[134284] in North American Network Operators' Group
RE: The tale of a single MAC
daemon@ATHENA.MIT.EDU (Daniel Dib)
Mon Jan 3 04:40:18 2011
From: "Daniel Dib" <daniel.dib@reaper.nu>
To: "'Mikael Abrahamsson'" <swmike@swm.pp.se>,
"'Dobbins, Roland'" <rdobbins@arbor.net>
In-Reply-To: <alpine.DEB.1.10.1101030703120.13151@uplift.swm.pp.se>
Date: Mon, 3 Jan 2011 10:40:02 +0100
Cc: 'Nanog' <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mon, jan 03, 2011 at 07:05:24, Mikael Abrahamsson wrote:
> Subject: Re: The tale of a single MAC
>
> On Mon, 3 Jan 2011, Dobbins, Roland wrote:
>
> > I remember that there were several high-profile instances of
> duplicate
> > MAC addresses being burnt into NICs during the 1990s - once every
> > 2-3 years, IIRC. And those were just the ones that were discussed
> publicly.
>
> D-Link shipped NAT-boxes around 2003-2004 or so with identical MAC
> addresses (and a "clone your PC mac address to the WAN interface"-
> functionality). I checked my then employer ADSL network and 5% of the
> customer ports had the same MAC address, D-Link support alledgedly
> said something about the MAC address not being "unique enough" and
> directed their customers to the cloning functionality to "solve" the
problem.
>
> --
> Mikael Abrahamsson email: swmike@swm.pp.se
Years ago D-link and Linksys and maybe other vendors used the source MAC of
00:00:00:00:00:00 which isn't very nice and could cause interesting issues.
At my current job we used to have a routine to find these MACs and tell the
users to change to a valid address.
