Setting alternate MAC addresses on e1000

[Carsten Aulbert <carsten.aulbert@aei.mpg.de>]

Hi,

I know that quite a few e1000 experts are reading here, so I hope to 
have some luck here:

I need to reprogram the MAC addresses of several 82573E/L NICs. I tried 
the obvious approach first using ethtool -E to write the numbers into 
the first six bytes and this works quite ok [1], except that I need to 
specifically change the second MAC not necessarily the first one. This 
approach only changed the first NIC and left the second unchanged.

I've browsed http://download.intel.com/design/network/manuals/31608004.pdf
quite a bit, but except finding that I seem to need to set word 0x37 to 
point to 12 free bytes I have not come up with much. For example, I 
don't know where I would find those 12 free bytes.

Anyone with a different approach or a hint how to succeed?

TIA

Carsten

[1] Along the lines of
ethtool -E eth0 magic $MAGIC offset 0x0 value 0x${numbers[0]}
[...]
where magic is MAGIC=0x108c8086

However this does not work on eth1 :(