[112539] in North American Network Operators' Group
Re: MAC address confusion
daemon@ATHENA.MIT.EDU (Kevin Oberman)
Tue Mar 3 16:51:15 2009
To: Saku Ytti <saku+nanog@ytti.fi>
In-reply-to: Your message of "Tue, 03 Mar 2009 08:42:16 +0200."
<20090303064216.GA23825@mx.ytti.net>
Date: Tue, 03 Mar 2009 13:50:33 -0800
From: "Kevin Oberman" <oberman@es.net>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
> Date: Tue, 3 Mar 2009 08:42:16 +0200
> From: Saku Ytti <saku+nanog@ytti.fi>
>
> On (2009-03-02 17:31 -0800), Kevin Oberman wrote:
>
> > > > > http://standards.ieee.org/regauth/oui/oui.txt
> > > > > 02-07-01 (hex) RACAL-DATACOM
>
> > > Would be interesting to see what are the historical reasons.Perhaps they simply
> > > predate the scheme or some might not even co-exist in ethernet network to begin
> > > with, in which case they might be better documented elsewhere.
> >
> > IEEE after 802.3 was ratified. IEEE agreed to retain existing
> > registrations and they have remained there.
>
> So where does this leave the current local scape addresses being globally
> assigned? Is it possible that we will run into legit 02 MAC addresses
> in the wild?
Thee are properly "locally assigned",not "local scope" addresses, but
the effect is the same.
This is only a problem if you have multiple systems running DECnet (or
some other protocol using this) with the same layer 3 address. That
should never happen, so there should be no duplication.
The only real issue I see is with IPv6 EUI-64 addresses and even in that
case, there would have to be two systems getting their address space
from the same router interface before there is a conflict.
--
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman@es.net Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4 EADA 927D EBB3 987B 3751
