Reed's views, was [e2e] Cannara's views

Cannara cannara at
Wed Apr 25 08:26:45 PDT 2001

And, analogously, IPv6 addresssing is what is being used to define uniqueness
for mobile devices, if only because the address space must be both vast &
permanent.  IPv4 addressing was less thoughtful than even Ethernet's and was
allowed to remain a huge administrative liability far too long. 


John Kristoff wrote:
> John Day wrote:
> > In fact, even Ethernet reflects the state of our understanding at the
> > time.  Then we didn't understand that addresses only had to have the
> > scope of the layer in which they were used.  I really doubt that
> > there will ever be an Ethernet segment or even a bridged ethernet
> > with 2**48 devices or anything remotely close to it.  16 bits would
> > have been more than enough.  What is interesting is that IEEE 802
> > still hasn't figured it out.  Look at firewire addresses.
> I was still learning how to dress myself while all this stuff was going
> on, but reading into what Seifert in his "The Switch Book" says, the
> thought about the 48-bit address space was done more for administrative
> purposes than for the purpose of actually needing that many addressable
> stations on a single data link.  An excerpt:
> "... the Ethernet designers consciously took a different approach to
> Data Link layer addressing.  Rather than trying to save transmission
> overhead by conserving bits, we instead opted to create a huge address
> space capable of providing a globally-unique Data-Link address to every
> device for all time.  The Ethernet address space was designed to allow a
> unique address to be permanently assigned to every device that would
> ever attach to a LAN."
> John

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