[c-nsp] Need help with setting up ip multicastrouting

[Peter Rathlev]

On Tue, 2010-10-12 at 21:07 +0200, Gert Doering wrote:
> On Tue, Oct 12, 2010 at 07:45:10PM +0200, Peter Rathlev wrote:
> > but I don't see why routed multicast traffic would need to have the
> > L2 group bit set.
> 
> Well, if you only ever have two routers in a subnet, it doesn't need
> to...
> 
> But what if you have 20 routers in a subnet and want the multicast
> traffic to be heard by only those 5 that are interested in it?

Ah, of course. Does the switch (e.g. some Catalyst 2k/3k) just learn
many mrouter ports and forward correctly? Or would one need to add some
specific configuration for that?

(Sorry for veering a little OT here.)

-- 
Peter