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From: torek@elf.ee.lbl.gov (Chris Torek)
Newsgroups: comp.unix.questions
Subject: Re: Determining my ethernet address
Message-ID: <11292@dog.ee.lbl.gov>
Date: 22 Mar 91 00:21:08 GMT
References: <1467@babcock.cerc.wvu.wvnet.edu>
Reply-To: torek@elf.ee.lbl.gov (Chris Torek)
Organization: Lawrence Berkeley Laboratory, Berkeley
Lines: 21
X-Local-Date: Thu, 21 Mar 91 16:21:09 PST

In article <1467@babcock.cerc.wvu.wvnet.edu>
bigbroth@cathedral.cerc.wvu.wvnet.edu (James M. Coleman) writes:
>I need to find out the ethernet address of the machine my
>program is running on ...

Why do you assume that you even *have* an Ethernet address?  The
machine I am typing at is on the Internet but is not on an Ethernet.
(It happens to have an Ethernet address anyway, as it is a Sparcstation
SLC.)  Any machine may have any number of Ethernet addresses, from 0
to infinity (well... :-) ).

Although the intent of the original Xerox Ethernet design was that each
machine would have a single Ethernet address (wired into its backplane,
or in a PROM, or---as in this SLC---in a piece of battery-backed-up RAM
[and what happens when the battery dies, anyway?  The TOD clock fails,
but the machine also forgets not only its ether address but also that
it is a Sun-4/XX.  Yow!]), there have been plenty of violations.  You
must not count on having exactly one ether address per machine.
-- 
In-Real-Life: Chris Torek, Lawrence Berkeley Lab CSE/EE (+1 415 486 5427)
Berkeley, CA		Domain:	torek@ee.lbl.gov