Nokia Exam 4A0-116 Topic 3 Question 15 Discussion

The exhibit shows that both R-LFA and TI-LFA have been enabled on router R1. R-LFA (Remote Loop-Free Alternate) is a method that is used to protect the active segment of a tunnel, and it allows the router to find a backup path that coincides with the path that will become active after IGP reconvergence. TI-LFA (Topology Independent LFA) is a method that is used to protect an end-to-end multi-segment tunnel, it allows the router to find a backup path that does not rely on the IGP topology, but on the segment routing topology.

With R-LFA and TI-LFA enabled, router R1 will use a D-LFA (Dual-Loop-Free Alternate) path, which is a combination of both R-LFA and TI-LFA, this path will coincide with the path after IGP re-convergence.

A standard LFA, R-LFA, and D-LFA which do not coincide with the path after IGP re-convergence are not the options.