This checklist provides the steps and commands to troubleshoot a problem establishing Fast Reroute (FRR) link protection in a Multiprotocol Label Switching (MPLS)-based VPN. Specifically, FRR requires a load balancing policy for the correct installation of routes in the forwarding table and fast local repair. The principles and solution used in this case study apply to all forms of local protection. For an overview of local protection, see Local Protection in an MPLS Network.The checklist provides links to a brief summary of the FRR problem within the context of an MPLS-based VPN, an example network scenario, and more details about commands used to troubleshoot and resolve the problem. (See Table 11
The troubleshooting process described in this case study should not be followed rigidly; it is a basis from which you can develop your own process to suit your particular situation.
Table 11: Troubleshooting Fast Reroute Checklist
Tasks |
Command or Action |
|---|---|
| Fast Reroute Problem Overview |
|
| Symptom | Local repair is taking about one second) to complete, which is slow. show route forwarding-table extensive |
| Cause | The forwarding table does not include the necessary next-hops to support local repair. |
| Troubleshooting Commands | show configuration routing-instances routing-instance-name
|
Enable load-balancing and ensure that multiple next-hop forwarding table entries appear in the forwarding table for each destination. show configuration policy-options |
|
| Conclusion | A load balancing policy is required for link protection to work effectively. The principles are the same for the configuration of the fast reroute and the node-link-protection statements. |
| Router Configurations | show configuration | no-more |
