Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!rutgers!ucla-cs!zen!ucbvax!CU20B.COLUMBIA.EDU!sy.Ken
From: sy.Ken@CU20B.COLUMBIA.EDU (Ken Rossman)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: IBM TCP. Really DECnet and Ethernet addresses
Message-ID: <12325522493.139.SY.KEN@CU20B.COLUMBIA.EDU>
Date: Mon, 10-Aug-87 23:17:13 EDT
Article-I.D.: CU20B.12325522493.139.SY.KEN
Posted: Mon Aug 10 23:17:13 1987
Date-Received: Wed, 12-Aug-87 02:02:46 EDT
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
Lines: 26


	"A station's physical address should be distinct from the
	physical address of any other station on @i(any) Ethernet."

  The italics are in the book.  Time marches on... standards change...

It would seem to me that it would be hopelessly difficult to try to
administer a flat global set of ethernet addresses, and that some sort of
mechanism, such as the global/local bits at the beginning would have to
exist.  In any case, regardless of how a spec says it SHOULD be, the real
world appears to be allocating blocks of ethernet addresses to vendors to
be used as they (or their customers) see fit.

Along slightly different lines, I fail to see how the global ethernet
addressing scheme, whether managed as a flat address space or in some
hierarchical fashion, hasn't blown up yet.  I mean there just aren't that
many addresses available.  Just as an isolated example, what happens to
ethernet addresses on failing boards?  We've probably had the ethernet
board on one of our -20's replaced three times already.  Am I to believe
that DEC Field Service records these hardware addresses, and when bad
boards come back that can't be repaired, they tell some global address
administrator that this particular hardware address has now been freed and
can be used again?

/Ken
-------