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Re: [Fwd:] Nvidia NICs with duplicate mac addresses

  • From: Robert E. Seastrom
  • Date: Fri Sep 05 13:19:51 2008 
"David W. Hankins" <[email protected]> writes:

> On Fri, Sep 05, 2008 at 10:32:46AM -0400, Robert E. Seastrom wrote:
>> Forwarded to NANOG in the interests of wider awareness...  having been
>> there and torn out my already scarce hair, duplicate MAC addresses can
>> really mess up your day...
>
> Out of curiosity, does this happen often enough we might want to
> consider an automated means to negotiate out of the problem state
> (e.g. detect collisions and negotiate MAC address by DHCP)?
>
> It would take years to deploy but might save thousands of hairs.

The same DHCP server (ip helper-address blah) serves my office, my
home, and the colo.  Can you give me an idea of a good heuristic for
telling the difference between moving my laptop around and finding MAC
address collisions?  Or are you suggesting that you hand out a MAC
address along with an IP address when the client DHCPs and the client
then changes it?

-r