Configuring Basic IGMP Proxy Functions
Context
In a simple tree topology, multicast routers directly connected to user network segments do not need to run any complicated multicast routing protocol (such as PIM). However, the upstream access devices have to manage many users because the multicast routers transparently transmit all IGMP messages from hosts. In this case, configure the IGMP proxy function on the multicast router so that the router collects IGMP Report and Leave messages from receiver hosts before sending these messages to the upstream access device. In addition, the router maintains membership and forwards multicast messages based on the membership. To the upstream access device, the multicast router configured with IGMP proxy is a host.
IGMP proxy is configured on upstream interfaces of an IGMP proxy device, and IGMP is configured on its downstream interfaces.