[comp.protocols.tcp-ip] MAC BOFs

baker@VITAM6.UUCP (Fred Baker) (09/29/89)

May I suggest that the folks going to the FDDI or Toekn Ring BOFs look at
IEEE 802.1A Rev 8, which has passed TCCC and is well on the way to being an
ANSI Standard.  This specifies (section 5.2.1) how a MAC address should
be encoded when found at a layer above the MAC.

The principal part of the problem with bit ordering relates to the fact
that end stations DO encode MAC addresses in layers other than the MAC -
ARP and XNS IDP for example.  Building an 802.3/802.5 bridge is significantly
complicated when the ES must know that the device it is addressing may
be specifying its address in an ARP response in the reverse order from the
way the receiving station needs to use them.

The most elegant enswer - IEEE's - is to specify a generic format, and
require the MAC layer to swap them at its interface if it needs to.  Anything
else forces the bridge to understand all possible protocols and swap them
in the HLL headers as well in at least some cases.

I can bring some copies to the meeting if people need them - send me a
request at:

Fred Baker
baker@vitalink.com