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From: koning@koning.enet.dec.com (Paul Koning)
Newsgroups: comp.dcom.lans,comp.protocols.tcp-ip
Subject: Re: Zero manufacturer code in SNAP?
Message-ID: <13803@shlump.nac.dec.com>
Date: 24 Jul 90 14:41:30 GMT
References: <64420@sgi.sgi.com> <1990Jul17.010234.12077@portia.Stanford.EDU>
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Reply-To: koning@koning.enet.dec.com (Paul Koning)
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::...
::
:: My understanding, which has no more authority in this case than "urban legend"
:: (and should probably be taken with the same degree of confidence), is that the
:: 24-bit "organization" identifier was not originally intended to be identical
:: with the upper 24 (well, 23) bits of some assigned MAC address, but was to be
:: a separate space assigned/managed by IEEE.
:: 
:: (The obvious hack of making it be the same as a manufacturer's 23-bit unique
:: MAC-address prefix came later, if at all. [*Is* that the way the IEEE assigns
:: them?] After all, it *is* possible that a manufacturer could make more than
:: 2^24 network interfaces and need some more addresses, so why mix SNAP IDs with
:: MAC addresses?)

I don't know about the "original intent".  However, the final result, as
described in IEEE standard 802.1A, is that the OUI (the SAME one) is used
to create individual MAC addresses, multicast addresses, and Protocol IDs.
There is only a single registry, and it is used for all of these purposes.

	paul koning