4000 Router Series Interface Command Reference

Field Description

Link

Physical link state of the interface:

• UP—The link is up.

• ADM—The link has been administratively shut down. To

recover its physical state, perform the undo shutdown

command.

Protocol Protocol connection state of the interface: UP or DOWN.

Main IP Main IP address of the interface.

Description Description of the interface.

Cause

Cause of a DOWN physical link. If the port has been shut down

with the shutdown command, this field displays Administratively.

To restore the physical state of the interface, use the undo

shutdown command. Not connected means no physical

connection (no cable is available or the cable is faulty).

Related commands

reset counters interface

display interface serial

Use display interface serial to display information about serial interfaces.

Syntax

display interface [ serial ] [ brief [ down | description ] ]

display interface [ serial [ interface-number ] ] [ brief [ description ] ]

Views

Any view

Predefined user roles

network-admin

network-operator

Parameters

interface-number: Specifies a serial interface by its number.

brief: Displays brief interface information. If you do not specify this keyword, the command displays

detailed interface information.

down: Displays information about interfaces in physically DOWN state and the causes. If you do not

specify this keyword, this command displays information about interfaces in all states.

description: Displays complete interface descriptions. If you do not specify this keyword, the command

displays only the first 27 characters of interface descriptions.

Usage guidelines

If you do not specify the serial keyword, this command displays information about all interfaces on the

device.