Symptom
The TI-LFA backup path provisioned by OSPF has invalid label stack and causes problems for the forwarding entry in very specific cases
Conditions
This problem is hit ONLY when ALL of the following conditions are true:
- OSPF SR is enabled along with TI-LFA
- both the primary and TI-LFA backup paths do not have LDP enabled but LDP is enabled on some other interfaces on the router
- the TI-LFA repair path consists of a single PQ remote node which is not SR enabled but is running LDP
Workaround
Any change in config or topology so that any of the above conditions can be avoided
Further Problem Description
This issue is applicable for all XR platforms with releases 6.1.3 or later until this fix is integrated.
