Hi
I have a multicast setup based on Catalyst 9500 switches which are terminating SVIs for clients and servers. There are two of them involved: the source and the client are both on VLANs terminated on one (R1), and the RP for the group in question is a loopback interface on the other (R2). The server is on VLAN 80, the client on VLAN 32, and VLAN 65 is the link between R1 and R2. I'm using iperf v2 for testing. The first odd thing is that although IGMP snooping on R1 shows that there is a client for the group, if I do "show ip igmp membership" it shows no entry for that group. So, with server and client both running, if I do "show ip mroute 239.255.11.11" (group in question) on R1, I get:
(*, 239.255.11.11), 01:41:54/stopped, RP <valid-RP>, flags: SPF
Incoming interface: Vlan65, RPF nbr <valid neighbour>
Outgoing interface list: Null
(<source>, 239.255.11.11), 01:41:54/00:02:19, flags: PFT
Incoming interface: Vlan80, RPF nbr 0.0.0.0
Outgoing interface list: Null
But if I do "ip igmp join-group 239.255.11.11" on the SVI that the client is connected to, that changes to:
(*, 239.255.11.11), 01:39:49/stopped, RP <valid-RP>, flags: SJCLF
Incoming interface: Vlan65, RPF nbr <valid neighbour>
Outgoing interface list:
Vlan32, Forward/Sparse, 00:00:20/00:02:52
(<source>, 239.255.11.11), 01:39:49/00:02:24, flags: LFT
Incoming interface: Vlan80, RPF nbr 0.0.0.0
Outgoing interface list:
Vlan32, Forward/Sparse, 00:00:22/00:02:50
At the same time, the client starts receiving packets from the source (being on the VLAN whose SVI I joined. So it's clearly not the snooping that is failing. It just seems that routing engine on R1 is not seeing the client as a member of the group, even though the switching engine is. I am completely baffled by this. Does anyone have any ideas?
Thanks
Max
