Enabling multicast enhancement

FortiOS can translate multicast traffic into unicast traffic to send to clients, maintaining its own multicast client through Internet Group Management Protocol (IGMP) snooping. You can configure this in the CLI:

config wireless-controller vap

edit example_wlan

set multicast-enhance enable

set me-disable-thresh 32

end

If the number of clients on the SSID is larger than me-disable-thresh, multicast enhancement is disabled.

Enabling IGMP Snooping

IGMP snooping on SSID can prevent WiFi clients and hosts from receiving traffic for a multicast group they have not explicitly joined. Upon detecting clients' multicast group IDs, FortiAPs join the corresponding multicast groups and the controller sends multicast packets to only CAPWAP multicast groups. Thus, the controller can prune multicast traffic from managed APs that do not contain a multicast listener (an IGMP client).

To enable or disable IGMP snooping in the CLI:

config wireless-controller vap

edit example_wlan

set igmp-snooping {enable | disable}

next

end

To debug IGMP snooping:

diagnose wireless-controller wlac -c vap-mcgrp