Router> show async status
Async protocol statistics:
  Rcvd: 5448 packets, 7682760 bytes
        1 format errors, 0 checksum errors, 0 overrun, 0 no buffer
  Sent: 5455 packets, 7682676 bytes, 0 dropped
 Int           Local          Remote Qd InPack OutPac Inerr  Drops  MTU Qsz
   1     192.31.7.84         Dynamic  0      0      0     0      0 1500  10

Table 25 describes significant fields shown in the display.


Table 25: Show Async Status Field Descriptions
Field Description
Rcvd: Statistics on packets received.
5548 packets Packets received.
7682760 bytes Total number of bytes.
1 format errors Packets with a bad IP header, even before the checksum is calculated.
0 checksum errors Count of checksum errors.
0 overrun Number of giants received.
0 no buffer Number of packets received when no buffer was available.
Sent: Statistics on packets sent.
5455 packets Packets sent.
7682676 bytes Total number of bytes.
0 dropped Number of packets dropped.
Int Interface number.
* Line currently in use.
Local Local IP address on the link.
Remote Remote IP address on the link; "Dynamic" indicates that a remote address is allowed but has not been specified; "None" indicates that no remote address is assigned or being used.
Qd Number of packets on hold queue (Qsz is max).
InPack Number of packets received.
OutPac Number of packets sent.
Inerr Number of total input errors; sum of format errors, checksum errors, overruns and no buffers.
Drops Number of packets received that would not fit on the hold queue.
MTU Current maximum transmission unit size.
Qsz Current output hold queue size.
Related Commands

async default ip address
async dynamic address
async dynamic routing
async mode dedicated
async mode interactive
interface async

show compress

To display compression statistics, use the show compress EXEC command.

show compress
Syntax Description

This command has no arguments or parameters.

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 compress command:

Router# show compress
Serial0
uncompressed bytes xmt/rcv 10710562/11376835
1  min avg ratio xmt/rcv 2.773/2.474
5  min avg ratio xmt/rcv 4.084/3.793
10 min avg ratio xmt/rcv 4.125/3.873
no bufs xmt 0 no bufs rcv 0
resets 0

Table 26 describes the fields shown in the display.


Table 26: Show Compress Field Descriptions
Field Description
Serial0 Name and number of the interface.
uncompressed bytes xmt/rcv Total number of uncompressed bytes sent and received.
1 min avg ratio xmt/rcv
5 min avg ratio xmt/rcv
10 min avg ratio xmt/rcv
Static compression ratio for bytes sent and received, averaged over 1, 5, and 10 minutes.
no bufs xmt Number of times buffers were not available to compress data being sent.
no bufs rcv Number of times buffers were not available to uncompress data being received.
resets Number of resets.
Related Command

compress

show controllers async

Use the show controllers async EXEC command to display information about interface hardware, registers, and random access memory on the Cisco 1005 router.

show controllers async number
Syntax Description
Number of the asynchronous interface.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following is sample output from the show controllers async command:

1005# show controllers async 1
QUICC Async unit 1, idb at 0x22A3950, driver data structure at 0x22A7F78
SCC Registers:
General [GSMR]=0x62:0x00028034, Protocol-specific [PSMR]=0x7000
Events [SCCE]=0x0000, Mask [SCCM]=0x022F, Status [SCCS]=0x0003
Transmit on Demand [TODR]=0x0, Data Sync [DSR]=0x7E7E
Interrupt Registers:
Config [CICR]=0x00368460, Pending [CIPR]=0x8500C804
Mask   [CIMR]=0x48000012, In-srv  [CISR]=0x00000000
Command register [CR]=0x6C0
Port A [PADIR]=0x0008, [PAPAR]=0x5AC3
       [PAODR]=0x0000, [PADAT]=0xB8EA
Port B [PBDIR]=0x020F1F, [PBPAR]=0x0000C0
       [PBODR]=0x000000, [PBDAT]=0x000EC0
Port C [PCDIR]=0x0384, [PCPAR]=0x0009
       [PCSO]=0x0030,  [PCDAT]=0x0300, [PCINT]=0x0000
DTE V.24 (RS-232) serial cable attached.
SCC GENERAL PARAMETER RAM (at 0xFF00F00)
Rx BD Base [RBASE]=0x560, Fn Code [RFCR]=0x18
Tx BD Base [TBASE]=0x5E0, Fn Code [TFCR]=0x18
Max Rx Buff Len [MRBLR]=1500
Rx State [RSTATE]=0x18001000, BD Ptr [RBPTR]=0x5A8
 --More--
Tx State [TSTATE]=0x0, BD Ptr [TBPTR]=0x5E0
SCC UART PARAMETER RAM (at 0xFF00F00)
Maximum idle characters 5
Break Character 1
Received Parity Error 0
Received Frame Error 0
Received Noise Error 0
Number of break conditions 0
Break length 0
uart1 0
uart2 0
Out of sequence 0
cc[0] = 8000
cc[1] = 8000
cc[2] = 8000
cc[3] = 8000
cc[4] = 8000
cc[5] = 8000
cc[6] = 8000
cc[7] = 8000
rccm = C0FF
rccr = 0
rlbc = 0
RX ring with 16 entries at 0xFF00560, Buffer size 1500
Rxhead = 0xFF005A8 (9), Rxp = 0x22A7FB8 (9)
00 pak=0x22AA3E8 buf=0x23B3440 status=9000 pak_size=0
01 pak=0x22AA23C buf=0x23B2DA0 status=9000 pak_size=0
02 pak=0x22AAA98 buf=0x23B4EC0 status=9000 pak_size=0
03 pak=0x22AAC44 buf=0x23B5560 status=9000 pak_size=0
04 pak=0x22AA8EC buf=0x23B4820 status=9000 pak_size=0
05 pak=0x22AA594 buf=0x23B3AE0 status=9000 pak_size=0
06 pak=0x22AA740 buf=0x23B4180 status=9000 pak_size=0
07 pak=0x22AA090 buf=0x23B2700 status=9000 pak_size=0
08 pak=0x22A9EE4 buf=0x23B2060 status=9000 pak_size=0
09 pak=0x22A99E0 buf=0x23B0C80 status=9000 pak_size=0
10 pak=0x22A9834 buf=0x23B05E0 status=9000 pak_size=0
11 pak=0x22A9688 buf=0x23AFF40 status=9000 pak_size=0
12 pak=0x22A94DC buf=0x23AF8A0 status=9000 pak_size=0
13 pak=0x22A9330 buf=0x23AF200 status=9000 pak_size=0
14 pak=0x22A9184 buf=0x23AEB60 status=9000 pak_size=0
15 pak=0x22A8FD8 buf=0x23AE4C0 status=B000 pak_size=0
TX ring with 2 entries at 0xFF005E0, tx_count = 0
tx_head = 0xFF005E0 (0), head_txp = 0x22A7FF0 (0)
tx_tail = 0xFF005E0 (0), tail_txp = 0x22A7FF0 (0)
00 pak=0x0000000 buf=0x0000000 status=0000 pak_size=0
01 pak=0x0000000 buf=0x0000000 status=2000 pak_size=0
QUICC SCC specific errors:
0 input aborts on receiving flag sequence
0 throttles, 0 enables
0 overruns
0 transmitter underruns
0 transmitter CTS losts

show controllers cbus

To display all information under the cBus controller card, use the show controllers cbus privileged EXEC command on the Cisco 7000, Cisco RSP/7000, Cisco 7500, or Cisco 7513 routers. This command also shows the capabilities of the card and reports controller-related failures.

show controllers cbus
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 Displays

The following is partial sample output from the show controllers cbus command on a Cisco 7500 series router with one VIP2 interface processor. This example does not show output from additional interface processors that are usually installed in a Cisco 7500 series router.

Router# show controller cbus
MEMD at 40000000, 2097152 bytes (unused 2752, recarves 1, lost 0)
  RawQ 48000100, ReturnQ 48000108, EventQ 48000110
  BufhdrQ 48000138 (2849 items), LovltrQ 48000150 (42 items, 1632 bytes)
  IpcbufQ 48000158 (32 items, 4096 bytes)
  3570 buffer headers (48002000 - 4800FF10)
  pool0: 15 buffers, 256 bytes, queue 48000140
  pool1: 368 buffers, 1536 bytes, queue 48000148
  pool2: 260 buffers, 4544 bytes, queue 48000160
  pool3: 4 buffers, 4576 bytes, queue 48000168
slot1: VIP2, hw 2.2, sw 200.50, ccb 5800FF30, cmdq 48000088, vps 8192
    software loaded from system
    FLASH ROM version 255.255
    FastEthernet1/0/0, addr 0000.0c41.6c20 (bia 0000.0c41.6c20)
      gfreeq 48000148, lfreeq 480001D0 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A00, txacc 48001A02 (value 0), txlimit 20
    Ethernet1/1/0, addr 0000.0c41.6c28 (bia 0000.0c41.6c28)
      gfreeq 48000148, lfreeq 480001D8 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A08, txacc 48001A0A (value 0), txlimit 20
    Ethernet1/1/1, addr 0000.0c41.6c29 (bia 0000.0c41.6c29)
      gfreeq 48000148, lfreeq 480001E0 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A10, txacc 48001A12 (value 0), txlimit 20
    Ethernet1/1/2, addr 0000.0c41.6c2a (bia 0000.0c41.6c2a)
      gfreeq 48000148, lfreeq 480001E8 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A18, txacc 48001A1A (value 0), txlimit 20
    Ethernet1/1/3, addr 0000.0c41.6c2b (bia 0000.0c41.6c2b)
      gfreeq 48000148, lfreeq 480001F0 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A20, txacc 48001A22 (value 0), txlimit 20
    Ethernet1/1/4, addr 0000.0c41.6c2c (bia 0000.0c41.6c2c)
      gfreeq 48000148, lfreeq 480001F8 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A28, txacc 48001A2A (value 0), txlimit 20
    Ethernet1/1/5, addr 0000.0c41.6c2d (bia 0000.0c41.6c2d)
      gfreeq 48000148, lfreeq 48000200 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A30, txacc 48001A32 (value 0), txlimit 20
    Ethernet1/1/6, addr 0000.0c41.6c2e (bia 0000.0c41.6c2e)
      gfreeq 48000148, lfreeq 48000208 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A38, txacc 48001A3A (value 0), txlimit 20
    Ethernet1/1/7, addr 0000.0c41.6c2f (bia 0000.0c41.6c2f)
      gfreeq 48000148, lfreeq 48000210 (1536 bytes), throttled 0
      rxlo 4, rxhi 30, rxcurr 0, maxrxcurr 0
      txq 48001A40, txacc 48001A42 (value 0), txlimit 20

The following is partial sample output of the show controllers cbus command for a Packet over SONET Interface Processor (POSIP) in slot 0; its single Packet OC-3 interface is Posi0/0:

slot0: POSIP, hw 2.1, sw 200.01, ccb 5800FF30, cmdq 48000080, vps 8192
    software loaded from flash slot0:rsp_posip.new
    FLASH ROM version 160.4, VPLD version 2.2
    Posi0/0, applique is SONET
      gfreeq 48000148, lfreeq 48000158 (4480 bytes), throttled 0
      rxlo 4, rxhi 226, rxcurr 0, maxrxcurr 186
      txq 48000160, txacc 48000082 (value 150), txlimit 150

The following is partial output of the show controllers cbus command for a Multichannel Interface Processor (MIP). Not all of the 23 channels defined on serial interface 1/0 are shown.

slot1: MIP, hw 1.1, sw 205.03, ccb 5800FF40, cmdq 48000088, vps 8192
    software loaded from system
    T1 1/0, applique is Channelized T1
      gfreeq 48000130, lfreeq 480001B0 (1536 bytes), throttled 0
      rxlo 4, rxhi 360, rxcurr 0, maxrxcurr 3
      Serial1/0:0, txq 480001B8, txacc 48000082 (value 3), txlimit 3
      Serial1/0:1, txq 480001B8, txacc 4800008A (value 3), txlimit 3
      Serial1/0:2, txq 480001B8, txacc 48000092 (value 3), txlimit 3
      Serial1/0:3, txq 480001B8, txacc 4800009A (value 3), txlimit 3
      Serial1/0:4, txq 480001B8, txacc 480000A2 (value 3), txlimit 3
      Serial1/0:5, txq 480001B8, txacc 480000AA (value 3), txlimit 3
      Serial1/0:6, txq 480001B8, txacc 480000B2 (value 3), txlimit 3
      Serial1/0:7, txq 480001B8, txacc 480000BA (value 3), txlimit 3

Table 27 describes significant fields in the per-slot part of these displays.


Table 27: Show Controllers cBus Command Per-Slot Field Descriptions for Cisco 7500
Field Description
slot1: POSIP Slot location of the specific interface processor (in this case Packet over SONET Interface Processor).
hw 2.3 Version number of the card.
sw 200.01 Version number of the card's internal software (in read-only memory).
Software loaded from Source device and file name from which the router software was loaded.
FLASH ROM version 160.5, VPLD version 2.2 Version of flash ROM
Posi1/0, applique is SONET Location of the specific interface and the hardware applique type (in this case a Packet OC-3 interface).
gfreeq Location of the global free queue that is shared among similar interfaces.
lfreeq Location of the local free queue, which is a private queue of MEMD buffers.
throttled Number of times input packet processing has been throttled on this interface.
rxlo Minimum number of MEMD buffers held on local free queue. When idle, the interface returns buffers from its local queue to the global free queue until only this number of buffers remain in the local queue.
rxhi Maximum number of MEMD buffers that the interface can remove from the global free queue in order to populate its local queue.
rxcurr Number of MEMD buffers currently on the local free queue.
maxrxcurr Maximum number of MEMD buffers that were enqueued on the local free queue.
txq Address of the transmit queue.
txacc Address of the transmit queue accumulator.
txlimit Maximum number of buffers allowed in the transmit queue.

The following is sample output from the show controllers cbus command on a Cisco 7000 router:

Router# show controllers cbus
cBus 1, controller type 3.0, microcode version 2.0
  128 Kbytes of main memory, 32 Kbytes cache memory
  40 1520 byte buffers, 14 4484 byte buffers
  Restarts: 0 line down, 0 hung output, 0 controller error
HSCI 1, controller type 10.0, microcode version 129.3
  Interface 6 - Hssi0, electrical interface is Hssi DTE
    5 buffer RX queue threshold, 7 buffer TX queue limit, buffer size 1520
    ift 0004, rql 2, tq 0000 0000, tql 7
    Transmitter delay is 0 microseconds
 MEC 3, controller type 5.1, microcode version 130.6
  Interface 18 - Ethernet2, station address 0000.0c02.a03c (bia 0000.0c02.a03c)
    10 buffer RX queue threshold, 7 buffer TX queue limit, buffer size 1520
    ift 0000, rql 10, tq 0000 0000, tql 7
    Transmitter delay is 0 microseconds
  Interface 19 - Ethernet3, station address 0000.0c02.a03d (bia 0000.0c02.a03d)
    10 buffer RX queue threshold, 7 buffer TX queue limit, buffer size 1520
    ift 0000, rql 10, tq 0000 0000, tql 7
    Transmitter delay is 0 microseconds

Table 28 describes the fields shown in the following lines of output from the display.

cBus 1, controller type 3.0, microcode version 2.0
  128 Kbytes of main memory, 32 Kbytes cache memory
  40 1520 byte buffers, 14 4484 byte buffers
  Restarts: 0 line down, 0 hung output, 0 controller error

    


Table 28: Show Controllers cBus Field Descriptions for a Cisco 7000 Router--Part 1
Field Description
cBus 1 Card type and number (varies depending on card).
controller type 3.0 Version number of the card.
microcode version 2.0 Version number of the card's internal software (in read-only memory).
128 Kbytes of main memory Amount of main memory on the card.
32 Kbytes cache memory Amount of cache memory on the card.
40 1520 byte buffers Number of buffers of this size on the card.
14 4484 byte buffers Number of buffers of this size on the card.
Restarts
   0 line down
   0 hung output
   0 controller error
Count of restarts due to the following conditions:
   Communication line down
   Output unable to transmit
   Internal error

Table 29 describes the fields shown in the following lines of output from the display:

HSCI 1, controller type 10.0, microcode version 129.3
  Interface 6 - Hssi0, electrical interface is Hssi DTE
    5 buffer RX queue threshold, 7 buffer TX queue limit, buffer size 1520
    ift 0004, rql 2, tq 0000 0000, tql 7
    Transmitter delay is 0 microseconds


Table 29: Show Controllers cBus Field Descriptions for a Cisco 7000 Router--Part 2
Field Description
HSCI 1 Card type and number (varies depending on card).
controller type 10.0 Version number of the card.
microcode version 129.3 Version number of the card's internal software (in read-only memory).
Interface 6 Physical interface number.
Hssi 0 Logical name for this interface.
electrical interface is Hssi DTE Self-explanatory.
5 buffer RX queue threshold Maximum number of buffers allowed in the receive queue.
7 buffer TX queue limit Maximum number of buffers allowed in the transmit queue.
buffer size 1520 Size of the buffers on this card (in bytes).
ift 0004 Interface type code.
0 = EIP
1 = FSIP
4 = HIP
5 = TRIP
6 = FIP
7 = AIP
rql 2 Receive queue limit. Current number of buffers allowed for the receive queue. It is used to limit the number of buffers used by a particular inbound interface. When equal to 0, all of that interface's receive buffers are in use.
tq 0000 0000 Transmit queue head and tail pointers.
tql 7 Transmit queue limit. Current number of buffers allowed for transmit queue. It limits the maximum cBus buffers allowed to sit on a particular interface's transmit queue.
Transmitter delay is 0 microseconds Transmitter delay between the packets.

The following is sample output of the show controllers cbus display for an AIP installed in IP slot 4, the running AIP microcode is Version 170.30, the PLIM type is 4B/5B, and the available bandwidth is 100 Mbps:

Router# show controllers cbus
Switch Processor 5, hardware version 11.1, microcode version 170.46
  Microcode loaded from system
  512 Kbytes of main memory, 128 Kbytes cache memory
  60 1520 byte buffers, 91 4496 byte buffers
  Restarts: 0 line down, 0 hung output, 0 controller error
 AIP 4, hardware version 1.0, microcode version 170.30
  Microcode loaded from system
  Interface 32 - ATM4/0, PLIM is 4B5B(100Mbps)
    15 buffer RX queue threshold, 36 buffer TX queue limit, buffer size 4496
    ift 0007, rql 12, tq 0000 0620, tql 36
    Transmitter delay is 0 microseconds

The following is sample output of the show controllers cbus display for SMIP:

Router# show controllers cbus
SMIP 2, hardware version 1.0, microcode version 10.0 
 Microcode loaded from system
 Interface 16 - T1 2/0, electrical interface is Channelized T1 
   10 buffer RX queue threshold, 14 buffer TX queue limit, buffer size 1580 ift 0001, rql    7, tq 0000 05B0, tql 14
   Transmitter delay is 0 microseconds

show controllers e1

Use the show controllers e1 privileged EXEC command on the Cisco 4000, Cisco 7000, and Cisco 7500 series to display information about the E1 links supported by the Network Processor Module (NPM) (Cisco 4000) or MultiChannel Interface Processor (MIP) (Cisco 7000 series and Cisco 7500 series).

show controllers e1 [slot/port]
Syntax Description
slot (Optional) Backplane slot number; value can be 0, 1, 2, 3, or 4.
port (Optional) Port number of the controller; value can be 0 or 1.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

The NPM or MIP can query the port adapters to determine their current status. Issue a show controllers e1 command to display statistics about the E1 link.

If you specify a slot and port number, each 15-minute period will be displayed.

This command displays controller status that is specific to the controller hardware. The information displayed is generally useful for diagnostic tasks performed by technical support personnel only.

Sample Display

The following is sample output from the show controllers e1 command on the Cisco 7000 series:

Router# show controllers e1
e1 0/0 is up.
  Applique type is Channelized E1 - unbalanced
  Framing is CRC4, Line Code is HDB3
  No alarms detected.
  Data in current interval (725 seconds elapsed):
     0 Line Code Violations, 0 Path Code Violations
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
  Total Data (last 24 hours)
     0 Line Code Violations, 0 Path Code Violations,
     0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins,
     0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

Following is an example of the show controllers e1 display including the board identifier type:

Router# show cont e1
E1 4/1 is up.
  No alarms detected.
  Framing is CRC4, Line Code is hdb3
  Data in current interval (0 seconds elapsed): 
     0 Line Code Violations, 0 Path Code Violations 0 Slip Secs, 0 Fr Loss Secs, 
     0 Line Err Secs, 0 Degraded Mins 0 Errored Secs, 0 Bursty Err Secs, 
     0 Severely Err Secs, 0 Unavail Secs 
  Total Data (last 79 15 minute intervals): 
     0 Line Code Violations, 0 Path Code Violations, 0 Slip Secs, 0 Fr Loss Secs, 
     0 Line Err Secs, 0 Degraded Mins, 0 Errored Secs, 0 Bursty Err Secs, 
     0 Severely Err Secs, 0 Unavail Secs 

Table 30 describes the show controllers e1 display fields.


Table 30: Show Controllers E1 Field Descriptions
Field Description
e1 0/0 is up. The E1 controller 0 in slot 0 is operating. The controller's state can be up, down, or administratively down. Loopback conditions are shown by (Locally Looped) or (Remotely Looped).
Applique type The applique type is shown and will indicate balanced or unbalanced.
Framing is Shows the current framing type.
Linecode is Shows the current linecode type.
No alarms detected. Any alarms detected by the controller are displayed here. Possible alarms are as follows:

  • Transmitter is sending remote alarm.

  • Transmitter is sending AIS.

  • Receiver has loss of signal.

  • Receiver is getting AIS.

  • Receiver has loss of frame.

  • Receiver has remote alarm.

  • Receiver has no alarms.

Data in current interval (725 seconds elapsed)

Shows the current accumulation period, which rolls into the 24 hour accumulation every 15 minutes. Accumulation period is from 1 to 900 seconds. The oldest 15-minute period falls off the back of the 24-hour accumulation buffer.
Line Code Violations Indicates the occurrence of either a Bipolar Violation (BPV) or Excessive Zeros (EXZ) error event.
Path Code Violations Indicates a frame synchronization bit error in the D4 and E1-noCRC formats, or a CRC error in the ESF and E1-CRC formats.
Slip Secs Indicates the replication or deletion of the payload bits of a DS1 frame. A slip might be performed when there is a difference between the timing of a synchronous receiving terminal and the received signal.
Fr Loss Secs Indicates the number of seconds an Out Of Frame (OOF) error is detected.
Line Err Secs Line Errored Seconds (LES) is a second in which one or more Line Code Violation errors are detected.
Degraded Mins A Degraded Minute is one in which the estimated error rate exceeds 1E-6 but does not exceed 1E-3.
Errored Secs In ESF and E1 CRC links, an Errored Second is a second in which one of the following are detected: one or more Path Code Violations; one or more Out of Frame defects; one or more Controlled Slip events; a detected AIS defect.

For SF and E1 no-CRC links, the presence of Bipolar Violations also triggers an Errored Second.

Bursty Err Secs A second with fewer than 320 and more than 1 Path Coding Violation error, no Severely Errored Frame defects and no detected incoming AIS defects. Controlled slips are not included in this parameter.
Severely Err Secs For ESF signals, a second with one of the following errors: 320 or more Path Code Violation errors; one or more Out of Frame defects; a detected AIS defect.

