i have seen dups in 3com, dell, and hp kit over the years. the best was moving mac addresses btwn 802,3 and 802.5 cards.
--bill On Sun, Jan 02, 2011 at 03:03:24PM +1030, Mark Smith wrote: > On Sat, 01 Jan 2011 20:59:16 -0700 > Brielle Bruns <br...@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 ... They9re 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. > > This was actually the intended way to use "MAC" addresses, to used as > host addresses rather than as individual interface addresses, according > to the following paper - > > "48-bit Absolute Internet and Ethernet Host Numbers" > Yogan K. Dalal and Robert S. Printis, July 1981 > http://ethernethistory.typepad.com/papers/HostNumbers.pdf > > That paper also discusses why 48 bits were chosen as the size, despite > "Ethernet systems" being limited to 1024 hosts. > > I think things evolved into MAC per NIC because when add-in NICs > were invented there wasn't any appropriate non-volatile storage on the > host to store the address. > > Regards, > mark. >
