installing new ethernet address equipment with VMS 6.1

[a.carlini at ntlworld.com]

Gil Carrick wrote:

> DEC might not have supported LAAs in any given environment, of
> course. But I doubt if the 802.3 spec specifically exempts a
> VMSCluster. ;) 

DEC *owned* AA-00-03 (I have an early DEQNA that has such
an address) and AA-00-04 (and quite possibly a couple of
other AA-00-xx ones, I forget). IIRC DEC gave up those so that
locally-administered addresses could be standardised. I'd
be surprised if they then forgot to support these!

AA-00-04 is, of course, used by DECnet.

> DEC was an early player in this area. After all, DIX Ethernet format
> refers to DEC, Intel & Xerox. They did all manner of strange things.
> 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.

Did anything actually do this? It seems very odd. I know that
gear like the DECnis was assigned a block of addresses, but that
was perfectly legal (i.e. the CPU card had an address of, for example,
08-00-2B-00-AA-00 and that covered a range up to (again, for
example) 08-00-2B-00-AA-FF (i.e. sixteen addresses).

Playing with the OUI seems a bit mad to me (and it doesn't
gain you anything over the more obvious scheme used by DECnis
and other products).

Antonio

-- 

Antonio carlini
arcarlini at iee.org