interface loopback

[hungxuyen17]

Hi all!
I want config interface loopback. Can you please provide sample config commands

[andykai]

Hi you can add another loopback interface by adding loopback in the interface configuration
e.g:

configure
router
interface "loop1"
address 10.10.10.1/32
loopback
exit
exit

[khaledsaadeh1]

i have configure the loopback interface on SR7750 and insert that interface under MPLS but the MPLS stay down ,like below

A:SR1-TAR# show router mpls interface

==============================================================================
MPLS Interfaces
==============================================================================
Interface Port-id Adm Opr TE-metric
------------------------------------------------------------------------------
system system Up Up None
Admin Groups None
Srlg Groups None
CR1 1/1/1 Up Up None
Admin Groups None
Srlg Groups None
CR2 2/1/1 Up Up None
Admin Groups None
Srlg Groups None
Loopback 0 loopback Up Down None
Admin Groups None
Srlg Groups None
------------------------------------------------------------------------------
Interfaces : 4
==============================================================================

[thecandymancan]

What release are you using? I just created one and mine says Oper N/A (same goes for RSVP interfaces).

Are you trying to terminate an LSP on the loopback address as opposed to the system address? If you're doing LDP over RSVP remember the 7750 will only advertise LDP labels for the system address only by default.

MPLS Interfaces
===============================================================================
Interface Port-id Adm Opr TE-metric

loop1 loopback Up N/A None
Admin Groups None
Srlg Groups None

show router rsvp interface

===============================================================================
RSVP Interfaces
===============================================================================
Interface Total Active Total BW Resv BW Adm Opr
Sessions Sessions (Mbps) (Mbps)
loop1 0 0 100 0 Up N/A

[erwin]

Hi All,

I found this message when i am trying to add port on a loopback interface:

A:LAB# configure router interface "lo0"
*A:LAB>config>router>if# port 1/2/10
INFO: PIP #1323 Cannot modify the port binding, remove the port binding first
*A:LAB>config>router>if#

could we add port on a loopback interface?

[zeips]

not sure if its possible but also not sure why would u ever want to add port to the loopback interface?
anyway, issue this: show router interface | m 1/2/10
and verify if this port is already added to other interface, if yes then removed it and try again

[erwin]

not sure if its possible but also not sure why would u ever want to add port to the loopback interface?
anyway, issue this: show router interface | m 1/2/10
and verify if this port is already added to other interface, if yes then removed it and try again

i'm only curious what is the differences between system and loopback interface on ALU.

[Stoffen]

not sure if its possible but also not sure why would u ever want to add port to the loopback interface?
anyway, issue this: show router interface | m 1/2/10
and verify if this port is already added to other interface, if yes then removed it and try again

i'm only curious what is the differences between system and loopback interface on ALU.

The system interface is used by all routing protocols as default source, or destination for MPLS tunnels.
Until the latest SR releases, a MPLS tunnel's far end must be the system address.

But the difference of a "interface loopback0" with the loopback argument added, and "interface system" is close to none.

The system interface is a fullblown loopback, but an interface a lot of the OS are depended upon.