On 4/4/2010 08:46, Jonathan Lassoff wrote: > Excerpts from John Peach's message of Sun Apr 04 08:17:28 -0700 2010: > >> On Sun, 4 Apr 2010 11:10:56 -0400 >> David Andersen <d...@cs.cmu.edu> wrote: >> >> >>> There are some classical cases of assigning the same MAC address to every >>> machine in a batch, resetting the counter used to number them, etc.; >>> unless shown otherwise, these are likely to be errors, not accidental >>> collisions. >>> >>> -Dave >>> >>> On Apr 4, 2010, at 10:57 AM, jim deleskie wrote: >>> >>> >>>> I've seen duplicate addresses in the wild in the past, I assume there >>>> is some amount of reuse, even though they are suppose to be unique. >>>> >>>> -jim >>>> >>>> On Sun, Apr 4, 2010 at 11:53 AM, A.B. Jr. <skan...@gmail.com> wrote: >>>> >>>>> Hi, >>>>> >>>>> Lots of traffic recently about 64 bits being too short or too long. >>>>> >>>>> What about mac addresses? Aren't they close to exhaustion? Should be. Or >>>>> it >>>>> is assumed that mac addresses are being widely reused throughout the >>>>> world? >>>>> All those low cost switches and wifi adapters DO use unique mac addresses? >>>>> >>>>> >> Sun, for one, used to assign the same MAC address to every NIC in the >> same box. >> > I could see how that *could* work as long as each interface connected to > a different LAN. > That was a logic Sun used. Every NIC would be connected to a different subnet, so duplicate MACs shouldn't be a problem. For the most part this worked, but some situations required a unique MAC per NIC, and Sun had a bit you could flip to turn this on. I believe it was an OpenBoot prom variable called "local-mac-address?" which you'd set to true if you wanted it to use each NICs MAC instead of the "system MAC".
-Jim
