Operation Manual – MulticastH3C S3100 Series Ethernet Switches Chapter 2 IGMP Snooping Configuration2-14there is no member of the multicast group on the local subnet and remove thecorresponding path.To avoid this from happening, you can configure a port of the VLAN of the switch as amulticast group member. When the port receives IGMP query messages, the multicastswitch will respond. As a result, the port of the VLAN can continue to receive multicasttraffic.Through this configuration, the following functions can be implemented:z When an Ethernet port is configured as a simulated member host, the switchsends an IGMP report through this port. Meanwhile, the switch sends the sameIGMP report to itself and establishes a corresponding IGMP entry based on thisreport.z When receiving an IGMP general query, the simulated host responds with anIGMP report. Meanwhile, the switch sends the same IGMP report to itself toensure that the IGMP entry does not age out.z When the simulated joining function is disabled on an Ethernet port, the simulatedhost sends an IGMP leave message.Therefore, to ensure that IGMP entries will not age out, the port must receive IGMPgeneral queries periodically.Table 2-16 Configure a port as a simulated group memberOperation Command RemarksEnter system view system-view —Enter Ethernet port view interface interface-typeinterface-number —Configure the current portas a simulated multicastgroup memberigmp host-join group-address[source-ip source-address ]vlan vlan-idRequiredSimulated joining isdisabled by default.Caution:z Before configuring a simulated host, enable IGMP Snooping in VLAN view first.z The port to be configured must belong to the specified VLAN; otherwise theconfiguration does not take effect.z You can use the source-ip source-address command to specify a multicast sourceaddress that the port will join as a simulated host. This configuration takes effectwhen IGMPv3 Snooping is enabled in the VLAN.
