[e2e] use of MAC addresses

Charles M. Hannum mycroft at netbsd.org
Thu Apr 13 11:59:56 PDT 2006

On Thu, Apr 13, 2006 at 10:39:04AM -0700, Joe Touch wrote:
> Fahad Dogar wrote:
> > IMHO, we have to change these protocols because they have been
> > designed keeping in view the presence of MAC addresses and how they
> > work. If we were to redesign Internet and networking technologies
> > (clean slate approach), do we need to have a different MAC address.
> > Shouldn't IP address be sufficient? It is like assigning a globally
> > unique name to every person and then asking him to maintain an
> > additional name for 'local' identification.

I'm still trying to figure out where this notion of IP addresses being
"globally unique" came from.  IP addresses are *not* globally unique.
Even if we ignore NAT, they are still ephemeral due to DHCP, ND, etc.
The big selling point of MAC addresses is to make it easy to implement
determistic algorithms for discovering and maintaining IP address
mappings.  (Spanning tree came later, but is also important.)  If you
ditch MAC addresses, then you just have to create some other unique ID
for this -- and if you go with something like the person's name, as has
been suggested, then it's in direct control of the user, and that will
only make things worse.

MAC addresses as currently implemented are simple and sane.  They are
not a scourge that needs to be destroyed.

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