Operation Manual – MulticastH3C S7500 Series Ethernet Switches Chapter 6 IGMP Configuration6-6To do... Use the command... RemarksEnter system view system-view —Enable the multicastrouting protocolmulticastrouting-enableEnable the multicastrouting protocol.Enter VLAN interface view interface Vlan-interfaceinterface-number —Enable IGMP on thecurrent interface igmp enableRequiredBy default, if IP multicastrouting is enabledglobally, IGMP is enabledon all the layer-3interfaces automatically.Configure the IGMPversion for the Layer 3switch (router)igmp version { 1 | 2 }OptionalIGMPv2 is used bydefault.Caution:An IGMP version cannot be switched to other versions automatically. So all the Layer 3switches on a subnet must be configured to use the same IGMP version.6.2.2 Configuring IGMP Query MessagesI. IGMP general query messagesThe Layer 3 switch sends IGMP general query messages to the connected networksegment periodically to get to know which multicast groups in the network segmenthave members according to the returned IGMP report messages. The multicast routeralso sends query messages periodically. When it receives the IGMP report message ofa group member, it will refresh the membership information of the network segment.II. IGMP group-specific messagesThe query router (querier for short) maintains the IGMP report messages on interfacesof the shared network. After the related features are configured, the IGMP querier willsend IGMP group-specific query messages at the user-defined interval for theuser-defined times when it receives the IGMP leave messages from the host.Suppose a host in a multicast group decides to leave the multicast group. The detailedprocedures are as follows:z The host sends an IGMP leave message.
