Explanation
Reverse path forwarding (RPF) mechanisms are used to prevent loops and duplicate packets in multicast deployments [1]. The RPF check verifies that all multicast traffic received on a router is sourced from the expected direction, ensuring that multicast traffic is not looped back in the network. The RPF check works by comparing the source IP address of a multicast packet with the routing table, and only forwarding it if it matches the expected entry.