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Date:      Sat, 26 May 2001 14:23:57 -0700
From:      "Ted Mittelstaedt" <tedm@toybox.placo.com>
To:        "Mike Oligny" <moligny@kanotech.com>, "Brian" <ircd@wrath.com>, <freebsd-questions@FreeBSD.ORG>
Subject:   RE: duplex mismatch or something bad like that?
Message-ID:  <000601c0e62a$2c9ee680$1401a8c0@tedm.placo.com>
In-Reply-To: <76928F3E231DE4478876350F08358336044AF9@kt-exchange.edmonton.kanotech.net>

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Unfortunately, the problem is that small shops that generally
don't have the money to spend $10 per patch cable usually have
a drawer with a cable crimper and a bunch of ends.  I've seen
that even Home Depot carries RJ45 crimpers and ends.  These
small shops also all have the property that since they are
small their runs are generally not very long.

As a result, the admins that are crimping up those drop cables
are doing naughty things like not following color codes,
not putting the twisted pairs to pins 1-2 and 3-6, pair-splitting,
using Type 66 punch blocks, and all kinds of other things that
would make your skin crawl.  These admins probably have never
seen a Pentascanner in their lives much less know how to use one.
They are getting away with all this rubbish because on a short
run you can get away with it.  So then they learn how to do things
wrong then think that this is how everyone does things everywhere.

Don't listen to this talk - read all of the documentation and
follow the standards rigoriously.  If you ever work in a truly
large shop with many hundreds of drops in it, if they catch
you pulling the crap that small shops do they will ban you from
the hubroom.

Incidentally, when I'm hiring network admins this is one of the
tests that I give them - I hand them a toolbox and 3 feet of
CAT-5 and ask them to crimp a cable.  If I don't see them check
the plastic ends to make sure that they are for the correct type
of wire, or set the wires in properly, or follow code, then that
tells me I'm dealing with an amateur, not a professional.

Ted Mittelstaedt                      tedm@toybox.placo.com
Author of:          The FreeBSD Corporate Networker's Guide
Book website:         http://www.freebsd-corp-net-guide.com


>-----Original Message-----
>From: owner-freebsd-questions@FreeBSD.ORG
>[mailto:owner-freebsd-questions@FreeBSD.ORG]On Behalf Of Mike Oligny
>Sent: Saturday, May 26, 2001 2:12 PM
>To: Brian; freebsd-questions@FreeBSD.ORG
>Subject: RE: duplex mismatch or something bad like that?
>
>
>> <snip>
>> 
>> > 6k/second is not a lot of fun.  Especially after doing stupid things
>> > like making new cables thinking that the old ones might 
>> have split pairs
>> > or something.  (Everyone I work with seems to think that it doesn't
>> > matter which wires you put where when making cables, as 
>> long as they go
>> > straight through...  is this a common misconception? Grrr...)
>> 
>> A lot of people are used to the niceties of newer nics that 
>> are smarter than
>> the people that make the cables.
>
>I'm not referring to incorrect polarity...  I don't think even the
>newest/best NIC can compensate for a split pair down two hundred feet of
>CAT5 cable.
>
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