SSH into the AP and run the following commands to see if it's already enabled by default:
>show run include-factory | include ip igmp or >show context include-factory | include ip igmp[/code]You should see something like this:[/code] ip igmp snooping
ip igmp snooping forward-unknown-multicast
no ip igmp snooping querier
ip igmp snooping querier max-response-time 10
ip igmp snooping querier timer expiry 60
ip igmp snooping querier version 3
ip igmp snooping querier query-interval 60
ip igmp snooping querier robustness-variable 2
no ip igmp snooping fast-leave[/code]What do you get when you run these commands?