JUNOSe 9.1.x Command Reference Guide A to M > I Commands > interface loopback

interface loopback

Description: 

Defines a loopback interface, which 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. The no version deletes the loopback interface.

NOTE: Do not confuse loopback with the null 0 interface. Traffic routed to null 0 is discarded on the line module.

Syntax: 

[ no ] interface loopback interfaceSpecifier

• interfaceSpecifier—Particular interface; format varies according to interface type; see Interface Types and Specifiers in About This Guide

Mode(s): 

Global Configuration

    Release Information    Command introduced before JUNOSe Release 7.1.0.

    Related Topics    

• Configuring an MPLS Pseudowire with VCC Cell Relay Encapsulation
• Configuring Local ATM Cross-Connects with AAL5 Encapsulation
• Configuring Local Cross-Connects Between Ethernet/VLAN Interfaces
• Configuring the Loopback Interface and Router ID for BGP for L2VPNs
• Configuring the Loopback Interface and Router ID for VPLS