Which description is true about how remote IP Fast Reroute addresses failures in the ring topologies?
Click on the arrows to vote for the correct answerA. B. C. D. E. F.
Remote IP Fast Reroute (FRR) is a mechanism used to address failures in ring topologies. It is a feature that is commonly used in MPLS-based networks. In the event of a failure in a ring topology, Remote IP Fast Reroute provides a mechanism to quickly redirect traffic to a backup path.
Out of the given options, B is the correct answer. Routers in the ring topology establish an MPLS TE tunnel with both edge ring routers. This MPLS TE tunnel is used as a backup path in the event of a failure in the ring.
When the ring topology is operational, traffic flows around the ring in a clockwise or anti-clockwise direction. When a failure occurs, the MPLS TE tunnel is used as a backup path. This backup path bypasses the failed link or node and restores the connectivity.
Option A is incorrect because targeted LDP session is used for label distribution and not for providing backup path in case of failures. Option C is incorrect because GRE tunnels are not used in MPLS-based networks. Option D is incorrect because establishing a GRE tunnel with the closest PQ node in the ring does not provide a backup path for the entire ring topology. Option E is incorrect because establishing a targeted LDP session with the closest router that is in a PQ space does not provide a backup path for the entire ring topology. Option F is incorrect because establishing an MPLS TE tunnel with all PQ nodes in the ring is not necessary and may result in inefficient use of network resources.