3Com 3CR17501-91 - SuperStack 3 Switch 3250 - IGMP Multicast Filtering

Multicast Filtering and Your Switch 31
Figure 4 The effect of multicast filtering
Multicast Filtering
and Your Switch
Your Switch provides automatic multicast filtering support using IGMP
(Internet Group Management Protocol) Snooping. It also supports IGMP
query mode.
Snooping Mode
Snooping Mode allows your Switch to forward multicast packets only to
the appropriate ports. The Switch “snoops” on exchanges between
endstations and an IGMP device, typically a router, to find out the ports
that wish to join a multicast group and then sets its filters accordingly
The Switch 3226 and Switch 3250 are compatible with any device that
conforms to the IGMP v2 protocol. The Switch does not support IGMP v3.
If you have an IGMP v3 network, you should disable IGMP snooping for
the Switch using the snoopMode command on the Web Interface.
IGMP Multicast
Filtering
IGMP is the system that all IP-supporting network devices use to register
endstations with multicast groups. It can be used on all LANs and VLANs
that contain a multicast capable IP router and on other network devices
that support IP.