Odd network issue ... *very* slow scp between two servers
don at sandvine.com
Sun Mar 7 16:52:29 PST 2004
From: Marc G. Fournier [mailto:scrappy at hub.org]
> On Sat, 6 Mar 2004, Tim Wilde wrote:
> > On Sat, 6 Mar 2004, Marc G. Fournier wrote:
> > > I have two servers on the same network switch, sitting
> one on top of the
> > > other ... one is running an em (Dual-Xeon 2.4Ghz) device,
> the other an fxp
> > > (Dual-PIII 1.3Ghz) device ...
> > Is it a Cisco Catalyst switch? If so, you need to switch
> the em's to
> > autoselect, on both the server and switch end. For some
> reason, the em
> > driver will not properly lock down its rate when talking to a Cisco
> > Catalyst switch. At least, I had an identical problem with
> em's talking
> > to a Catalyst 2950 and that was the fix I came up with.
> Give it a try and
> > see how your results go.
> Note that forcing it to 100baseT half-duplex (or 10baseT/UTP
> corrects the problem ... turns out it is only in full-duplex
> mode that its
> hosed ...
Actually, this is normal behaviour according to the 802.3u spec.
If a device in 'auto' mode is connected to one that is
forced 100FDX, the auto one will negotiate 100HDX.
For example, see HP faq:
has a nice table of this.
More information about the freebsd-net