UNICOM Electric 8 - Manual (Page 51)

5-4-6. Filter Database
5-4-6-1. IGMP Snooping
The SmartGST-801M supports IP Multicast. IGMP protocol can be
enabled on the web management s Advanced page. On the IGMP
Snooping information page, you can view different multicast groups,
VIDs, and member ports. IP multicast addresses range from 224.0.0.0
through 239.255.255.255.
The Internet Group Management Protocol (IGMP) is an internal protocol
of the Internet Protocol (IP) suite.
IP manages multicast traffic by using switches, routers, and hosts that
support IGMP. Enabling IGMP allows the ports to detect IGMP queries,
report packets, and manage IP multicast traffic through the switch. IGMP
has three fundamental types of messages as follows:
Message Description
Query
A message sent from the querier (IGMP router or switch) asking for a
response from each host belonging to the multicast group.
Report
A message sent by a host to the querier to indicate that the host wants to be
or is a member of a given group indicated in the report message.
Leave
Group
A message sent by a host to the querier to indicate that the host has quit to
be a member of a specific multicast group.