Refer to the exhibit. On this MPLS-based networking ring, links have failed between router A and router E. These failures formed microloops while the network converged, when A forwarded traffic to…

Standard Loop-Free Alternate is limited to directly connected neighbors as repair nodes; in a ring topology this often leaves nodes on the far side of a failure without a qualifying loop-free alternate.

Remote LFA extends standard LFA by using existing LDP-signaled tunnels to reach a PQ node beyond the immediate neighbor, giving loop-free repair coverage for destinations that a standard LFA cannot protect - a common gap in ring topologies. Because LDP is already running in an MPLS network, RLFA does not require enabling any new protocol, making it the simplest viable solution.

IP Fast ReRoute is the overarching framework that encompasses both LFA and RLFA; selecting it as an answer does not identify the specific mechanism that solves ring-topology microloops without a new protocol.

TE Fast ReRoute requires a full MPLS Traffic Engineering deployment including RSVP-TE, which constitutes enabling a new protocol and is therefore not the simplest solution.