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Date: Mon, 11 Aug 1997 17:35:40 -0700 (PDT)
From: Tom Samplonius <tom@sdf.com>
To: David Greenman <dg@root.com>
cc: hackers@freebsd.org
Subject: Re: fxp driver full duplex packet loss problem 
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On Mon, 11 Aug 1997, David Greenman wrote:

> >  I have a Intel Etherexpress Pro100/B conneted into a 10BT port on a
> >lightly loaded Catlyst 1900 etherswitch.  The system is running 2.2-stable
> >(last week), and traffic ranges from about 50 to 150KB/s output (as
> >measured with netstat -I fxp0 -w 1)
> >
> >  When I use "link0 link2" to enable full-duplex operation, I start seeing
> >about 1 to 4% packet loss (measured with ping to and from the server).
> >When I disable full-duplex, the packet loss disappears.
> >
> >  Is it safe to change the full-duplex vs. half-duplex on-the-fly?  Should
> >I power-cycle/reboot between changes?
> >
> >  Anyone else running this card in this kind of configuration?
> 
>    At least some Cisco fast ethernet interfaces (those on the 7000/7500 series
> routers, for instance), don't support auto-negotiation. So when you force full
> duplex on your end, the Cisco is still in half duplex. The behavior you're
> describing is indicative of this.

  I'm only running 10BT ethernet, not fast.  That isn't a problem is it?
There seems to be a lot of beating around the bush in the Cisco docs about
full-duplex on 10BT ports.

  The Catalyst 1900 switch is supposed to auto-negotiate full-duplex.  It

>    To fix this, you'll need to set full duplex in the Cisco as well.
> 
> -DG
> 
> David Greenman
> Core-team/Principal Architect, The FreeBSD Project
> 
> 

Tom