Multicast traffic received by a subnet that uses IGMP/PIM snooping may be efficiently processed so that only required multicast router interfaces are used. A router may, for example, receive a source-specific PIM join/prune message indicating that a multicast receiver of the multicast traffic is to join/leave a multicast group to receive/stop traffic from a multicast source; determine whether the router is a first hop router relative to a subnet of the multicast source; and forward, when the router is a first hop router relative to the subnet of the multicast source and is a non-designated router, the source-specific PIM join/prune message towards the subnet.