APs accept IGMP queries only from the router & muticast packets with a source IP address of the WLC to which they are currently associated.
Unicast- the WLC unicasts ever multicast packet to every AP associated to the controller. This is inefficient
Multicast- the WLC sends multicast packets to a multicast group. Packet replication is done by the network.
Broadcast & Multicast traffic must be enabled seperately.
Broadcast is disabled by default
config network broadcast enable
it uses the mulicast mode configured on the WLC, even if multicast is not turned on.
To enable broadcast without enabling mutlicast, you must use the CLI. You cannot set the IP address or multicast mode unless multicast is enabled in the GUI.
config network multicast mode multicast
config network multicast unicast
IGMP snooping must be enabled on the WLC to make multicast with AAA override.
IGMP snooping is not supported on 2000, 2100 or ISR modules