Subject: Re: ipv6 on sun3
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Gordon W. Ross <gwr@netbsd.org>
List: port-sun3
Date: 07/16/1999 01:17:47
Manuel Bouyer writes:
 > On Wed, Jul 14, 1999 at 12:44:21AM +0900, Izumi Tsutsui wrote:
 > > bouyer@antioche.lip6.fr wrote:
 > > 
 > > > here's what I got on my sun3/60:
 > > > le0: not multicast capable, IPv6 not enabled
 > > 
 > > > Is it a limitation of the driver or hardware ?
 > > 
 > > sun3 (not sun3x) config files have "options LANCE_LEVC_BUG" and
 > > multicast is disabled in lance.c.
 > 
 > Well, I removed LANCE_LEVC_BUG from my kernel, and I can now ping6 my sun3
 > (it's ready to enter the 21th century :).
 > I didn't notice any problems but I only use the network to log in, and sup
 > the sources (I have local disks).
 > Does someone know what the bug it, and what effects it has ?

The bug is that LANCE Rev. C chip may sometimes give you packets
with garbage inserted where the first bits should be, with the
correct bits shifted later.  So instead of the destination MAC
address at the beginning, you get something random looking.

The work-around is to examine the beginning of the packet and
throw away anything that's not for us (my MAC or broadcast).

I think the LANCE Rev. C chip was only used in the 3/50, so on a
3/60 it might be worth your time to try building a kernel without
the LANCE_REVC_BUG option and see how it goes...

I wish the Rev. C bug work-around could be switched on or off
at run time with a global variable.  Someday project...

Gordon
(Not quite completely dissappeared yet:)