All things related to multicast

[Hitoshi Asaeda <>]

> I can't really think of any problems a "rogue querier" can cause.
> All IGMP routers listen to membership reports and time groups out
> independently.

I agree with John.
One of the examples;
http://www1.ietf.org/mail-archive/working-groups/magma/current/msg00027.html

But, unfortunately, as a protocol level, it's a little difficult to
avoid bogus or rogue queriers, since IMO some security addendum to
IGMP/MLD for this purpose would be burden.
Anyway, if looking for the solution, I believe there is some proposal
related to it in MSEC WG or something.

In addition, this is also just my opinion and isn't related to the
concerning point, though, using "lowest IP address" for selecting
querier is in any case poor. At least, querier selection should've
been done by another mechanism like PIM's DR selection mechanism. But
the problem is how to make a compatibility with old routers, which
only use a lowest IP address for selecting a querier...
--
Hitoshi Asaeda

p.s. My IGMPv3/MLDv2 host-side kernel implementations have a static
configuration option to set querier's IGMP/MLD version, in order to
fix the problem stated in a magma ML.