How to Configure MPLS LDP Session Protection• Enabling MPLS LDP Session Protection, page 33
• Verifying MPLS LDP Session Protection, page 35
• Troubleshooting Tips, page 36
Enabling MPLS LDP Session Protection
You use the mpls ldp session protection command to enable MPLS LDP Session Protection. This command
enables LDP sessions to be protected during a link failure. By default, the command protects all LDP
sessions. The command has several options that enable you to specify which LDP sessions to protect. The
vrfkeyword lets you protect LDP sessions for a specified VRF. The for keyword lets you specify a
standard IP access control list (ACL) of prefixes that should be protected. The duration keyword enables
you to specify how long the router should retain the LDP Targeted Hello Adjacency following the loss of
the LDP Link Hello Adjacency.
LSRs must be able to respond to LDP targeted hellos. Otherwise, the LSRs cannot establish a targeted
adjacency. All routers that participate in MPLS LDP Session Protection must be enabled to respond to
targeted hellos. Both neighbor routers must be configured for session protection or one router must be
configured for session protection and the other router must be configured to respond to targeted hellos.
SUMMARY STEPS
1. enable
2. configure terminal
3. ip cef [distributed]
4. interface loopback number
5. ip address {prefix mask}
6. interface interface
7. mpls ip
8. mpls label protocol {ldp | tdp | both}
9. exit
10.mpls ldp session protection [vrf vpn-name] [for acl] [duration seconds]
DETAILED STEPS
Command or Action Purpose
Step 1 enable
Example:
Router> enable
Enables privileged EXEC mode.
• Enter your password if prompted.
Enabling MPLS LDP Session Protection
How to Configure MPLS LDP Session Protection
MPLS LDP Configuration Guide, Cisco IOS Release 12.4
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