Refer to the exhibit. As part of a redesign project, you must predict multicast behavior. What happens to the multicast traffic received on the shared tree (,G), if it is received on the LHR…

The RPF check for (*,G) shared tree traffic is performed against the RP address, not the multicast source address, so an RPF failure tied to the source is not applicable here.

An RPF check IS performed on (*,G) shared tree traffic - it verifies the traffic arrived on the RPF interface toward the RP - so traffic is never switched without an RPF check.

On a PIM-SM shared tree (*,G), the router performs an RPF check by consulting the unicast routing table to find the best path toward the Rendezvous Point (RP), not the multicast source. If the multicast traffic arrives on the interface that the router would use to reach the RP, the RPF check succeeds and traffic is switched downstream. This is the fundamental difference between shared tree (*,G) and source tree (S,G) RPF behavior.

RPF checks are never performed against the multicast receiver; they verify the reverse path toward either the RP (shared tree) or the source (source tree) to prevent forwarding loops.