494 G8264 Application Guide for ENOS 8.4IGMP TermsThe following are commonly used IGMP terms: Multicast traffic: Flow of data from one source to multiple destinations. Group: A multicast stream to which a host can join. Multicast groups have IPaddresses in the range: 224.0.1.0 to 239.255.255.255. IGMP Querier: A router or switch in the subnet that generates MembershipQueries. IGMP Snooper: A Layer 3 device that forwards multicast traffic only to hoststhat are interested in receiving multicast data. This device can be a router or aLayer 3 switch. Multicast Router: A router configured to make routing decisions for multicasttraffic. The router identifies the type of packet received (unicast or multicast)and forwards the packet to the intended destination. IGMP Proxy: A device that filters Join messages and Leave messages sentupstream to the Mrouter to reduce the load on the Mrouter. Membership Report: A report sent by the host that indicates an interest inreceiving multicast traffic from a multicast group. Leave: A message sent by the host when it wants to leave a multicast group. FastLeave: A process by which the switch stops forwarding multicast traffic to aport as soon as it receives a Leave message. Membership Query: Message sent by the Querier to verify if hosts are listeningto a group. General Query: A Membership Query sent to all hosts. The Group address fieldfor general queries is 0.0.0.0 and the destination address is 224.0.0.1. Group‐specific Query: A Membership Query sent to all hosts in a multicast group.
