The tale of a single MAC

Graham Wooden graham at g-rock.net
Sat Jan 1 22:47:38 CST 2011


Two different suppliers - one was out of Wisconsin (I believe; it's been
some time), and the other of Phoenix for the most recent batch.

I have lots and lots of HP server gear - and never encountered such bizarre
issue.


On 1/1/11 9:59 PM, "Brielle Bruns" <bruns at 2mbit.com> wrote:

> 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.






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