Re: setting duplex mode on ethernet cards

[Paul Furness <paul.furness@vil.ite.mee.com>]

Yeah, thanks, I know it's not usually the right way to do it. We thought
we might possibly have a faulty switch, and I also thought that the
version of the kernel I had compiled might have gone wrong.

It turned out to be a fault on the cat 5E patch panel (some almost but
not quite touching bare wires) that was causing all kinds of havoc.

It is now all behaving itself properly, including autoneg to 100M FD.

I should have learned by now: "Check no.1 - is it plugged in right?"

:)

P.


On Mon, 2002-06-17 at 17:10, Glynn Clements wrote:
> 
> Paul Furness wrote:
> 
> > Thanks, and thanks to everyone who made some suggestions.
> > 
> > mii-tool worked just great to tell me what I was using (100M HD) and
> > putting:
> > 
> > options 3c59x full_duplex=1
> > 
> > in /etc/modules.conf persuaded the card to go at 100M FD.
> 
> Are you aware that forcing full-duplex is usually the wrong thing to
> do?
> 
> If the network is switched, full-duplex should get enabled
> automatically. If the network isn't switched, enabling full-duplex
> will usually have an adverse effect upon performance, due to
> collisions.
> 
> IOW, are you using full-duplex because you just assumed that it would
> better than half-duplex, or are you aware of the issues, and know of a
> particular reason why, in spite of the fact that the driver doesn't
> enable full-duplex, it really is OK to use it?
> 
> -- 
> Glynn Clements <glynn.clements@virgin.net>
> 
-- 
Paul Furness

Systems Manager

Visual Information Laboratory
Mitsubishi Electric ITE BV