nanog mailing list archives

RE: The tale of a single MAC


From: "Daniel Dib" <daniel.dib () reaper nu>
Date: Mon, 3 Jan 2011 10:40:02 +0100

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.



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