[Fwd:] Nvidia NICs with duplicate mac addresses

Date: Fri, 5 Sep 2008 10:36:24 -0400
From: "Jay R. Ashworth" <jra@baylink.com>

> mac address 04:4b:80:80:80:03, was showing up in multiple places
> across the network. I googled the mac address and discovered that
> other people are having the same issue with this mac address. Below
> are some links describing the problem:
> The Official NVIDIA Forums | NVIDIA
> http://www.nvnews.net/vbulletin/archive/index.php/t-73469.html
> I just wanted everyone to know about this problem in case you run
> across similar slow "connectivity" issues. I believe the network card
> is made by NVIDIA.

FWIW, IEEE's OUI lookup page says that's not assigned to *anyone*.

  IEEE SA - Registration Authority

No, the IEEE page does not say anything. For many years IEEE considered
OUIs to be confidential by default. IEEE would list the OUI only if a
box was checked on the application for the OUI. At some point the
default was changes to make the OUIs public, but existing "private"
entries remain private.

That said, it turns out the nVidia's OUI is 00:04:4B. So it looks like
the addressing was completely hosed and the MAC was shifted over 1 byte.

What mess! This used to happen in the early days of Ethernet, but I
have not seen it in some time.

Ah, then you're correct; I characterised it worng. Thanks for the
clarification; I hadn't realised that.

-- jra