Path: utzoo!attcan!uunet!cs.utexas.edu!rice!sun-spots-request
From: mea@sparta.com (Mike Anderson)
Newsgroups: comp.sys.sun
Subject: Re: Rarpd problems under 4.1
Keywords: Hardware
Message-ID: <9457@brazos.Rice.edu>
Date: 29 Jun 90 12:05:02 GMT
Sender: root@rice.edu
Organization: Sun-Spots
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Approved: Sun-Spots@rice.edu
X-Refs:  Original: v9n231
X-Sun-Spots-Digest: Volume 9, Issue 243, message 1

Are you aware that when you have two ethernet controllers in a Sun
backplane that they have the same 48-bit ethernet address?  Yes, Virginia,
this may seem a bit strange (and a somewhat undocumented "feature"), but
it is true.  This caused me (and my machine) some amount of confusion at
first.  If both ethernet controllers are attached to the same LAN segment,
it is possible for the IP addresses to get a bit screwed up when ARP
requests go out and two interfaces respond at the same address :-(.
However, there is a fix.  As root, use the "ifconfig" command and the
"ether address family" attribute to change the ethernet address of ie1 (I
assume your using ie devices, but this would work for other devices as
well) to an unused ethernet address (excercise some caution here to pick a
DEFINATELY UNUSED address or the problem will remanifest itself).  Sun
evidently figured that the only use for two ethernet controllers was to
act as a bridge between two completely separate LANs.  I also believe that
ie1 actually has a separate ethernet address prom (can anyone confirm or
deny this?), but at a quick glance I couldn't pick it out on the board.
Good Luck...

Mike Anderson        "It is useless for sheep to pass resolutions in favor
SPARTA, Inc.          of vegetarianism while wolves remain of a different
mea@sparta.com        opinion."
(703) 448-0210                     William R. Inge, D.D.  1860-1954