On Fri, 2013-01-11 at 16:13 +0100, Paweł Brodacki wrote: > 2013/1/9 Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>: > > > > They are supposed to be unique *per machine* - you can have two nics on > > the same machine with the same MAC although this is rare. > > > > Alan > > Alan, please, verify information before dissemination. > MAC address assigned to a physical NIC ought to be globally unique. > Ethernet frames are sent to MAC address, so two identical addresses > present in any broadcast domain would awfully confuse network > switches. See e.g. Wikipedia article on MAC > https://en.wikipedia.org/wiki/MAC_address. Hardware producers reserve > prefixes (first 3 bytes of the address) and are responsible for not > manufacturing devices with identical suffixes (last 3 bytes of the > address). > This should result in globally unique MAC addresses, however > I did encounter NICs with identical ones (cheap stuff of unknown and > dubious provenance). You try to call out Alan, THEN your last sentence above, states exactly what Alan said, they *can* have identical in the same machine *BUT RARE*. And you just stated you encountered it once? Sounds like what he stated to me. -- Mike Chambers Madisonville, KY "Best little town on Earth!" -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
