Subject: Re: Multicast and PIM
To: Emmanuel Dreyfus <manu@netbsd.org>
From: Manuel Bouyer <bouyer@antioche.lip6.fr>
List: tech-net
Date: 04/13/2004 19:46:55
On Sat, Apr 10, 2004 at 05:29:05PM +0200, Emmanuel Dreyfus wrote:
> Manuel Bouyer <bouyer@antioche.eu.org> wrote:
> 
> > > Can't it be set by hand? 
> > I don't think it's possible, at last not easily.
> 
> What about making an ioctl on the interface with IFF_ALLMULTI? Won't
> that do the trick?

Hum, I'm not sure this will be enouth. Multicast frame should still
be filtered by the ethernet layer.

> 
> > Sorry, I meant igmp, which I think is still mandatory, even with PIM.
> 
> But IGMP packets are alwyas sent to 224.0.0.0/3, aren't they? So this
> rule would match?
>  
> pass in on fxp0 to fxp1 from any to 224.0.0.0/3  
> pass in on fxp1 to fxp0 from any to 224.0.0.0/3

It will, but igmp (and the 224.0.0.0/24 addresses in general) is supposed to
be for the local network only. I don't know how it will behave when forwarded
to another IP network.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
     NetBSD: 26 ans d'experience feront toujours la difference
--