Subject: [multimob] An open MLD proxy implementation

From: Stig Venaas <[email-masked]>
Date: Mon, 18 Jan 2010 17:29:04 -0800

One open source MLD proxy implementation is ecmh, see
http://sourceforge.net/news/?group_id=98613

This proxy is used to provide IPv6 multicast with some
IPv6 tunnel brokers. In particular as tunnels go up and
down, the proxy will add/remove the tunnel interfaces
to/from its list of downstream interfaces.

One thing worth looking into, is perhaps whether it
immediately sends an MLD query on new downstream interfaces.

I think it would be useful to collect a list of IGMP/MLD
proxy implementations, in particular open source ones. We
may then see how close they are to what we want.

What I think we need in addition to what is specified in 4605,
is as follows.

Dynamic config changes:
That we can add/remove downstream interfaces while a proxy is running
(without losing any existing state, restarting the proxy to change
config would not be so good).

Multiple proxy instances:
Can we have multiple instances/processes can be run simultaneously, each
with a different upstream and a different set of downstreams? E.g. on a
UNIX-like system, I think you should be able to have a single proxy
binary that can be run multiple times to have multiple independent
processes. And any configuration must be unique to each process.

Sending general query when new downstream is added:
I don't think this is mentioned in 4605, but it's pretty obvious that
you don't want to wait for a global timer whenever an interface comes
up (or is added).

Stig