Long Ethernet Cable Doesn't Work

[Bruno Del Rio]

Long Ethernet Cable Doesn't Work when I connect it to the Wall Jack, which is connected to this Trendnet Switch, and the Switch is connected to the DSL router/modem.

I was trying to hookup a PC with a slightly longer ethernet cable (40ft long that i made) from a room with an ethernet wall jack (which is 1 of the 12 ports derived from the Switch wired in the basement), but it doesn't work.

I'm certain the port from that wall jack connection works, as I tested it with a laptop using a short 6ft ethernet cable, and was able to connect to the internet. The 40ft cable should be fine as well as I tested by connecting one end to the PC and the other end to the actual DSL router/modem (stretching the cable like a straight line across the living room and thru the furniture to the closet that houses the router/modem). Now when I tried to connect the PC to the wall jack via this 40ft cable, I cannot connect to the internet. I see the green and orange lights on at the back of the PC, but from the PC screen's system tray, that computer icon shows a yellow triangle in the middle. I need to use this long ethernet cable because the PC sits from the opposite side of the room, which is about 10ft away from the wall jack.

I'm wondering if cable from the wall jack to the Switch in the basement is too long already, so adding the 40ft ethernet cable makes it too long that it doesn't connect. My rough estimate of the cable inside the wall jack to the Switch is less than 100ft. If a cat5e or cat6 cable is good for 100m, then it should not be a problem.

I'm stuck...
Help.

 

[makkem]

Hi
Distance should not be the problem.
Have you tried your laptop with the 40' cable ?

Could be you have crossed a couple of wires in the 40' cable and produced a crossover cable.
The modem could be detecting and compensating for this as most modern equipment does but the switch in the basement is not and so does not transfer data,also explaining the lights on the PC.

 

[Bruno Del Rio]

Hi
Distance should not be the problem.
Have you tried your laptop with the 40' cable ?

Could be you have crossed a couple of wires in the 40' cable and produced a crossover cable.
The modem could be detecting and compensating for this as most modern equipment does but the switch in the basement is not and so does not transfer data,also explaining the lights on the PC.

Yes, I tried the 40ft cable with the laptop, but it did not work. I checked the wires on that 40ft cable many times to make sure it's ok (done in the B standard). I even made another cable about the same length (it's a cat6 this time), but still doesn't work. It's leading me to think something to do with the length of the cable when connecting to the wall jack and the problem somewhere comes up.

 

[makkem]

It may be worth checking the connections in the wall jack and at the basement switch as a poor(high resistance) connection can have the effect of a long cable length.

 

[Bruno Del Rio]

It may be worth checking the connections in the wall jack and at the basement switch as a poor(high resistance) connection can have the effect of a long cable length.

How do I check the connections in the wall jack? Open up the wall plate, and extract the socket to see if the colored wires are punched down correctly? Same for the basement switch? See if the punch downs are solid? I can't distinguish what's poor or good. I'd imagine either it works, or it doesn't.

It's strange that a short cable would work, but a long cable doesn't.
****
I made another 25ft cat5 cable to test another wall jack in an adjacent room (it's also one of the 12 ports derived from the Switch in the basement), and it works fine. So I brought that same 25ft cable back to the original room (with the wall jack problem), and tried to connect, but it still doesn't work. ahhh!!!!

I think I should make a 568-A standard cable just to try it out.
What other ways should I try?

 

[Bruno Del Rio]

I just tried the 568-A standard (a 25ft) cable, but still doesn't work. It seems I'm running out of options...

 

[Bruno Del Rio]

when it connects the laptop successfully using a short 6ft cable (T568B standard) , and ipconfig reads:
Connection-specific DNS suffix: attlocal.net
IP Address: 192.168.1.91
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.1.254

when it does NOT work using a 25ft cable (T568B standard), and ipconfig reads:
Connection-specific DNS suffix:
Autoconfiguration IP Address: 169.254.196.147
Subnet Mask: 255.255.0.0
Default Gateway:

**I made both of the 6ft and 25ft cables (both are T568B standard) from the same box in a large cable-roll - just to make sure the cables have no defect and the creation has no problem. The only difference is the length.

 

[makkem]

How do I check the connections in the wall jack? Open up the wall plate, and extract the socket to see if the colored wires are punched down correctly? Same for the basement switch? See if the punch downs are solid? I can't distinguish what's poor or good. I'd imagine either it works, or it doesn't.
If there is enough spare wire then remove the wires from the connections cut off the used section and repunch them down.
This will ensure a good connection and break through any oxidation,especially important if your basement is damp.

 

[Nijinski]

Get a cable tester

http://www.screwfix.com/p/philex-network-cable-tester/93219

 

[Bruno Del Rio]

Get a cable tester

http://www.screwfix.com/p/philex-network-cable-tester/93219

i have a cable tester. it doesn't help with this case.

 

[bill001g]

Your problem is likely a connection that is wired properly but is just not making contact correctly in one of the connections. This can be anything from a slightly bent wire in the jack to a poor connection between the wire and the punch down connectors.
It tends to be impossible to find for sure without a very expensive tester called a TDR meter.

The 100m limitation is really only a guideline. The actual limitation is based on things like resistance in the wires. All it takes is a bad jack/connection...or worse a damaged wire and the cable could appear to be much longer than it really is.

As stated by makkem really the only thing you can do is redo both ends of the cable and hope to get lucky. It could be a bad jack so when you get desperate you replace that too.

 

[Cynete]

I faced a similar situation. Router -> Router/AP
I tried connection shorter CAT6 cable, it works fine

but when I connected long 35m CAT6, internet stops working. I can see Router/AP light glow for LAN port but it does not connect to internet.

I tested wire with line tester, its perfectly fine. (Just like many complained)

I got away with this issue by just doing a Crossover color code for crimping instead of straight through color code

Try 568b Crossover color code. I learnt somewhere that connecting 2 devices of same type, then its best to use corssover color code. It worked for me

 

[Wolfshadw]

This thread is over five years old.

Closing.
Wolfshadw
Moderator