30 Oct
2005
30 Oct
'05
1:40 p.m.
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