The Ethernet Loop Test

Tech Corner

Problem: Your computer says "Network Cable Unplugged" but you have checked that the ethernet cable is connected properly from your computer to your router or gateway. The ethernet light for your connection is off. And you only have one computer and one ethernet cable.

The scenario above indicates either a computer-related issue, a modem trouble or a broken ethernet cable. Now, how will you determine the actual root cause of your connectivity problem?

Simple: perform a loop test.

Here's what you need to do:

1. Disconnect the ethernet cable from your computer.
2. Plug the end of that cord to another ethernet port at the back of the router/gateway. Let's say you plug one end to Ethernet Port 1 and the other end to Ethernet Port 2.
3. Check for the light indicators for Ethernet Port 1 and 2. If they're on, then the problem is with the computer.
4. If the light indicators for Ethernet Port 1 and 2 didn't lit up, try the other Ethernet ports at the back. You can try 1&3 or 3&4 and other possible combinations. If the lights still didn't turn on, probable root cause is a broken ethernet cable. If some of the combinations lit up, then, you're facing an Ethernet failure on some of the ports of your gateway/router.

Closing Spiel: Again, this is Yallit and thank you for visiting. Have a Nice Day!

The Power of Powercycle

And yet another self-help tip from me.



Powercycle is simply turning off your modem and router for a few seconds then turning them back on. This is a very useful troubleshooting step and mostly resolves 80% of sync no browse** issues.

The best way to perform a powercycle is to unplug and replug the power cords of your modem or gateway and router. Now if you are using both a modem and a router, it's best to perform a sequenced powercycle. What do I mean about that? First, turn off your modem by unplugging its power cord, then, followed by the router. After about 10 seconds, turn the modem back on first. Wait for the DSL light (might be a Link light for some modems) to turn solid green before turning the router back on.


**Sync No Browse is a state where the modem is detecting a DSL signal from the phone line but the computers aren't able to pull up websites. The DSL and Internet lights on the modem are always solid green.

Closing Spiel: Again, this is Yallit and thank you for visiting. Have a Nice Day!