For E1-CRC signals, a second with one of the following errors: 832 or more Path Code Violation errors; one or more Out of Frame defects.

For E1-nonCRC signals, a second with 2048 Line Code Violations or more.

For D4 signals, a count of 1-second intervals with Framing Errors, or an Out of Frame defect, or 1544 Line Code Violations.

Unavail Secs A count of the total number of seconds on the interface.

show controllers ethernet

Use the show controllers ethernet EXEC command to display information on the Cisco 2500 series, Cisco 3000, or Cisco 4000 series.

show controllers ethernet number
Syntax Description
number Interface number of the Ethernet interface.
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 controllers ethernet command on the Cisco 4000:

Router# show controllers ethernet 0
LANCE unit 0, NIM slot 1, NIM type code 4, NIM version 1
Media Type is 10BaseT, Link State is Up, Squelch is Normal
idb 0x4060, ds 0x5C80, regaddr = 0x8100000
IB at 0x600D7AC: mode=0x0000, mcfilter 0000/0001/0000/0040
station address 0000.0c03.a14f  default station address 0000.0c03.a14f
buffer size 1524
RX ring with 32 entries at 0xD7E8
Rxhead = 0x600D8A0 (12582935), Rxp = 0x5CF0(23)
00 pak=0x60336D0 ds=0x6033822 status=0x80 max_size=1524 pak_size=98
01 pak=0x60327C0 ds=0x6032912 status=0x80 max_size=1524 pak_size=98
02 pak=0x6036B88 ds=0x6036CDA status=0x80 max_size=1524 pak_size=98
03 pak=0x6041138 ds=0x604128A status=0x80 max_size=1524 pak_size=98
04 pak=0x603FAA0 ds=0x603FBF2 status=0x80 max_size=1524 pak_size=98
05 pak=0x600DC50 ds=0x600DDA2 status=0x80 max_size=1524 pak_size=98
06 pak=0x6023E48 ds=0x6023F9A status=0x80 max_size=1524 pak_size=1506
07 pak=0x600E3D8 ds=0x600E52A status=0x80 max_size=1524 pak_size=1506
08 pak=0x6020990 ds=0x6020AE2 status=0x80 max_size=1524 pak_size=386
09 pak=0x602D4E8 ds=0x602D63A status=0x80 max_size=1524 pak_size=98
10 pak=0x603A7C8 ds=0x603A91A status=0x80 max_size=1524 pak_size=98
11 pak=0x601D4D8 ds=0x601D62A status=0x80 max_size=1524 pak_size=98
12 pak=0x603BE60 ds=0x603BFB2 status=0x80 max_size=1524 pak_size=98
13 pak=0x60318B0 ds=0x6031A02 status=0x80 max_size=1524 pak_size=98
14 pak=0x601CD50 ds=0x601CEA2 status=0x80 max_size=1524 pak_size=98
15 pak=0x602C5D8 ds=0x602C72A status=0x80 max_size=1524 pak_size=98
16 pak=0x60245D0 ds=0x6024722 status=0x80 max_size=1524 pak_size=98
17 pak=0x6008328 ds=0x600847A status=0x80 max_size=1524 pak_size=98
18 pak=0x601EB70 ds=0x601ECC2 status=0x80 max_size=1524 pak_size=98
19 pak=0x602DC70 ds=0x602DDC2 status=0x80 max_size=1524 pak_size=98
20 pak=0x60163E0 ds=0x6016532 status=0x80 max_size=1524 pak_size=98
21 pak=0x602CD60 ds=0x602CEB2 status=0x80 max_size=1524 pak_size=98
22 pak=0x6037A98 ds=0x6037BEA status=0x80 max_size=1524 pak_size=98
23 pak=0x602BE50 ds=0x602BFA2 status=0x80 max_size=1524 pak_size=98
24 pak=0x6018988 ds=0x6018ADA status=0x80 max_size=1524 pak_size=98
25 pak=0x6033E58 ds=0x6033FAA status=0x80 max_size=1524 pak_size=98
26 pak=0x601BE40 ds=0x601BF92 status=0x80 max_size=1524 pak_size=98
27 pak=0x6026B78 ds=0x6026CCA status=0x80 max_size=1524 pak_size=98
28 pak=0x6024D58 ds=0x6024EAA status=0x80 max_size=1524 pak_size=74
29 pak=0x602AF40 ds=0x602B092 status=0x80 max_size=1524 pak_size=98
30 pak=0x601FA80 ds=0x601FBD2 status=0x80 max_size=1524 pak_size=98
31 pak=0x6038220 ds=0x6038372 status=0x80 max_size=1524 pak_size=98
TX ring with 8 entries at 0xDA20, tx_count = 0
tx_head = 0x600DA58 (12582919), head_txp = 0x5DC4 (7)
tx_tail = 0x600DA58 (12582919), tail_txp = 0x5DC4 (7)
00 pak=0x000000 ds=0x600CF12 status=0x03 status2=0x0000 pak_size=118
01 pak=0x000000 ds=0x602126A status=0x03 status2=0x0000 pak_size=60
02 pak=0x000000 ds=0x600CF12 status=0x03 status2=0x0000 pak_size=118
03 pak=0x000000 ds=0x600CF12 status=0x03 status2=0x0000 pak_size=118
04 pak=0x000000 ds=0x600CF12 status=0x03 status2=0x0000 pak_size=118
05 pak=0x000000 ds=0x600CF12 status=0x03 status2=0x0000 pak_size=118
06 pak=0x000000 ds=0x600CF12 status=0x03 status2=0x0000 pak_size=118
07 pak=0x000000 ds=0x6003ED2 status=0x03 status2=0x0000 pak_size=126
0 missed datagrams, 0 overruns, 2 late collisions, 2 lost carrier events
0 transmitter underruns, 0 excessive collisions,  0 tdr, 0 babbles
0 memory errors, 0 spurious initialization done interrupts
0 no enp status, 0 buffer errors, 0 overflow errors
10 one_col, 10 more_col, 22 deferred, 0 tx_buff
0 throttled, 0 enabled
Lance csr0 = 0x73

show controllers fastethernet

To display information about initialization block information, transmit ring, receive ring and errors for the Fast Ethernet controller chip on the Cisco 4500 series, Cisco 7000 series, Cisco 7200 series, or Cisco 7500 series, use the show controllers fastethernet EXEC command.

show controllers fastethernet number Cisco 4500 series
show controllers fastethernet
slot/port (Cisco 7000 series and Cisco 7200 series)
show controllers fastethernet slot/port-adapter/port (Cisco 7500 series)

Syntax Description
number Port, connector, or interface card number. On a Cisco 4500 or Cisco 4700 router, specifies the NPM number. The numbers are assigned at the factory at the time of installation or when added to a system.
slot On the Cisco 7000 series, slot location of the FEIP. On the Cisco 7200, slot 0 is the Fast Ethernet port on the I/O controller.
port On the Cisco 7000 series, port number on the interface.
port-adapter On the Cisco 7000 and Cisco 7500 series, port bay on a VIP card. The value can be 0 or 1.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

The output of this command is generally useful for diagnostic tasks performed by technical support only.

Sample Displays

The following is sample output from the show controllers fastethernet command on a Cisco 4500 series router:

c4500-1# show controllers fastethernet 0 
DEC21140 Slot 0, Subunit 0
dec21140_ds=0x60001234, registers=0x3c001000, ib=0x42301563, ring entries=256
rxring=0x40235878, rxr shadow=0x64528745, rx_head=0, rx_tail=10
txring=0x43562188, txr shadow=0x65438721, tx_head=17, tx_tail=34, tx_count=17
DEC21140 Registers
CSR0=0x23457667, CSR3=0x12349878, CSR4=0x34528745, CSR5=0x76674565
CSR6=0x76453676, CSR7=0x76456574, CSR8=0x25367648, CSR9=0x87253674
CSR11=0x23456454, CSR12=0x76564787, CSR15=0x98273465
DEC21140 PCI registers
bus_no=0, device_no=0
CFID=0x12341234, CFCS=0x76547654, CFRV=0x87658765, CFLT=0x98769876
CBIO=0x12344321, CBMA=0x23454321, CFIT=0x34567654, CFDA=0x76544567
MII registers
Register 0x00: 0x1234 0x1234 0x2345 0x3456 0x4567 0x5678 0x6789 0x7890
Register 0x08: 0x9876 0x8765 0x7654 0x6543 0x5432 0x4321 0x3210 0x2109
Register 0x10: 0x1234 0x2345 0x3456            0x4567 0x5678 0x6789 0x7890
Register 0x18: 0x9876 0x8765 0x7654 0x6543 0x5432 0x4321
DEC21140 statistics
filtered_in_sw=1000, throttled=10, enabled=10
rx_fifo_overflow=10, rx_no_enp=12, rx_late_collision=18
rx_watchdog=15, rx_process_stopped=15, rx_buffer_unavailable=1500
tx_jabber_timeout=10, tx_carrier_loss=2, tx_deffered=15
tx_no_carrier=1, tx_late_collision=10, tx_excess_coll=10
tx_process_stopped=1, fata_tx_err=0

The following is sample output from the show controllers fastethernet command on a Cisco 7000 router:

router# show controllers fastethernet 0/0
Interface FastEthernet0/0
Hardware is DEC21140
 dec21140_ds=0x60895888, registers=0x3C018000, ib=0x4B019500
 rx ring entries=128, tx ring entries=128
 rxring=0x4B019640, rxr shadow=0x60895970, rx_head=0, rx_tail=0
 txring=0x4B019EC0, txr shadow=0x60895B98, tx_head=77, tx_tail=77, tx_count=0
 CSR0=0xFFFA4882, CSR3=0x4B019640, CSR4=0x4B019EC0, CSR5=0xFC660000
 CSR6=0xE20CA202, CSR7=0xFFFFA241, CSR8=0xFFFE0000, CSR9=0xFFFDD7FF
 CSR11=0xFFFE0000, CSR12=0xFFFFFF98, CSR15=0xFFFFFEC8
 DEC21140 PCI registers:
  bus_no=0, device_no=6
  CFID=0x00091011, CFCS=0x02800006, CFRV=0x02000012, CFLT=0x0000FF00
  CBIO=0x7C5AFF81, CBMA=0x48018000, CFIT=0x0000018F, CFDA=0x0000AF00
 MII registers:
  Register 0x00:   2000  780B  2000  5C00  01E1  0000  0000  0000
  Register 0x08:   0000  0000  0000  0000  0000  0000  0000  0000
  Register 0x10:   0000  0000  0000  0000        0000  0000  8040
  Register 0x18:   8000  0000  0000  3800  A3B9
 throttled=0, enabled=0, disabled=0
 rx_fifo_overflow=0, rx_no_enp=0, rx_discard=0
 tx_underrun_err=0, tx_jabber_timeout=0, tx_carrier_loss=1
 tx_no_carrier=1, tx_late_collision=0, tx_excess_coll=0
 tx_collision_cnt=0, tx_deferred=0, fatal_tx_err=0, mult_ovfl=0
HW addr filter: 0x60895FC0, ISL Enabled
  Entry= 0: Addr=0100.0CCC.CCCC
  Entry= 1: Addr=0300.0000.0001
  Entry= 2: Addr=0100.0C00.0000
  Entry= 3: Addr=FFFF.FFFF.FFFF
  Entry= 4: Addr=FFFF.FFFF.FFFF
  Entry= 5: Addr=FFFF.FFFF.FFFF
  Entry= 6: Addr=FFFF.FFFF.FFFF
  Entry= 7: Addr=FFFF.FFFF.FFFF
  Entry= 8: Addr=FFFF.FFFF.FFFF
  Entry= 9: Addr=FFFF.FFFF.FFFF
  Entry=10: Addr=FFFF.FFFF.FFFF
  Entry=11: Addr=FFFF.FFFF.FFFF
  Entry=12: Addr=FFFF.FFFF.FFFF
  Entry=13: Addr=FFFF.FFFF.FFFF
  Entry=14: Addr=FFFF.FFFF.FFFF
  Entry=15: Addr=0060.3E28.6E00
Related Command

show interface fastethernet

show controllers fddi

To display all information under the FDDI Interface Processor (FIP) on the Cisco 7000 series, Cisco 7200 series, and Cisco 7500 series, use the show controllers fddi user EXEC command.

show controllers fddi
Syntax Description

This command has no arguments or keywords.

Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command reflects the internal state of the chips and information the system uses for bridging and routing that is specific to the interface hardware. The information displayed is generally useful for diagnostic tasks performed by technical support personnel only.

Sample Display

The following is sample output from the show controllers fddi command:

Router# show controllers fddi
Fddi2/0 - hardware version 2.2, microcode version 1.2
  Phy-A registers:
    cr0 4, cr1 0, cr2 0, status 3, cr3 0
  Phy-B registers:
    cr0 4, cr1 4, cr2 0, status 3, cr3 0
  FORMAC registers:
    irdtlb  71C2, irdtneg F85E, irdthtt F5D5, irdmir  FFFF0BDC
    irdtrth F85F, irdtmax FBC5, irdtvxt 5959, irdstmc 0810
    irdmode 6A20, irdimsk 0000, irdstat 8060, irdtpri 0000
  FIP registers
    ccb:   002C  cmd:   0006  fr:   000F  mdptr: 0000  mema: 0000
    icb:   00C0  arg:   0003  app:  0004  mdpg:  0000  af:   0603
    clm:   E002  bcn:   E016  clbn: 0198  rxoff: 002A  en:   0001
    clmbc: 8011  bcnbc: 8011  robn: 0004  park:  0000  fop:  8004
    txchn: 0000  pend:  0000  act:  0000  tail:  0000  cnt:  0000
    state: 0003  check: 0000  eof:  0000  tail:  0000  cnt:  0000
    rxchn: 0000  buf0:  0534  nxt0: 0570  eof:   0000  tail: 0000
    eofch: 0000  buf1:  051C  nxt1: 0528  pool:  0050  err:  005C
    head:  0984  cur:   0000  t0:   0030  t1:    0027  t2:   000F
    tail:  0984  cnt:   0001  t3:   0000  rxlft: 000B  used: 0000
    txq_s: 0018  txq_f: 0018  Aarm: 0000  Barm:  1388  fint: 8004
 Total LEM: phy-a 6, phy-b 13

The last line of output indicates how many times the specific PHY encountered an "UNKNOWN LINE STATE" event on the fiber.

show controllers lex

To show hardware and software information about the LAN Extender chassis, use the show controllers lex EXEC command.

show controllers lex [number]
show controllers lex
[slot/port] (for the Cisco 7000 series)
Syntax Description
number (Optional) Number of the LAN Extender interface about which to display information.
slot (Optional) Specifies the backplane slot number on the Cisco 7000 series, and can be 0, 1, 2, 3, or 4.
port (Optional) Specifies the port number of the controller and can be 0 or 1.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.0.

Use the show controllers lex command to display information about the hardware revision level, software version number, Flash memory size, serial number, and other information related to the configuration of the LAN Extender.

Sample Display

The following is sample output from the show controllers lex command:

Router# show controllers lex 0 
Lex0:
FLEX Hardware revision 1
FLEX Software version 255.0
128K bytes of flash memory
Serial number is 123456789
Station address is 0000.4060.1100

The following is sample output from the show controllers lex command when the LAN Extender interface is not bound to a serial interface:

Router# show controller lex 1
Lex1 is not bound to a serial interface

Table 31 describes the fields shown in the output.


Table 31: Show Controllers Lex Field Description
Field Description
Lex0: Number of the LAN Extender interface
FLEX Hardware revision Revision number of the Cisco 1000 series LAN Extender chassis
FLEX Software version Revision number of the software running on the LAN Extender chassis
128K bytes of Flash memory Amount of Flash memory in the LAN Extender
Serial number Serial number of the LAN Extender chassis
Station address MAC address of the LAN Extender chassis

show controllers mci

Use the show controllers mci privileged EXEC command to display all information under the Multiport Communications Interface card or the SCI.

show controllers mci
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.

This command displays information the system uses for bridging and routing that is specific to the interface hardware. The information displayed is generally useful for diagnostic tasks performed by technical support personnel only.

Sample Display

The following is sample output from the show controllers mci command:

Router# show controllers mci
MCI 0, controller type 1.1, microcode version 1.8
   	128 Kbytes of main memory, 4 Kbytes cache memory
22 system TX buffers, largest buffer size 1520
   	Restarts: 0 line down, 0 hung output, 0 controller error
Interface 0 is Ethernet0, station address 0000.0c00.d4a6
   	15 total RX buffers, 11 buffer TX queue limit, buffer size 1520
   	Transmitter delay is 0 microseconds
Interface 1 is Serial0, electrical interface is V.35 DTE
   	15 total RX buffers, 11 buffer TX queue limit, buffer size 1520
   	Transmitter delay is 0 microseconds
   	High speed synchronous serial interface
Interface 2 is Ethernet1, station address aa00.0400.3be4
   	15 total RX buffers, 11 buffer TX queue limit, buffer size 1520
   	Transmitter delay is 0 microseconds
Interface 3 is Serial1, electrical interface is V.35 DCE
   	15 total RX buffers, 11 buffer TX queue limit, buffer size 1520
   	Transmitter delay is 0 microseconds
   	High speed synchronous serial interface 

Table 32 describes significant fields shown in the display.


Table 32: Show Controllers MCI Field Descriptions
Field Description
MCI 0 Card type and unit number (varies depending on card).
controller type 1.1 Version number of the card.
microcode version 1.8 Version number of the card's internal software (in read-only memory).
128 Kbytes of main memory Amount of main memory on the card.
4 Kbytes cache memory Amount of cache memory on the card.
22 system TX buffers Number of buffers that hold packets to be transmitted.
largest buffer size 1520 Largest size of these buffers (in bytes).
Restarts
   0 line down
   0 hung output
   0 controller error
Count of restarts due to the following conditions:
   Communication line down
   Output unable to transmit
   Internal error
Interface 0 is Ethernet0 Names of interfaces, by number.
electrical interface is V.35 DTE Line interface type for serial connections.
15 total RX buffers Number of buffers for received packets.
11 buffer TX queue limit Maximum number of buffers in transmit queue.
Transmitter delay is 0 microseconds Delay between outgoing frames.
Station address 0000.0c00.d4a6 Hardware address of the interface.

Note The interface type is only queried at startup. If the hardware changes subsequent to initial startup, then the wrong type is reported. This has no adverse effect on the operation of the software. For instance, if a DCE cable is connected to a dual-mode V.35 applique after the unit has been booted, then the display presented for show interfaces incorrectly reports attachment to a DTE device although the software recognizes the DCE interface and behaves accordingly.
Related Command

tx-queue-limit

show controllers pcbus

To display all information about the ISA bus interface, use the show controllers pcbus privileged EXEC command.

show controllers pcbus
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.

This command is valid on LanOptics' Branchcard or Stacknet 2000 products only.

Sample Display

The following is sample output from the show controllers pcbus command:

Router# show controllers pcbus
PCbus unit 0,  Name = PCbus0  Hardware is ISA PCbus shared RAM
IDB at 0x3719B0,  Interface driver data structure at 0x3735F8
Control/status register at 0x2110008,  Shared memory at 0xC000000
Shared memory is initialized
 
Shared memory interface control block :
Magic no = 0x41435A56 (valid)  Version = 1.0
Shared memory size = 64K bytes,  Interface is NOT shutdown
Interface state is up, line protocol is up
 
Tx buffer : (control block at 0xC000010)
Start offset = 0x30,  Size = 0x7FE8,  Overflows = 1
GET_ptr = 0x4F6C,  PUT_ptr = 0x4F6C,  WRAP_ptr = 0x3BB0
 
Rx buffer : (control block at 0xC000020)
Start offset = 0x8018,  Size 0x7FE8,  Overflows = 22250698
GET_ptr = 0x60,  PUT_ptr = 0x60,  WRAP_ptr = 0x7FD0
 
Interrupts received = 567

show controllers serial

Use the show controllers serial privileged EXEC command to display information that is specific to the interface hardware.

show controllers serial
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.

The information displayed is generally useful for diagnostic tasks performed by technical support personnel only.

Sample Display

Sample output of the show controllers serial command on the Cisco 4000 follows:

Router# show controllers serial
MK5 unit 0, NIM slot 1, NIM type code 7, NIM version 1
idb = 0x6150, driver structure at 0x34A878, regaddr = 0x8100300
IB at 0x6045500: mode=0x0108, local_addr=0, remote_addr=0
N1=1524, N2=1, scaler=100, T1=1000, T3=2000, TP=1
buffer size 1524
DTE V.35 serial cable attached
RX ring with 32 entries at 0x45560 : RLEN=5, Rxhead 0
00 pak=0x6044D78  ds=0x6044ED4 status=80 max_size=1524 pak_size=0
01 pak=0x60445F0  ds=0x604474C status=80 max_size=1524 pak_size=0
02 pak=0x6043E68  ds=0x6043FC4 status=80 max_size=1524 pak_size=0
03 pak=0x60436E0  ds=0x604383C status=80 max_size=1524 pak_size=0
04 pak=0x6042F58  ds=0x60430B4 status=80 max_size=1524 pak_size=0
05 pak=0x60427D0  ds=0x604292C status=80 max_size=1524 pak_size=0
06 pak=0x6042048  ds=0x60421A4 status=80 max_size=1524 pak_size=0
07 pak=0x60418C0  ds=0x6041A1C status=80 max_size=1524 pak_size=0
08 pak=0x6041138  ds=0x6041294 status=80 max_size=1524 pak_size=0
09 pak=0x60409B0  ds=0x6040B0C status=80 max_size=1524 pak_size=0
10 pak=0x6040228  ds=0x6040384 status=80 max_size=1524 pak_size=0
11 pak=0x603FAA0  ds=0x603FBFC status=80 max_size=1524 pak_size=0
12 pak=0x603F318  ds=0x603F474 status=80 max_size=1524 pak_size=0
13 pak=0x603EB90  ds=0x603ECEC status=80 max_size=1524 pak_size=0
14 pak=0x603E408  ds=0x603E564 status=80 max_size=1524 pak_size=0
15 pak=0x603DC80  ds=0x603DDDC status=80 max_size=1524 pak_size=0
16 pak=0x603D4F8  ds=0x603D654 status=80 max_size=1524 pak_size=0
17 pak=0x603CD70  ds=0x603CECC status=80 max_size=1524 pak_size=0
18 pak=0x603C5E8  ds=0x603C744 status=80 max_size=1524 pak_size=0
19 pak=0x603BE60  ds=0x603BFBC status=80 max_size=1524 pak_size=0
20 pak=0x603B6D8  ds=0x603B834 status=80 max_size=1524 pak_size=0
21 pak=0x603AF50  ds=0x603B0AC status=80 max_size=1524 pak_size=0
22 pak=0x603A7C8  ds=0x603A924 status=80 max_size=1524 pak_size=0
23 pak=0x603A040  ds=0x603A19C status=80 max_size=1524 pak_size=0
24 pak=0x60398B8  ds=0x6039A14 status=80 max_size=1524 pak_size=0
25 pak=0x6039130  ds=0x603928C status=80 max_size=1524 pak_size=0
26 pak=0x60389A8  ds=0x6038B04 status=80 max_size=1524 pak_size=0
27 pak=0x6038220  ds=0x603837C status=80 max_size=1524 pak_size=0
28 pak=0x6037A98  ds=0x6037BF4 status=80 max_size=1524 pak_size=0
29 pak=0x6037310  ds=0x603746C status=80 max_size=1524 pak_size=0
30 pak=0x6036B88  ds=0x6036CE4 status=80 max_size=1524 pak_size=0
31 pak=0x6036400  ds=0x603655C status=80 max_size=1524 pak_size=0
TX ring with 8 entries at 0x45790 : TLEN=3, TWD=7
tx_count = 0, tx_head = 7, tx_tail = 7
00 pak=0x000000 ds=0x600D70C status=0x38 max_size=1524 pak_size=22
01 pak=0x000000 ds=0x600D70E status=0x38 max_size=1524 pak_size=2
02 pak=0x000000 ds=0x600D70E status=0x38 max_size=1524 pak_size=2
03 pak=0x000000 ds=0x600D70E status=0x38 max_size=1524 pak_size=2
04 pak=0x000000 ds=0x600D70E status=0x38 max_size=1524 pak_size=2
05 pak=0x000000 ds=0x600D70E status=0x38 max_size=1524 pak_size=2
06 pak=0x000000 ds=0x600D70E status=0x38 max_size=1524 pak_size=2
07 pak=0x000000 ds=0x6000000 status=0x38 max_size=1524 pak_size=0
XID/Test TX desc at 0xFFFFFF, status=0x30, max_buffer_size=0, packet_size=0
XID/Test RX desc at 0xFFFFFF, status=0x0, max_buffer_size=0, packet_size=0
Status Buffer at 0x60459C8: rcv=0, tcv=0, local_state=0, remote_state=0
phase=0, tac=0, currd=0x00000, curxd=0x00000
bad_frames=0, frmrs=0, T1_timeouts=0, rej_rxs=0, runts=0
0 missed datagrams, 0 overruns, 0 bad frame addresses
0 bad datagram encapsulations, 0 user primitive errors
0 provider primitives lost, 0 unexpected provider primitives
0 spurious primitive interrupts, 0 memory errors, 0 tr
%LINEPROTO-5-UPDOWN: Linansmitter underruns
mk5025 registers: csr0 = 0x0E00, csr1 = 0x0302, csr2 = 0x0704
                  csr3 = 0x5500, csr4 = 0x0214, csr5 = 0x0008

show controllers t1

Use the show controllers t1 privileged EXEC command on the Cisco 4000 series, Cisco 7000 series and Cisco 7500 series to display information about the T1 links supported by the Network Processor Module (NPM) (Cisco 4000) or the Multichannel Interface Processor (MIP) (Cisco 7000).

show controllers t1 [slot/port]
Syntax Description
slot (Optional) Backplane slot number; value can be 0, 1, 2, 3, or 4.
port (Optional) Port number of the controller; value can be 0 or 1.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command displays controller status that is specific to the controller hardware. The information displayed is generally useful for diagnostic tasks performed by technical support personnel only.

