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Date:      Wed, 26 Dec 2001 13:02:11 -0500
From:      Allen Landsidel <all@biosys.net>
To:        sthaug@nethelp.no
Cc:        freebsd-stable@freebsd.org
Subject:   Re: 4.5 PRERELEASE - Call for testing
Message-ID:  <5.1.0.14.0.20011226125628.00b08e10@rfnj.org>
In-Reply-To: <2353.1009389293@verdi.nethelp.no>
References:  <Your message of "Wed, 26 Dec 2001 12:45:08 -0500"> <5.1.0.14.0.20011226123443.00aafe40@rfnj.org>

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At 06:54 PM 12/26/2001 +0100, you wrote:
> > This is a pretty silly, uninformed response.  First, just off the top, it
> > doesn't make any sense.  What if you have a "dumb" auto-negotiating
> > switch?  I have such a switch, a Linksys EtherFast II 16port 
> 10/100.  There
> > is no way to tell the switch what setting any of the ports should be in,
> > nor have I ever needed such an option.
>
>As long as auto-negotiation works (and any cards plugged into this switch
>are set to auto-negotiate), you should be fine.

Autonegotiation should always work.  It's a standard.  Autosensing isn't, 
and that's why it's been replaced/superceeded.

> > The switch has never failed to negotiate the correct setting with whatever
> > is plugged into it, nor has it ever had a problem matching whatever I
> > assign to an interface I have plugged into it.
>
>If whatever you plug into the switch is set *not* to autonegotiate (ie.
>is set manually to full duplex), you cannot count on the switch to get
>the duplex setting correct. In some cases it'll work, in other cases
>it won't. If it always works for you - great. But don't count on this
>working as a general rule - there are plenty of examples to disprove it.

You're confusing two things, auto-negotiation and auto-sensing, as is Tom.

Auto-negotiation is *always* on, even if you force a certain 
speed/duplex.  This is what tells the switch/hub/whatever it's settings.

Auto-sensing is the old method if determining the line speed only, not the 
duplex, and was full of all kinds of problems.  As a general rule, if you 
have an auto *negotiating* switch/hub and an auto *negotiating* NIC, then 
this will always work.

If one or or the other is auto *sensing* then problems may occur, but this 
is why the two terms exist, and why auto-sensing hasn't been available for 
quite some time.

Tom's reply stated that if you turned auto-negotiation off by forcing a 
speed/duplex setting on either end that it would cause problems.  This 
simply isn't true because you can't turn auto-negotating off, and forcing a 
speed/duplex setting doesn't do this.. what it does do is forces the other 
end to negotiate this setting, if it is available.  The negotiation still 
occurs.


> > I think perhaps you should stop repeating yourself and go read up on how
> > autonegotiation actually works.. what you've been saying is only true (in
> > my experience) if you're plugging one NIC directly into another via a
> > crossover cable.
>
>He's certainly not the only one who firmly believes that one end set to
>auto-negotiate and one end set manually is a good way to create problems
>for yourself.

See above.



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