BGP

[The_guroo_2]

guys when we config loopback addresses i have seen we normally use /32 mask like 1.1.1.1 255.255.255.255 why not normal mask....thanks in advance

[mohammedmahmoud]

Hi,

A simple answer would be that the loopback interface is a logical interface, with no adjacent interfaces on the same subnet (no connected interfaces on its data-link), and thus no mean for using more than a /32 for it.

BR,

Mohammed Mahmoud.

[Giuseppe Larosa]

Hello,

one case when a network mask different from /32 could be used is when the loopback is used to advertise a nat pool of addresses in a routing protocol.

In a MPLS environment a /32 is mandatory because the loopback address is the node identifier for MPLS TE

best regards

Giuseppe

[cisco_lad2004]

I second Giusessepe with regards to MPLS, and add that you also want to save ip addresses even the private ones.

HTH

Sam