invalid MAC addresses?

[David DeSimone]

Oliver Lehmann <oliver at FreeBSD.org> wrote:
>
> when I update the BIOS of my new AM3+ Mainboard, The MAC address of
> my re0 card gets changed from c8:60:00:60:3b:c6 to ed:0b:00:00:e0:00
> With this change, no communication with any other FreeBSD system is
> possible.

The mac address ed:0b:00:00:e0:00 is a multicast mac (first octet has
bit 1 set), which means it is not suitable for use with a unicast IP.
Other systems when they see your ARP reply with a multicast mac, are
going to treat this as an error, and ignore your ARP.

You could work around the problem by forcing the mac to something else,
(such as 22:44:66:11:22:33) and then other systems will believe that the
mac is acceptable for unicast.

However, it's clear that your NIC's eeprom has been programmed with an
incorrect mac setting, which it sounds like you are already trying to
fix.

-- 
David DeSimone == Network Admin == fox at verio.net
  "I don't like spinach, and I'm glad I don't, because if I
   liked it I'd eat it, and I just hate it." -- Clarence Darrow


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