4-42 ES3000 User Guide
4.2.30IGMP
The Internet Group Management Protocol (IGMP) is an Internet protocol allowing a host to report its multicast group membership to multicast routers. Multicasting allows one computer on the Internet to send information to other computers having identified themselves as interested in receiving the information. The ES3000 can “snoop” the messaging protocol to keep track of multicast groups and to insure multicast traffic is sent only to the appropriate ports within a VLAN. In networks where multimedia applications generate multicast traffic, IGMP can reduce unnecessary bandwidth by limiting traffic forwarding otherwise broadcast to the network. Enabling IGMP allows individual ports to detect IGMP queries, report packets, and manage IP multicast traffic through the switch.
