[Coco] [off-topic] cabling problems

Paulo Lindoso paulo.lindoso at gmail.com
Mon Sep 3 15:32:42 EDT 2012

Hi List,

Way back by the end of April, I posted this quick OT question.  I cannot
thank you enough for all your hints.  It actually took me this much time to
post back as I was flooded with work and had little time (and patience) to
sort this one out.

Some will remember: needed to drive a long Ethernet cable around my house
and although length was far from Ethernet limits (100m ~ 300ft), I couldn't
get my computers to talk.

SHORT EXPLANATION (for those who do not/need not read through the entire
Defective hub prevented any valid testing whatsoever.  Once the hub was
replaced, everything sorted itself out...

That said, before figuring out the problem was with the hub, I had already
cut the cable in two, so I had to resolder it together, which always
introduce some signal loss, but so far I'm OK with the final solution.  One
nice, long cable linking the two areas of the house! ;-)

>From the very beginning, I was puzzled by the fact that at one stage there
was electrical connectivity, but no logical connectivity.  Given the fact
that the cable was NOT that much long (about 45m or 140ft), noise was a
possibility but, as far as I thought, a small one.

This weekend I was decided to fix the problem.  My first approach to was to
go up the roof, sever the cable in two somewhere in the middle of the way,
and test each end.  That test came OK.

I then went down and (these ideas always come up a moment too late...)
decided that I should test every single bit of equipment/machinery/cabling
I was going to use.  I wasn't going to trust nothing this time...

Much to my surprise, when I hooked up my Mac and an old PC to the
hub/switch I was about to use, I got all sorts of funny connectivity issues
from my Mac.  Sometimes, it would signal it was not connected, sometimes it
would connect but wouldn't ping (same net, just the mac and the PC)... Very
bizarre.  The hub itself is a VERY old one, so it hit me whether my
"younger" mac could be having some signal incompatibility... To be honest,
I didn't poke around any longer once this was spotted...

By that time, I was very angry at myself, not having paid attention to this
before and having severed the cable... Anyway... bought new RJ45 jacks, a
brand-new hub/switch, replugged the ends and tested everything and voilá! :)

Sucess at first attempt....

Wrapped up everything by soldering together the severed cable (very boring
stuff to do up on a roof...), retested it OK and considered the job done
for all, feeling at the same time very happy AND angry.


On Fri, Apr 20, 2012 at 11:25 PM, Luis Fernández <luis46coco at hotmail.com>wrote:

> Hi I had that problem in my earlyin my case was the order of colors
> The terminals used are the 1-2 and 3-6 others are not used
> and these must be linked or do not exceed 20 meters
> example
> 1-2 intertwined protocols eg orange and orange-white
> and
> 3-6 intertwined with another color (same color, and white) example:
> blue-Azulblanco
> others do not matter
> ---------------------------------------------------------------------------------
> Making
> CoCoDskUtilPack V 1.0.10.zip
> http://cococoding.com/cocodskutil/ Thank Aaron Wolfe
> My personal blog: http://www.luis45ccs.blogspot.com
> ---------------------------------------------------------------------------------
> > Date: Tue, 17 Apr 2012 10:56:59 -0300
> > From: paulo.lindoso at gmail.com
> > To: coco at maltedmedia.com
> > Subject: [Coco] [off-topic] cabling problems
> >
> > Hi List,
> >
> > It's completely off-topic, but since it seems there are a few Electronic
> > Engineers in the list, I hope you can shed some light here...
> >
> > I have installed a Cat6 cable between two extremes at my place to build a
> > network bridge.  The cable extends itself for about 60m (that 180ft
> > roughly), which means it's  well within Ethernet parameters (100m,
> > right?)...
> >
> > The problem is: when tested with a standard wire tester (for electrical
> > connectivity), it passes; when you hook it to a router on one end and a
> > computer on the other, it doesn't work. It doesn't pick up an IP address
> > through DHCP and even if I force an IP within the network range, traffic
> > doesn't flow.  On my Mac, it shows it is "Connected", but nothing
> happens...
> >
> > I have changed plugs (cut the ends, re-wired with new RJ45), router and
> > tested with a different computer to no avail... so I am really at a loss,
> > here...
> >
> > Can any of the EEs in the "house" shed me some light or give me any hint?
> >  Is there any other Ethernet limitation I am not aware?
> >
> > Thanks for any help!
> >
> > Paulo
> >
> > --
> > -------------------------------------------------------------
> > Paulo Lindoso
> > paulo.lindoso at gmail.com
> > http://about.me/pbal<
> http://email.about.me/wf/click?c=e86tqVWFYsEogZdu8cwmbpAZwRtFkPjZS8Z3nwSDfjU%3D&rp=TDQggGXPgxMn1%2FQoMR%2F7Bsr00fO9wne%2B4zDSBQ93vWI1BH%2FOlrnU7zrQ0H0iAWgQyYyB6YfryJhLcifwbBLZ98yd6yex7cp06Yzq3Q1SplHrq%2FIu7OFPSwv8LqPdUbWL&u=njPbVRRXSvmg3PMz9cXBSg%2Fh0
> >
> >
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Paulo Lindoso
paulo.lindoso at gmail.com

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