Question for IP Mulitcast Routing

ivancheng · ‎09-01-2002

Hi,

R1, R2 & R3 can ping each other thru the frame relay (FR).

R1 works as a RP. Spare mode was configured on all serials of the routers and RP-address also define on them.

I have created two groups by using IGMP join-group on R1 (237.1.1.1) and R2 (238.1.1.1) for testing.

After the configuration, I have found that R3 can only see 238.1.1.1 group. However, R1 and R2 can see all groups. On R3, no response from R1 if ping 237.1.1.1. Is it correct ?

Thanks in advance.

Rgds,

Ivan Cheng

bbaley · ‎09-10-2002

The purpose of the Cisco Group Management Protocol (CGMP) and Internet Group Management Protocol (IGMP) Snooping is to restrain multicast traffic in a switched network. It does not provide layer 3 interconnectivity. Ensure this is in place prior to the implementation of CGMP/IGMP.

ayandam · ‎09-19-2002

Ivan,

You need to also join group 237.1.1.1 on R2 on the interface adjacent to R3.

Thanks

Ayanda