Hi All,
I have an odd multicast forwarding issue. I have two Nexus 3548-XL (not a VPC pair) running in WARP mode, that act as Anycast RPs and use PIM (sparse mode) updates to keep in sync. They have a common VLAN that contains the multicast source. These feed the multicast out of 10GE L3 ports to a pair of 8300 series routers, which forward it on to third parties using static joins. OSPF is used for unicast routing and I have checked that I have no RPF failures. The trouble is that the multicast does not come out the far end.
I can see the packets arriving using a debug. I can see the [S,G]s being set up on the switches (RPs). I can see the [*,G]s on the routers when I add the static joins. All the PIM neighbors are good, and I can see that the switches and routers have their outgoing Interface lists populated correctly, but the traffic just doesn't get through. The switches are telling me that they are forwarding the multicast to the routers, but the inbound packet count on the routers isn't increasing. Moreover, the multicast forwarding on the router is at zero.
Now here is the real twist - If I put a join-group on one of the loopback interfaces of routers and ping the multicast group-ID from the secondary switch pointing to the source VLAN, I get a response from the router, so suddenly this works, but not if I do the same thing from the server on that VLAN.
Switches running 9.3.11
Routers running 17.6.5 using 10GE ports to connect to switches and 1GE ports to connect to third parties.
Thanks in advance for any clues.
Dave