The NPM or MIP can query the port adapters to determine their current status. Issue a show controller t1 command to display statistics about the T1 link.

If you specify a slot and port number, each 15 minute period will be displayed.

Sample Display

The following is sample output from the show controller t1 command on the Cisco 7000 series:

Router# show controllers t1
T1 4/1 is up.
  No alarms detected.
  Framing is ESF, Line Code is AMI, Clock Source is line
  Data in current interval (0 seconds elapsed): 
     0 Line Code Violations, 0 Path Code Violations 0 Slip Secs, 0 Fr Loss Secs, 
     0 Line Err Secs, 0 Degraded Mins 0 Errored Secs, 0 Bursty Err Secs, 
     0 Severely Err Secs, 0 Unavail Secs 
  Total Data (last 79 15 minute intervals): 
     0 Line Code Violations, 0 Path Code Violations, 0 Slip Secs, 0 Fr Loss Secs, 
     0 Line Err Secs, 0 Degraded Mins, 0 Errored Secs, 0 Bursty Err Secs, 
     0 Severely Err Secs, 0 Unavail Secs 
Router#

Table 33 describes the show controllers t1 display fields.


Table 33: Show Controller T1 Field Descriptions
Field Description
T1 0/0 is up. The T1 controller 0 in slot 0 is operating. The controller's state can be up, down, administratively down. Loopback conditions are shown by (Locally Looped) or (Remotely Looped).
No alarms detected. Any alarms detected by the controller are displayed here. Possible alarms are as follows:

Transmitter is sending remote alarm.

Transmitter is sending AIS.

Receiver has loss of signal.

Receiver is getting AIS.

Receiver has loss of frame.

Receiver has remote alarm.

Receiver has no alarms.

Data in current interval (725 seconds elapsed) Shows the current accumulation period, which rolls into the 24-hour accumulation every 15 minutes. Accumulation period is from 1 to 900 seconds. The oldest 15 minute period falls off the back of the 24-hr accumulation buffer.
Line Code Violations Indicates the occurrence of either a Bipolar Violation (BPV) or Excessive Zeros (EXZ) error event.
Path Code Violations Indicates a frame synchronization bit error in the D4 and E1-noCRC formats, or a CRC error in the ESF and E1-CRC formats.
Slip Secs Indicates the replication or deletion of the payload bits of a DS1 frame. A slip may be performed when there is a difference between the timing of a synchronous receiving terminal and the received signal.
Fr Loss Secs Indicates the number of seconds an Out Of Frame (OOF) error is detected.
Line Err Secs Line Errored Seconds (LES) is a second in which one or more Line Code Violation errors are detected.
Degraded Mins A Degraded Minute is one in which the estimated error rate exceeds 1E-6 but does not exceed 1E-3.
Errored Secs In ESF and E1-CRC links, an Errored Second is a second in which one of the following are detected: one or more Path Code Violations; one or more Out of Frame defects; one or more Controlled Slip events; a detected AIS defect.

For D4 and E1-noCRC links, the presence of Bipolar Violations also triggers an Errored Second.

Bursty Err Secs A second with fewer than 320 and more than 1 Path Coding Violation error, no Severely Errored Frame defects and no detected incoming AIS defects. Controlled slips are not included in this parameter.
Severely Err Secs For ESF signals, a second with one of the following errors: 320 or more Path Code Violation errors; one or more Out of Frame defects; a detected AIS defect.

For E1-CRC signals, a second with one of the following errors: 832 or more Path Code Violation errors; one or more Out of Frame defects.

For E1-nonCRC signals, a second with 2048 Line Code Violations or more.

For D4 signals, a count of 1-second intervals with Framing Errors, or an Out of Frame defect, or 1544 Line Code Violations.

Unavail Secs A count of the total number of seconds on the interface.

show controllers token

To display information about memory management and error counters on the Token Ring Interface Processor (TRIP) for the Cisco 7000 series and Cisco 7500 series, use the show controllers token privileged EXEC command.

show controllers token
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.

Depending on the card being used, the output can vary. This command also displays information that is proprietary to Cisco Systems. Thus, the information that show controllers token displays is of primary use to Cisco technical personnel. Information that is useful to users can be obtained with the show interfaces tokenring command, which is described later in this chapter.

Sample Display

Sample output for the show controllers token command on the Cisco 7000 follows:

Router> show controllers token
Tokenring4/0: state administratively down
  current address: 0000.3040.8b4a, burned in address: 0000.3040.8b4a
  Last Ring Status: none
    Stats: soft: 0/0, hard: 0/0, sig loss: 0/0
           tx beacon: 0/0, wire fault 0/0, recovery: 0/0
           only station: 0/0, remote removal: 0/0
  Monitor state: (active), chip f/w: '000000........', [bridge capable]
    ring mode: 0"
    internal functional: 00000000 (00000000), group: 00000000 (00000000)
    internal addrs: SRB: 0000, ARB: 0000, EXB 0000, MFB: 0000
                    Rev: 0000, Adapter: 0000, Parms 0000
    Microcode counters:
      MAC giants 0/0, MAC ignored 0/0
      Input runts 0/0, giants 0/0, overrun 0/0
      Input ignored 0/0, parity 0/0, RFED 0/0
      Input REDI 0/0, null rcp 0/0, recovered rcp 0/0
      Input implicit abort 0/0, explicit abort 0/0
      Output underrun 0/0, tx parity 0/0, null tcp 0/0
      Output SFED 0/0, SEDI 0/0, abort 0/0
      Output False Token 0/0, PTT Expired 0/0
    Internal controller counts:
      line errors: 0/0,  internal errors: 0/0
      burst errors: 0/0,  ari/fci errors: 0/0
      abort errors: 0/0, lost frame: 0/0
      copy errors: 0/0, rcvr congestion: 0/0
      token errors: 0/0, frequency errors: 0/0
    Internal controller smt state:
      Adapter MAC:     0000.0000.0000, Physical drop:     00000000
      NAUN Address:    0000.0000.0000, NAUN drop:         00000000
      Last source:     0000.0000.0000, Last poll:         0000.0000.0000
      Last MVID:       0000,           Last attn code:    0000
      Txmit priority:  0000,           Auth Class:        0000
      Monitor Error:   0000,           Interface Errors:  0000
      Correlator:      0000,           Soft Error Timer:  0000
      Local Ring:      0000,           Ring Status:       0000
      Beacon rcv type: 0000,           Beacon txmit type: 0000
      Beacon type:     0000,           Beacon NAUN:       0000.0000.0000
      Beacon drop:     00000000,       Reserved:          0000
      Reserved2:       0000

Table 34 describes key show controllers token display fields.


Table 34: Show Controllers Token Field Descriptions for the Cisco 7000
Field Description
Tokenring4/0 Interface processor type, slot, and port.
Last Ring Status Last abnormal ring condition. Can be any of the following:

  • Signal Loss

  • HW Removal

  • Remote Removal

  • Counter Overflow

  • Only station

  • Ring Recovery

Related Commands

show interfaces tokenring
show source bridge

show dhcp

To display the current DHCP settings on point-to-point interfaces, use the show dhcp privileged EXEC command.

show dhcp {server | lease [interface async [number]]}
Syntax Description
server Show known DHCP servers.
lease Show DHCP addresses leased from a server.
interface async [number] (Optional) Specify asynchronous interfaces and, optionally, a specific interface number.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

If you omit the optional argument, the show dhcp command displays information about all interfaces.

You can use this command on any point-to-point type of interface (for example, serial, ISDN, and asynchronous) that uses DHCP for temporary IP address allocation.

Sample Display
Router# show dhcp server
IP address pooling for Point to Point clients is: DHCP Proxy Client
DHCP Proxy Client Status:
   DHCP server: ANY (255.255.255.255)
    Leases:   0
    Offers:   0      Requests: 0     Acks: 0     Naks: 0
    Declines: 0      Releases: 0     Bad:  0

Table 35 describes the fields shown in the display.


Table 35: Show DHCP Field Descriptions
Field Description
Leases Number of current leased IP addresses.
Offers Number of offers for an IP address sent to a proxy-client from the server.
Requests Number of requests for an IP address to the server.
Acks Number of 'acknowledge' messages sent by the server to the proxy-client.
Naks Number of 'not acknowledge' messages sent by the server to the proxy-client.
Declines Number of offers from the server that are declined by the proxy-client.
Releases Number of times IP addresses have been relinquished gracefully by the client.
Bad Number of bad packets received from wrong length, wrong field type, etc.
Related Commands

ip address-pool
ip dhcp-server
peer default ip address

show diagbus

To display diagnostic information about the controller, interface processor, and port adapters associated with a specified slot of a Cisco 7000 series, Cisco 7200 series, or Cisco 7500 series router, use the show diagbus privileged EXEC command.

show diagbus [slot]
Syntax Description
slot (Optional) Number of a specific slot. If not specified, this command displays information about all slots.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Output

The following is sample output for the Cisco 7513 with a VIP2 interface processor board in slot 8. This card has two 4-port Token Ring port adapters located in port adapter bays 0 and 1.

Router# show diagbus 8
Slot 8:
        Physical slot 8, ~physical slot 0x7, logical slot 8, CBus 0
        Microcode Status 0x4
        Master Enable, LED, WCS Loaded
        Board is analyzed 
        Pending I/O Status: None
        EEPROM format version 1
        VIP2 controller, HW rev 2.2, board revision UNKNOWN
        Serial number: 03341418  Part number: 73-1684-02
        Test history: 0x00        RMA number: 00-00-00
        Flags: cisco 7000 board; 7500 compatible
 
        EEPROM contents (hex):
          0x20: 01 15 02 02 00 32 FC 6A 49 06 94 02 00 00 00 00
          0x30: 07 2B 00 2A 1A 00 00 00 00 00 00 00 00 00 00 00
 
        Slot database information:
        Flags: 0x4      Insertion time: 0x3188 (01:20:53 ago)
 
        Controller Memory Size: 8 MBytes
 
        PA Bay 0 Information:
                Token Ring PA, 4 ports
                EEPROM format version 1
                HW rev 1.1, Board revision 0
                Serial number: 02827613  Part number: 73-1390-04 
 
        PA Bay 1 Information:
                Token Ring PA, 4 ports
                EEPROM format version 1
                HW rev 1.1, Board revision 88
                Serial number: 02023786  Part number: 73-1390-04 

The following is sample output from the show diagbus command for the Ethernet interface in slot 2 on a Cisco 7200 series router:

Router# show diag 2
Slot 2:
        Ethernet port adapter, 8 ports
        Port adapter is analyzed
        Port adapter insertion time 1d18h ago
        Hardware revision 1.0           Board revision K0
        Serial number     2023387       Part number    73-1391-03
        Test history      0x0           RMA number     00-00-00
        EEPROM format version 1
        EEPROM contents (hex):
          0x20: 01 01 01 00 00 1E DF DB 49 05 6F 03 00 00 00 00
          0x30: A0 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

show hub

To display information about the hub (repeater) on an Ethernet interface of a Cisco 2505 or Cisco 2507, use the show hub EXEC command.

show hub [ethernet number [port [end-port]]]
Syntax Description
ethernet (Optional) Indicates that this is an Ethernet hub.
number (Optional) Hub number, starting with 0. Since there is currently only one hub, this number is 0.
port (Optional) Port number on the hub. On the Cisco 2505, port numbers range from 1 through 8. On the Cisco 2507, port numbers range from 1 through 16. If a second port number follows, then this port number indicates the beginning of a port range.
end-port (Optional) Ending port number of a range.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

If you do not specify a port or port range for the show hub command, the command displays all ports (for example, ports 1 through 16 on a Cisco 2507) by default. Therefore, the commands show hub, show hub ethernet 0, and show hub ethernet 0 1 16 all produce the same result.

If no ports are specified, the command displays some additional data about the internal port. The internal port is the hub's connection to Ethernet interface 0 inside the box. Ethernet interface 0 still exists; physical access to the interface is via the hub.

Sample Displays

The following is sample output from the show hub command for hub 0, port 2 only:

Router# show hub ethernet 0 2
Port 2 of 16 is administratively down, link state is down
  0 packets input, 0 bytes
  0 errors with 0 collisions
     (0 FCS, 0 alignment, 0 too long,
      0 short, 0 runts, 0 late,
      0 very long, 0 rate mismatches)
  0 auto partitions, last source address (none)
  Last clearing of "show hub" counters never
 
Repeater information (Connected to Ethernet0)
  2792429 bytes seen with 18 collisions, 1 hub resets
  Version/device ID 0/1 (0/1)
  Last clearing of "show hub" counters never

The following is sample output from the show hub command for hub 0, all ports:

Router# show hub ethernet 0 
Port 1 of 16 is administratively down, link state is up
  2458 packets input, 181443 bytes
  3 errors with 18 collisions
     (0 FCS, 0 alignment, 0 too long,
      0 short, 3 runts, 0 late,
      0 very long, 0 rate mismatches)
  0 auto partitions, last source address was 0000.0cff.e257
  Last clearing of "show hub" counters never
.
.
.
Port 16 of 16 is down, link state is down
  0 packets input, 0 bytes
  0 errors with 0 collisions
     (0 FCS, 0 alignment, 0 too long,
      0 short, 0 runts, 0 late,
      0 very long, 0 rate mismatches)
  0 auto partitions, last source address (none)
  Last clearing of "show hub" counters never
 
Repeater information (Connected to Ethernet0)
  2792429 bytes seen with 18 collisions, 1 hub resets
  Version/device ID 0/1 (0/1)
  Last clearing of "show hub" counters never
          
Internal Port (Connected to Ethernet0)
  36792 packets input, 4349525 bytes
  0 errors with 14 collisions
     (0 FCS, 0 alignment, 0 too long,
      0 short, 0 runts, 0 late,
      0 very long, 0 rate mismatches)
  0 auto partitions, last source address (none)
  Last clearing of "show hub" counters never

Table 36 describes significant fields shown in the display.


Table 36: Show Hub Field Descriptions
Field Description
Port ... of ... is administratively down Port number out of total ports; indicates whether the interface hardware is currently active, or down due to the following:

  • The link-state test failed.

  • The MAC address mismatched when source address configured.

  • It has been taken down by an administrator.

link state is up

Indicates whether port has been disabled by the link-test function. If the link-test function is disabled by the user, nothing will be shown here.
packets input Total number of error-free packets received by the system.
bytes Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
errors Sum of FCS, alignment, too long, short, runts, very long, and rate mismatches.
collisions Number of messages retransmitted due to Ethernet collisions.
FCS Counter for the number of frames detected on the port with an invalid frame check sequence.
alignment Counter for the number of frames of valid length (64 bytes to 1518 bytes) that have been detected on the port with an FCS error and a framing error.
too long Counter for the number of frames that exceed the maximum valid packet length of 1518 bytes.
short Counter for the number of instances when activity is detected with duration less than 74-82 bit times.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size. For example, any Ethernet packet that is less than 64 bytes is considered a runt.
late Counter for the number of instances when a collision is detected after 480-565 bit times in the frame.
very long Counter for the number of times the transmitter is active in excess of 4 ms to 7.5 ms.
rate mismatches Counter for the number of occurrences when the frequency, or data rate of incoming signal is noticably different from the local transmit frequency.
auto partitions Counter for the number of instances where the repeater has partitioned the port from the network.
last source address Source address of last packet received by this port. Indicates "none" if no packets have been received since power on or a hub reset.
Last clearing of "show hub" counters Elapsed time since clear hub counters command. Indicates "never" if counters have never been cleared.
Repeater information (Connected to Ethernet0) Indicates that the following information is about the hub connected to the Ethernet interface shown.
... bytes seen with ... collisions, ... hub resets Hub resets is the number of times the hub has been reset by network management software or by the clear hub command.
Version/device ID 0/1 (0/1) Hub hardware version. IMR+ version device of daughter board.
Internal Port (Connected to Ethernet0) Set of counters for the internal AUI port connected to the Ethernet interface.
Related Command

hub

show interfaces

Use the show interfaces EXEC command to display statistics for all interfaces configured on the router or access server. The resulting output varies, depending on the network for which an interface has been configured.

show interfaces [type number] [first] [last] [accounting]
show interfaces [type slot/port] [accounting]  (for the Cisco 7000 series and Cisco 7200 series, and for the Cisco RSP/7000 and Cisco 7500 series with a Packet over SONET Interface Processor)
show interface [type slot/port-adapter/port] [ethernet | serial]  (for ports on VIP cards in the Cisco 7000 and the Cisco 7500 series routers)

Syntax Description
type (Optional) Interface type. Allowed values for type include async, bri0, ethernet, fastethernet, fddi, hssi, loopback, null, serial, tokenring, and tunnel.

For the Cisco 4000 series, type can be e1, ethernet, fastethernet, fddi, serial, t1, and token. For the Cisco 4500 series, type can also include atm.

For the Cisco 7000 family, type can be atm, e1, ethernet, fastethernet, fddi, serial, t1, and tokenring.

For the Cisco 7500 series or the Cisco RSP/7000, type can also include posi.

number (Optional) Port number on the selected interface.
first last (Optional) For the Cisco 2500 and 3000 ISDN Basic Rate Interface (BRI) only. The argument first can be either 1 or 2. The argument last can only be 2, indicating B-channels 1 and 2.

D-channel information is obtained by using the command without the optional arguments.

accounting (Optional) Displays the number of packets of each protocol type that has been sent through the interface.
slot (Optional) Specifies the backplane slot number and can be 0, 1, 2, 3, or 4. For the Cisco 7200, the slot number can be 0, 1, 2, 3, 4, 5, or 6; slot 0 is the Fast Ethernet port on the Cisco 7200 I/O controller, and slots 1 through 6 are chassis slot numbers.
port (Optional) Port number of the interface. On the Cisco 7200, the number of ports depends on the type of port adapter installed. On the Cisco 7000 series and Cisco 7200 series, the values depend on the type of interface, as follows:

· AIP (ATM Interface Processor): 0

· EIP (Ethernet Interface Processor): 0, 1, 2, 3, 4, or 5

· FEIP (Fast Ethernet Interface Processor): 0, 1

· FIP (FDDI Interface Processor): 0

· FSIP (Fast Serial Interface Processor): 0, 1, 2, 3, 4, 5, 6, or 7

· HIP (HSSI Interface Processor): 0

· MIP (Multichannel Interface Processor): 0 or 1

· TRIP (Token Ring Interface Processor): 0, 1, 2, or 3

(Optional) Port number of the interface. For the VIP card this argument is optional, and the value can be the following:

· 1-port Fast Ethernet interfaces: 0

· 4-port Ethernet interfaces: 0, 1, 2, or 3

· 4-port serial interfaces: 0, 1, 2, or 3

· 4-port Token Ring interfaces: 0, 1, 2, or 3

· 1-port FDDI interfaces: 0

On the Cisco 7500 series with a Packet over SONET Interface Processor, the value must be 0.

port-adapter (Optional) On the Cisco 7000 and Cisco 7500 series, specifies a port adapter on a VIP or VIP2 card. The value can be 0 or 1.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

The show interfaces command displays statistics for the network interfaces. The resulting display on the Cisco 7000 series and Cisco 7200 series shows the interface processors in slot order. If you add interface processors after booting the system, they will appear at the end of the list, in the order in which they were inserted.

If you use the show interfaces command on the Cisco 7000 series and Cisco 7200 series without the slot/port arguments, information for all interface types will be shown. For example, if you type show interfaces ethernet you will receive information for all ethernet, serial, Token Ring, and FDDI interfaces. Only by adding the type slot/port argument can you specify a particular interface.

If you enter a show interfaces command for an interface type that has been removed from the router or access server, interface statistics will be displayed accompanied by the following text: "Hardware has been removed."

If you use the show interfaces command on a router or access server for which interfaces are configured to use weighted fair queueing through the fair-queue interface command, additional information is displayed. This information consists of the current and high-water mark number of flows.

You will use the show interfaces command frequently while configuring and monitoring devices. The various forms of the show interfaces commands are described in detail in the sections immediately following this command.

Sample Display

The following is sample output from the show interfaces command. Because your display will depend on the type and number of interface cards in your router or access server, only a portion of the display is shown.

