(usagi-users 02905) Re: IPv6 Multicast on recent Linux Kernels

[David Stevens <dlstevens@xxxxxxxxxx>]

Nicholas Humfrey <njh@xxxxxxxxxxxxxxx> wrote on 04/14/2004 11:16:03 AM:

> The symptoms are that it is unable to join Multicast groups, however
> if there is another machine on the subnet, already a member of the
> group, then it picks up the packets ok. Linux will also will remain a
> member of the multicast group, even with the other machine leaves.

Are you running a multicast router? Do the other machines on the network
have the same ICMPv6 "type" code for reports (206) ? This number isn't
assigned by IANA last I checked, so implementations had to choose a 
number--
won't interoperate if they aren't using the same one.

Also, you could try reverting to MLDv1 by:

sysctl -w net.ipv6.conf.eth0.force_mld_version=1

(where "eth0" is the interface). If you have an MLD-snooping switch
that doesn't do MLDv2, or if the switch or anything you're interoperating
with is using a different type code for reports in v2, you need to
either change the type code or revert to v1. If you have a multicast
router on the link and it's using MLDv1, that should also make the
Linux host use v1.

                                        +-DLS