Operation Manual – MulticastH3C S5600 Series Ethernet Switches Chapter 3 IGMP Configuration3-5Figure 3-2 shows an IGMP Proxy diagram for a stub network. The upstream interface,VLAN-interface 1 of Switch B is the proxy interface for the downstream interfaceVLAN-interface 2.Configure Switch B as follows:Enable multicast routing, and then enable PIM and IGMP on VLAN-interface 1 andVLAN-interface 2. Run the igmp proxy command on VLAN-interface 1 to configure itas the proxy interface for VLAN-interface 2.Configure Switch A as follows:z Enable multicast routing, enable IGMP and PIM on VLAN-interface 1.z Configure the pim neighbor-policy command to filter PIM neighbors in thenetwork segment 33.33.33.0/24. That is, Switch A does not consider Switch B asits PIM neighbor.In this case, when Switch B of the stub network receives from VLAN-interface 2 anIGMP join or IGMP leave message sent by the host, it changes the source address ofthe IGMP information to the address of VLAN-interface 1, 33.33.33.2, and sends theinformation to VLAN-interface 1 of Switch A. For Switch A, this works as if there is ahost directly connected to VLAN-interface 1.Similarly, when Switch B receives the IGMP general or group-specific query messagefrom the Layer 3 Switch A, Switch B also changes the source address of the querymessage to the IP address of VLAN-interface 2, 22.22.22.1, and send the messagefrom VLAN-interface 2.3.2 Configuring IGMP3.2.1 IGMP Configuration Task ListComplete the following tasks to configure IGMP:Task RemarksEnabling IGMP RequiredConfiguring IGMP Version OptionalConfiguring Options Related to IGMP Query Messages OptionalConfiguring the Maximum Allowed Number of Multicast Groups OptionalConfiguring a Multicast Group Filter OptionalConfiguring Simulated Joining OptionalConfiguring IGMP Proxy OptionalRemoving Joined IGMP Groups from an Interface Optional
