Cable nightmare

I have some cat5 run under my house, after hours of troubleshooting I
determined one of the connecters was bad. I bought a crimping tool and
RJ45 connectors, cut the ends off and discovered I have 4 colored wires
and 4 solid white wires, rather than white/color and color pairs like
normal. It's a lot of very dirty work to pull the cable out, which I'd
have to do to use a multimeter to label the identical white wires
myself. This is a 10/100BaseT network, which apparently only uses 4 of
the 8 wires, so I use this scheme:

1 - green
2 - blue
3 - brown
4 - white
5 - white
6 - orange
7 - white
8 - white

And of course the whire wires could be connected to any of ther other
white wires on the other end, I have no way to tell, but 4/5/7/8
shouldn't be used so it shouldn't matter. When I plug the cable in the
link light comes on at the linux system and on the hub at the other end
of the house, and the activity light on both starts flashing like mad
and never stops. All ping attempts on the system I'm trying to connect
with this cable give me "destination host unreachable". Routing table
is very simple and correct, interface is up, I can ping my IP
(192.168.2.8), can't ping my gateway (192.168.2.1). Routing table has
correct entry for that subnet.

I've put an insane amount of hours into extending network access into
this room, it's truly ridiculous, and now after all this I'm
considering buying a whole new cable and routing it beside this one.
Any other suggestions welcomed, my second option is to flip out and
remove the cable with a sledgehammer from inside.

On 22 Jun 2006 16:54:22 -0700, hobosalesman@gmail.com wrote:

> And of course the whire wires could be connected to any of ther other
> white wires on the other end, I have no way to tell,

sure you do, clip/tie white to another color at one end, go back to
other end and hunt for the shorted pair to get white's pin number.

On 22 Jun 2006 16:54:22 -0700, hobosalesman@gmail.com
<hobosalesman@gmail.com> wrote:

> 1 - green
> 2 - blue
> 3 - brown
> 4 - white
> 5 - white
> 6 - orange
> 7 - white
> 8 - white
>
> And of course the whire wires could be connected to any of ther other
> white wires on the other end, I have no way to tell, but 4/5/7/8
> shouldn't be used so it shouldn't matter.

But it does matter because you are supposed to have twisted pairs to
prevent the send and receive from interfering with each other. If you
just randomly hook up the wires you probably will end up with one wire
from one pair and one wire from a different pair being used together.
Which will be unreliable at best and probably won't work at all if the
run is of any length. Your symptom of the link light "going crazy"
indicates that you may have a crosstalk problem.

Maybe you could go to Radio Shack and get a tone tester. Like the phone
company uses to trace wires.

Or, you could hook different value resistors between the pairs (1-2,
3-6, etc) on the end that has the factory connector on it. Maybe get
one of those RJ-45 jacks with punch terminations to facilitate this
(Radio Shack and Home Depot have them). Then use a meter to measure the
resistance on the far end. You should be able to deduce which wires are
pairs from that.

But first, look real carefully at the wires. Maybe there is a color
stripe on the "white" wires, but it is intermittent or very faint.


--
-| Bob Hauck
-| A proud member of the unhinged moonbat horde.
-| http://www.haucks.org/

Bit Twister wrote:
> On 22 Jun 2006 16:54:22 -0700, hobosalesman@gmail.com wrote:
>
> > And of course the whire wires could be connected to any of ther other
> > white wires on the other end, I have no way to tell,
>
> sure you do, clip/tie white to another color at one end, go back to
> other end and hunt for the shorted pair to get white's pin number.

Moot point, I just tested another cable that was under there does the
same thing, works intermittantly. Wiggle the cable the link light goes
out. THe cables are fucked, I wasted a dozen hours and now I'm going to
buy more wire and rip this old shit out, right after I destroy
something.

Bob Hauck wrote:
> But it does matter because you are supposed to have twisted pairs to
> prevent the send and receive from interfering with each other. If you
> just randomly hook up the wires you probably will end up with one wire
> from one pair and one wire from a different pair being used together.
> Which will be unreliable at best and probably won't work at all if the
> run is of any length. Your symptom of the link light "going crazy"
> indicates that you may have a crosstalk problem.

