vrIpMcastFwdReversePathForwardingNeighbor 1.3.6.1.4.1.562.2.4.1.100.6.26.6.10.1.5

This attribute indicates the address of the upstream neighbor (RPF neighbor) from which IP datagrams from these sources to this multicast address are received, or 0.0.0.0 if the upstream is unknown (e.g., in CBT).