[c-nsp] multicast on layer 2

[Tim Stevenson]

Ok, I'll say it one more time. ;)

There is no need for a router. In fact there is no need for a querier 
either. You can disable IGMP snooping and flood the multicast everywhere. 
That's L2 multicast.

If you want IGMP snooping to work, so you can actually constrain your L2 
multicast to the ports w/interested receivers, then a querier, any querier, 
is required.

HTH,

Tim

At 07:25 AM 6/29/2005, Andrew K Ho noted:

>Howevever, sources do send membership reports.  I'm thrown off by the fact 
>that the multicast session never goes past the first hop router, hence, 
>there should be no need for the router to participate in the multicast 
>session.
>
>
>Gert Doering <gert at greenie.muc.de>
>
>06/29/2005 09:52 AM
>To
>"Tantsura, Jeff" <jtantsura at ugceurope.com>
>cc
>"'Andrew K Ho'" <aho at yorku.ca>, Tim Stevenson <tstevens at cisco.com>, 
>cisco-nsp at puck.nether.net
>Subject
>Re: [c-nsp] multicast on layer 2
>
>
>
>
>Hi,
>
>On Mon, Jun 27, 2005 at 04:14:42PM +0200, Tantsura, Jeff wrote:
> > Presence of layer 3 interface on the same VLAN could change the picture.
> > Since sources and receivers would register on it enabling PIM could help.
>
>Sources do not register - they just send packets.  Routers attached
>to the source register at the PIM RP, but this is independent of
>directly attached receivers.
>
>gert
>--
>Gert Doering
>Mobile communications ... right now writing from * Isola dei Gabbiani *



Tim Stevenson, tstevens at cisco.com
Routing & Switching CCIE #5561
Technical Marketing Engineer, Catalyst 6500
Cisco Systems, http://www.cisco.com
IP Phone: 408-526-6759
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