User's Manual

48-56
Multicast Configuration:
Suppose the server provides programs through the multicast address 224.1.1.1, and some hosts subscribe
that program on the edge of the network. The host reports their IGMP multicast group membership to Switch 2
and Switch 3 through downstream ports. Switch 2 and Switch 3 then aggregate and forward them to Switch 1
which then forwards the information to multicast router. When multicast dataflow arrives, the IGMP Proxy
enabled switches re-distribute the group membership through upstream ports and downstream ports. When
the multicast router receives the multicast dataflow from IGMP proxy, it will consider the multicast data source
is directly connected to the router, and determine the identity of DR and ORIGINATOR. The multicast dataflow
will be redistributed according to the PIM protocol.
48.11.4 IGMP Proxy Troubleshooting
When IGMP Proxy function configuration and usage, IGMP Proxy might not run properly because of physical
connection or configuration mistakes. So the users should note that:
 Make sure physical connection correctly;
 Activate IGMP Proxy on whole Global mode (use ip igmp proxy);
 Make sure configure one upstream port and at least one downstream port under interface configuration
mode (Use ip igmp proxy upstream, ip igmp proxy downstream);
 Use show ip igmp proxy command to check if the IGMP Proxy information is correct.
If the IGMP Proxy problem remains unsolved, please use debug IGMP Proxy and other debugging command
and copy the DEBUG message within three minutes, send the recorded message to the technical service
center of our company.