Multiple Replies to IGMP Group Pings

[gkirsch]

I often see multiple replies for serial and ethernet interfaces for a multicast ping to a group. For example a ping to group 224.4.4.4 will be replied to several times by a serial or ethernet port on one router if the only group interface for 224.4.4.4 is on the loopback.

Any ideas on the reason behind the multiple replies? Multiple routes via an IGP to the interfaces which repplies several times?

Thanks.

[vmoopeung]

If all the multicast-capable routers and access servers that you administer are members of a multicast group, pinging that group causes all routers to respond, which can be a useful administrative and debugging tool. check out the following troubleshooting link for more information :

http://www.cisco.com/en/US/tech/tk828/technologies_tech_note09186a0080094b55.shtml