Sorry from my side , as i think i made some confusion here !! . Ok , there is unicast route back to the source.But that is not relevent here. My question is how i can prevent multicast to be forwarded by RP even if there is no RPF neighborship back to the source. I can see that multicast is forwarded by using source register msg which will be process switched. That means there is no native multicast from source up to the RP in order to forward streams. So if the source is from an unknown unicast address  , how RP can stop forwarding multicast towards the client . Thanks, Anil. ... View more

There is no RPF interface for this source inorder to send reg stop msg. Here RP will fail in RPF lookup for this source. If RP know how to perform RPF lookup for this source then there is no  problems and in such case multicast will work fine. ... View more

RPF lookup will not be performed for the unicast source reg msg. Once RP decapsulate uni source reg msg then (S,G) entry will be installed and will use that entry to forward the traffic only if the incoming interface is NOT null (ie. pass RPF lookup). But the strange thing is even (S,G) is installed with incoming int as Null and i can see multicast packet is forwarding. After doing more debugs, i say that packet is forward from source up to the RP by uni reg ms, which is strange ans must not happen. I think this is some technology limitation or a grey area. Please check the output from RP ( No SPT is built in this design, only using shared tree) CE#sh ip mroute IP Multicast Routing Table Flags: D - Dense, S - Sparse, B - Bidir Group, s - SSM Group, C - Connected,        L - Local, P - Pruned, R - RP-bit set, F - Register flag,        T - SPT-bit set, J - Join SPT, M - MSDP created entry, E - Extranet,        X - Proxy Join Timer Running, A - Candidate for MSDP Advertisement,        U - URD, I - Received Source Specific Host Report,        Z - Multicast Tunnel, z - MDT-data group sender,        Y - Joined MDT-data group, y - Sending to MDT-data group,        V - RD & Vector, v - Vector Outgoing interface flags: H - Hardware switched, A - Assert winner Timers: Uptime/Expires Interface state: Interface, Next-Hop or VCD, State/Mode (*, 239.195.0.3), 00:09:55/00:03:22, RP 9.9.9.9, flags: S Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list:    Tunnel102, Forward/Sparse, 00:09:55/00:03:22 (10.0.183.2, 239.195.0.3), 00:09:38/00:03:29, flags: Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list:    Tunnel102, Forward/Sparse, 00:09:38/00:03:22 (172.21.36.2, 239.195.0.3), 00:09:38/00:03:29, flags: Incoming interface: Null, RPF nbr 0.0.0.0 Outgoing interface list:    Tunnel102, Forward/Sparse, 00:09:38/00:03:22 CE#sh ip rpf 10.0.183.2 failed, no route exists CE#sh ip mroute count Use "show ip mfib count" to get better response time for a large number of mroutes. IP Multicast Statistics 3 routes using 1578 bytes of memory 1 groups, 2.00 average sources per group Forwarding Counts: Pkt Count/Pkts per second/Avg Pkt Size/Kilobits per second Other counts: Total/RPF failed/Other drops(OIF-null, rate-limit etc) Group: 239.195.0.3, Source count: 2, Packets forwarded: 634, Packets received: 642 RP-tree: Forwarding: 6/0/100/0, Other: 14/7/1 Source: 10.0.183.2/32, Forwarding: 314/0/100/0, Other: 314/0/0 Source: 172.21.36.2/32, Forwarding: 314/0/100/0, Other: 314/0/0 ... View more

Hi Peter, You are right. But  i don't want to use default mroute for RPF check , instead i use specific subnet as source for multicast. But if some reason multicast is sourcing from an unknown source then RPF lookup is failed and traffic from source up to the  RP is using  unicast source register msg and not native multicast. So  the end result must be : If multicast source from an unknown address then the packets must not forward by using source reg msg . Cheers, Anil. ... View more

Hi Ashish, I also did the same , it worked after setting local pref while impporting. Many thanks for the support. Thanks, Anil. ... View more