Router# show interfaces
Ethernet 0 is up, line protocol is up
  Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c)
  Internet address is 131.108.28.8, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set, keepalive set (10 sec)
  ARP type: ARPA, ARP Timeout 4:00:00
  Last input 0:00:00, output 0:00:00, output hang never
  Last clearing of "show interface" counters 0:00:00
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 2000 bits/sec, 4 packets/sec
     1127576 packets input, 447251251 bytes, 0 no buffer
     Received 354125 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     5332142 packets output, 496316039 bytes, 0 underruns
     0 output errors, 432 collisions, 0 interface resets, 0 restarts
---More---
Sample Display with Custom Output Queuing

The following shows partial sample output when custom output queuing is enabled:

Last clearing of "show interface" counters 0:00:06
Input queue: 0/75/0 (size/max/drops); Total output drops: 21
Output queues: (queue #: size/max/drops)
     0: 14/20/14  1: 0/20/6  2: 0/20/0 3: 0/20/0 4: 0/20/0 5: 0/20/0 
     6: 0/20/0 7: 0/20/0  8: 0/20/0  9: 0/20/0  10: 0/20/0  

When custom queuing is enabled, the drops accounted for in the output queues result from bandwidth limitation for the associated traffic and leads to queue length overflow. Total output drops include drops on all custom queues as well as the system queue. Fields are described with the Weighted Fair Queuing output in Table 37.

Sample Display Including Weighted-Fair-Queuing Output

For each interface on the router or access server configured to use weighted fair queuing, the show interfaces command displays the information beginning with Input queue: in the following display:

Router# show interfaces
Ethernet 0 is up, line protocol is up
  Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c)
  Internet address is 131.108.28.8, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set, keepalive set (10 sec)
  ARP type: ARPA, ARP Timeout 4:00:00
  Last input 0:00:00, output 0:00:00, output hang never
  Last clearing of "show interface" counters 0:00:00
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 2000 bits/sec, 4 packets/sec
     1127576 packets input, 447251251 bytes, 0 no buffer
     Received 354125 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     5332142 packets output, 496316039 bytes, 0 underruns
     0 output errors, 432 collisions, 0 interface resets, 0 restarts
Input queue: 0/75/0 (size/max/drops); Total output drops: 0
Output queue: 7/64/0 (size/threshold/drops)
				     Conversations 2/9 (active/max active)

Table 37 describes the input queue and output queue fields shown in this display.


Table 37: Weighted-Fair-Queuing Output Fields
Field Description
Input queue:

  • size

Current size of the input queue.

  • max

Maximum size of the queue.

  • drops

Number of messages discarded in this interval.

  • Total output drops

Total number of messages discarded in this session.

Output queue:

  • size

Current size of the output queue.

  • threshold

Congestive-discard threshold. Number of messages in the queue after which new messages for high-bandwidth conversations are dropped.

  • drops

Number of dropped messages.

  • Conversations: active

Number of currently active conversations.

  • Conversations: max active

Maximum number of concurrent conversations allowed.

Sample Display with Accounting Option

To display the number of packets of each protocol type that have been sent through all configured interfaces, use the show interfaces accounting EXEC command. When you use the accounting option, only the accounting statistics are displayed.


Note Except for protocols that are encapsulated inside other protocols, such as IP over X.25, the accounting option also shows the total of all bytes sent and received, including the MAC header. For example, it totals the size of the Ethernet packet or the size of a packet that includes HDLC encapsulation.

Table 38 lists the protocols for which per-packet accounting information is kept.


Table 38: Per-Packet Counted Protocols
Protocol Notes
Apollo No note.
AppleTalk No note.
ARP For IP, Apollo, Frame Relay, SMDS.
CLNS No note.
DEC MOP The routers use MOP packets to advertise their existence to Digital Equipment Corporation machines that use the MOP protocol. A router periodically broadcasts MOP packets to identify itself as a MOP host. This results in MOP packets being counted, even when DECnet is not being actively used.
DECnet No note.
HP Probe No note.
IP No note.
LAN Manager LAN Network Manager and IBM Network Manager.
Novell No note.
Serial Tunnel SDLC.
Spanning Tree No note.
SR Bridge No note.
Transparent Bridge No note.
VINES No note.
XNS No note.
Sample Display

The following is sample output from the show interfaces accounting command:

Router# show interfaces accounting
Interface TokenRing0 is disabled
Ethernet0
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
                      IP     873171  735923409      34624    9644258
                  Novell     163849   12361626      57143    4272468
                 DEC MOP          0          0          1         77
                     ARP      69618    4177080       1529      91740
Interface Serial0 is disabled
Ethernet1
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
                      IP          0          0         37      11845
                  Novell          0          0       4591     275460
                 DEC MOP          0          0          1         77
                     ARP          0          0          7        420
Interface Serial1 is disabled
Interface Ethernet2 is disabled
Interface Serial2 is disabled
Interface Ethernet3 is disabled
Interface Serial3 is disabled
Interface Ethernet4 is disabled
Interface Ethernet5 is disabled
Interface Ethernet6 is disabled
Interface Ethernet7 is disabled
Interface Ethernet8 is disabled
Interface Ethernet9 is disabled
Fddi0
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
                  Novell          0          0        183      11163
                     ARP          1         49          0          0

When the output indicates an interface is "disabled," the router has received excessive errors (over 5000 in a keepalive period).

show interfaces async

Use the show interfaces async privileged EXEC command to display information about the asynchronous serial interface.

show interfaces async [number] [accounting]
Syntax Description
number (Optional) Must be 1.
accounting (Optional) Displays the number of packets of each protocol type that has been sent through the interface.
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 interfaces async command:

Router# show interfaces async 1
Async 1 is up, line protocol is up
   	Hardware is Async Serial
Internet address is 1.0.0.1, subnet mask is 255.0.0.0
MTU 1500 bytes, BW 9 Kbit, DLY 100000 usec, rely 255/255, load 56/255
Encapsulation SLIP, keepalive set (0 sec)
Last input 0:00:03, output 0:00:03, output hang never
Last clearing of "show interface" counters never
Output queue 0/3, 2 drops; input queue 0/0, 0 drops
Five minute input rate 0 bits/sec, 1 packets/sec
Five minute output rate 2000 bits/sec, 1 packets/sec
273 packets input, 13925 bytes, 0 no buffer
Received 0 broadcasts, 0 runts, 0 giants
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
221 packets output, 41376 bytes, 0 underruns
0 output errors, 0 collisions, 0 interface resets, 0 restarts
0 carrier transitions

Table 39 describes the fields shown in the display.


Table 39: Show Interfaces Async Field Descriptions
Field Description
Async... is {up | down}
...is administratively down
Indicates whether the interface hardware is currently active (whether carrier detect is present) and if it has been taken down by an administrator.
line protocol
is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol think the line is usable (that is, whether keepalives are successful).
Hardware is Hardware type.
Internet address is Internet address and subnet mask, followed by packet size.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. The calculation uses the value from the bandwidth interface configuration command.
Encapsulation Encapsulation method assigned to interface.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds
24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing The time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.
packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffers Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
input errors Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum may not balance with the other counts.
CRC Cyclic redundancy checksum generated by the originating LAN station or far end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRC's is usually the result of collisions or a station transmitting bad data. On a serial link, CRC's usually indicate noise, gain hits or other transmission problems on the data link.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented.
abort Illegal sequence of one bits on a serial interface. This usually indicates a clocking problem between the serial interface and the data link equipment.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.
carrier transitions Number of times the carrier detect signal of a serial interface has changed state. Indicates modem or line problems if the carrier detect line is changing state often.
Protocol Protocol that is operating on the interface.
Pkts In Number of packets received for that protocol.
Chars In Number of characters received for that protocol.
Pkts Out Number of packets transmitted for that protocol.
Chars Out Number of characters transmitted for that protocol.
Sample Display with Accounting Option

The following is a sample display from the show interfaces async accounting command:

Router# show interfaces async 0 accounting
Async 0
   Protocol  	Pkts In   	Chars In  	Pkts Out   	Chars Out
   	IP        	7344      	4787842   	1803       	1535774
   	DEC MOP 	  0 	        0 	        127 	       9779
   	ARP 	      7  	       420	       39	         2340

The show line and show slip commands can also be useful in monitoring asynchronous interfaces.

show interfaces atm

Use the show interfaces atm privileged EXEC command to display information about the ATM interface.

show interfaces atm [slot/port]
Syntax Description
slot (Optional) Slot number. On the Cisco 7000, values can be 0, 1, 2, 3, or 4; on the Cisco 7010, values can be 0, 1, or 2.
port (Optional) Port number; the value must be 0.
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 interfaces atm command:

Router# show interfaces atm 4/0
ATM4/0 is up, line protocol is up
  Hardware is cxBus ATM
  Internet address is 131.108.97.165, subnet mask is 255.255.255.0
  MTU 4470 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
  Encapsulation ATM, loopback not set, keepalive set (10 sec)
  Encapsulation(s): AAL5, PVC mode
  256 TX buffers, 256 RX buffers, 1024 Maximum VCs, 1 Current VCs
  Signalling vc = 1, vpi = 0, vci = 5
  ATM NSAP address: BC.CDEF.01.234567.890A.BCDE.F012.3456.7890.1234.13
  Last input 0:00:05, output 0:00:05, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     144 packets input, 3148 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     154 packets output, 4228 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets, 0 restarts

Table 40 describes the fields shown in the display.


Table 40: Show Interfaces ATM Field Descriptions
Field Description
ATM... is {up | down}
...is administratively down
Indicates whether the interface hardware is currently active (whether carrier detect is present) and if it has been taken down by an administrator.
line protocol
is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol think the line is usable (that is, whether keepalives are successful).
Hardware is Hardware type.
Internet address is Internet address and subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. The calculation uses the value from the bandwidth interface configuration command.
Encapsulation Encapsulation method assigned to interface.
AAL5 PVC mode AAL5, and either PVC or SVC mode.
TX buffers Number of buffers configured with the atm txbuff command.
RX buffers Number of buffers configured with the atm rxbuff command.
Maximum VCs Maximum number of virtual circuits.
Current VCs Current number of virtual circuits.
Signaling VC Number of the signaling PVC.
vpi Virtual path identifier number.
vci Virtual channel identifier number.
ATM NSAP address NSAP address of the ATM interface.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds
24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing The time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.
packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
input errors Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum may not balance with the other counts.
CRC Cyclic redundancy checksum generated by the originating LAN station or far end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRC's is usually the result of collisions or a station transmitting bad data. On a serial link, CRC's usually indicate noise, gain hits or other transmission problems on the data link.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented.
abort Illegal sequence of one bits the interface. This usually indicates a clocking problem between the interface and the data link equipment.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the transmitter has been running faster than the router can handle. This may never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.

show interfaces ethernet

Use the show interfaces ethernet privileged EXEC command to display information about an Ethernet interface on the router.

show interfaces ethernet unit [accounting]
show interfaces ethernet [slot/port] [accounting] (for the Cisco 7000 series and Cisco 7200 series)
show interfaces ethernet [type slot/port-adapter/port] (for ports on VIP cards in the Cisco 7000 and the 7500 series routers)

Syntax Description
unit Must match a port number on the selected interface.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
slot (Optional) On the Cisco 7000 series, slot location of the interface processor. On the Cisco 7200 series, slot in which the port adapters are installed.
port (Optional) Port number on the interface. For the VIP card the port value can be the following:

· 0 for one-port Fast Ethernet interfaces

· 0, 1, 2, or 3 for four-port Ethernet interfaces

port-adapter (Optional) On the Cisco 7000 and 7500 series, specifies the ports on a VIP card. The value can be 0 or 1.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you do not provide values for the argument unit (or slot and port on the Cisco 7000 and Cisco 7200 series or slot and port-adapter on the Cisco 7500 series), the command will display statistics for all network interfaces. The optional keyword accounting displays the number of packets of each protocol type that have been sent through the interface.

Sample Display

The following is sample output from the show interfaces command for the Ethernet 0 interface:

Router# show interfaces ethernet 0
Ethernet 0 is up, line protocol is up
   Hardware is MCI Ethernet, address is aa00.0400.0134 (bia 0000.0c00.4369)
	   Internet address is 131.108.1.1, subnet mask is 255.255.255.0
	   MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 255/255, load 1/255
	   Encapsulation ARPA, loopback not set, keepalive set (10 sec)
   	ARP type: ARPA, PROBE, ARP Timeout 4:00:00
	   Last input 0:00:00, output 0:00:00, output hang never
	   Output queue 0/40, 0 drops; input queue 0/75, 2 drops
	   Five minute input rate 61000 bits/sec, 4 packets/sec
	   Five minute output rate 1000 bits/sec, 2 packets/sec
		       2295197 packets input, 305539992 bytes, 0 no buffer
		       Received 1925500 broadcasts, 0 runts, 0 giants
		       3 input errors, 3 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
       0 input packets with dribble condition detected
		       3594664 packets output, 436549843 bytes, 0 underruns
		       8 output errors, 1790 collisions, 10 interface resets, 0 restarts

Table 41 describes significant fields shown in the display.


Table 41: Show Interfaces Ethernet Field Descriptions
Field Description
Ethernet ... is up
...is administratively down
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator. "Disabled" indicates the router has received over 5000 errors in a keepalive interval, which is 10 seconds by default.
line protocol
is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol believe the interface is usable (that is, whether keepalives are successful) or if it has been taken down by an administrator.
Hardware Hardware type (for example, MCI Ethernet, SCI, cBus Ethernet) and address.
Internet address Internet address followed by subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
ARP type: Type of Address Resolution Protocol assigned.
loopback Indicates whether loopback is set or not.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output Number of hours, minutes, and seconds since the last packet was successfully transmitted by the interface. Useful for knowing when a dead interface failed.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds
24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, input queue, drops Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic).

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffers Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
Received ... broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size. For instance, any Ethernet packet that is less than 64 bytes is considered a runt.
giants Number of packets that are discarded because they exceed the medium's maximum packet size. For example, any Ethernet packet that is greater than 1,518 bytes is considered a giant.
input error Includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams may have more than one error; therefore, this sum may not balance with the sum of enumerated input error counts.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device.
overrun Number of times the receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
input packets with dribble condition detected Dribble bit error indicates that a frame is slightly too long. This frame error counter is incremented just for informational purposes; the router accepts the frame.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the transmitter has been running faster than the router can handle. This may never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Number of messages retransmitted due to an Ethernet collision. This is usually the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). A packet that collides is counted only once in output packets.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times a Type 2 Ethernet controller was restarted because of errors.
Sample Display on Cisco 7000

The following sample output illustrates the show interfaces ethernet command on the Cisco 7000:

Router> show interfaces ethernet 4/2
Ethernet4/2 is up, line protocol is up
  Hardware is cxBus Ethernet, address is 0000.0c02.d0ce (bia 0000.0c02.d0ce)
  Internet address is 131.108.7.1, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set, keepalive set (10 sec)
  ARP type: ARPA, ARP Timeout 4:00:00
  Last input 0:00:00, output 0:00:09, output hang never
  Last clearing of "show interface" counters 0:56:40
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 3000 bits/sec, 4 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     4961 packets input, 715381 bytes, 0 no buffer
     Received 2014 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     567 packets output, 224914 bytes, 0 underruns
     0 output errors, 168 collisions, 0 interface resets, 0 restarts
Sample Display with Accounting Option

The following is sample output from the show interfaces ethernet command with the accounting option on the Cisco 7000:

Router# show interfaces ethernet 4/2 accounting
Ethernet4/2
       Protocol    Pkts In   Chars In   Pkts Out  Chars Out
             IP       7344    4787842       1803    1535774
      Appletalk      33345    4797459      12781    1089695
        DEC MOP          0          0        127       9779
            ARP          7        420         39       2340

show interfaces fastethernet

To display information about the FastEthernet interfaces, use the show interface fastethernet EXEC command.

show interfaces fastethernet [number] (Cisco 4500 series and Cisco 4700 series)
show interfaces fastethernet
[slot/port] (Cisco 7000 series and Cisco 7200 series)
show interfaces fastethernet [slot/port-adapter/port] (Cisco 7500 series with a VIP card)

Syntax Description
number (Optional) Port, connector, or interface card number. On a Cisco 4500 or Cisco 4700 router, specifies the NIM or NPM number. The numbers are assigned at the factory at the time of installation or when added to a system.
slot (Optional) On the Cisco 7000 series, slot location of the FEIP. On the Cisco 7200, slot 0 is the Fast Ethernet port on the I/O controller.
port (Optional) On the Cisco 7000 family, port number on the interface.
port-adapter (Optional) On the Cisco 7000 and Cisco 7500 series, port bay on a VIP card. The value can be 0 or 1.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Display

The following is a sample display for the show interface fastethernet on a Cisco 4500 router:

c4500-1# show interfaces fastethernet 0
FastEthernet0 is up, line protocol is up 
  Hardware is DEC21140, address is 0000.0c0c.1111 (bia 0002.eaa3.5a60)
  Internet address is 11.0.0.1 255.0.0.0
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set, keepalive not set, hdx, 100BaseTX
  ARP type: ARPA, ARP Timeout 4:00:00
  Last input never, output 0:00:16, output hang 0:28:01
  Last clearing of "show interface" counters 0:20:05
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 1786161921 ignored, 0 abort
     0 watchdog, 0 multicast
     0 input packets with dribble condition detected
     67 packets output, 8151 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets, 0 restarts
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

The following shows information specific to the first FEIP port in slot 0 on a Cisco 7000 router:

Router# show interface fastethernet 0/1
FastEthernet0/1 is administratively down, line protocol is down
  Hardware is cxBus FastEthernet, address is 0000.0c35.dc16 (bia 0000.0c35.dc16)
  Internet address is 1.1.0.64 255.255.0.0
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set, keepalive not set, half-duplex, RJ45 (or MII)
  ARP type: ARPA, ARP Timeout 4:00:00
  Last input never, output 2:03:52, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 1 drops
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 watchdog, 0 multicast
     0 input packets with dribble condition detected
     5 packets output, 805 bytes, 0 underruns
     0 output errors, 0 collisions, 4 interface resets, 0 restarts
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier
     0 output buffer failures, 0 output buffers swapped out

Table 42 describes the fields in these displays.


Table 42: Show Interfaces FastEthernet Field Descriptions
Field Description
FastEthernet0 is ... is up
...is administratively down
Indicates whether the interface hardware is currently active and if it has been taken down by an administrator.
line protocol is Indicates whether the software processes that handle the line protocol consider the line usable or if it has been taken down by an administrator.
Hardware Hardware type (for example, MCI Ethernet, SCI, cBus Ethernet) and address.
Internet address Internet address followed by subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
ARP type: Type of Address Resolution Protocol assigned.
loopback Indicates whether loopback is set or not.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
output Number of hours, minutes, and seconds since the last packet was successfully transmitted by the interface. Useful for knowing when a dead interface failed.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds
24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.
*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.
Output queue, input queue, drops Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes. If the interface is not in promiscuous mode, it senses network traffic it sends and receives (rather than all network traffic).

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
Received ... broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size. For instance, any Ethernet packet that is less than 64 bytes is considered a runt.
giants Number of packets that are discarded because they exceed the medium's maximum packet size. For example, any Ethernet packet that is greater than 1,518 bytes is considered a giant.
input errors Includes runts, giants, no buffer, CRC, frame, overrun, and ignored counts. Other input-related errors can also cause the input errors count to be increased, and some datagrams may have more than one error; therefore, this sum may not balance with the sum of enumerated input error counts.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device.
overrun Number of times the receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort Number of packets whose receipt was aborted.
watchdog Number of times watchdog receive timer expired. It happens when receiving a packet with length greater than 2048.
multicast Number of multicast packets received.
input packets with dribble condition detected Dribble bit error indicates that a frame is slightly too long. This frame error counter is incremented just for informational purposes; the router accepts the frame.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the transmitter has been running faster than the router can handle. This may never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Number of messages retransmitted due to an Ethernet collision. This is usually the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). A packet that collides is counted only once in output packets.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times a Type 2 Ethernet controller was restarted because of errors.
babbles The transmit jabber timer expired.
late collision Number of late collisions. Late collision happens when a collision occurs after transmitting the preamble.
deferred Deferred indicates that the chip had to defer while ready to transmit a frame because the carrier was asserted.
lost carrier Number of times the carrier was lost during transmission.
no carrier Number of times the carrier was not present during the transmission.

show interfaces fddi

Use the show interfaces fddi EXEC command to display information about the FDDI interface.

show interfaces fddi number [accounting]
show interfaces fddi [slot/port] [accounting]  (for the Cisco 7000 series and Cisco 7500 series)

Syntax Description
number Port number on the selected interface.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
slot (Optional) On the Cisco 7000 and 7500 series, slot location of the interface processor.
port (Optional) On the Cisco 7000 and 7500 series, port number on interface.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Displays

The following is a sample partial display of FDDI-specific data from the show interfaces fddi command:

Router> show interfaces fddi 0
Fddi0 is up, line protocol is up 
  Hardware is cBus Fddi, address is 0000.0c06.8de8 (bia 0000.0c06.8de8)
  Internet address is 131.108.33.9, subnet mask is 255.255.255.0
  MTU 4470 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
  Encapsulation SNAP, loopback not set, keepalive not set
  ARP type: SNAP, ARP Timeout 4:00:00
  Phy-A state is  active, neighbor is   B, cmt signal bits 008/20C, status ILS
  Phy-B state is connect, neighbor is unk, cmt signal bits 20C/000, status QLS
  ECM is insert, CFM is c_wrap_a, RMT is ring_op
  token rotation 5000 usec, ring operational 1d01
  Upstream neighbor 0000.0c06.8b7d, downstream neighbor 0000.0c06.8b7d
  Last input 0:00:08, output 0:00:08, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 5000 bits/sec, 1 packets/sec
  Five minute output rate 76000 bits/sec, 51 packets/sec
     852914 packets input, 205752094 bytes, 0 no buffer
     Received 126752 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     8213126 packets output, 616453062 bytes, 0 underruns
     0 output errors, 0 collisions, 4 interface resets, 0 restarts
     5 transitions, 0 traces

The following is a sample partial display of FDDI-specific data from the show interfaces fddi command on a Cisco 7000:

Router> show interfaces fddi 3/0 
Fddi3/0 is up, line protocol is up
  Hardware is cxBus Fddi, address is 0000.0c02.adf1 (bia 0000.0c02.adf1)
  Internet address is 131.108.33.14, subnet mask is 255.255.255.0
  MTU 4470 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 1/255
  Encapsulation SNAP, loopback not set, keepalive not set
  ARP type: SNAP, ARP Timeout 4:00:00
  Phy-A state is  active, neighbor is   B, cmt signal bits 008/20C, status ILS
  Phy-B state is  active, neighbor is   A, cmt signal bits 20C/008, status ILS
  ECM is in, CFM is thru, RMT is ring_op
  Token rotation 5000 usec, ring operational 21:32:34
  Upstream neighbor 0000.0c02.ba83, downstream neighbor 0000.0c02.ba83
  Last input 0:00:05, output 0:00:00, output hang never
  Last clearing of "show interface" counters 0:59:10
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 69000 bits/sec, 44 packets/sec
  Five minute output rate 0 bits/sec, 1 packets/sec
     113157 packets input, 21622582 bytes, 0 no buffer
     Received 276 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     4740 packets output, 487346 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets, 0 restarts
     0 transitions, 2 traces, 3 claims, 2 beacons

The following is output from the show interfaces fddi command on a Cisco 7513 with a VIP2 card in slot 3, and an FDDI interface on the 3/0/0 port:

Router# show interfaces fddi 3/0/0  (PA-FDDI-SS)
Fddi3/0/0 is up, line protocol is up 
  Hardware is cxBus FDDI, address is 0000.0c0c.4444 (bia 0060.3e47.4360)
  Internet address is 14.0.0.2/8
  MTU 4470 bytes, BW 100000 Kbit, DLY 100 usec, rely 255/255, load 10/255
  Encapsulation SNAP, loopback not set, keepalive not set
  ARP type: SNAP, ARP Timeout 04:00:00
  Phy-A state is connect, neighbor is Unknown, status QLS 
  Phy-B state is active, neighbor is A, status SILS
  ECM is in, CFM is c_wrap_b, RMT is ring_op,
  Requested token rotation 5000 usec, negotiated 0 usec
  Configured tvx is 2500 usec
  LER for PortA = 09, LER for PortB = 0C ring operational 11:36:23
  Upstream neighbor 0000.0c0c.8888, downstream neighbor 0000.0c0c.8888
  Last input 00:02:22, output 00:00:06, output hang never
  Last clearing of "show interface" counters 14:57:58
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  5 minute input rate 3922000 bits/sec, 147 packets/sec
  5 minute output rate 3962000 bits/sec, 148 packets/sec
     7523044 packets input, 631964210 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     7523554 packets output, 625092443 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 transitions, 0 traces,  0 claims, 0 beacon

The following is an example that includes the accounting option. When you use the accounting option, only the accounting statistics are displayed.

