Re: IGMP packets?

From: Chris Wright
Date: Wed Dec 08 2004 - 16:35:19 EST

* FoObArf00@xxxxxxxxxxxx (FoObArf00@xxxxxxxxxxxx) wrote:
> I have 3 machines. A (eth0) is connected to B (eth1) with a cross over
> cable and B (eth0) and C (eth0) are on a switch. I want to forward the
> igmp queries and reports that A (eth1) generates when joining/leaving a
> multicast group on B (eth1) from B(eth0) to C (eth0). I put the code to
> do this on different places such as ip_rcv, ip_route_input, etc and no
> luck. The weird thing is that it works when I do a tcpdump on B's eth1.

Sounds like B(eth1) is filtering the packets. Does it also work if you
enable IFF_ALLMULTI on eth1 (instead of IFF_PROMISC)? Also, what kernel
are you using? Does a group join on A generate a v1 or v3 report?

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