We recently moved to a new place that has ethernet wiring. Initially we didn't use it, as I set up a wifi network using eero. I recently decided to explore how I can use it, especially to connect a NAS. I've a few things including using a laptop to try and find out which wiring delivers internet through each of these cables. However, I can't figure it out.

The questions I have are:

  1. how can I figure out how the wiring works, and
  2. how can I use this network?

Thank you!

Following is some more detail about the wiring in the house.

Currently, we have our internet delivered through a fiber optic cable to the house. I've connected the output of it to the eero router:

(living room) incoming internet

(living room) eero router

This is the wiring I have in the garage, including a tp-link TL-SG116 and a Leviton T568A:

wiring in the garage

There are 4 wires coming from behind the DSHOT box, labeled office, back room, living room 1, and living room 2. I suppose there are corresponding outlets in each of those rooms:

labeled wires in the garage

However, in the living room, there are two wires that I suspect are the other ends of the two wires labeled living room 1 and living room 2 (but I'm not sure):

two unlabeled wires in the living room

I've connected each of those two wires to the eero ethernet port and tried connecting the other one to my laptop. However, that didn't seem to work.


Using the suggestions in here I was able to verify that most of the wiring actually works. Out of the 7 wires coming out of the switch I was able to label 5 of them. The other 2 (including the white wire labeled Living Room 1 showed no sign of life. If I find a way to diagnose those, I will. However, for now I'm not sure how to do that.

enter image description here enter image description here

  • I'm undecided re whether this is a home improvement question or a networking question. It's really the latter, but I've found he networking stack doesn't want to talk to anyone but commercial users, even if the question is about pro-level equipment.
    – keshlam
    Jul 31, 2023 at 18:13
  • 1
    Cable jacket color (and looking to see where it's connected on the back of the patch panel) should disambiguate which living room is which. The blue cable should be blue all the way...
    – Ecnerwal
    Jul 31, 2023 at 18:20
  • Wait - you didn't take your laptop to the FAR END IN THE GARAGE? You plugged into one in the living room, and into the other in the living room? Arrgh. That leaves you open to multiple sources of failure. Take the laptop to the garage, check for signal coming out of the patch panel, (given it's unlabeled, look to verify which ports) and only then involve more parts that can fail.
    – Ecnerwal
    Jul 31, 2023 at 18:24
  • Thanks @Ecnerwal. I'll try that and keep you posted. You're right about the cable jacket, but since they are all either gray or blue, it's not easy to know which one is which.
    – oxtay
    Jul 31, 2023 at 20:45
  • 1
    The bend on the fibre cable looks painful. I'd try to relieve it a bit
    – Martin
    Aug 7, 2023 at 10:46

2 Answers 2


Plugs crimped on wall cables are notoriously unreliable.

Wall jacks (or punchdown patch panels) are much more reliable.

Labels may be wrong. I note that the cables are labeled, but the ports on the patch are not labeled.

If the switch is powered up (looks it) you should see a link light if the far end of the cable that it's patched into is live (such as plugged into your laptop, even if it doesn't connect to anything else and "get network") if it connects to the switch the light for that port should go green at the switch.

At least this appears to have been set up for ethernet, not phone, but that doesn't mean it was done well. It probably is recoverable, but before investing much I'd try really fundamental basics like "do any of the cables make a connection when you plug into them" (even if they don't lead to the right room) and "are the places that patch cables are plugged into on the front of the patch panel actually corresponding to where the cables are connected on the back?"

You'll probably want to spend the $5-10 on a basic pair tester for ethernet that will plug two parts into opposite ends of the same cable to test it (such as they do.) You don't need to, but it's not too expensive.

However, upon re-reading your question, as commented, I think you're not doing your testing well. Plug in a living room cable. Go out to the garage, plug your laptop into the patch panel (and/or look to see if the switch now has link on one port - if so, plug into another port on the switch.) If that works, you have some basics. If it doesn't work, try the other cable, and do pay attention to the possibility that maybe one of those cables actually goes to port 2 or 6-12 on the patch panel (or pull it off the wall and check where they go.)

If you get signal into the switch, you should be able to get signal out to the other cables in the house. But if all the far ends are plug-on-wall-cable, expect at least one if not more to be bad. Replace them with punch-down jacks.

  • 1
    If everything is good except for bad crimps on the far ends, it's an easy fix -- go out and buy proper jacks, and redo the ends as jacks instead of crimped-on plugs. It's easy to do with a little bit of equipment that's not too expensive. Jul 31, 2023 at 18:46
  • 2
    Which is why taking a few minutes to try and see if at least one of the cables is able to connect from laptop to switch is a good thing - that gives some hope that putting jacks on the others will solve the problem. And if the actual problem for the described test is that one of those living room cables was in port 2, who knows, they might all work! I'd still recommend replacing with jacks for reliability, though.
    – Ecnerwal
    Jul 31, 2023 at 18:50

You've been left with a bit of a rat's nest of poorly labelled connections.

One of the plugs into the tp-link switch should connect back to your network router. The rest should connect to sockets in different rooms. That switch helpfully has LED indicators on each socket to tell you what is happening. No lights = no connection. Steady light = something connected, but no data flowing. Flashing light = data flowing. So if no lights are flashing, you have no connection to the router and nothing is going to work.

Try connecting the laptop stright to the tp-link switch and see if you get a connection. If you do, then it's worthwhile trying to trace all those wires and seeing what goes where.

PS. On some laptops, turning on the WiFi turns off the Ethernet port. You may need to turn off the WiFi, or see if there is a setting to turn on both hidden away somewhere.

  • There's absolutely no reason to expect the left-behind TP link to be connected to the new owner's new service internet until the cables get sorted.
    – Ecnerwal
    Aug 1, 2023 at 0:17

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.