Router> show interfaces fddi 3/0 accounting
Fddi3/0
       Protocol    Pkts In   Chars In   Pkts Out  Chars Out
             IP       7344    4787842       1803    1535774
      Appletalk      33345    4797459      12781    1089695
        DEC MOP          0          0        127       9779
            ARP          7        420         39       2340

Table 43 describes the show interfaces fddi display fields.


Table 43: Show Interfaces FDDI Field Descriptions
Field Description
Fddi is {up |down}
...is administratively down
Gives the interface processor unit number and tells whether the interface hardware is currently active and can transmit and receive or if it has been taken down by an administrator. "Disabled" indicates the router has received over 5000 errors in a keepalive interval, which is 10 seconds by default.
line protocol
is {up | down |
administratively down}
Indicates whether the interface hardware is currently active and can transmit and receive or if it has been taken down by an administrator.
Hardware Provides the hardware type, followed by the hardware address.
Internet address IP address, followed by subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
loopback Indicates whether or not loopback is set.
keepalive Indicates whether or not keepalives are set.
ARP type: Type of Address Resolution Protocol assigned.
Phy-{A | B} Lists the state the Physical A or Physical B connection is in; one of: off, active, trace, connect, next, signal, join, verify, or break.
neighbor State of the neighbor:

  • A--Indicates that the CMT process has established a connection with its neighbor. The bits received during the CMT signaling process indicate that the neighbor is a Physical A type dual-attachment station or concentrator that attaches to the primary ring IN and the secondary ring OUT when attaching to the dual ring.

  • S--Indicates that the CMT process has established a connection with its neighbor and that the bits received during the CMT signaling process indicate that the neighbor is one Physical type in a single-attached station (SAS).

  • B--Indicates that the CMT process has established a connection with its neighbor and that the bits received during the CMT signaling process indicate that the neighbor is a Physical B dual-attached station or concentrator that attaches to the secondary ring IN and the primary ring OUT when attaching to the dual ring.

  • M--Indicates that the CMT process has established a connection with its neighbor and that the bits received during the CMT signaling process indicate that the router's neighbor is a Physical M-type concentrator that serves as a Master to a connected station or concentrator.

  • unk--Indicates that the network server has not completed the CMT process, and as a result, does not know about its neighbor. See the section "Setting Bit Control" for an explanation of the bit patterns.

cmt signal bits

Shows the transmitted/received CMT bits. The transmitted bits are 0x008 for a Physical A type and 0x20C for Physical B type. The number after the slash (/) is the received signal bits. If the connection is not active, the received bits are zero (0); see the line beginning Phy-B earlier in this display.
status Status value displayed is the actual status on the fiber. The FDDI standard defines the following values:

  • LSU--Line State Unknown, the criteria for entering or remaining in any other line state have not been met.

  • NLS--Noise Line State is entered upon the occurrence of 16 potential noise events without satisfying the criteria for entry into another line state.

  • MLS--Master Line State is entered upon the reception of eight or nine consecutive HQ or QH symbol pairs.

  • ILS--Idle Line State is entered upon receipt of four or five idle symbols.

  • HLS--Halt Line State is entered upon the receipt of 16 or 17 consecutive H symbols.

  • QLS--Quiet Line State is entered upon the receipt of 16 or 17 consecutive Q symbols or when carrier detect goes low.

  • ALS--Active Line State is entered upon receipt of a JK symbol pair when carrier detect is high.

  • OVUF--Elasticity buffer Overflow/Underflow. The normal states for a connected Physical type are ILS or ALS. If the report displays the QLS status, this indicates that the fiber is disconnected from Physical B, or that it is not connected to another Physical type, or that the other station is not running.

Off

Indicates that the CMT is not running on the Physical Sublayer. The state will be off if the interface has been shutdown or if the cmt disconnect command has been issued for Physical A or Physical B.
Brk Break State is the entry point in the start of a PCM connection.
Tra Trace State localizes a stuck beacon condition.
Con Connect State is used to synchronize the ends of the connection for the signaling sequence.
Nxt Next State separates the signaling performed in the Signal State and transmits Protocol Data Units (PDUs) while MAC Local Loop is performed.
Sig Signal State is entered from the Next State when a bit is ready to be transmitted.
Join Join State is the first of three states in a unique sequence of transmitted symbol streams received as line states--the Halt Line State, Master Line State, and Idle Line State, or HLS-MLS-ILS--that leads to an active connection.
Vfy Verify State is the second state in the path to the Active State and will not be reached by a connection that is not synchronized.
Act Active State indicates that the CMT process has established communications with its physical neighbor.
The transition states are defined in the X3T9.5 specification. You are referred to the specification for details about these states.
ECM is ... ECM is the SMT entity coordination management, which overlooks the operation of CFM and PCM. The ECM state can be one of the following:

  • out--The router is isolated from the network.

  • in--The router is actively connected to the network. This is the normal state for a connected router.

  • trace--The router is trying to localize a stuck beacon condition.

  • leave--The router is allowing time for all the connections to break before leaving the network.

  • path_test--The router is testing its internal paths.

  • insert--The router is allowing time for the optical bypass to insert.

  • check--The router is making sure optical bypasses switched correctly.

  • deinsert--The router is allowing time for the optical bypass to deinsert.

CFM is ...

Contains information about the current state of the MAC connection. The Configuration Management state can be one of the following:

  • isolated--The MAC is not attached to any Physical type.

  • wrap_a--The MAC is attached to Physical A. Data is received on Physical A and transmitted on Physical A.

  • wrap b--The MAC is attached to Physical B. Data is received on physical B and transmitted on Physical B.

  • wrap_s--The MAC is attached to Physical S. Data is received on Physical S and transmitted on Physical S. This is the normal mode for a single attachment station (SAS).

  • thru--The MAC is attached to Physical A and B. Data is received on Physical A and transmitted on  Physical B. This is the normal mode for a dual attachment station (DAS) with one MAC. The ring has been operational for 1 minute and 42 seconds.

RMT is ...

  • RMT (Ring Management) is the SMT MAC-related state machine. The RMT state can be one of the following:

  • isolated--The MAC is not trying to participate in the ring. This is the initial state.

  • non_op--The MAC is participating in ring recovery and ring is not operational.

  • ring_op--The MAC is participating in an operational ring. This is the normal state while the MAC is connected to the ring.

  • detect--The ring has been nonoperational for longer than normal. Duplicate address conditions are being checked.

  • non_op_dup--Indications have been received that the address of the MAC is a duplicate of another MAC on the ring. Ring is not operational.

  • ring_op_dup--Indications have been received that the address of the MAC is a duplicate of another MAC on the ring. Ring is operational in this state.

  • directed--The MAC is sending beacon frames notifying the ring of the stuck condition.

  • trace--Trace has been initiated by this MAC and the RMT state machine is waiting for its completion before starting an internal path test.

token rotation

Token rotation value is the default or configured rotation value as determined by the fddi token-rotation-time command. This value is used by all stations on the ring. The default is 5000 microseconds.
ring operational When the ring is operational, the displayed value will be the negotiated token rotation time of all stations on the ring. Operational times are displayed by the number of hours:minutes:seconds the ring has been up. If the ring is not operational, the message "ring not operational" is displayed.
Upstream | downstream neighbor Displays the canonical MAC address of outgoing upstream and downstream neighbors. If the address is unknown, the value will be the FDDI unknown address (0x00 00 f8 00 00 00).
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, input queue, drops Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five-minute input rate
Five-minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.

The five-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data.
frame Number of packets received incorrectly that have a CRC error and a noninteger number of octets. On a LAN, this is usually the result of collisions or a malfunctioning Ethernet device. On an FDDI LAN, this also may be the result of a failing fiber (cracks) or a hardware malfunction.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of transmit aborts (when the router cannot feed the transmitter fast enough).
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, because some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Because an FDDI ring cannot have collisions, this statistic is always zero.
interface resets Number of times an interface has been reset. The interface may be reset by the administrator or automatically when an internal error occurs.
restarts Should always be zero for FDDI interfaces.
transitions The number of times the ring made a transition from ring operational to ring nonoperational, or vice versa. A large number of transitions indicates a problem with the ring or the interface.
traces Trace count applies to both the FCI, FCIT, and FIP. Indicates the number of times this interface started a trace.
claims Pertains to FCIT and FIP only. Indicates the number of times this interface has been in claim state.
beacons Pertains to FCIT and FIP only. Indicates the number of times the interface has been in beacon state.
Protocol Protocol that is operating on the interface.
Pkts In Number of packets received for that protocol.
Chars In Number of characters received for that protocol.
Pkts Out Number of packets transmitted for that protocol.
Chars Out Number of characters transmitted for that protocol.

show interfaces hssi

Use the show interfaces hssi privileged EXEC command to display information about the HSSI interface.

show interfaces hssi unit [accounting]
show interfaces hssi [slot/port] [accounting] (for the Cisco 7000 series)

Syntax Description
unit Must match a port number on the selected interface.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
slot (Optional) On the Cisco 7000 series, slot location of the interface processor.
port (Optional) On the Cisco 7000 series, port number on interface.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Displays

The following is sample output from the show interfaces hssi command when HSSI is enabled:

Router# show interfaces hssi 0
HSSI 0 is up, line protocol is up
	Hardware is cBus HSSI
	Internet address is 150.136.67.190, subnet mask is 255.255.255.0
	MTU 4470 bytes, BW 45045 Kbit, DLY 20000 usec, rely 255/255, load 1/255
	Encapsulation HDLC, loopback not set, keepalive set (10 sec)
	Last input 0:00:03, output 0:00:00, output hang never
	Output queue 0/40, 0 drops; input queue 0/75, 0 drops
	Five minute input rate 0 bits/sec, 0 packets/sec
	Five minute output rate 0 bits/sec, 0 packets/sec
    		0 packets input, 0 bytes, 0 no buffer
	    	Received 0 broadcasts, 0 runts, 0 giants
              0 parity, 0 rx disabled
	0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
	17 packets output, 994 bytes, 0 underruns
	0 output errors, 0 applique, 4 interface resets, 0 restarts
	2 carrier transitions   

Table 44 describes significant fields shown in the display.


Table 44: Show Interfaces HSSI Field Descriptions
Field Description
HSSI is {up | down}
...is administratively down
Indicates whether the interface hardware is currently active (whether carrier detect is present) and if it has been taken down by an administrator. "Disabled" indicates the router has received over 5000 errors in a keepalive interval, which is 10 seconds by default.
line protocol
is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol considers the line usable (that is, whether keepalives are successful).
Hardware Specifies the hardware type.
Internet address Lists the Internet address followed by subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
loopback Indicates whether loopback is set and type of loopback test.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
Input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.
packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffers Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
parity Report of the parity errors on the HSSI.
rx disabled Indicates the HSSI could not find a free buffer on the ciscoBus controller to reserve for use for the HSSI receiver. When this happens, the HSSI shuts down its receiver and waits until a buffer is available. Data is not lost unless a packet comes in and overflows the HSSI FIFO. Usually, the receive disables are frequent but do not last for long, and the number of dropped packets is less than the count in the "rx disabled" field. A receive disabled condition can happen in systems that are under heavy traffic load and that have shorter packets. In this situation, the number of buffers available on the ciscoBus controller is at a premium. One way to alleviate this problem is to reduce the mtu on the HSSI interface from 4500 (FDDI size) to 1500 (Ethernet size). Doing so allows the software to take the fixed memory of the ciscoBus controller and divide it into a larger number of smaller buffers, rather than a small number of large buffers. Receive disables are not errors, so they are not included in any error counts.
input errors Sum of all errors that prevented the receipt of datagrams on the interface being examined. This may not balance with the sum of the enumerated output errors, because some datagrams may have more than one error and others may have errors that do not fall into any of the specifically tabulated categories.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. On a serial link, CRCs usually indicate noise, gain hits, or other transmission problems on the data link. CRC errors are also reported when a far-end abort occurs, and when the idle flag pattern is corrupted. This makes it possible to get CRC errors even when there is no data traffic.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort Number of packets whose receipt was aborted.
packets output Total number of messages transmitted by the system.
bytes output Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the far-end transmitter has been running faster than the near-end router's receiver can handle.
congestion drop Number of messages discarded because the output queue on an interface grew too long. This can happen on a slow, congested serial link.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
applique Indicates an unrecoverable error has occurred on the HSA applique. The system then invokes an interface reset.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds time. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.
carrier transitions Number of times the carrier detect signal of the interface has changed state. Indicates modem or line problems if the carrier detect line is changing state often.
Protocol Protocol that is operating on the interface.
Pkts In Number of packets received for that protocol.
Chars In Number of characters received for that protocol.
Pkts Out Number of packets transmitted for that protocol.
Chars Out Number of characters transmitted for that protocol.

The following is an example of the show interfaces hssi command on a Cisco 7000:

Router# show interfaces hssi 1/0
Hssi1/0 is up, line protocol is up
  Hardware is cxBus HSSI
  Internet address is 131.108.38.14, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 45045 Kbit, DLY 1000000 usec, rely 255/255, load 1/255
  Encapsulation HDLC, loopback not set, keepalive set (10 sec)
  Last input 0:00:00, output 0:00:08, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 1000 bits/sec, 2 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     630573548 packets input, 2077237628 bytes, 0 no buffer
     Received 2832063 broadcasts, 0 runts, 0 giants
              0 parity, 1970 rx disabled
     113 input errors, 20 CRC, 93 frame, 0 overrun, 0 ignored, 0 abort
     629721628 packets output, 1934313295 bytes, 0 underruns
     0 output errors, 0 applique, 62 interface resets, 0 restarts
     309 carrier transitions

The following is an example of the show interfaces hssi command with the accounting option on a Cisco 7000:

Router# show interfaces hssi 1/0 accounting
HIP1/0
       Protocol    Pkts In   Chars In   Pkts Out  Chars Out
             IP       7344    4787842       1803    1535774
      Appletalk      33345    4797459      12781    1089695
        DEC MOP          0          0        127       9779
            ARP          7        420         39       2340

show interfaces ip-brief

To display a brief summary of an IP interface's information and status, use the show interfaces ip-brief EXEC command.

show interfaces ip-brief
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 interfaces ip-brief command:

Router# show interfaces ip-brief
Any interface listed with OK? value "NO" does not have a valid configuration
Interface    IP-Address      OK?  Method     Status                 Protocol
Ethernet0    172.30.160.22   YES  NVRAM      up                     up

show interfaces lex

To display statistics about a LAN Extender interface, use the show interface lex EXEC command.

show interfaces lex number [ethernet | serial]
Syntax Description
number Number of the LAN Extender interface that resides on the core router about which to display statistics.
ethernet (Optional) Displays statistics about the Ethernet interface that resides on the LAN Extender chassis.
serial (Optional) Displays statistics about the serial interface that resides on the LAN Extender chassis.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

To display statistics about the LAN Extender interface on the core router, use the show interfaces lex command without any keywords.

Administratively, the physical serial interface that connects the core router to the LAN Extender is completely hidden. The show interfaces serial command will show only that the serial interface is present. However, it will not report any statistics about the traffic passing over the physical line. All statistics are report by the show interfaces lex command.

Sample Displays

The following is sample output from the show interfaces lex command, showing the LAN Extender interface on the host router. Note the "Bound to ..." field, which is displayed only on a LAN Extender interface.

Router# show interfaces lex 0
Lex0 is up, line protocol is up
  Hardware is Lan Extender, address is 0204.0301.1526 (bia 0000.0000.0000)
  MTU 1500 bytes, BW 10000 Kbit, DLY 20000 usec, rely 255/255, load 1/255
  Encapsulation ARPA, loopback not set
  ARP type: ARPA, ARP Timeout 4:00:00
  Bound to Serial3
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 1000 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     1022 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     2070 packets output, 23663 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets, 0 restarts

The following is sample output from the show interfaces lex command when you specify the ethernet keyword:

Router# show interfaces lex 0 ethernet
Lex0-Ethernet0 is up, line protocol is up
  Hardware is LAN-Extender, address is 0000.0c01.1526 (bia 0000.0c01.1526)
  Last input 6w3d, output 6w3d
  Last clearing of "show interface" counters 0:02:30
  Output queue 40/50, 60 drops; input queue 10/40, 2 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     3916 packets input, 960303 bytes, 3 no buffer
     Received 2 broadcasts, 3 runts, 3 giants
     2 input errors, 1 CRC, 1 frame, 1 overrun, 3 ignored, 2 abort
     2500 packets output, 128288 bytes, 1 underruns
     1 output errors, 1 collisions, 0 interface resets, 0 restarts

The following is sample output from the show interfaces lex command when you specify the serial keyword:

Router# show interfaces lex 0 serial
Lex0-Serial0 is up, line protocol is up
  Hardware is LAN-Extender
  Last input 6w3d, output 6w3d
  Last clearing of "show interface" counters 0:03:05
  Input queue: 5/15/4 (size/max/drops); Total output drops: 450
  Output queue: high 25/35/90, medium 70/80/180, normal 40/50/120, low 10/20/60
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     1939 packets input, 30998 bytes, 6 no buffer
     Received 4 broadcasts, 6 runts, 6 giants
     4 input errors, 2 CRC, 2 frame, 2 overrun, 6 ignored, 4 abort
     1939 packets output, 219535 bytes, 2 underruns
     2 output errors, 2 collisions, 0 interface resets, 0 restarts
     2 carrier transitions

Table 45 describes the fields shown in these displays.


Table 45: Show Interfaces Lex Field Descriptions
Field Description
Lex0 is up, line protocol is up Indicates whether the logical LAN Extender interface on the core router is currently active (that is, whether carrier detect is present), inactive, or has been taken down by an administrator.
Lex0-Ethernet0 is up, line protocol is up
Lex0-Serial0 is up, line protocol is up
Indicates whether the physical Ethernet and serial interfaces on the LAN Extender chassis are currently active (that is, whether carrier detect is present) and if it has been taken down by an administrator.
Hardware is LAN-Extender Hardware type of the interfaces on the LAN Extender.
address is... Logical MAC address of the interface.
bia Burned-in MAC address of the interface. The LAN Extender interface does not have a burned in address; hence it appears as all zeroes.
MTU Maximum transmission unit size of the interface.
BW Value of the bandwidth parameter that has been configured for the interface (in kilobits per second). The bandwidth parameter is used to compute IGRP metrics only. If the interface is attached to a serial line with a line speed that does not match the default (1536 or 1544 for T1 and 56 for a standard synchronous serial line), use the bandwidth command to specify the correct line speed for this serial line.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
ARP type Type of Address Resolution Protocol assigned.
ARP Timeout Number of hours, minutes, and seconds an ARP cache entry will stay in the cache.
Bound to ... Number of the serial interface to which the logical LAN Extender interface is bound.
Last input Number of hours, minutes, and seconds (or never) since the last packet was successfully received by an interface. This is useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds (or never) since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing of "show interface" counters Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.

0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago

Output queue, drops
input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes Total number of bytes, including data and MAC encapsulation, in the error-free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
Received ... broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
input errors Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum might not balance with the other counts.
CRC Cyclic redundancy checksum generated by the originating station or far-end device does not match the checksum calculated from the data received. On a serial link, CRCs usually indicate noise, gain hits, or other transmission problems on the data link.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort Illegal sequence of one bits on a serial interface. This usually indicates a clocking problem between the serial interface and the data link equipment.
input packets with dribble condition detected Does not apply to a LAN Extender interface.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the transmitter has been running faster than the router can handle. This might never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this might not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Number of messages retransmitted due to an Ethernet collision. This usually is the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). Some collisions are normal. However, if your collision rate climbs to around 4 or 5%, you should consider verifying that there is no faulty equipment on the segment and/or moving some existing stations to a new segment. A packet that collides is counted only once in output packets.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds' time. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.

show interfaces loopback

Use the show interfaces loopback privileged EXEC command to display information about the loopback interface.

show interfaces loopback [number] [accounting]
Syntax Description
number (Optional) Port number on the selected interface.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Sample Displays

The following is sample output from the show interfaces loopback command:

Router# show interfaces loopback 0
Loopback0 is up, line protocol is up
  Hardware is Loopback
  MTU 1500 bytes, BW 1 Kbit, DLY 50 usec, rely 255/255, load 1/255
  Encapsulation UNKNOWN, loopback not set, keepalive set (10 sec)
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/0, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets, 0 restarts

The following is sample output when the accounting keyword is included:

Router# show interfaces loopback 0 accounting
Loopback0
                Protocol    Pkts In   Chars In   Pkts Out  Chars Out
No traffic sent or received on this interface.

Table 46 describes significant fields shown in the displays.


Table 46: Show Interfaces Loopback Field Descriptions
Field Description
Loopback is {up | down}
...is administratively down
Indicates whether the interface hardware is currently active (whether carrier detect is present), inactive, or has been taken down by an administrator.
line protocol
is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol considers the line usable (that is, whether keepalives are successful).
Hardware Hardware is Loopback.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
loopback Indicates whether loopback is set and type of loopback test.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
Input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.
packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
input errors Sum of all errors that prevented the receipt of datagrams on the interface being examined. This may not balance with the sum of the enumerated output errors, because some datagrams may have more than one error and others may have errors that do not fall into any of the specifically tabulated categories.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of collisions or a station transmitting bad data. On a serial link, CRCs usually indicate noise, gain hits, or other transmission problems on the data link. CRC errors are also reported when a far-end abort occurs, and when the idle flag pattern is corrupted. This makes it possible to get CRC errors even when there is no data traffic.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort Number of packets whose receipt was aborted.
packets output Total number of messages transmitted by the system.
bytes output Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the far-end transmitter has been running faster than the near-end router's receiver can handle. This may never happen (be reported) on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions A loopback interface does not have collisions.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds time. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.
Protocol Protocol that is operating on the interface.
Pkts In Number of packets received for that protocol.
Chars In Number of characters received for that protocol.
Pkts Out Number of packets transmitted for that protocol.
Chars Out Number of characters transmitted for that protocol.

show interfaces posi

To display the information about the Packet OC-3 interfaces in a Cisco RSP/7000 series or Cisco 7500 series, use the show interfaces posi EXEC command.

show interfaces posi [slot/port]
Syntax Description
slot (Optional) Slot number the POSIP is installed in.
port Port number of the interface.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

Sample Output

The following is sample output from the show interfaces posi command on a Cisco 7513 router with one Packet over SONET Interface Processor (POSIP).

