Back when we had a huge bridging network, we had multiple instances of MAC-address collisions in our network. This was one of the reasons why DECnet Phase IV reassigned all MAC addresses (i.e., to ensure that MAC addresses were indeed unique within the DECnet network).
It is possible that this issue is no longer a problem -- I just don't know. However, the gray-hairs among us remember the time when vendor-assigned MAC address uniqueness was a theoretical claim that far-too-often wasn't true in real-life. > -----Original Message----- >From Fred Templin > From: [email protected] [mailto:[email protected]] On Behalf Of > Robin Whittle > > I read all the material of all the proposals, including ILNP, and > commented on them all on the list. I haven't read the very latest > versions of the proposals. My critiques of ILNP and other such Loc/ID > Separation (Core-Edge Elimination) architectures are well known: > > http://www.ietf.org/mail-archive/web/rrg/current/msg06219.html > > and are not solvable by the small details which change from one > version of a draft to another. So forgive me if I haven't read all of > Ran's latest versions end-to-end. > > > > As has been documented for years, and has been patiently explained > > many times on this list, it is recommended to synthesize a > > global-scope > > EUI-64 ID from one of a host's globally unique hardware IDs, such as > > an Ethernet MAC address. > > Sure - but that doesn't eliminate the possibility of clashes. > > There could be two Ethernet interfaces with the same MAC - and there > will be many devices which have no Ethernet interface or other > component with a MAC. The MANET Autoconf community has debated for years about the guaranteed uniqueness of MAC addresses without conclusion. The frequently heard argument is that MAC addresses are configured by vendors, and anything that can be configured can be misconfigured. Being an optimist, I am actually a believer in the assumed uniqueness of MAC addresses. But, there are many pessimists in the MANET Autoconf world and I'm sure elsewhere as well. Fred [email protected] _______________________________________________ rrg mailing list [email protected] http://www.irtf.org/mailman/listinfo/rrg
