Get ethernet MAC address without powering on machine?

[Jim Meyer]

Howdy!

We buy commodity boxes not only for our distributed computing needs (a
render farm) but also for our desktops. We like to use kickstart to set
up the box; we've honed the config for this pretty well. The problem is
we need to get the MAC address prior to kickstarting the box so that we
can give it a trusted IP which in turn allows it to NFS mount the disk
where the RedHat distributions are.

This leads me to my question: anyone know of a clever way to get the MAC
address from an ethernet device without needing to power the machine up,
load an OS, and probe around a bit. Having noted that ethernet devices
often seem to display link and traffic lights even when the computer is
powered down, I was thinking that a fairly special purpose device might
be designed (RJ45 plug and simple digital readout kinda thing) which led
me to wonder if such a device already exists.

Has anyone ever seen or heard of such a thing?

Thanks!

--j
-- 
Jim Meyer, Geek At Large                              purp at wildbrain.com