Summary

This chapter combined the previously explored concepts of TI-LFA node protection and TI-LFA SRLG protection, aiming to provide a comprehensive backup path solution that integrates both protection mechanisms. When a link or node failure occurs, TI-LFA on the PLR calculates an alternative path that bypasses not only the next-hop router but also local SRLGs, ensuring continuous traffic forwarding.

Building upon the preceding chapter where Global Weighted SRLG protection was removed from router P2 while local SRLG-disjoint protection remained configured, TI-LFA node protection was subsequently enabled on this router. This configuration instructed TI-LFA on P2 to compute backup paths that incorporate both node and SRLG protection. The outputs from the RIB, FIB, and LFIB confirmed that in the event of a failure on the P2–P3 link, the rerouted path through P6, P7, and P4 successfully provided backup connectivity.

During the examination of the RIB, it was observed that...