I have reviewed this document as part of the security directorate's ongoing effort to review all IETF documents being processed by the IESG. These comments were written primarily for the benefit of the security area directors. Document editors and WG chairs should treat these comments just like any other last call comments.

The document specifies how Topology Independent Loop-Free Alternate mechanisms with Multicast Only Fast ReRoute can be used with Protocol Independent Multicast (PIM) to allow selecting backup routes in complex topologies.

I'm not an expert in routing (in particular in multicast routing), but to my best understanding of the described technology, the Security Considerations section accurately describes all new security concerns that could raise due this technology and provides reasonable measures to mitigate them.