Long ethernet cable, how to find the bad section?

[CaptainEven]

I have a long ethernet cable (200ft in length) that is connecting two buildings across a small dirt road. The cable goes up and over the road and is not in danger of being run over or struck by cars or trucks. My current issue is finding where the fault is in the currently cable. My Ubiquiti UnFi Access Point is giving a message of "Connected (10 FDX)" which according to Ubiquiti support means there is a cabling issue but with 200 feet of cable I am unsure where. I tested the cable with my HDE Network Cable Tester and it tested fine with all 8 lights displaying as expected. There is about 3ft of slack on either end of the cable so I can cut and recrimp but I'd rather be specific than taking a hack and slash approach.

Thoughts? Ideas? Thanks.

 

[bill001g]

It will be cheaper to rerun a completely new cable than to even rent a tester. Many people call them fluke meters but that is a brand name. Many of the models can tell you to a point where the cable is damaged. It is easy if it is completely broken but when it is something like extra resistance in the middle of a run even those meters can not tell for sure. It can see for example a patch panel int he path but it does a much better job on fiber than copper for that type of thing.

In most cases it is the ends of the cable so you can just cut them off and reterminate them.

With outdoor cable the issues are generally the insulation has deteriorated on one or more pairs. This is especially true if you ran indoor cable outdoors with no protection. The sun actually does more damage than water, but if you buried it then some soil will eat it in no time.

 

[mudpuppet]

Bill hit it pretty head on there. The easiest thing to do would be recrimp the ends and test again. If the cable wasn't properly shielded it could have deteriorated. Heck a visual inspection may even help spot if a bird got at the cable or something in a spot. I haven't had to run that much cable, especially outside, so I can't help too much but I would make sure you have some sort of weathershield on the cable you're using, or look in to it if you don't. You could probably get away with something like http://www.amazon.com/dp/B00AWQ13R6?psc=1 for CCA (and 1,000ft) and http://www.amazon.com/Outdoor-Waterproof-Ethernet-Direct-Shielded/dp/B002HFO8JA/ref=sr_1_fkmr0_2?s=pc&ie=UTF8&qid=1444921883&sr=8-2-fkmr0&keywords=weatherproof+full+copper+cat6 for a prefab one at 200ft and full copper.

 

[jsmithepa]

HDE Network Cable Tester[/url] and it tested fine with all 8 lights displaying as expected.

This kind of tester only tests for continuity, meaning completely on or completely off, it does not test for signal quality. For a tester that can tell you where along the cable is a problem you are looking at spending over usd$1,000.

 

[kanewolf]

Bill hit it pretty head on there. The easiest thing to do would be recrimp the ends and test again. If the cable wasn't properly shielded it could have deteriorated. Heck a visual inspection may even help spot if a bird got at the cable or something in a spot. I haven't had to run that much cable, especially outside, so I can't help too much but I would make sure you have some sort of weathershield on the cable you're using, or look in to it if you don't. You could probably get away with something like http://www.amazon.com/dp/B00AWQ13R6?psc=1 for CCA (and 1,000ft) and http://www.amazon.com/Outdoor-Waterproof-Ethernet-Direct-Shielded/dp/B002HFO8JA/ref=sr_1_fkmr0_2?s=pc&ie=UTF8&qid=1444921883&sr=8-2-fkmr0&keywords=weatherproof+full+copper+cat6 for a prefab one at 200ft and full copper.

I would not recommend using CCA cable for anything. Outdoor rated cable is important because the UV will break down the plastics. Since the tester you have is very simple, I would recommend verifying that you have the 568B color code correct on both ends. Having 8 wires connected is different than having 4 pairs correctly connected.

I do concur that if it isn't a termination issue, it is cheaper to get a new cable, verify it on the ground and then install it and re-verify it.

 

[CaptainEven]

Thank you, everyone, for this help. I'll go ahead and recrimp both ends of the cable but if it doesn't work we'll buy the outdoor rated cable and redo it entirely. Thank you!!

 

[kanewolf]

Are you using POE on the Ubiquiti? Is it possible that your long cable is causing too much voltage drop and the Ubuquiti is unhappy about that?

 

[CaptainEven]

The ethernet cable from the POE to Ubiquiti AP (UAP) is about 4 feet but the incoming LAN cable is about 200ft. It was working until we rerouted the cable and likely broke it somewhere. I'm going to recrimp it later this evening and hope the crimps were damaged in the rerouting as this very setup worked perfectly up until a the rerouting we did.

We have 12 UAPs here and they are amazing.

 

[kanewolf]

The ethernet cable from the POE to Ubiquiti AP (UAP) is about 4 feet but the incoming LAN cable is about 200ft. It was working until we rerouted the cable and likely broke it somewhere. I'm going to recrimp it later this evening and hope the crimps were damaged in the rerouting as this very setup worked perfectly up until a the rerouting we did.

We have 12 UAPs here and they are amazing.

This was an after-though on my part, but I could see someone using a POE switch and having the voltage drop be enough that the AP would be unhappy.... Since you have power near the AP with the injector close to the AP, that won't be a problem.

 

[CaptainEven]

Turned out to be a bad crimp on one end. I recrimped it and now all works as expected. Thanks to everyone who offered their suggestions and support!