Router# show interfaces posi
Posi0/0 is up, line protocol is up
  Hardware is cyBus Packet over Sonet
  Internet address is 3.3.3.2/24
  MTU 4470 bytes, BW 155000 Kbit, DLY 100 usec, rely 255/255, load 15/255
  Encapsulation HDLC, loopback not set, keepalive not set
  Last input 00:00:40, output 00:00:00, output hang never
  Last clearing of "show interface" counters 00:03:54
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  5 minute input rate 9158000 bits/sec, 13969 packets/sec
  5 minute output rate 9194000 bits/sec, 14061 packets/sec
     5423133 packets input, 271157590 bytes, 0 no buffer
     Received 4 broadcasts, 640 runts, 0 giants
              0 parity
     1563 input errors, 1563 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     5459899 packets output, 272994950 bytes, 0 underruns
     0 output errors, 0 applique, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out
     0 carrier transitions

Table 47 describes significant fields in this output.


Table  47: Show Interfaces Posi Field Descriptions
Field Description
Posi0/0 is up, line protocol is up Indicates whether the interface hardware is currently active and can transmit and receive or if it has been taken down by an administrator.
Hardware is cyBus Packet over Sonet Hardware type.
Internet address is Internet address and subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes. The calculation uses the value from the bandwidth interface configuration command.
Encapsulation Encapsulation method assigned to interface.
loopback Indicates whether loopbacks are set.
keepalive Indicates whether keepalives are set.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
(Last) output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
Output queue, drops
input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped because a queue was full.
5 minute input rate
5 minute output rate
Average number of bits and packets received or transmitted per second in the last 5 minutes.
packets input Total number of error-free packets received by the system.
bytes (input) Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
parity Report of the parity errors on the interface.
input errors Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum may not balance with the other counts.
CRC Cyclic redundancy checksum generated by the originating LAN station or far end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRC's is usually the result of collisions or a station transmitting bad data. On a serial link, CRC's usually indicate noise, gain hits or other transmission problems on the data link.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented.
abort Illegal sequence of one bits on the interface.
packets output Total number of messages transmitted by the system.
bytes (output) Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the far-end transmitter has been running faster than the near-end router's receiver can handle.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
applique Indicates an unrecoverable error has occurred on the POSIP applique. The system then invokes an interface reset.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within a certain interval. If the system notices that the carrier detect line of an interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an unrecoverable interface processor error occurred, or when an interface is looped back or shut down.
carrier transitions Number of times the carrier detect signal of the interface has changed state.
Related Command

interface posi

show interfaces serial

Use the show interfaces serial privileged EXEC command to display information about a serial interface.

show interfaces serial [number] [accounting]
show interfaces serial [number[:channel-group] [accounting] (for the Cisco 4000 series)
show interfaces serial [slot/port] [accounting] (for the Cisco 7200 series)
show interfaces serial [slot/port [:channel-group]] [accounting] (for the Cisco 7000 series)
show interfaces serial [slot/port-adapter/port] [accounting] (for ports on VIP cards in the Cisco 7000 series and Cisco 7500 series)

Syntax Description
number (Optional) Port number.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
:channel-group (Optional) On the Cisco 4000 with an NPM or Cisco 7000 series with a MIP, specifies the T1 channel group number in the range of 0 to 23 defined with the channel-group controller configuration command.
slot (Optional) On the Cisco 7000 series, slot location of the interface processor. On the Cisco 7200 series, slot location of the port adapter.
port (Optional) Port number on the interface. For the VIP card, the port value can be 0, 1, 2, or 3 for 4-port serial interfaces. On the Cisco 7200 series, the port numbers depend on the type of port adapters installed.
port-adapter (Optional) On the Cisco 7000 and Cisco 7500 series, specifies the ports on a VIP card. The value can be 0 or 1.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0 for the Cisco 4000 series.
This command first appeared in Cisco IOS Release 11.0 for the Cisco 7000 series.

Sample Displays

The following is sample output from the show interfaces command for a synchronous serial interface:

Router# show interfaces serial
Serial 0 is up, line protocol is up
   Hardware is MCI Serial
	   Internet address is 150.136.190.203, subnet mask is 255.255.255.0
	   MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
	   Encapsulation HDLC, loopback not set, keepalive set (10 sec)
	   Last input 0:00:07, output 0:00:00, output hang never
	   Output queue 0/40, 0 drops; input queue 0/75, 0 drops
	   Five minute input rate 0 bits/sec, 0 packets/sec
	   Five minute output rate 0 bits/sec, 0 packets/sec
		       16263 packets input, 1347238 bytes, 0 no buffer
		       Received 13983 broadcasts, 0 runts, 0 giants
		       2 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 2 abort
1 carrier transitions 
     22146 packets output, 2383680 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets, 0 restarts

Table 48 describes significant fields shown in the display.


Table 48: Show Interfaces Serial Field Descriptions
Field Description
Serial ... is {up | down}
...is administratively down
Indicates whether the interface hardware is currently active (whether carrier detect is present), inactive, or has been taken down by an administrator.
line protocol
is {up | down}
Indicates whether the software processes that handle the line protocol consider the line usable (that is, whether keepalives are successful) or if it has been taken down by an administrator.
Hardware is Specifies the hardware type.
Internet address is Specifies the Internet address and subnet mask.
MTU Maximum Transmission Unit of the interface.
BW 1544 Kbit Indicates the value of the bandwidth parameter that has been configured for the interface (in kilobits per second). The bandwidth parameter is used to compute IGRP metrics only. If the interface is attached to a serial line with a line speed that does not match the default (1536 or 1544 for T1 and 56 for a standard synchronous serial line), use the bandwidth command to specify the correct line speed for this serial line.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
loopback Indicates whether loopback is set or not.
keepalive Indicates whether keepalives are set or not.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Output queue, drops

input queue, drops

Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffers Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
Received ... broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
input error Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum may not balance with the other counts.
CRC Cyclic redundancy checksum generated by the originating station or far-end device does not match the checksum calculated from the data received. On a serial link, CRCs usually indicate noise, gain hits, or other transmission problems on the data link.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort Illegal sequence of one bits on a serial interface. This usually indicates a clocking problem between the serial interface and the data link equipment.
packets output Total number of messages transmitted by the system.
bytes output Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the transmitter has been running faster than the router can handle. This may never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Number of messages retransmitted due to an Ethernet collision. This usually is the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). Some collisions are normal. However, if your collision rate climbs to around 4 or 5%, you should consider verifying that there is no faulty equipment on the segment and/or moving some existing stations to a new segment. A packet that collides is counted only once in output packets.
interface resets Number of times an interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds' time. On a serial line, this can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a serial interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when an interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.
carrier transitions Number of times the carrier detect signal of a serial interface has changed state. For example, if data carrier detect (DCD) goes down and comes up, the carrier transition counter will increment two times. Indicates modem or line problems if the carrier detect line is changing state often.
alarm indications, remote alarms, rx LOF, rx LOS Number of CSU/DSU alarms, and number of occurrences of receive loss of frame and receive loss of signal.
BER inactive, NELR inactive, FELR inactive Status of G.703-E1 counters for bit error rate (BER) alarm, near-end loop remote (NELR), and far-end loop remote (FELR). Note that you cannot set the NELR or FELR.

The following is sample output of the show interfaces serial command for the HDLC synchronous serial interface on a Cisco 7000:

Router# show interfaces serial 1/0

Serial1/0 is up, line protocol is up
  Hardware is cxBus Serial
  Internet address is 150.136.190.203, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
  Encapsulation HDLC, loopback not set, keepalive set (10 sec)
  Last input 0:00:07, output 0:00:00, output hang never
  Last clearing of "show interface" counters 2w4d
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     16263 packets input, 1347238 bytes, 0 no buffer
     Received 13983 broadcasts, 0 runts, 0 giants
     2 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 2 abort
     22146 packets output, 2383680 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets, 0 restarts
     1 carrier transitions 

The following is sample output of the show interfaces serial command for a G.703 interface on which framing is enabled:

Router# show interfaces serial 2/3

Serial2/3 is up, line protocol is up
  Hardware is cxBus Serial
  Internet address is 5.4.4.1, subnet mask is 255.255.255.0
  MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
  Encapsulation HDLC, loopback not set, keepalive not set
  Last input 0:00:21, output 0:00:21, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     53 packets input, 7810 bytes, 0 no buffer
     Received 53 broadcasts, 0 runts, 0 giants
     2 input errors, 2 CRC, 0 frame, 0 overrun, 0 ignored, 2 abort
     56 packets output, 8218 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets, 0 restarts
     1 carrier transitions
     2 alarm indications, 333 remote alarms, 332 rx LOF, 0 rx LOS
     RTS up, CTS up, DTR up, DCD up, DSR up
     BER inactive, NELR inactive, FELR inactive

Table 48 describes significant fields shown in the display.

Sample Display with Frame Relay Encapsulation

When using the Frame Relay encapsulation, use the show interfaces command to display information on the multicast DLCI, the DLCI of the interface, and the LMI DLCI used for the local management interface.

The multicast DLCI and the local DLCI can be set using the frame-relay multicast-dlci and the frame-relay local-dlci configuration commands, or provided through the local management interface. The status information is taken from the LMI, when active.

The following is sample output from the show interfaces serial command when using Frame Relay encapsulation:

Router# show interfaces serial
Serial 2 is up, line protocol is up
   Hardware type is MCI Serial
   Internet address is 131.108.122.1, subnet mask is 255.255.255.0
	   MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
	   Encapsulation FRAME-RELAY, loopback not set, keepalive set (10 sec)
	   multicast DLCI 1022,  status defined, active
	   source DLCI    20, status defined, active
	   LMI DLCI 1023, LMI sent 10, LMI stat recvd 10, LMI upd recvd 2
	   Last input 7:21:29, output 0:00:37, output hang never
	   Output queue 0/100, 0 drops; input queue 0/75, 0 drops
	   Five minute input rate 0 bits/sec, 0 packets/sec
	   Five minute output rate 0 bits/sec, 0 packets/sec
		       47 packets input, 2656 bytes, 0 no buffer
		       Received 5 broadcasts, 0 runts, 0 giants
		       5 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 57 abort
		       518 packets output, 391205 bytes
	       0 output errors, 0 collisions, 0 interface resets, 0 restarts
		       1 carrier transitions

In this display, the multicast DLCI has been changed to 1022 with the frame-relay multicast-dlci interface configuration command.

The display shows the statistics for the LMI are the number of status inquiry messages sent (LMI sent), the number of status messages received (LMI recvd), and the number of status updates received (upd recvd). See the Frame Relay Interface specification for additional explanations of this output.

Sample Display with ANSI LMI

For a serial interface with the ANSI LMI enabled, use the show interfaces command to determine the LMI type implemented.

The following is a sample display from the show interfaces output for a serial interface with the ANSI LMI enabled:

Router# show interfaces serial
Serial 1 is up, line protocol is up
   	Hardware is MCI Serial
	   Internet address is 131.108.121.1, subnet mask is 255.255.255.0
	   MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
	   Encapsulation FRAME-RELAY, loopback not set, keepalive set
	   LMI DLCI    0, LMI sent 10, LMI stat recvd 10
	   LMI type is ANSI Annex D
	   Last input 0:00:00, output 0:00:00, output hang never
	   Output queue 0/40, 0 drops; input queue 0/75, 0 drops
	   Five minute input rate 0 bits/sec, 1 packets/sec
	   Five minute output rate 1000 bits/sec, 1 packets/sec
		       261 packets input, 13212 bytes, 0 no buffer
		       Received 33 broadcasts, 0 runts, 0 giants
		       0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
		       238 packets output, 14751 bytes, 0 underruns
		       0 output errors, 0 collisions, 0 interface resets, 0 restarts

Notice that the show interfaces output for a serial interface with ANSI LMI shown in this display is very similar to that for encapsulation set to Frame Relay, as shown in the previous display.
Table 49 describes the few differences that exist.


Table 49: Show Interfaces Serial Field Description with ANSI LMI
Field Description
LMI DLCI 0 Identifies the DLCI used by the LMI for this interface. Default: 1023.
LMI sent 10 Number of LMI packets the router sent.
LMI type is ANSI Annex D Indicates that the interface is configured for the ANSI-adopted Frame Relay specification T1.617 Annex D.
Sample Display with LAPB Encapsulation

Use the show interfaces serial command to display operation statistics for an interface that uses LAPB encapsulation.

The following is sample output from the show interfaces serial command for a serial interface that uses LAPB encapsulation:

Router# show interfaces serial 
LAPB state is DISCONNECT, T1 3000, N1 12000, N2 20, K7, TH 3000
Window is closed
IFRAMEs 12/28 RNRs 0/1 REJs 13/1 SABMs 1/13 FRMRs 3/0 DISCs 0/11

Table 50 shows the fields relevant to all LAPB connections.


Table 50: Show Interfaces Serial Field Descriptions when LAPB Is Enabled
Parameter Description
LAPB state is DISCONNECT State of the LAPB protocol.
T1 3000, N1 12000, ... Current parameter settings.
Window is closed Indicates that no more frames can be transmitted until some outstanding frames have been acknowledged.
IFRAMEs 12/28 RNRs 0/1 ... Count of the different types of frames in the form of
sent/received.
Show Interfaces Serial with PPP

An interface configured for synchronous PPP encapsulation differs from the standard show interface serial output. An interface configured for PPP might include the following information.

  lcp state = OPEN
  ncp ipcp state = OPEN   ncp osicp state = NOT NEGOTIATED
  ncp ipxcp state = NOT NEGOTIATED   ncp xnscp state = NOT NEGOTIATED
  ncp vinescp state = NOT NEGOTIATED   ncp deccp state = NOT NEGOTIATED
  ncp bridgecp state = NOT NEGOTIATED   ncp atalkcp state = NOT NEGOTIATED

Table 51 show the fields relevant to PPP connections.


Table 51: Show Interfaces Serial Field Descriptions with PPP Encapsulation
Field Description
lcp state Link Control Protocol
ncp ipcp state Network Control Protocol Internet Protocol Control Protocol
ncp osicp state Network Control Protocol OSI (CLNS) Control Protocol
ncp ipxcp state Network Control Protocol IPX (Novell) Control Protocol
ncp xnscp state Network Control Protocol XNS Control Protocol
ncp vinescp state Network Control Protocol VINES Control Protocol
ncp deccp state Network Control Protocol DECnet Control Protocol
ncp bridgecp state Network Control Protocol Bridging Control Protocol
ncp atalkcp state Network Control Protocol AppleTalk Control Protocol
Sample Display with SDLC Connections

Use the show interfaces serial command to display the SDLC information for a given SDLC interface. The following is sample output from the show interfaces serial command for an SDLC primary interface supporting the SDLLC function.

Router# show interfaces serial
Serial 0 is up, line protocol is up
	Hardware is MCI Serial
	MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
	Encapsulation SDLC-PRIMARY, loopback not set
    		Timers (msec): poll pause 100 fair poll 500. Poll limit 1
    		[T1 3000, N1 12016, N2 20, K 7] timer: 56608 Last polled device: none
    		SDLLC [ma: 0000.0C01.14--, ring: 7 bridge: 1, target ring: 10
             largest token ring frame 2052]
SDLC addr C1 state is CONNECT
     		VS 6, VR 3, RCNT 0, Remote VR 6, Current retransmit count 0
     		Hold queue: 0/12 IFRAMEs 77/22 RNRs 0/0 SNRMs 1/0 DISCs 0/0
     		Poll: clear, Poll count: 0, chain: p: C1 n: C1
     		SDLLC [largest SDLC frame: 265, XID: disabled]
 	Last input 00:00:02, output 00:00:01, output hang never
 	Output queue 0/40, 0 drops; input queue 0/75, 0 drops
	 Five minute input rate 517 bits/sec, 30 packets/sec
	 Five minute output rate 672 bits/sec, 20 packets/sec
     		357 packets input, 28382 bytes, 0 no buffer
     		Received 0 broadcasts, 0 runts, 0 giants
	     	0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
		     926 packets output, 77274 bytes, 0 underruns
		     0 output errors, 0 collisions, 0 interface resets, 0 restarts
		     2 carrier transitions

Table 52 shows the fields relevant to all SDLC connections.


Table 52: Show Interfaces Serial Field Descriptions when SDLC Is Enabled
Parameter Description
Timers (msec): poll pause, fair poll, Poll limit Current values of these timers, as described in the configuration section, for this interface.
T1, N1, N2, K Values for these parameters, as described in the configuration section, for this interface.

Table 53 shows other data given for each SDLC secondary configured to be attached to this interface.


Table 53: SDLC Secondary Descriptions
SDLC Secondary Description
addr Address of this secondary.
state is

  DISCONNECT

  CONNECT

  DISCSENT

  SNRMSENT

  THEMBUSY

  USBUSY

  BOTHBUSY

  ERROR

Current state of this connection, which is one of the following:

No communication is being attempted to this secondary.

A normal connect state exists between this router and this secondary.

This router has sent a disconnect request to this secondary and is awaiting its response.

This router has sent a connect request (SNRM) to this secondary and is awaiting its response.

This secondary has told this router that it is temporarily unable to receive any more information frames.

This router has told this secondary that it is temporarily unable to receive any more information frames.

Both sides have told each other that they are temporarily unable to receive any more information frames.

This router has detected an error and is waiting for a response from the secondary acknowledging this.

VS Sequence number of the next information frame this station sends.
VR Sequence number of the next information frame from this secondary that this station expects to receive.
Remote VR Last frame transmitted by this station that has been acknowledged by the other station.
Current retransmit count: Number of times the current I-frame or sequence of I-frames has been retransmitted.
Hold Queue Number of frames in hold queue/Maximum size of hold queue.
IFRAMEs, RNRs, SNRMs, DISCs Sent/received count for these frames.
Poll "Set" if this router has a poll outstanding to the secondary; "clear" if it does not.
Poll Count Number of polls in a row that have been given to this secondary at this time.
Chain Shows the previous (p) and next (n) secondary address on this interface in the round robin loop of polled devices.
Sample Display with SDLLC

Use the show interfaces serial command to display the SDLLC statistics for SDLLC configured interfaces.

The following is sample output from the show interfaces serial command for an a serial interface configured for SDLLC:

Router# show interfaces serial
Serial 0 is up, line protocol is up
   	Hardware is MCI Serial
	   MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, rely 255/255, load 1/255
	   Encapsulation SDLC-PRIMARY, loopback not set
		       Timers (msec): poll pause 100 fair poll 500. Poll limit 1
		       [T1 3000, N1 12016, N2 20, K 7] timer: 56608 Last polled device: none
		       SDLLC [ma: 0000.0C01.14--, ring: 7 bridge: 1, target ring: 10
             largest token ring frame 2052]
	   SDLC addr C1 state is CONNECT
		       VS 6, VR 3, RCNT 0, Remote VR 6, Current retransmit count 0
		       Hold queue: 0/12 IFRAMEs 77/22 RNRs 0/0 SNRMs 1/0 DISCs 0/0
		       Poll: clear, Poll count: 0, chain: p: C1 n: C1
		       SDLLC [largest SDLC frame: 265, XID: disabled]
	   Last input 00:00:02, output 00:00:01, output hang never
	   Output queue 0/40, 0 drops; input queue 0/75, 0 drops
	   Five minute input rate 517 bits/sec, 30 packets/sec
	   Five minute output rate 672 bits/sec, 20 packets/sec
		       357 packets input, 28382 bytes, 0 no buffer
		       Received 0 broadcasts, 0 runts, 0 giants
		       0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
		       926 packets output, 77274 bytes, 0 underruns
		       0 output errors, 0 collisions, 0 interface resets, 0 restarts
		       6608 Last polled device: none
		       SDLLC [ma: 0000.0C01.14--, ring: 7 brid2 carrier transitions 

Most of the output shown in the display is generic to all SDLC encapsulated interfaces and is described in the "LLC2 and SDLC Commands" chapter. Table 54 shows the parameters specific to SDLLC.


Table 54: SDLLC Parameters
Parameter Description
SDLLC ma Lists the MAC address configured for this interface. The last byte is shown as "--" to indicate that it is filled in with the SDLC address of the connection.
ring, bridge, target ring Lists the parameters as configured by the sdllc traddr command.
largest token ring frame Shows the largest Token Ring frame that is accepted on the LLC2 side of the connection.
largest SDLC frame Shows the largest SDLC frame that is accepted and will be generated on the SDLC side of the connection.
XID Enabled or disabled: Shows whether XID processing is enabled on the SDLC side of the connection. If enabled, it will show the XID value for this address.
Sample Display with Accounting Option

The following example illustrates the show interfaces serial command with the accounting option on a Cisco 7000:

Router# show interfaces serial 1/0 accounting
Serial1/0
       Protocol    Pkts In   Chars In   Pkts Out  Chars Out
             IP       7344    4787842       1803    1535774
      Appletalk      33345    4797459      12781    1089695
        DEC MOP          0          0        127       9779
            ARP          7        420         39       2340

show interfaces tokenring

Use the show interfaces tokenring privileged EXEC command to display information about the Token Ring interface and the state of source route bridging.

show interfaces tokenring unit [accounting]
show interfaces tokenring slot/port [accounting] (for the Cisco 7000 series and Cisco 7200 series)
show interfaces tokenring [slot/port-adapter/port] (for ports on VIP cards in the Cisco 7000 and Cisco 7500 series routers)

Syntax Description
unit Must match the interface port line number.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
slot On the Cisco 7000 series, slot location of the interface processor. On the 7000, value can be 0, 1, 2, 3, or 4. On the 7010, value can be 0, 1, or 2.

On the Cisco 7200 series, slot location of the port adapter; the value can be 1, 2, 3, 4, 5, or 6.

port Port number on the interface. On the Cisco 7000 series this argument is required, and the values can be 0, 1, 2, or 3.

(Optional) For the VIP card this argument is optional, and the port value can be 0, 1, 2, or 3 for 4-port Token Ring interfaces.

On the Cisco 7200 series, the number depends on the type of port adapter installed.

port-adapter (Optional) On the Cisco 7000 and 7500 series, specifies the ports on a VIP card. The value can be 0 or 1.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

If you do not provide values for the parameters slot and port, the command will display statistics for all the network interfaces. The optional keyword accounting displays the number of packets of each protocol type that have been sent through the interface.

