Description

This article explains steps taken to bring up l2circuit pseudowire between two peers.

Symptoms

L2circuit is down with remote peer 192.168.1.1 Status is showing as OL - no outgoing label

user@router> show l2circuit connections 

Layer-2 Circuit Connections:

Legend for connection status (St)  

EI -- encapsulation invalid   NP -- interface h/w not present  

MM -- mtu mismatch        Dn -- down            

EM -- encapsulation mismatch   VC-Dn -- Virtual circuit Down   

CM -- control-word mismatch   Up -- operational         

VM -- vlan id mismatch      CF -- Call admission control failure

OL -- no outgoing label     IB -- TDM incompatible bitrate 

NC -- intf encaps not CCC/TCC  TM -- TDM misconfiguration 

BK -- Backup Connection     ST -- Standby Connection

CB -- rcvd cell-bundle size bad SP -- Static Pseudowire

LD -- local site signaled down  RS -- remote site standby

RD -- remote site signaled down HS -- Hot-standby Connection

XX -- unknown



Legend for interface status  

Up -- operational       

Dn -- down          

Neighbor: 192.168.1.1

  Interface         Type St   Time last up     # Up trans

  et-0/1/9:1.0(vc 1000)  rmt  OL  

 

 

  • Check configuration for L2circuit. Verify peer IP and VC-ID.

 

 

set interfaces et-0/1/9:1 mtu 9114

set interfaces et-0/1/9:1 encapsulation ethernet-ccc

set interfaces et-0/1/9:1 unit 0 family ccc

set protocols l2circuit neighbor 192.168.1.1 interface et-0/1/9:1.0 virtual-circuit-id 1000

set protocols l2circuit neighbor 192.168.1.1 interface et-0/1/9:1.0 encapsulation-type ethernet

 

 

  • Verify configuration for this l2circuit on remote peer 192.168.1.1. VC-ID should be same. In this case, configuration for l2circuit was correct.

 

  • Verify if targeted LDP session is established with remote peer. In below output, we don't see LDP neighborship with 192.168.1.1

 

 

user@router> show ldp neighbor brief 

Address               Interface    Label space ID   Hold time

192.168.10.1           ae1.0      10.10.1.1:0   12

192.168.20.1           ae10.0     10.20.1.1:0    12

192.168.30.1          ae15.0     10.30.1.1:0    12

 

 

 

Solution

  • In this case, "show ldp neighbor" output shows neighborship is not established with remote peer.
  • Verified the configuration for protocol ldp and checked that loopback 0 interface was not configured in protocol ldp.
  • After adding loopback 0 in ldp, neighborship came up with remote peer.
user@router#set protocols ldp interface lo0.0 

user@router#commit



user@router> show ldp neighbor brief 



Address               Interface    Label space ID   Hold time

192.168.10.1           ae1.0      10.10.1.1:0   12

192.168.20.1           ae10.0     10.20.1.1:0    12

192.168.30.1          ae15.0     10.30.1.1:0    12

10.10.10.1           lo0.0      192.168.1.1    44

 Note: LDP requires the loopback interface (lo0) to be configured.

 

 

  • L2circuit came up after adding above configuration.

 

user@router> show l2circuit connections 

Layer-2 Circuit Connections:

Legend for connection status (St)  

EI -- encapsulation invalid   NP -- interface h/w not present  

MM -- mtu mismatch        Dn -- down            

EM -- encapsulation mismatch   VC-Dn -- Virtual circuit Down   

CM -- control-word mismatch   Up -- operational         

VM -- vlan id mismatch      CF -- Call admission control failure

OL -- no outgoing label     IB -- TDM incompatible bitrate 

NC -- intf encaps not CCC/TCC  TM -- TDM misconfiguration 

BK -- Backup Connection     ST -- Standby Connection

CB -- rcvd cell-bundle size bad SP -- Static Pseudowire

LD -- local site signaled down  RS -- remote site standby

RD -- remote site signaled down HS -- Hot-standby Connection

XX -- unknown



Legend for interface status  

Up -- operational       

Dn -- down          

Neighbor: 192.168.1.1 

  Interface         Type St   Time last up     # Up trans

  et-0/1/9:1.0(vc 1000)  rmt  Up   Jun 11 07:03:50 2024      1

   Remote PE: 192.168.1.1, Negotiated control-word: Yes (Null)

   Incoming label: 155559, Outgoing label: 25053

   Negotiated PW status TLV: No

   Local interface: et-0/1/9:1.0, Status: Up, Encapsulation: ETHERNET

   Flow Label Transmit: No, Flow Label Receive: N

 

 

 

Modification History

2024-06-12 : Article Created