I think that's probably what's happening then. I've reached the limits
of my patience though, I'm just buying a new cable.

> But first, look real carefully at the wires. Maybe there is a color
> stripe on the "white" wires, but it is intermittent or very faint.

That's what I thought, I ripped up 5 feet of cable and examined it in
full sunlight, 4 identical white wires.

Thanks for the help though, at least I learned a few things about
network cables.

hobosalesman@gmail.com writes:

> Bob Hauck wrote:
> > But it does matter because you are supposed to have twisted pairs to
> > prevent the send and receive from interfering with each other. If you
> > just randomly hook up the wires you probably will end up with one wire
> > from one pair and one wire from a different pair being used together.
> > Which will be unreliable at best and probably won't work at all if the
> > run is of any length. Your symptom of the link light "going crazy"
> > indicates that you may have a crosstalk problem.
>
> I think that's probably what's happening then. I've reached the limits
> of my patience though, I'm just buying a new cable.
>
> > But first, look real carefully at the wires. Maybe there is a color
> > stripe on the "white" wires, but it is intermittent or very faint.
>
> That's what I thought, I ripped up 5 feet of cable and examined it in
> full sunlight, 4 identical white wires.
>
> Thanks for the help though, at least I learned a few things about
> network cables.

I've never seen CAT 5 cable that hasn't had stripes on its white wires.
However, one of the white wires will be twisted around orange--treat it
as white with an orange stripe. Similarly for green, blue and brown.
Then, attach a pair to pins 1&2, another pair to 3&6, another pair to
4&5 and the last pair to 7&8. Use the same color/white assignment
on each end of the cable.

If you want to follow standards, use EIA/TIA 568B:

pin 1 -- white/orange
pin 2 -- orange
pin 3 -- white/green
pin 4 -- blue
pin 5 -- white/blue
pin 6 -- green
pin 7 -- white/brown
pin 8 -- brown

Scott
--
Scott Hemphill hemphill@alumni.caltech.edu
"This isn't flying. This is falling, with style." -- Buzz Lightyear

<hobosalesman@gmail.com> wrote in message
news:1151020462.544496.50880@m73g2000cwd.googlegro ups.com...

> I have some cat5 run under my house, after hours of troubleshooting I
> determined one of the connecters was bad. I bought a crimping tool and
> RJ45 connectors, cut the ends off and discovered I have 4 colored wires
> and 4 solid white wires, rather than white/color and color pairs like
> normal.

You ain't got cat5 then. cat5 is more than just 8-strand, it's a particular
twisted pattern among the strands. Coloured/white is in the specs for cat5.

> This is a 10/100BaseT network, ...

Not unless you install cat5e or greater it ain't.

hobosalesman@gmail.com wrote:

> Moot point, I just tested another cable that was under there does the
> same thing, works intermittantly. Wiggle the cable the link light goes
> out. THe cables are fucked, I wasted a dozen hours and now I'm going to
> buy more wire and rip this old shit out, right after I destroy
> something.

I understand that sentiment all too well sometimes...
FWIW: Here's some links with detailed info and pics about
Ethernet/Cat5e wiring;

(watch for line-wrapping)
<http://www.bluemax.net/techtips/networking/Wiring_Tips/Wiring100TX/letsmakesomecables.htm>

<http://www.duxcw.com/digest/Howto/network/cable/cable5.htm>
<http://www.mycableshop.com/techarticles/patchcabbes.htm>

Regards

On Thu, 22 Jun 2006 20:25:53 -0400, Bob Hauck wrote:

> If you just randomly hook up the wires you probably will end up with
> one wire from one pair and one wire from a different pair being used
> together. Which will be unreliable at best and probably won't work at
> all if the run is of any length.

Even a short run may not work at all if your cards are fussy. I once
found an incorrectly wired 10m run that worked fine with a RTL9139 but
refused to work with a CNet Technology card until it was rewired. The
8139 might have been clever enough to switch to half duplex - didn't check
for that.



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