Using A Loopback Interface - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - SYSTEM BASICS CONFIGURATION GUIDE 2010-10-04 Configuration Manual

JunosE 11.3.x System Basics Configuration Guide

Using a Loopback Interface

interface loopback
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Use to display information about the interface that the current virtual router uses to
exchange messages with the NFS server.
Field descriptions
Source address—IP address of the interface that the current virtual router uses to
exchange messages with the NFS server.
Source interface—Type and specifier of the interface that the current virtual router
uses to exchange messages with the NFS server. For information about interface
types and specifiers, see Interface Types and Specifiers in JunosE Command Reference
Guide.
Example
host1#show ip nfs
Source address is 1.1.1.1
See show ip nfs.
The loopback interface provides a stable address for protocols (for example, BGP, Telnet,
or LDP) to use so that they can avoid any impact if a physical interface goes down.
The loopback interface sends packets back to the router or access server for local
processing. Any packets routed from the loopback interface, but not destined to the
loopback interface, are dropped.
NOTE: Do not confuse loopback with the null 0 interface. Traffic routed to
null 0 is discarded on the line module.
The no version deletes the loopback interface.
Use to access and configure the loopback interface.
Provides a stable address to minimize impact of a physical interface going down.
Example
host1(config)#interface loopback 20
host1(config-if)#ip address 10.10.20.5 255.255.255.254
Use the no version to delete the loopback interface.
See interface loopback.
Copyright © 2010, Juniper Networks, Inc.