IGMP Snooping within a VLAN

[mmelbourne]

We have a POC environment with a Nexus 7K, NX-OS 5.1.(3), with two downstream switches. A multicast source is on one switch and a receiver on the other.

I've enabled an IGMP querier (defaults to IGMPv3 on Nexus) on the particular VLAN on Nexus, and the downstream switches (a 4948 and a 2960G) have dynamically learned it and the mrouter port.

Is there any other configuration to make this work? We do see IGMP Joins propagating to the Nexus but the m/cast receiver does not receive any traffic.

On the switch with the source, will the traffic just be sent out the mrouter-facing port (unless other ports on the same switch join the group)?

[Jon Marshall]

Have a look at this recent thread which may provide the answer to your problem -

https://supportforums.cisco.com/message/3429880#3429880

Jon

[mmelbourne]

Thanks Jon; I saw that post - we have an IGMP Querier configured on Nexus and all the downstream switches have IGMP Snooping enabled. I could disable the IGMP Querier on Nexus and then turn up an SVI on Nexus with PIM enabled, though I understand that this will have the same effect as an IGMP Querier on a VLAN on Nexus (for the case where multicast routing is not enabled, and multicast traffic is constrained to a single VLAN, where the aim is to optimise multicast flooding).