lamy@cs.toronto.edu (Jean-Francois Lamy) (09/09/89)
A friend who shall remain nameless working for an equally anonymous company is apparently seeking to redress some anomalous situation with respect of the assignement of the ethernet addresses for some piece of equipment they adapt or manufacture. (I promised not to implicate him :-). In short, can anyone point me (and hence him) in the right direction for guidelines/procedures for assigning ethernet addresses (and I do mean ethernet and not Internet addresses). Thanking you premat... err, in advance, Jean-Francois Lamy lamy@ai.utoronto.ca, uunet!ai.utoronto.ca!lamy AI Group, Department of Computer Science, University of Toronto, Canada M5S 1A4
pat@hprnd.HP.COM (Pat Thaler) (09/19/89)
When you order a block of addresses from IEEE, the standards office sends
out a letter describing in gruesome detail the relationship of the hex
to bits on the wire. I presume that those who already have address blocks
can ask the Standards Office for a copy of the letter. The copy I have
is signed by Vincent Condello, Standards Program Manager and the subject
is IEEE Assignment of a 48-Bit Globally Assigned Address Block.
The address and phone number are
IEEE Standards Office
The Institute of Electrical and Electronics Engineers, Inc.
445 Hoes Lane, P.O. Box 1331, Piscataway, NJ 08855-1331
(201) 562-3800
One reason people get confused is because 802.5 writes the hex address
one way and 802.3 and 802.4 another. For any address assignment, they
all send the bits on the wire in the same order. 802.3 and 802.4 define
the first bit of each byte as the least significant bit. 802.5 defines
it as the most significant bit. The first bit (on the wire) of the 48
bit address is the Individual/Group bit. The next bit is Universal/Local
bit. The remainder of the first 3 bytes of a univeral address is the
organizationally unique identifier.
If you send
0000 1111 0111 0100 1010 1000 0011 0110 1110 1110 1101 1001
802.3 and .4 would call it
F0 2E 15 6C 77 9B
and 802.5 would call it
0F 74 A8 36 EE D9
but it is really the same address under either name.
Regards,
Pat Thaler