If you do not have multicast support enabled\configured on your WLAN controller likely this is where your issue is. You will need to configure multicast to use this even if the devices are in the same VLAN.
The wireless multicast traffic will not behave like standard multicast traffic in a L2 network where the switch will either use IGMP snooping to forward multicast streams to "listening ports" or flood the traffic if IGMP snooping is not enabled.
To fix the issue, enable multicast support on your controller – it’s actually only a few steps for a basic setup, the only caveat may be the multicast distribution part of it – this is how the controller gets the multicast traffic to the Aps. You can do unicast mode or multicast mode. Without getting into too many details check out the link below from Cisco on how to enable support for apple bonjour service which requires multicast support and has the steps you need and explanations to follow.
http://www.cisco.com/c/en/us/support/docs/wireless/aironet-1100-series-access-point/113443-cuwn-apple-bonjour-dg-00.html
You should be able to grab the bits and pieces you need for your setup from that doc – in essence:
- Enable multicast globally
- Enable IGMP snooping
- Enable the controller to send multicast traffic to the Aps
There is a Cisco live presentation on this as well to get the basics covered.
Mark
