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Nortel WLAN—Security Switch 2300 Series Configuration Guide

Configuring and managing IGMP

snooping

Internet Group Management Protocol (IGMP) snooping controls multicast traffic on a WSS by forwarding packets for a
multicast group only on the ports that are connected to members of the group. A multicast group is a set of IP hosts that
receive traffic addressed to a specific Class D IP address, the group address.
The WSS listens for multicast packets and maintains a table of multicast groups, as well as their sources and receivers,
based on the traffic. IGMP snooping is enabled by default.
You can configure IGMP snooping parameters and enable or disable the feature on an individual VLAN basis.
The current software version supports IGMP versions 1 and 2.

Disabling or reenabling IGMP snooping

IGMP snooping is enabled by default. To disable or reenable the feature, use the following command:
set igmp {enable | disa ble} [vlan vlan-id]
If you do not specify a VLAN ID, the change is applied to all VLANs on the WSS.

Disabling or reenabling proxy reporting

Proxy reporting reduces multicast overhead by sending only one report for each active group to the multicast routers,
instead of sending a separate report from each multicast receiver. For example, if the WSS receives reports from three
receivers for multicast group 237.255.255.255, the switch sends only one report for the group to the routers. One report
is sufficient to cause the routers to continue sending data for the group. Proxy reporting is enabled by default.
Disabling or reenabling IGMP snooping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
Disabling or reenabling proxy reporting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465
Enabling the pseudo-querier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
Changing IGMP timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 466
Enabling router solicitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471
Configuring static multicast ports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472
Displaying multicast information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474