3-10Configuring a multicast group filter in interface viewFollow these steps to configure a multicast group filter in VLAN interface view:To do... Use the command... RemarksEnter system view system-view —Enter interface view interface interface-type interface-number —In VLAN interfaceviewigmp group-policyacl-number [ 1 | 2 | portinterface-list ]Configuring a multicastgroup filterIn LoopBackinterface viewigmp group-policyacl-number [ 1 | 2 ]OptionalNo multicast group filter isconfigured by defaultConfiguring a multicast group filter in Ethernet port viewFollow these steps to configure a multicast group filter in Ethernet port view:To do... Use the command... RemarksEnter system view system-view —Enter Ethernet port view interface interface-typeinterface-number —Configuring a multicast group filter igmp group-policy acl-numbervlan vlan-idOptionalNo multicast group filter isconfigured by default. The portmust belong to the specified VLAN.Configuring Simulated JoiningGenerally, hosts running IGMP respond to the IGMP query messages of the IGMP querier. If hosts fail torespond for some reason, the multicast router may consider that there is no member of the multicastgroup on the local subnet and remove the corresponding path.To avoid this situation from happening, you can enable simulated joining on a port of the switch, namelyconfigure the port as a simulated member host for a multicast group. When the port receives IGMPquery messages, the simulated member host will respond. As a result, the subnet attached to the Layer3 interface can continue to receive multicast traffic.Through this configuration, the following functions can be implemented:z When an Ethernet port is configured as a simulated member host, the switch sends an IGMP reportthrough this port. Meanwhile, the simulated host sends the same IGMP report to itself andestablishes a corresponding IGMP entry based on this report.z When receiving an IGMP general query, the simulated host responds with an IGMP report.Meanwhile, the simulated host sends the same IGMP report to itself to ensure that the IGMP entrydoes not age out.z When the simulated joining function is disabled on an Ethernet port, the simulated host sends anIGMP leave message.Therefore, to ensure that IGMP entries will not age out, the port must receive IGMP general queriesperiodically.
