Troubleshooting Mpls - 3Com MSR 50 Series Configuration Manual

Troubleshooting MPLS

[RouterC] mpls
[RouterC-mpls] lsp-trigger all
[RouterC-mpls] quit
After completing the above configurations, you will see the LSPs established when
you execute the display mpls ldp lsp command. The following takes Router A as
an example:
[RouterA] display mpls ldp lsp
-------------------------------------------------------------------
SN DestAddress/Mask
------------------------------------------------------------------
1 1.1.1.9/32
2 2.2.2.9/32
3 3.3.3.9/32
4 20.1.1.0/24
-------------------------------------------------------------------
A '*' before an LSP means the LSP is not established
A '*' before a Label means the USCB or DSCB is stale
Symptom
An interface with LDP enabled cannot establish an LDP session with its peer.
Analysis
An LDP session is established in two steps: establishing the TCP connection;
initializing the session and negotiating the session parameters. Failure in either of
the steps will lead to the failure of LDP session establishment.
The TCP connection established uses LSR ID as the address by default. Therefore, if
you do not configure the mpls ldp transport-address command, the route to
the address of LSR ID must be advertised to the peer.
Solution:
Check whether the current LSR has obtained the route to the LSR ID of the
■
peer by issuing the display ip routing-table command.
Check whether the label advertisement mode configured locally is the same as
■
that configured for the peer using the display mpls ldp interface command.
If not, use the mpls ldp advertisement command to correct the
■
configuration.
LDP LSP Information
In/OutLabel Next-Hop
3/NULL 127.0.0.1
NULL/3 10.1.1.2
NULL/1025 10.1.1.2
NULL/3 10.1.1.2
Troubleshooting MPLS 1343
In/Out-Interface
Ser1/0/InL0
-------/Ser1/0
-------/Ser1/0
-------/Ser1/0