Explains how LFA-based fast reroute provides rapid traffic recovery through local and remote backup paths, repair path selection, and protocol support in IS-IS and OSPF.
This chapter describes how LFA-based fast reroute operates, how backup paths are calculated, and how routing protocols such as IS-IS and OSPF support local and remote LFA implementations, including repair path selection and loop prevention.
Fast reroute with local loop-free alternate
Explains how loop-free alternate fast reroute protects traffic by calculating backup paths and redirecting packets quickly around failed links or nodes through remote alternates.
FRR recirculation avoidance
Explains how the Fast Reroute recirculation avoidance mechanism eliminates packet recirculation during failover events, and describes its benefits for PE router deployments by improving bandwidth efficiency, preserving line-rate throughput, and reducing congestion and traffic loss during successive FRR events.
Fast reroute with remote loop-free alternate
Describes how remote LFA tunnels traffic to a precomputed backup node more than one hop away to minimize loss during failures and speed recovery.