Sample Displays

The following is sample output from the show interfaces tokenring command:

Router# show interfaces tokenring
TokenRing 0 is up, line protocol is up
Hardware is 16/4 Token Ring, address is 5500.2000.dc27 (bia 0000.3000.072b)
   	Internet address is 150.136.230.203, subnet mask is 255.255.255.0
	   MTU 8136 bytes, BW 16000 Kbit, DLY 630 usec, rely 255/255, load 1/255
   	Encapsulation SNAP, loopback not set, keepalive set (10 sec)
	   ARP type: SNAP, ARP Timeout 4:00:00
	   Ring speed: 16 Mbps
	   Single ring node, Source Route Bridge capable
	   Group Address: 0x00000000, Functional Address: 0x60840000
   	Last input 0:00:01, output 0:00:01, output hang never
   	Output queue 0/40, 0 drops; input queue 0/75, 0 drops
   	Five minute input rate 0 bits/sec, 0 packets/sec
   	Five minute output rate 0 bits/sec, 0 packets/sec
	   16339 packets input, 1496515 bytes, 0 no buffer
		        Received 9895 broadcasts, 0 runts, 0 giants
		        0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     32648 packets output, 9738303 bytes, 0 underruns
0 output errors, 0 collisions, 2 interface resets, 0 restarts
     5 transitions

Table 55 describes significant fields shown in the display.


Table 55: Show Interfaces Tokenring Field Descriptions
Field Description
Token Ring is up | down Interface is either currently active and inserted into ring (up) or inactive and not inserted (down).

On the Cisco 7000 series, gives the interface processor type, slot number, and port number.

Token Ring is Reset Hardware error has occurred.
Token Ring is Initializing Hardware is up, in the process of inserting the ring.
Token Ring is
Administratively Down
Hardware has been taken down by an administrator.
line protocol
is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol believe the interface is usable (that is, whether keepalives are successful).
Hardware Hardware type. "Hardware is Token Ring" indicates that the board is a CSC-R board. "Hardware is 16/4 Token Ring" indicates that the board is a CSC-R16 board. Also shows the address of the interface.
Internet address Lists the Internet address followed by subnet mask.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method assigned to interface.
loopback Indicates whether loopback is set or not.
keepalive Indicates whether keepalives are set or not.
ARP type: Type of Address Resolution Protocol assigned.
Ring speed: Speed of Token Ring--4 or 16 Mbps.
{Single ring/multiring node} Indicates whether a node is enabled to collect and use source routing information (RIF) for routable Token Ring protocols.
Group Address: Interface's group address, if any. The group address is a multicast address; any number of interfaces on the ring may share the same group address. Each interface may have at most one group address.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
Input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffers Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of a station transmitting bad data.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
packets output Total number of messages transmitted by the system.
bytes output Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the far-end transmitter has been running faster than the near-end router's receiver can handle. This may never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Since a Token Ring cannot have collisions, this statistic is nonzero only if an unusual event occurred when frames were being queued or dequeued by the system software.
interface resets Number of times an interface has been reset. The interface may be reset by the administrator or automatically when an internal error occurs.
Restarts Should always be zero for Token Ring interfaces.
transitions Number of times the ring made a transition from up to down, or vice versa. A large number of transitions indicates a problem with the ring or the interface.

The following is sample output from the show interfaces tokenring command on a Cisco 7000:

Router# show interfaces tokenring 2/0
TokenRing2/0 is administratively down, line protocol is down
  Hardware is cxBus Token Ring, address is 0000.3040.8b4a (bia 0000.3040.8b4a)
  MTU 8136 bytes, BW 16000 Kbit, DLY 630 usec, rely 255/255, load 1/255
  Encapsulation SNAP, loopback not set, keepalive set (10 sec)
  ARP type: SNAP, ARP Timeout 4:00:00
  Ring speed: 0 Mbps
  Single ring node, Source Route Transparent Bridge capable
  Ethernet Transit OUI: 0x0000F8
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/40, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 1 interface resets, 0 restarts
     1 transitions

The following example on the Cisco 7000 includes the accounting option.When you use the accounting option, only the accounting statistics are displayed.

Router# show interfaces tokenring 2/0 accounting
TokenRing2/0
       Protocol    Pkts In   Chars In   Pkts Out  Chars Out
             IP       7344    4787842       1803    1535774
      Appletalk      33345    4797459      12781    1089695
        DEC MOP          0          0        127       9779
            ARP          7        420         39       2340

show interfaces tunnel

To list tunnel interface information, use the show interfaces tunnel privileged EXEC command.

show interfaces tunnel number [accounting]
Syntax Description
number Port line number.
accounting (Optional) Displays the number of packets of each protocol type that have been sent through the interface.
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 interface tunnel command:

Router# show interfaces tunnel 4
Tunnel4 is up, line protocol is down
  Hardware is Routing Tunnel
  MTU 1500 bytes, BW 9 Kbit, DLY 500000 usec, rely 255/255, load 1/255
  Encapsulation TUNNEL, loopback not set, keepalive set (10 sec)
  Tunnel source 0.0.0.0, destination 0.0.0.0
  Tunnel protocol/transport GRE/IP, key disabled, sequencing disabled
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/0, 0 drops; input queue 0/75, 0 drops
  Five minute input rate 0 bits/sec, 0 packets/sec
  Five minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets, 0 restarts    

Table 56 describes significant fields shown in the display.


Table 56: Show Interfaces Tunnel Field Descriptions
Field Description
Tunnel is up | down Interface is currently active and inserted into ring (up) or inactive and not inserted (down).

On the Cisco 7000 series, gives the interface processor type, slot number, and port number.

line protocol is {up | down | administratively down} Shows line protocol up if a valid route is available to the tunnel destination. Shows line protocol down if no route is available, or if the route would be recursive.
Hardware Specifies the hardware type.
MTU Maximum Transmission Unit of the interface.
BW Bandwidth of the interface in kilobits per second.
DLY Delay of the interface in microseconds.
rely Reliability of the interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over 5 minutes.
load Load on the interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over 5 minutes.
Encapsulation Encapsulation method is always TUNNEL for tunnels.
loopback Indicates whether loopback is set or not.
keepalive Indicates whether keepalives are set or not.
Tunnel source IP address used as the source address for packets in the tunnel.
destination IP address of the host destination.
Tunnel protocol Tunnel transport protocol (the protocol the tunnel is using). This is based on the tunnel mode command, which defaults to GRE.
key ID key for the tunnel interface, unless disabled.
sequencing Indicates whether the tunnel interface drops datagrams that arrive out of order. Can be disabled.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by an interface. Useful for knowing when a dead interface failed.
Last output Number of hours, minutes, and seconds since the last packet was successfully transmitted by an interface.
output hang Number of hours, minutes, and seconds (or never) since the interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing Time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
Input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last 5 minutes.

The 5-minute input and output rates should be used only as an approximation of traffic per second during a given 5-minute period. These rates are exponentially weighted averages with a time constant of 5 minutes. A period of four time constants must pass before the average will be within two percent of the instantaneous rate of a uniform stream of traffic over that period.

packets input Total number of error-free packets received by the system.
bytes input Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffers Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
CRC Cyclic redundancy checksum generated by the originating LAN station or far-end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRCs is usually the result of a station transmitting bad data.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be increased.
abort Illegal sequence of one bits on a serial interface. This usually indicates a clocking problem between the serial interface and the data link equipment.
packets output Total number of messages transmitted by the system.
bytes output Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the far-end transmitter has been running faster than the near-end router's receiver can handle. This may never be reported on some interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the interface being examined. Note that this may not balance with the sum of the enumerated output errors, as some datagrams may have more than one error, and others may have errors that do not fall into any of the specifically tabulated categories.
collisions Number of messages retransmitted due to an Ethernet collision. This usually is the result of an overextended LAN (Ethernet or transceiver cable too long, more than two repeaters between stations, or too many cascaded multiport transceivers). Some collisions are normal. However, if your collision rate climbs to around 4 or 5%, you should consider verifying that there is no faulty equipment on the segment and/or moving some existing stations to a new segment. A packet that collides is counted only once in output packets.
interface resets Number of times an interface has been reset. The interface may be reset by the administrator or automatically when an internal error occurs.
Restarts Number of times the controller was restarted because of errors.
Related Commands

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

show interfaces
show ip route
+
show route +

show interfaces vty

Use the show interfaces vty EXEC command to display information about virtual asynchronous interfaces.

show interfaces vty number
Syntax Description
number Number of the virtual terminal (VTY) that has been configured for asynchronous protocol features (vty-async).
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 interfaces vty command:

Router# show interfaces vty 17
VTY-Async17 is up, line protocol is up
  Hardware is Virtual Async Serial
  Interface is unnumbered.  Using address of Ethernet0 (171.69.60.44)
MTU 1500 bytes, BW 9 Kbit, DLY 100000 usec, rely 255/255, load 1/255
  Encapsulation SLIP, loopback not set
  DTR is pulsed for 5 seconds on reset
  Last input never, output never, output hang never
  Last clearing of "show interface" counters never
  Output queue 0/10, 0 drops; input queue 0/75, 0 drops
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts, 0 runts, 0 giants
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets, 0 restarts
     0 carrier transitions

Table 57 describes the fields shown in the sample display.


Table 57: Show Interfaces VTY Field Descriptions
Field Description
Async ... is {up | down |
administratively down}
Indicates whether the interface is currently active (whether carrier detect is present), inactive, or has been taken down by an administrator.
line protocol is {up | down |
administratively down}
Indicates whether the software processes that handle the line protocol think the line is usable (that is, whether keepalives are successful).
Hardware is Hardware type.
Internet address | unnumbered IP address, or IP unnumbered for the line. If unnumbered, the output lists the interface and IP address to which the line is assigned (Ethernet0 at 171.69.60.44 in this example).
MTU Maximum transmission unit of the vty-async interface.
BW Bandwidth of the vty-async interface in kilobits per second.
DLY Delay of the vty-async interface in microseconds.
rely Reliability of the vty-async interface as a fraction of 255 (255/255 is 100% reliability), calculated as an exponential average over five minutes.
load Load on the vty-async interface as a fraction of 255 (255/255 is completely saturated), calculated as an exponential average over five minutes. The calculation uses the value from the bandwidth interface configuration command.
Encapsulation Encapsulation method assigned to the vty-async interface.
loopback Test in which signals are sent and then directed back toward the source at some point along the communication path. Used to test network interface usability.
DTR Data Terminal Ready. An RS232-C circuit that is activated to let the DCE know when the DTE is ready to send and receive data.
Last input Number of hours, minutes, and seconds since the last packet was successfully received by a vty-async interface. Useful for knowing when a dead interface failed.
output The number of hours, minutes, and seconds since the last packet was successfully transmitted by a vty-async interface.
output hang Number of hours, minutes, and seconds (or never) since the vty-async interface was last reset because of a transmission that took too long. When the number of hours in any of the "last" fields exceeds 24 hours, the number of days and hours is printed. If that field overflows, asterisks are printed.
Last clearing The time at which the counters that measure cumulative statistics (such as number of bytes transmitted and received) shown in this report were last reset to zero. Note that variables that might affect routing (for example, load and reliability) are not cleared when the counters are cleared.

*** indicates the elapsed time is too large to be displayed.
0:00:00 indicates the counters were cleared more than 231ms (and less than 232ms) ago.

Output queue, drops
input queue, drops
Number of packets in output and input queues. Each number is followed by a slash, the maximum size of the queue, and the number of packets dropped due to a full queue.
Five minute input rate,
Five minute output rate
Average number of bits and packets transmitted per second in the last five minutes.
packets input Total number of error-free packets received by the system.
bytes Total number of bytes, including data and MAC encapsulation, in the error free packets received by the system.
no buffer Number of received packets discarded because there was no buffer space in the main system. Compare with ignored count. Broadcast storms on Ethernets and bursts of noise on serial lines are often responsible for no input buffer events.
broadcasts Total number of broadcast or multicast packets received by the vty-async interface.
runts Number of packets that are discarded because they are smaller than the medium's minimum packet size.
giants Number of packets that are discarded because they exceed the medium's maximum packet size.
input errors Total number of no buffer, runts, giants, CRCs, frame, overrun, ignored, and abort counts. Other input-related errors can also increment the count, so that this sum might not balance with the other counts.
CRC The cyclic redundancy checksum generated by the originating LAN station or far end device does not match the checksum calculated from the data received. On a LAN, this usually indicates noise or transmission problems on the LAN interface or the LAN bus itself. A high number of CRC's is usually the result of collisions or a station transmitting bad data. On a serial link, CRC's usually indicate noise, gain hits or other transmission problems on the data link.
frame Number of packets received incorrectly having a CRC error and a noninteger number of octets. On a serial line, this is usually the result of noise or other transmission problems.
overrun Number of times the serial receiver hardware was unable to hand received data to a hardware buffer because the input rate exceeded the receiver's ability to handle the data.
ignored Number of received packets ignored by the vty-async interface because the interface hardware ran low on internal buffers. These buffers are different than the system buffers mentioned previously in the buffer description. Broadcast storms and bursts of noise can cause the ignored count to be incremented.
abort Illegal sequence of one bits on a vty-async interface. This usually indicates a clocking problem between the vty-async interface and the data link equipment.
packets output Total number of messages transmitted by the system.
bytes Total number of bytes, including data and MAC encapsulation, transmitted by the system.
underruns Number of times that the far-end transmitter has been running faster than the near-end communication server's receiver can handle. This might never be reported on some vty-async interfaces.
output errors Sum of all errors that prevented the final transmission of datagrams out of the vty-async interface being examined. Note that this might not balance with the sum of the enumerated output errors, as some datagrams might have more than one error, and others might have errors that do not fall into any of the specifically tabulated categories.
collisions Number of packets colliding.
interface resets Number of times a vty-async interface has been completely reset. This can happen if packets queued for transmission were not sent within several seconds. This can be caused by a malfunctioning modem that is not supplying the transmit clock signal, or by a cable problem. If the system notices that the carrier detect line of a vty-async interface is up, but the line protocol is down, it periodically resets the interface in an effort to restart it. Interface resets can also occur when a vty-async interface is looped back or shut down.
restarts Number of times the controller was restarted because of errors.
carrier transitions Number of times the carrier detect signal of a vty-async interface has changed state. Indicates modem or line problems if the carrier detect line is changing state often.

show ip interface

To list a summary of an interface's IP information and status, use the show ip interface privileged EXEC command.

show ip interface [brief] [type] [number]
Syntax Description
brief (Optional) Displays a brief summary of IP status and configuration.
type (Optional) Specifies that information be displayed about that interface type only. The possible value depends on the type of interfaces the system has. For example, it could be ethernet, null, serial, tokenring, and so forth.
number (Optional) Interface number.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Sample Displays

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

Router# show ip interface
Ethernet0 is administratively down, line protocol is down
  Internet address is 1.0.46.10, subnet mask is 255.0.0.0
  Broadcast address is 255.255.255.255
  Address determined by setup command
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is enabled
  Multicast groups joined: 224.0.0.1 224.0.0.2
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP SSE switching is disabled
  Router Discovery is disabled
  IP accounting is disabled
  TCP/IP header compression is disabled
  Probe proxy name replies are disabled
  Gateway Discovery is disabled
PCbus0 is administratively down, line protocol is down
  Internet address is 198.135.1.43, subnet mask is 255.255.255.0
  Broadcast address is 255.255.255.255
  Address determined by setup command
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is enabled
  Multicast groups joined: 224.0.0.1 224.0.0.2
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP SSE switching is disabled
  Router Discovery is disabled
  IP accounting is disabled
  TCP/IP header compression is disabled
  Probe proxy name replies are disabled
  Gateway Discovery is disabled
Serial0 is administratively down, line protocol is down
  Internet address is 198.135.2.49, subnet mask is 255.255.255.0
  Broadcast address is 255.255.255.255
  Address determined by setup command
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is enabled
  Multicast groups joined: 224.0.0.1 224.0.0.2
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP SSE switching is disabled
  Router Discovery is disabled
  IP accounting is disabled
  TCP/IP header compression is disabled
  Probe proxy name replies are disabled
  Gateway Discovery is disabled

The following is sample output from the show ip interface brief command:

Router# show ip interface brief
Interface    IP-Address      OK?  Method     Status                 Protocol
Ethernet0    1.0.46.10       YES  manual     administratively down  down    
PCbus0       198.135.1.43    YES  manual     administratively down  down    
Serial0      198.135.2.49    YES  manual     administratively down  down    

The following is sample output from the show ip interface brief pcbus 0 command:

Router# show ip interface brief pcbus 0
Interface    IP-Address      OK?  Method     Status                 Protocol
PCbus0       198.135.1.43    YES  manual     administratively down  down    
Related Command

show interfaces

show ip local pool

To display statistics for any defined IP address pools, use the show ip local pool command.

show ip local pool [name]
Syntax Description
name (Optional) Name of a specific IP address pool.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

If you omit the variable name, the software will display a generic list of all defined address pools and the IP addresses that belong to them. If you specify a name, the software displays more detailed information for that pool.

Sample Display
Router# show ip local pool
Scope    Begin           End             Free InUse
 Dialin   172.30.228.11   172.30.228.26   16   0  
Available addresses:
   172.30.228.12                             
   172.30.228.13                             
   172.30.228.14                             
   172.30.228.15                             
   172.30.228.16                             
   172.30.228.17                             
   172.30.228.18                             
   172.30.228.19                             
   172.30.228.20                             
   172.30.228.21                             
   172.30.228.22                             
   172.30.228.23                             
   172.30.228.24                             
   172.30.228.25                             
   172.30.228.26                             
   172.30.228.11        Async5               
Inuse addresses:
     None

Table 58 describes the fields shown in the display.


Table 58: Show IP Local Pool Field Descriptions
Field Description
Scope The type of access.
Begin The first IP address in the defined range of addresses in this pool.
End The last IP address in the defined range of addresses in this pool.
Free The number of addresses currently available.
InUse The number of addresses currently in use.
Related Commands

ip address-pool
ip local pool

show rif

Use the show rif EXEC command to display the current contents of the RIF cache.

show rif
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 rif command:

Router# show rif
Codes: * interface, - static, + remote
Hardware Addr  How   Idle (min)  Routing Information Field
5C02.0001.4322 rg5           -   0630.0053.00B0
5A00.0000.2333 TR0           3   08B0.0101.2201.0FF0
5B01.0000.4444 -             -   -
0000.1403.4800 TR1           0   -
0000.2805.4C00 TR0           *   -
0000.2807.4C00 TR1           *   -
0000.28A8.4800 TR0           0   -
0077.2201.0001 rg5          10   0830.0052.2201.0FF0

In the display, entries marked with an asterisk (*) are the router/bridge's interface addresses. Entries marked with a dash (-) are static entries. Entries with a number are cached entries. If the RIF timeout is set to something other than the default of 15 minutes, the timeout is displayed at the top of the display.

Table 59 describes significant fields shown in the display.


Table 59: Show RIF Cache Display Field Descriptions
Field Description
Hardware Addr Lists the MAC-level addresses.
How Describes how the RIF has been learned. Possible values include a ring group (rg), or interface (TR).
Idle (min) Indicates how long, in minutes, since the last response was received directly from this node.
Routing Information Field Lists the RIF.

show service-module serial

To display the performance report for an integrated CSU/DSU in a Cisco 2524 or Cisco 2525 router, use the show service-module serial privileged EXEC command.

show service-module serial number [performance-statistics [interval-range]]
Syntax Description
number Interface number 0 or 1.
performance-statistics (Optional) Displays the CSU/DSU performance statistics for the past 24 hours. This keyword applies only to the fractional T1/T1 module.
interval-range (Optional) Specifies the number of 15-minute intervals displayed. You can choose a range from 1 to 96, where each value represents the CSU/DSU activity performed in that 15-minute interval. For example, a range of 2-3 displays the performance statistics for the intervals two and three.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command applies to the 2- and 4-wire 56/64-kbps CSU/DSU module and FT1/T1 CSU/DSU module. The performance-statistics keyword applies only to the FT1/T1 CSU/DSU module.

Example

The following example shows CSU/DSU performance statistics for intervals 30 to 32. Each interval is 15 minutes long. All the data is zero because no errors were discovered on the T1 line:

Router#show service-module serial 1 performance-statistics 30-32
Total Data (last 58 15 minute intervals):
    0 Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Data in current interval (131 seconds elapsed):
    0 Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Data in Interval 30:
    0 Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Data in Interval 31:
    0 Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Data in Interval 32:
    0 Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs

The following example is sample output from the show service-module interface command:

Router1#show service-module serial 0
Module type is T1/fractional
    Hardware revision is B, Software revision is 1.1 ,
    Image checksum is 0x2160B7C, Protocol revision is 1.1
Receiver has AIS alarm,
Unit is currently in test mode:
    line loopback is in progress
Framing is ESF, Line Code is B8ZS, Current clock source is line,
Fraction has 24 timeslots (64 Kbits/sec each), Net bandwidth is 1536 Kbits/sec.
Last user loopback performed:
    remote loopback
    Failed to loopup remote
Last module self-test (done at startup): Passed
Last clearing of alarm counters 0:05:50
    loss of signal        :    1, last occurred 0:01:50
    loss of frame         :    0,
    AIS alarm             :    1, current duration 0:00:49
    Remote alarm          :    0,
    Module access errors  :    0,
Total Data (last 0 15 minute intervals):
Line Code Violations, 0 Path Code Violations
    0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs
Data in current interval (351 seconds elapsed):
    1466 Line Code Violations, 0 Path Code Violations
    25 Slip Secs, 49 Fr Loss Secs, 40 Line Err Secs, 1 Degraded Mins
    0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 49 Unavail Secs
Router1#show service-module serial 1
Module type is 4-wire Switched 56
    Hardware revision is B, Software revision is 1.00,
    Image checksum is 0x44453634, Protocol revision is 1.0
Connection state: active,
Receiver has loss of signal, loss of sealing current,
Unit is currently in test mode:
    line loopback is in progress
Current line rate is 56 Kbits/sec
Last user loopback performed:
    dte loopback
    duration 00:00:58
Last module self-test (done at startup): Passed
Last clearing of alarm counters 0:13:54
    oos/oof               :    3, last occurred 0:00:24
    loss of signal        :    3, current duration 0:00:24
    loss of sealing curren:    2, current duration 0:04:39
    loss of frame         :    0,
    rate adaption attempts:    0,

Table 60 describes the fields displayed by the show service-module command.

     


Table 60: Show Service-Module Output Field Descriptions
Field Description
Module type The CSU/DSU module installed in the router. The possible modules are T1/fractional, 2-wire switched 56-kbps, and 4-wire 56/64-kbps.

Receiver has AIS alarm

Alarms detected by the FT1/T1 CSU/DSU module or 2- and 4-wire 56/64-kbps CSU/DSU modules.

Possible T1 alarms are as follows:

  • Transmitter is sending remote alarm.

  • Transmitter is sending AIS.

  • Receiver has loss of signal.

  • Receiver has loss of frame.

  • Receiver has remote alarm.

  • Receiver has no alarms.

