vRtrPimNgIfRxNbrUnknown 1.3.6.1.4.1.6527.3.1.2.50.2.6.1.11

The value of vRtrPimNgIfRxNbrUnknown indicates the number of PIM messages (other than Hello messages) which were received on this interface and were rejected because the adjacency with the neighbor router was not already established.