On Sat, 2 Sep 2000, Alan B. Pearce wrote:

> I think every NIC I have seen has a small EEPROM on it to hold the MAC address
> for the card. It would not take much effort at all to remove one of these and
> copy it. What happens on a system when you have multiple NIC's with the same
> MAC?

Not a problem on the PC, as far as I know, as even the 4-port NICs have
different MAC addresses per port.  I know Suns do this, but this hardware
is PC.

You could indeed change the MAC by hardware hacking the SEEPROM.  I
strongly suspect there's a very simple way, using either documented or
undocumented commands, to do it with an application program on a PC as
well.  I haven't looked into it in several years, but I have seen it done.
In fact, we used to keep backup NICs for our critical servers that had the
same MAC programmed in as the old ones.  That way if a NIC failed we could
replace it and not worry about one or two devices with 4-hour ARP cache
timeouts and no convenient way to reset 'em.

Dale
---
The most exciting phrase to hear in science, the one that heralds new
discoveries, is not "Eureka!" (I found it!) but "That's funny ..."
                -- Isaac Asimov

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