yay for stubborn network cable.

[Jayce]

I've got a couple boxes of 1,000 foot Cat 5e cable. I'm wiring up a school for wireless. I put about a dozen lines in the ceiling, thinking I would get the hardest stuff done first and start with the runs of cable that are farthest away from the network closet. lolololol.

So I crimp everything, B standard, everything looks good, blah blah. Easy enough.

I wanted to test each line, so I plugged the lines in empty ports on a typical 10/100 network switch in the closet that is currently active and in use. Then I walked around to each line and plugged them in individually to my laptop.

Not a single line worked.

-Each port on the switch was tested and works.
-Each line I pulled wasn't twisted, snagged, or ripped.
-Each end is B standard crimped.
-Checked pattern of wires and quality of crimp, looks almost machine-made.

I have no idea what's up with this. I have made hundreds of network cables. I've had my fair share of failed lines, but, seriously... a dozen lines and not a single one works?

Is it friday yet?

 

[oldskool]

Do you have access to an Ethernet cable tester ? That is a sure-fire way to find out if they are good. We use those at work when we have a problem of that sort of nature.

 

[Jayce]

I do, but at the time it was being used, so I was simply using my laptop to see if I get active ethernet lights on the ports.

I'm pretty certain we have, not 1, but 2 bad boxes of cable, seeing as though I ran these cables in pairs from 2 boxes and every line except 2 is bad. The other 2 magically started working today.

I don't understand it, but holy ****ing **** am I ever ****ed. The last thing anybody wants is to work a 14 hour day and come in the next day realizing, OH WAIT LOL ALL THE OVERTIME YOU DID YESTERDAY WAS FOR NOTHING CAUSE THE CABLE IS BAD ROFL!

EDIT - My boss just called me and I gave him the scoop. He gave his 2 cents on the issue as he ran into this problem before. He said certain combinations of certain RJ45 connectors + cat 5e cable can be hit or miss, and that he's ran into RJ45 ends that have bigger pins than others, and that one bag of RJ45's he got had huge pins that if you crimped them down extra hard, it actually ripped through the wire and didn't make a connection solid enough to grab connectivity.

The lightbulb in this situation is I crimped those suckers down mad hard just because I wanted them done precisely right. I didn't think about this, but I'll give it a shot tomorrow with slightly lighter crimp jobs and see how it does.

 

[Hefemeister]

Well that sucks. How long is the run you made?

 

[Jayce]

Well that sucks. How long is the run you made?

I made about a dozen runs of cable, emptying two boxes of 1,000 foot cable.

weeeeeeeeeeeeeeeeeeeeeeeeeeeeee

 

[oldskool]

I do, but at the time it was being used, so I was simply using my laptop to see if I get active ethernet lights on the ports.

I'm pretty certain we have, not 1, but 2 bad boxes of cable, seeing as though I ran these cables in pairs from 2 boxes and every line except 2 is bad. The other 2 magically started working today.

I don't understand it, but holy ****ing **** am I ever ****ed. The last thing anybody wants is to work a 14 hour day and come in the next day realizing, OH WAIT LOL ALL THE OVERTIME YOU DID YESTERDAY WAS FOR NOTHING CAUSE THE CABLE IS BAD ROFL!

EDIT - My boss just called me and I gave him the scoop. He gave his 2 cents on the issue as he ran into this problem before. He said certain combinations of certain RJ45 connectors + cat 5e cable can be hit or miss, and that he's ran into RJ45 ends that have bigger pins than others, and that one bag of RJ45's he got had huge pins that if you crimped them down extra hard, it actually ripped through the wire and didn't make a connection solid enough to grab connectivity.

The lightbulb in this situation is I crimped those suckers down mad hard just because I wanted them done precisely right. I didn't think about this, but I'll give it a shot tomorrow with slightly lighter crimp jobs and see how it does.

Interesting, the crimpers we use close to a certain depth, so the amount of pressure is non-applicable - with ours, that is. It crimps and stops at a certain point, so squeezing harder does nothing with the particular tools we use.

I will say, in one of my networking classes we were making these jumpers up and where I have made oodles of them before I was just buzzing right through but one thing I noticed is the crimpers they were using were IMO junk. The ones we use at my job (military contractor) are high quality and so I wonder if that might be the difference in some cases. I'm sure it does.

 

[Jayce]

Yeah, crimpers can make a night or day difference. I've used the same pair of crimpers since I was in tech school though, and mine have worked great with other cable so I didn't really see it applicable to blame my crimpers when all along they hadn't had any other issues.

It's just so **** baffling... Why did I sign up for IT again?

 

[oldskool]

Yeah, crimpers can make a night or day difference. I've used the same pair of crimpers since I was in tech school though, and mine have worked great with other cable so I didn't really see it applicable to blame my crimpers when all along they hadn't had any other issues.

It's just so **** baffling... Why did I sign up for IT again?

^ LOL ! The prestige, of course !

 

[Jayce]

Okay, so... I'm going to bounce back and forth between white wire and blue wire. The blue wire is ethernet wire we have laying around and the white wire is the new ethernet wire we got that seems to be problematic. However, both are still Category 5e wire.

So I decided to get tricky with a little test here that was suggested to me by another techie in the department... I first put a blue cable in the ceiling in place of the one white cable that was acting up. I was really sloppy with it, pulling hard on the cable and just kinda slapped ends on it - worked first try. Okay, great. So I took an extra section (20ft) of this blue cable and hooked up a multimeter to the individual 8 wires to check resistance. The blue cable yielded .05 on every single wire instantly.

I did the same on a similar length white cable. On most of the wires I got .05, but it seemed to bounce around a bit until it leveled off at .05. It didn't just BAM hit .05 like the blue cable did. I'd say 5/8 wires on the white cable did that. The remaining 3 cables I got other numbers, ranging anywhere from .02 to 1.5. I can't help but to wonder this variation was enough to knock the signal off. Perhaps that might explain why I got power lights from the cable, but not connectivity lights... because these cables are going to run with POE access points. The APs must have been seeing some sort of power cause they lit up, however, the connectivity portion was probably too off the wall to pinpoint an active connection from the console switch. I also tested these lines with my laptop, with the other ends of the cable in the network closet being hooked up to a typical 10/100 Dell switch that I know works. That too failed to connect.

The above was done with 20 ft runs of cable, for both the blue and white. I ended up pulling another cable out of the ceiling, a white one, at about 60 foot. That sucker gave me even more off the wall numbers than .02 to 1.5... I got 2.9 on the one wire I tested out of the 8 in the cable.

But, fortunately, gorilla tape exists, and I'll be able to slap on the new cable we get to the old white cable and just yank it through the ceiling.

This has by far been the most baffling network problem I had to troubleshoot. And considering I wanted this network to be wired by monday, maybe not functional, but at least WIRED, it's a real crapper to realize those hours of work yielded nothing positive except a learning experience I wished I hadn't had to l earn the hard way.

Yayyyyyyyyyyyy for monday tomorrow...