•What is RPF?
•A router forwards a
multicast datagram only if received on the up stream interface to
the source (i.e. it follows the distribution tree).
•The RPF Check
•The source IP address of
incoming multicast packets are checked against a unicast
routing table.
•If the datagram arrived
on the interface specified in the
routing table for the
source address; then the RPF check
succeeds.
•Otherwise, the RPF Check
fails.