This case study describes 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 chapter includes a brief summary of the FRR problem within the context of an MPLS-based VPN, an example network scenario, and commands to troubleshoot and resolve the problem.
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.
