Configuring and Managing IGMP
Snooping
Changing IGMP Timers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Internet Group Management Protocol (IGMP) snooping controls multicast traffic on an WSS switch 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 switch 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 | disable} [vlan vlan-id]
If you do not specify a VLAN ID, the change is applied to all VLANs on the WSS switch.
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 switch 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.
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