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Builder wired Cat 5e, only 1 of 3 gets an IP

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Barddzen

Occasional Visitor
I purchased a house built ~5 years ago and the builder wired cat5e for land line phones and had RJ11 ports in 3 locations throughout the house. I replaced all of the RJ11 with RJ45 and re-crimped the media panel cables.

After labeling everything (locations) I tested each line in each room and my tester (Master CT468) lit up all 8 wires as properly receiving a signal.

However, only 1 of the 3 ethernet lines run from the builder work properly. The odd thing is with my signal tester I get all 8 wires reporting properly, but won’t connect and get an IP. The lights on the switch don’t even light up. I tried all the usual suspects: bad crimp on both ends, cable, switch port, etc. and nothing seemed to resolve the issue.

My gut is telling me there are stapled lines somewhere but I haven’t got up in the attic and traced things yet. Before I start crawling, is there anything else I can do to diagnose the other two lines?
 
I purchased a house built ~5 years ago and the builder wired cat5e for land line phones and had RJ11 ports in 3 locations throughout the house. I replaced all of the RJ11 with RJ45 and re-crimped the media panel cables.

After labeling everything (locations) I tested each line in each room and my tester (Master CT468) lit up all 8 wires as properly receiving a signal.

However, only 1 of the 3 ethernet lines run from the builder work properly. The odd thing is with my signal tester I get all 8 wires reporting properly, but won’t connect and get an IP. The lights on the switch don’t even light up. I tried all the usual suspects: bad crimp on both ends, cable, switch port, etc. and nothing seemed to resolve the issue.

My gut is telling me there are stapled lines somewhere but I haven’t got up in the attic and traced things yet. Before I start crawling, is there anything else I can do to diagnose the other two lines?
Did you follow T568B wiring standard? Builders/home wiring electricians usually do not do Ethernet correctly.
 
Bring a laptop to the switch, test the ports. If all good, you obviously have wiring issues. The wire itself or the connectors.
 
Did you follow T568B wiring standard? Builders/home wiring electricians usually do not do Ethernet correctly.
Absolutely. They ran Cat5e and only had two of the 8 wires connected on the RJ11 for land lines, they left the others just wrapped at each outlet. I trimmed up everything, added a new jack at the panel (and validated the crimp) and used keystone punch downs at each of the wall outlets and confirmed those as well.
 
Bring a laptop to the switch, test the ports. If all good, you obviously have wiring issues. The wire itself or the connectors.
8 port switch

1 - In from Eero router: Good
2 - Doesn’t work (laptop)
3 - Doesn’t work (laptop)
4 - Connected to Office, works at switch and wall (laptop)
5-8 - Works with laptop

I connected the Main BR and Kitchen cables to the working ports (on the switch) and still no IP at the wall. As I said above, if I use my testing tool, there is signal on all 8 wires and from the test tool it “looks” like it’s working, but clearly not.

Could the fact that there are non-working ports result in the issues I’m experiencing?
 
If your laptop works when connected to confirmed working LAN ports, you definitely have wiring issue somewhere after the switch. Ports 2-3 may have been zapped in a thunder storm, it happens. They may need cleaning only. I would replace the switch down the road, but your current issue is in wiring.
 
If your laptop works when connected to confirmed working LAN ports, you definitely have wiring issue somewhere after the switch. Ports 2-3 may have been zapped in a thunder storm, it happens. They may need cleaning only. I would replace the switch down the road, but your current issue is in wiring.
That’s what my experience and gut was telling me, but thanks for double checking my work.
 
You perhaps have tried to save some cable length when doing the connectors. Old cables may oxidize up to few inches after the cable end. You obviously know what are you doing and sometimes routine tasks leave very simple issues undetected. I'm sure you'll find shortly what the issue is.
 
You perhaps have tried to save some cable length when doing the connectors. Old cables may oxidize up to few inches after the cable end. You obviously know what are you doing and sometimes routine tasks leave very simple issues undetected. I'm sure you'll find shortly what the issue is.
In the MBR the jerk builder shorted the wire a ton, I barely had any to work with so that could entirely be the case there to the point that, but kitchen had plenty so I may just try to repunch that at the wall.

At the switch I trimmed a lot at the box before I put the jacks on so I feel pretty confident there.

I do have a 4th wire that is run somewhere but only found 3 jacks in the house, will need to do an attic crawl to figure that out.
 
You don’t need forum’s help. Just a little luck to find faster where the fault is. :)
 
tried all the usual suspects: bad crimp on both ends,
OP, to clarify, did you crimp the ends with rj45 8p8c plugs, or punch down with keystone jacks?

If any crimps, what brand crimper and plugs?

Note: crimping is not easy. Well, crimping successfully is not.

If you used keystones: what brand? And you punched down with a good quality punch down tool?

The Cat5e cable: solid or stranded, and can you see the brand of cable printed on the jacket?

After your attic reconnaissance, can you let us know what you find—if you make it back??
 
8 port switch

1 - In from Eero router: Good
2 - Doesn’t work (laptop)
3 - Doesn’t work (laptop)
4 - Connected to Office, works at switch and wall (laptop)
5-8 - Works with laptop
If two of the switch’s ports are demonstrated to not work, I’d want to try an entirely different switch, at least for testing … even if supposedly connecting to a “working” switch port. (What’s to say the port works for a short Ethernet patch cable but not a longer run.).
 
If any crimps, what brand crimper and plugs?

Note: crimping is not easy. Well, crimping successfully is not.
I’d read a few threads recently debating the ease/difficulty of getting a proper crimp for a RJ45 connector, given all the possible mismatches between solid vs stranded cable, and cable gauge. (edit: fresh example from Reddit) If spare length isn’t an issue at the panel, re-terminating using the same keystone punchdowns as used in-room might be an interesting test.

if you make it back??
Chuckle.
 
Last edited:
I purchased a house built ~5 years ago and the builder wired cat5e for land line phones and had RJ11 ports in 3 locations throughout the house. I replaced all of the RJ11 with RJ45 and re-crimped the media panel cables.

After labeling everything (locations) I tested each line in each room and my tester (Master CT468) lit up all 8 wires as properly receiving a signal.

However, only 1 of the 3 ethernet lines run from the builder work properly. The odd thing is with my signal tester I get all 8 wires reporting properly, but won’t connect and get an IP. The lights on the switch don’t even light up. I tried all the usual suspects: bad crimp on both ends, cable, switch port, etc. and nothing seemed to resolve the issue.

My gut is telling me there are stapled lines somewhere but I haven’t got up in the attic and traced things yet. Before I start crawling, is there anything else I can do to diagnose the other two lines?
I think you divided 1 cable to 3 ports.
 
I think you divided 1 cable to 3 ports.
I assumed the same thing unti rereading the statement: “I replaced all of the RJ11 with RJ45 and re-crimped the media panel cables.”

This makes it seems as though the associated cables are home run and were identified.
 
I assumed the same thing unti rereading the statement: “I replaced all of the RJ11 with RJ45 and re-crimped the media panel cables.”

This makes it seems as though the associated cables are home run and were identified.
Yes. I saw it.
Our first thought may correct.
1. 8 wires as properly receiving a signal.
2. only 1 of the 3 ethernet lines run.
I think he doesn't know how to terminate cables properly.o_O
 
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