30 Oct
2005
30 Oct
'05
2:10 p.m.
>>>> "arcarlini" == arcarlini
<a.carlini at ntlworld.com> writes:
> .... For example, the first three bytes of a MAC
> address are the vendor code. DEC used 4, and on a given adapter
> they might use any of the 4 possible variants of the MAC address
> using the same low order 3 bytes but varying the high order 3
> bytes to any of their 4 vendor codes.
arcarlini> Did anything actually do this? It seems very odd.
Yes, and I am quite sure that DEC did NOT do anything like that. It
would have been a very clear violation of the Ethernet standards we
maintained internally, and 802.3 wouldn't be happy about it either.
acarlini> I know
arcarlini> that gear like the DECnis was assigned a block of
arcarlini> addresses, but that was perfectly legal (i.e. the CPU card
arcarlini> had an address of, for example, 08-00-2B-00-AA-00 and that
arcarlini> covered a range up to (again, for example)
arcarlini> 08-00-2B-00-AA-FF (i.e. sixteen addresses).
That would be 256, actually... but yes, block assignment like that was
standard in multiport devices. The address ROM would actually list
the range.
paul