3-6Figure 3-3 shows an IGMP Proxy diagram for a stub network. The upstream interface, VLAN-interface 1of Switch B is the proxy interface for the downstream interface VLAN-interface 2.Configure Switch B as follows:Enable multicast routing, and then enable PIM and IGMP on VLAN-interface 1 and VLAN-interface 2.Run the igmp proxy command on VLAN-interface 1 to configure it as the proxy interface forVLAN-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 the network segment33.33.33.0/24. That is, Switch A does not consider Switch B as its PIM neighbor.In this case, when Switch B of the stub network receives from VLAN-interface 2 an IGMP join or IGMPleave message sent by the host, it changes the source address of the IGMP information to the addressof VLAN-interface 1, 33.33.33.2, and sends the information to VLAN-interface 1 of Switch A. For SwitchA, this works as if there is a host directly connected to VLAN-interface 1.Similarly, when Switch B receives the IGMP general or group-specific query message from the Layer 3Switch A, Switch B also changes the source address of the query message to the IP address ofVLAN-interface 2, 22.22.22.1, and send the message from VLAN-interface 2.Configuring IGMPIGMP 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 OptionalEnabling IGMPFirst, IGMP must be enabled on the interface on which the multicast group memberships are to beestablished and maintained.Follow these steps to enable IGMP:To do... Use the command... RemarksEnter system view system-view —Enable IP multicast routing multicast routing-enable Required
