> 
> I've occasionally wished I had a prefix I could allocate MAC addresses
> out of for such machines.

You can use any address with the 'locally administered' bit set
- that is what it is for [1].
(ie any address where the first byte has the 0x02 bit set).

In practise addresses only have to be unique on your local LAN
segment, so it doesn't really matter what you use :-)

	David

[1] You shouldn't see any cards with such addresses set by their
manufacturer.  However what you see on cards, and what the IEEE
expect you to see are completely different!

-- 
David Laight: david@l8s.co.uk