[31897] in North American Network Operators' Group
Re: Service Provider Exchange requirements
daemon@ATHENA.MIT.EDU (Simon Leinen)
Thu Oct 26 16:20:01 2000
To: John Fraizer <nanog@EnterZone.Net>
Cc: hardie@equinix.com, mduckett@bellsouth.net,
"'nanog@merit.edu'" <nanog@merit.edu>
From: Simon Leinen <simon@limmat.switch.ch>
In-Reply-To: John Fraizer's message of "Mon, 23 Oct 2000 12:04:43 -0400 (EDT)"
Date: 26 Oct 2000 22:16:29 +0200
Message-ID: <aak8avbboi.fsf@limmat.switch.ch>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Errors-To: owner-nanog-outgoing@merit.edu
>>>>> "jf" == John Fraizer <nanog@EnterZone.Net> writes:
> If your switch is MCAST aware, you should be able to keep mcast
> traffic on ports tagged for it to begin with.
Is the idea that you can statically configure which of the IXP
switch's ports should be multicast-capable at all? This would cause
administrative overhead and would still not solve the problem of
multicast-capable routers that receive copies of multicast traffic
they aren't currently interested in.
> If your switch isn't mcast aware. you need to find a new switch.
It is actually quite hard for switches to be "mcast aware" enough to
copy multicast packets to exactly the set of who are interested in
them. They either have to listen to and understand the multicast
routing-protocol-of-the-day, or there must be some explicit protocol
between multicast routers and the switch.
In any case this is much more difficult than what most "multicast
aware" switches currently do, i.e. IGMP snooping (which helps for
end-systems, not routers, connected to the switch).
--
Simon.
