Corresponding Multilink interfaces

Unanswered Question
Nov 13th, 2007
User Badges:

I have an MLPPP link between a 7200 and a 2811 router over 2 T1 lines. One of the T1 lines is showing errors on the 2811 side. The catch is whoever setup the 2811 router did not label the serial interfaces with the circuit ID's. Is there any way to determine which T1 is which from the 7200 side without actually shutting down one of the interfaces?

  • 1
  • 2
  • 3
  • 4
  • 5
Overall Rating: 0 (0 ratings)
Edison Ortiz Tue, 11/13/2007 - 10:51
User Badges:
  • Super Bronze, 10000 points or more
  • Hall of Fame,

    Founding Member

You can do a show cdp neighbor detail and the output should list the source and destination interface.

erik.kneebone Tue, 11/13/2007 - 11:05
User Badges:

It doesn't, it only shows it through the Mulitlink interface. CDP is turned on from the global config. Here is that output for the multilink group:

Multilink2, bundle name is XXXXX

Bundle up for 6w3d, 87/255 load

Receive buffer limit 24384 bytes, frag timeout 1000 ms

0/0 fragments/bytes in reassembly list

0 lost fragments, 7141161 reordered

0/0 discarded fragments/bytes, 0 lost received

0x21349B received sequence, 0x1D557C sent sequence

Member links: 2 active, 0 inactive (max not set, min not set)

Se1/0/12:0, since 6w3d

Se1/0/13:0, since 6w3d

And the show cdp command:

Scotthead#show cdp neighbors Serial1/0/12:0 detail

Scotthead#show cdp neighbors multilink2 detail


Device ID: XXXXX

Entry address(es):

IP address: x.x.x.x

Platform: Cisco 2811, Capabilities: Router Switch IGMP

Interface: Multilink2, Port ID (outgoing port): Multilink1

Holdtime : 155 sec

Version :

Cisco IOS Software, 2800 Software (C2800NM-IPBASE-M), Version 12.4(3g), RELEASE SOFTWARE (fc2)

Technical Support:

Copyright (c) 1986-2006 by Cisco Systems, Inc.

Compiled Mon 06-Nov-06 02:36 by alnguyen

advertisement version: 2

VTP Management Domain: ''

CDP itself is turned on from the global config, maybe setting it on the specific interfaces?

Edison Ortiz Tue, 11/13/2007 - 11:22
User Badges:
  • Super Bronze, 10000 points or more
  • Hall of Fame,

    Founding Member

Hmm.. interesting --- yeah, I'm afraid bouncing the interface is the only other option I can think of...


This Discussion