Possible switched 56k alarms are as follows:

  • Receiver has loss of signal

  • Receiver has loss of sealing current

  • Receiver has loss of frame

  • Receiver has rate adaptation attempts

Unit is currently in test mode

Loopback tests are in progress.
Framing is ESF Indicates frame type used on the line. Can be extended super frame or super frame.
Line code is B8ZS Indicated line-code type configured. Can be alternate mark inversion (AMI) or binary 8-zero substitution (B8ZS).
Current clock source is line Clock source configured on the line, which can be supplied by the service provider (line) or the integrated CSU/DSU module (internal).
Fraction has 24 timeslots Number of timeslots defined for the FT1/T1 module, which can range from 1 to 24.
Net bandwidth Total bandwidth of the line (for example, 24 timeslots multiplied by 64 kbps equals a bandwidth of 1536 kbps).
Last user loopback performed Type and outcome of the last performed loopback.
Last module self-test (done at startup): passed Status of the last self test performed on an integrated CSU/DSU module.
Last clearing of alarm counters List of network alarms that were detected and cleared on the CSU/DSU module.
Total data
Data in current interval
Shows the current accumulation period, which rolls into the 24-hour accumulation every 15 minutes. The oldest 15-minute period falls off the back of the 24-hour accumulation buffer.
Line code violations Indicates the occurrence of either a bipolar violation or excessive zeroes error event.
Path code violations Indicates a frame synchronization bit error in the D4 and E1-no CRC formats or a CRC error in the ESF and E1-CRC formats.
Slip secs Indicates the replication or detection of the payload bits of a DS1 frame. A slip may be performed when there is a difference between the timing of a synchronous receiving terminal and the received signal.
Fr loss secs Indicates the number of seconds an out of frame error is detected.
Line err secs Line errored seconds is a second in which one or more line code violation errors are detected.
Errored secs In ESF and E1-CRC links, an errored second is a second in which one of the following is detected: one or more path code violations; one or more out of frame defects; one or more controlled slip events; a detected AIS defect.

For D4 and E1-no CRC links, the presence of bipolar violation also triggers an errored second.

Bursty err secs A second with fewer than 320 and more than 1 path coding violation errors. No severely errored frame defects or incoming AIS defects are detected. Controlled slips are not included in this parameter.
Severely err secs For ESF signals, a second with one of the following errors: 320 or more path code violation errors; one or more out of frame defects; a detected AIS defect.

For D4 signals, a count of 1-second intervals with framing errors, or an out of frame defect, or 1544 line code violations.

Unavail secs Total time the line was out of service.
Related Command

clear service-module

show tdm connections

To display a snapshot of the time-division multiplexing (TDM) bus connection memory in a Cisco AS5200 access server, use the show tdm connections EXEC command.

show tdm connections [motherboard | slot number]
Syntax Description
motherboard (Optional) Motherboard in the Cisco AS5200 access server.
slot number (Optional) Slot number.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

The show tdm connections command shows the connection memory for all TDM bus connections in the access server if you do not limit the display to the motherboard or a slot.

Sample Display

The following example shows source stream 3 (ST3) channel 2 switched out of stream 6 (ST6) channel 2:

AS5200# show tdm connections motherboard
MT8980 motherboard unit 0, Control Register = 0x1F, ODE Register = 0x06
Connection Memory for ST6:
Ch0:  0x62, Ch1:  0x00, Ch2:  0x00, Ch3:  0x00
Ch4:  0x00, Ch5:  0x00, Ch6:  0x00, Ch7:  0x00
Ch8:  0x00, Ch9:  0x00, Ch10: 0x00, Ch11: 0x00
Ch12: 0x00, Ch13: 0x00, Ch14: 0x00, Ch15: 0x00
Ch16: 0x00, Ch17: 0x00, Ch18: 0x00, Ch19: 0x00
Ch20: 0x00, Ch21: 0x00, Ch22: 0x00, Ch23: 0x00
Ch24: 0x00, Ch25: 0x00, Ch26: 0x00, Ch27: 0x00
Ch28: 0x00, Ch29: 0x00, Ch30: 0x00, Ch31: 0x00

To interpret the hexadecimal number 0x62 into meaningful information, you must translate it into binary code. These two hexadecimal numbers represent a connection from any stream and a channel on any stream. The number 6 translates into the binary code 0110, which represents the third-source stream. The number 2 translates into the binary code 0010, which represents the second-source channel.

Stream 6 (ST6) channel 0 is the destination for source stream 3 (ST3) channel 2 in this example.

show tdm data

To display a snapshot of the time-division multiplexing (TDM) bus data memory in a Cisco AS5200 access server, use the show tdm data EXEC command.

show tdm data [motherboard | slot number]
Syntax Description
motherboard (Optional) Motherboard in the Cisco AS5200 access server.
slot number (Optional) Slot number.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

The data memory for all TDM bus connections in the access server is displayed if you do not specify a motherboard or slot.

Sample Display

The following example shows a snapshot of TDM memory where the normal ISDN idle pattern (0x7E) is present on all channels of the TDM device resident on the motherboard:

AS5200# show tdm data motherboard
MT8980 motherboard unit 0, Control Register = 0x1F, ODE Register = 0x06
Data Memory for ST0:
Ch0:  0x7E, Ch1:  0x7E, Ch2:  0x7E, Ch3:  0x7E
Ch4:  0x7E, Ch5:  0x7E, Ch6:  0x7E, Ch7:  0x7E
Ch8:  0x7E, Ch9:  0x7E, Ch10: 0x7E, Ch11: 0x7E
Ch12: 0x7E, Ch13: 0x7E, Ch14: 0x7E, Ch15: 0x7E
Ch16: 0x7E, Ch17: 0x7E, Ch18: 0x7E, Ch19: 0x7E
Ch20: 0x7E, Ch21: 0x7E, Ch22: 0x7E, Ch23: 0x7E
Ch24: 0x7E, Ch25: 0x7E, Ch26: 0x7E, Ch27: 0x7E
Ch28: 0x7E, Ch29: 0x7E, Ch30: 0x7E, Ch31: 0x7E
Data Memory for ST1:
Ch0:  0x7E, Ch1:  0x7E, Ch2:  0x7E, Ch3:  0x7E
Ch4:  0x7E, Ch5:  0x7E, Ch6:  0x7E, Ch7:  0x7E
Ch8:  0x7E, Ch9:  0x7E, Ch10: 0x7E, Ch11: 0x7E
Ch12: 0x7E, Ch13: 0x7E, Ch14: 0x7E, Ch15: 0x7E
Ch16: 0x7E, Ch17: 0x7E, Ch18: 0x7E, Ch19: 0x7E
Ch20: 0x7E, Ch21: 0x7E, Ch22: 0x7E, Ch23: 0x7E
Ch24: 0x7E, Ch25: 0x7E, Ch26: 0x7E, Ch27: 0x7E
Ch28: 0x7E, Ch29: 0x7E, Ch30: 0x7E, Ch31: 0x7E

shutdown (hub configuration)

To shut down a port on an Ethernet hub of a Cisco 2505 or Cisco 2507, use the shutdown hub configuration command. To restart the disabled hub, use the no form of this command.

shutdown
no shutdown

Syntax Description

This command has no arguments or keywords.

Command Mode

Hub configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

Example

The following example shuts down hub 0, ports 1 through 3:

hub ethernet 0 1 3
shutdown
Related Command

hub

shutdown (interface)

To disable an interface, use the shutdown interface configuration command. To restart a disabled interface, use the no form of this command.

shutdown
no shutdown

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 10.0.

The shutdown command disables all functions on the specified interface. On serial interfaces, this command causes the DTR signal to be dropped. On Token Ring interfaces, this command causes the interface to be deinserted from the ring. On FDDI interfaces, this command causes the optical bypass switch, if present, to go into bypass mode.

This command also marks the interface as unavailable. To check whether an interface is disabled, use the EXEC command show interfaces. An interface that has been shut down is shown as administratively down in the display from this command.

Examples

The following example turns off Ethernet interface 0:

interface ethernet 0
shutdown

The following example turns the interface back on:

interface ethernet 0
no shutdown
Related Command

show interfaces

smt-queue-threshold

To set the maximum number of unprocessed FDDI station management (SMT) frames that will be held for processing, use the smt-queue-threshold global configuration command. Use the
no form of this command to restore the queue to the default.

smt-queue-threshold number
no smt-queue-threshold

Syntax Description
number Number of buffers used to store unprocessed SMT messages that are to be queued for processing. Acceptable values are positive integers.
Default

The default threshold value is equal to the number of FDDI interfaces installed in the router.

Command Mode

Global configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command helps ensure that the routers keep track of FDDI upstream and downstream neighbors, particularly when a router includes more than one FDDI interface.

In FDDI, upstream and downstream neighbors are determined by transmitting and receiving SMT Neighbor Information Frames (NIFs). The router can appear to lose track of neighbors when it receives an SMT frame and the queue currently contains an unprocessed frame. This occurs because the router discards incoming SMT frames if the queue is full. Discarding SMT NIF frames can cause the router to lose its upstream or downstream neighbor.


Note Use this command carefully, because the SMT buffer is charged to the inbound interface (input hold queue) until the frame is completely processed by the system. Setting this value to a high limit can impact buffer usage and the ability of the router to receive routable packets or routing updates.
Example

The following example specifies that the SMT queue can hold ten messages. As SMT frames are processed by the system, the queue is decreased by one:

smt-queue-threshold 10

snmp trap illegal-address

To issue an SNMP trap when a MAC address violation is detected on an Ethernet hub port of a Cisco 2505, Cisco 2507, or Cisco 2516 router, use the snmp trap illegal-address hub configuration command. Use the no form to disable this function.

snmp trap illegal-address
no snmp trap illegal-address

Syntax Description

This command has no arguments or keywords.

Default

No SNMP trap is issued.

Command Mode

Hub configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 11.1.

In addition to setting the snmp trap illegal-address command on the Ethernet hub, you can set the frequency that the trap is sent to the network management station (NMS). This is done on the NMS via the Cisco Repeater MIB. The frequency of the trap can be configured for once only or at a decaying rate (the default). If the decaying rate is used, the first trap is sent immediately, the second trap is sent after one minute, the third trap is sent after two minutes, and so on until 32 minutes at which time the trap is sent every 32 minutes. If you use a decaying rate, you can also set the trap acknowledgment so the trap will be acknowledged after it is received and will no longer be sent to the network management station. For more information, see the Cisco Repeater section in the Cisco Management Information Base (MIB) User Quick Reference.

Because traps are not reliable, additional information on a port basis is provided by the Cisco Repeater MIB. The network management function can query the following information: the last illegal MAC source address, the illegal address trap acknowledgment, the illegal address trap enabled, the illegal address first heard (timestamp), the illegal address last heard (timestamp), the last illegal address trap count for the port, and the illegal address trap total count for the port.

In addition to issuing a trap when a MAC address violation is detected, the port is also disabled as long as the MAC address is invalid. The port is enabled and the trap is no longer sent when the MAC address is valid (that is, either the address was configured correctly or learned).

Example

The following example enables an SNMP trap to be issued when a MAC address violation is detected on hub ports 2, 3, or 4. SNMP support must already be configured on the router.

hub ethernet 0 2 4
snmp trap illegal-address
Related Command

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

hub ethernet +

source-address

To configure source address control on a port on an Ethernet hub of a Cisco 2505 or Cisco 2507, use the source-address hub configuration command. To remove a previously defined source address, use the no form of this command.

source-address [mac-address]
no source-address

Syntax Description
mac-address (Optional) MAC address in the packets that the hub will allow to access the network.
Default

Disabled

Command Mode

Hub configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

If you omit the MAC address, the hub uses the value in the last source address register, and if the address register is invalid, it will remember the first MAC address it receives on the previously specified port, and allow only packets from that MAC address onto that port.

Examples

The following example configures the hub to allow only packets from MAC address 1111.2222.3333 on port 2 of hub 0:

hub ethernet 0 2
source-address 1111.2222.3333

The following example configures the hub use the value of the last source address register. If the address register is invalid, it will remember the first MAC address it receives on port 2, and allow only packets from the learned MAC address on port 2:

hub ethernet 0 2
source-address
Related Command

hub

squelch

To extend the Ethernet twisted-pair 10BaseT capability beyond the standard 100 meters on the Cisco 4000 platform, use the squelch interface configuration command. To restore the default, use the no form of this command.

squelch {normal | reduced}
no squelch {normal | reduced}

Syntax Description
normal Allows normal capability.
reduced Allows extended 10BaseT capability.
Default

Normal range

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

The following example extends the twisted-pair 10BaseT capability on the cable attached to Ethernet interface 2:

interface ethernet 2
squelch reduced

test interface fastethernet

To test the Fast Ethernet interface by pinging itself, use the test interface fastethernet EXEC command.

test interface fastethernet number
Syntax Description
number Port, connector, or interface card number. On a Cisco 4500 or Cisco 4700 router, specifies the NPM number. The numbers are assigned at the factory at the time of installation or when added to a system, and can be displayed with the show interfaces command.
Command Mode

EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

This command sends pings from the specified interface to itself. Unlike the ping command, the test interface fastethernet command does not require the use of an IP address.

Example

The following example tests a Fast Ethernet interface on a Cisco 4500:

test interface fastethernet 0
Related Command

ping

test service-module

To perform self-tests on an integrated CSU/DSU installed in a Cisco 2524 or Cisco 2525 router, use the test service-module privileged EXEC command.

test service-module type number
Syntax Description
type Interface type.
number Interface number.
Command Mode

Privileged EXEC

Usage Guidelines

This command first appeared in Cisco IOS Release 11.2.

A series of tests are performed on the CSU/DSU, which include a ROM checksum test, RAM test, EEPROM checksum test, flash checksum test, and a DTE loopback with an internal pattern test. These self-tests are also performed at power on.

This command cannot be used if a DTE loopback, line loopback, or remote loopback is in progress.

Data transmission is interrupted for five seconds when you issue this command. To view the output of the most recent self-tests, enable the show service-module command.

Example

The following example displays the test service-module command:

Router#test service-module serial 0
SERVICE_MODULE(0): Performing service-module self test
SERVICE_MODULE(0): self test finished: Passed
Related Commands

clear counters
clear service-module
show service-module

timeslot

To enable framed mode serial interface on a G.703 E1 port adapter on an FSIP, use the timeslot interface configuration command. To restore the default, use the no form of this command or set the start slot to 0.

timeslot start-slot - stop-slot
no timeslot

Syntax Description
start-slot The first subframe in the major frame. Range is 1 to 31 and must be less than or equal to stop-slot.
stop-slot The last subframe in the major frame. Range is 1 to 31 and must be greater than or equal to start-slot.
Default

A G.703 E1 interface is configured for unframed mode.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to a Cisco 4000 router or Cisco 7000 series and Cisco 7500 series router. G.703 E1 interfaces have two modes of operation, framed and unframed. When in framed mode, the range from start-slot to stop-slot gives the number of 64-Kbps slots in use. There are 32 64-Kbps slots available.

Example

The following example enables framed mode on a serial interface on a G.703 E1 port adapter:

timeslot 1-3
Related Command

ts16

transmit-clock-internal

When a DTE does not return a transmit clock, use the transmit-clock-internal interface command to enable the internally generated clock on a serial interface on a Cisco 7000 series, Cisco 7200 series, or Cisco 7500 series. Use the no form of this command to disable the feature.

transmit-clock-internal
no transmit-clock-internal

Syntax Description

This command has no keywords or arguments.

Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

Example

In the following example, the internally generated clock is enabled on serial interface 3/0 on a Cisco 7000 series or Cisco 7200 series router:

interface serial 3/0
transmit-clock-internal

transmitter-delay

To specify a minimum dead-time after transmitting a packet, use the transmitter-delay interface configuration command. The no form of this command restores the default.

transmitter-delay {delay}
no transmitter-delay

Syntax Description
delay On the FSIP, HSSI, and on the IGS router, the minimum number of HDLC flags to be sent between successive packets. On all other serial interfaces and routers, approximate number of microseconds of minimum delay after transmitting a packet. The valid range is 0 to 131071.
Default

0 flags or microseconds

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command is especially useful for serial interfaces that can send back-to-back data packets over serial interfaces faster than some hosts can receive them.

The transmitter delay feature is implemented for the following Token Ring cards: CSC-R16, CSC-R16M, CSC-1R, CSC-2R, and CSC-CTR. For the first four cards, the command syntax is the same as the existing command and specifies the number of milliseconds to delay between sending frames that are generated by the router. Transmitter delay for the CSC-CTR uses the same syntax, but specifies a relative time interval to delay between transmission of all frames.

Example

The following example specifies a delay of 300 microseconds on serial interface 0:

interface serial 0
transmitter-delay 300

ts16

To control the use of time slot 16 for data on a G.703 E1 interface, use the ts16 interface configuration command. To restore the default, use the no form of this command.

ts16
no ts16

Syntax Description

This command has no arguments or keywords.

Default

Time slot 16 is used for signaling.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.3.

This command applies to a Cisco 4000 router or Cisco 7000 series and Cisco 7500 series router. By default, time slot 16 is used for signaling. Use this command to configure time slot 16 to be used for data. When in framed mode, in order to get all possible subframes or timeslots, you must use the ts16 command.

Example

The following example configures time slot 16 to be used for data on a G.703 E1 interface:

ts16
Related Command

timeslot

tunnel checksum

To enable encapsulator-to-decapsulator checksumming of packets on a tunnel interface, use the tunnel checksum interface configuration command. To disable checksumming, use the no form of this command.

tunnel checksum
no tunnel checksum

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 10.0.

This command currently applies to generic route encapsulation (GRE) only. Some passenger protocols rely on media checksums to provide data integrity. By default, the tunnel does not guarantee packet integrity. By enabling end-to-end checksums, the routers will drop corrupted packets.

Example

In the following example, all protocols will have encapsulator-to-decapsulator checksumming of packets on the tunnel interface:

tunnel checksum

tunnel destination

To specify the destination for a tunnel interface, use the tunnel destination interface configuration command. To remove the destination, use the no form of this command.

tunnel destination {hostname | ip-address}
no tunnel destination

Syntax Description
hostname Name of the host destination
ip-address IP address of the host destination expressed in decimal in four-part, dotted notation
Default

No tunnel interface destination is specified.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You cannot have two tunnels using the same encapsulation mode with exactly the same source and destination address. The workaround is to create a loopback interface and source packets off of the loopback interface.

Examples

The following example enables Cayman tunneling:

interface tunnel0
tunnel source ethernet0
tunnel destination 131.108.164.19
tunnel mode cayman

The following example enables GRE tunneling:

interface tunnel0
appletalk cable-range 4160-4160 4160.19
appletalk zone Engineering
tunnel source ethernet0
tunnel destination 131.108.164.19
tunnel mode gre ip
Related Commands

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

appletalk cable-range +
appletalk zone +
tunnel mode
tunnel source

tunnel key

To enable an ID key for a tunnel interface, use the tunnel key interface configuration command. To remove the ID key, use the no form of this command.

tunnel key key-number
no tunnel key

Syntax Description
key-number Integer from 0 to 4294967295
Default

Disabled

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command currently applies to generic route encapsulation (GRE) only. Tunnel ID keys can be used as a form of weak security to prevent misconfiguration or injection of packets from a foreign source.


Note When using GRE, the ID key is carried in each packet. We do not recommend relying on this key for security purposes.
Example

In the following example, the tunnel key is set to 3:

tunnel key 3

tunnel mode

To set the encapsulation mode for the tunnel interface, use the tunnel mode interface configuration command. To set to the default, use the no form of this command.

tunnel mode {aurp | cayman | dvmrp | eon | gre ip | nos}
no tunnel mode

Syntax Description
aurp AppleTalk Update Routing Protocol (AURP).
cayman Cayman TunnelTalk AppleTalk encapsulation.
dvmrp Distance Vector Multicast Routing Protocol.
eon EON compatible CLNS tunnel.
gre ip Generic route encapsulation (GRE) protocol over IP.
nos KA9Q/NOS compatible IP over IP.
Default

GRE tunneling

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0. (The aurp and dvmrp options first appeared in Cisco IOS Release 10.3.)

You cannot have two tunnels using the same encapsulation mode with exactly the same source and destination address. The workaround is to create a loopback interface and source packets off of the loopback interface.

Cayman tunneling implements tunneling as designed by Cayman Systems. This enables our routers to interoperate with Cayman GatorBoxes. With Cayman tunneling, you can establish tunnels between two routers or between our router and a GatorBox. When using Cayman tunneling, you must not configure the tunnel with an AppleTalk network address. This means that there is no way to ping the other end of the tunnel.

Use DVMRP when a router connects to a mrouted router to run DVMRP over a tunnel. It is required to configure Protocol-Independent Multicast (PIM) and an IP address on a DVMRP tunnel.

Generic route encapsulation (GRE) tunneling can be done between our routers only. When using GRE tunneling for AppleTalk, you configure the tunnel with an AppleTalk network address. This means that you can ping the other end of the tunnel.

Examples

The following example enables Cayman tunneling:

interface tunnel 0
tunnel source ethernet 0
tunnel destination 131.108.164.19
tunnel mode cayman

The following example enables GRE tunneling:

interface tunnel 0
appletalk cable-range 4160-4160 4160.19
appletalk zone Engineering
tunnel source ethernet0
tunnel destination 131.108.164.19
tunnel mode gre ip
Related Commands

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

appletalk cable-range +
appletalk zone +
tunnel destination
tunnel source

tunnel sequence-datagrams

To configure a tunnel interface to drop datagrams that arrive out of order, use the tunnel sequence-datagrams interface configuration command. To disable this function, use the no form of this command.

tunnel sequence-datagrams
no tunnel sequence-datagrams

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 10.0.

This command currently applies to generic route encapsulation (GRE) only. This command is useful when carrying passenger protocols that behave poorly when they receive packets out of order (for example, LLC2-based protocols).

Example

In the following example, the tunnel is configured to drop datagrams that arrive out of order:

tunnel sequence-datagrams

tunnel source

To set a tunnel interface's source address, use the tunnel source interface configuring command. To remove the source address, use the no form of this command.

tunnel source {ip-address | type number}
no tunnel source

Syntax Description
ip-address IP address to use as the source address for packets in the tunnel.
type Interface type.
number Specifies the port, connector, or interface card number. The numbers are assigned at the factory at the time of installation or when added to a system, and can be displayed with the show interfaces command.
Default

No tunnel interface's source address is set.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

You cannot have two tunnels using the same encapsulation mode with exactly the same source and destination address. The workaround is to create a loopback interface and source packets off of the loopback interface.

When using tunnels to Cayman boxes, you must set the tunnel source to an explicit IP address on the same subnet as the Cayman box, not the tunnel itself.

Examples

The following example enables Cayman tunneling:

interface tunnel0
tunnel source ethernet0
tunnel destination 131.108.164.19
tunnel mode cayman

The following example enables GRE tunneling:

interface tunnel0
appletalk cable-range 4160-4160 4160.19
appletalk zone Engineering
tunnel source ethernet0
tunnel destination 131.108.164.19
tunnel mode gre ip
Related Commands

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

appletalk cable-range +
appletalk zone +
tunnel destination

tx-queue-limit

To control the number of transmit buffers available to a specified interface on the MCI and SCI cards, use the tx-queue-limit interface configuration command.

tx-queue-limit number
Syntax Description
number Maximum number of transmit buffers that the specified interface can subscribe.
Default

Defaults depend on the total transmit buffer pool size and the traffic patterns of all the interfaces on the card. Defaults and specified limits are displayed with the show controllers mci EXEC command.

Command Mode

Interface configuration

Usage Guidelines

This command first appeared in Cisco IOS Release 10.0.

This command should be used only under the guidance of a technical support representative.

Example

The following example sets the maximum number of transmit buffers on the interface to 5:

interface ethernet 0
tx-queue-limit 5
Related Command

show controllers mci

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