(usagi-users 03083) MLD version fallback on Linux 2.4.22

[Patcharee Basu <yoo@xxxxxxxxx>]

Hello,

I have one FC1 host <2.4.22+ usagi patch> and a FreeBSD 4.9 router 
running XORP which supports only MLDv1. The router tries to do mldv1 
membership query but never get a membership report from this host. This 
host just keep sending MLDv2 report to ff01::16 from time to time and 
never fall back to MLDv1.

This is the only message that the host keeps sending. <Although the icmp 
type is not yet 143 but it should not be the point of fallback problem>

14:03:23.397996 fe80::2e0:18ff:fea8:f2b9 > ff02::16: HBH icmp6: 
type-#206 [hlim1]


I take a look at mcast.c source code, it seems to have a portion of code 
that detects MLDv1 presence.

        if (len == 24) {
                int switchback;
                /* MLDv1 router present */

On this host, sysctl does not support mld version force yet so I cannot 
force it to use MLDv1 only.

Kindly suggest is there a way to make this host uses MLDv1 without 
changing kernel version(patch is OK)??

Best regards,
Patcharee