Table Of Contents

Null Interface Commands on Cisco IOS XR Software

interface null 0

show controllers null interface

Null Interface Commands on Cisco IOS XR Software

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This module describes the Cisco IOS XR commands used to configure null interfaces.

interface null 0

To enter null0 interface configuration mode, use the interface null 0 command in global configuration mode.

interface null 0

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

Global configuration

Command History

Release	Modification
Release 2.0	This command was introduced on the Cisco CRS-1.
Release 3.0	No modification.
Release 3.2	This command was first supported on the Cisco XR 12000 Series Router.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

When you issue the interface null 0 command in global configuration mode, the CLI prompt changes to "config-null0," indicating that you have entered interface configuration mode for the null interface. In the following sample output, the question mark (?) online help function displays all the commands available under the interface configuration mode for the null interface:

RP/0/RP0/CPU0:router(config)# interface null 0

RP/0/RP0/CPU0:router(config-null0)#?

  commit    Commit the configuration changes to running

  describe  Describe a command without taking real actions

  do        Run an exec command

  exit      Exit from this submode

  no        Negate a command or set its defaults

  show      Show contents of configuration

RP/0/RP0/CPU0:CRS-8_P1(config-null0)#

Task ID

Task ID	Operations
interface	read, write

Examples

The following example shows how to enter null0 interface configuration mode:

RP/0/RP0/CPU0:router(config)# interface null 0

RP/0/RP0/CPU0:router(config-null0)#

show controllers null interface

To display null interface counters, use the show controllers null interface command in EXEC mode.

show controllers null interface

Syntax Description

This command has no arguments or keywords.

Defaults

No default behavior or values

Command Modes

EXEC

Command History

Release	Modification
Release 3.0	This command was first introduced on the Cisco CRS-1.
Release 3.2	This command was first supported on the Cisco XR 12000 Series Router.
Release 3.3.0	No modification.
Release 3.4.0	No modification.
Release 3.5.0	No modification.

Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Task ID

Task ID	Operations
interface	read
sysmgr	read

Examples

The following is sample output from the show controllers null interface command, which displays null interface counters:

RP/0/RP0/CPU0:router#show controllers null interface

Null interface:

name     : Null0

handle   : 0x00080010

rx_count : 0

tx_count : 0

drops    : 0

.

Table 51 describes the significant fields shown in the display.

Table 51 show controllers null interface Field Descriptions

Field	Description
name	Interface whose controller information is displayed.
handle	Number that identifies the caps node that hosts the node whose controller information is displayed.
rx_count	Total number of packets currently received by the interface.
tx_count	Total number of packets currently transmitted by the interface.
drops	Total number of packets dropped by the interface.

Related Commands

Command	Description
show interfaces	Displays statistics for all interfaces configured on the router.