In IP multicast, RPF routes can be elected only from among unicast routes and multicast...

RPF (Reverse Path Forwarding) checks are used to prevent multicast loops. An RPF check uses the unicast routing table (or multicast static routes , if configured) to determine the correct incoming interface for a multicast packet.

Multicast protocols like PIM use the RPF mechanism , and the unicast routing table is the primary reference.

Multicast dynamic routing protocols do not maintain their own separate tables for RPF by default.

Reference from Huawei HCIP-Datacom-Core Technology Study Guide:

“RPF checks are performed using the unicast routing table or multicast static routes. The interface through which the multicast source is reachable is considered valid for RPF.”

(Chapter: Multicast – Section: RPF Principle)