The tale of a single MAC

Brielle Bruns bruns at 2mbit.com
Sat Jan 1 21:59:16 CST 2011


On 1/1/11 8:33 PM, Graham Wooden wrote:
> So ­ here is the interesting part... Both servers are HP Proliant DL380 G4s,
> and both of their NIC1 and NIC2 MACs addresses are exactly the same.  Not
> spoofd and the OS drivers are not mucking with them ... They¹re burned-in ­
> I triple checked them in their respective BIOS screen.  I acquired these two
> machines at different times and both were from the grey market.  The ³What
> the ...² is sitting fresh in my mind ...  How can this be?


 From the same grey market supplier?

I know HP has a disc they put out which updates all the firmware/bios in 
a specific server model, its not too far fetched that a vendor might 
have a modified version that also either purposely or accidentally 
changes the MAC address.  Off the top of my head, I'm not sure where the 
MAC is stored - maybe an eeprom or a portion of the bios flash.  Or, it 
could be botched flashing that blew away the portion of memory where 
that was stored and the system defaulted to a built in value.

Excellent example is, IIRC, the older sparc stuff, where the ethernet 
cards didn't have MAC addresses as part of the card, but were stored in 
non-volatile or battery backed memory.  Memory goes poof, and you'll 
have problems.  Some WRT54G/WAP54Gs suffer from the same problem when 
throwing third party firmware on there.

-- 
Brielle Bruns
The Summit Open Source Development Group
http://www.sosdg.org    /     http://www.ahbl.org




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