LevelOne ProCon GSW-4896, User Manual, Page: 105 / 287

User Manual
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3-11. IGMP Snooping
The function, IGMP Snooping, is used to establish the multicast groups to
forward the multicast packet to the member ports, and, in nature, avoids wasting the
bandwidth while IP multicast packets are running over the network. This is because
a switch that does not support IGMP or IGMP Snooping can not tell the multicast
packet from the broadcast packet, so it can only treat them all as the broadcast
packet. Without IGMP Snooping, the multicast packet forwarding function is plain
and nothing is different from broadcast packet.
A switch, which supports IGMP Snooping functions like: query, report and
leave, can update information of the Multicast table when a member (port) joins or
leaves an IP Multicast Destination Address. With this function, once a switch
receives an IP multicast packet, it will forward the packet to the members who
joined in a specified IP multicast group before.
Fig. 3-48
Function name:
IGMP Snooping Configuration
Function description:
IGMP snooping is used to snoop the status of IP multicast groups and display
its associated information in both tagged VLAN and non-tagged VLAN
networks. Enabling IGMP, you can monitor the IGMP snooping information,
which contains the multicast member list with the multicast groups, VID and
member port.