Subject: Re: de0 on 164LX gives poor throughput
To: Thor Lancelot Simon <>
From: Manuel Bouyer <>
List: port-alpha
Date: 04/10/1999 16:35:44
On Fri, Apr 09, 1999 at 01:49:52PM -0400, Thor Lancelot Simon wrote:
> DO NOT DO THIS!  Hardwire the _switch_ end of the link to full-duplex, and
> let the card autoselect.  I've been testing for about a week now with several
> "de" cards and switches and if the card is set to full-duplex, our driver
> seems to completely screw up the negotiation with the switch somehow leading
> to awful performance.  Leaving both ends on "auto" of course doesn't always
> work well, either -- Cisco switches are notorious for screwing this up --
> and all that I've found that *does* work reliably in every case is switch
> hardwired to "full", card on "auto".

I guess it depends on switches and board. I have 3com switches here,
and different models of DEC-based boards, all on i386. All the switch ports
are unwired. some boards don't properly negotiate and end-up in 10Mbs mode,
and won't work it I set them to 100Mbs (half or full-duplex). Some negotiate
100Mbs full-duplex properly. Some don't but will work if I hardwire them
to 100Mbs full-duplex.

Manuel Bouyer <>