We noticed the Ethernet connection between your ONT and your router has dropped in the last 24 hours

The LightSpeed network is constantly monitored for quality and dependability by expert systems designed to detect problems with your service. We will send you notification via email if an issue is detected.  

This post provides more explanation for the following message:

"We noticed the Ethernet connection between your ONT and your router has dropped XXX times in the last 24 hours."

Summary: Your Ethernet cord is disconnecting from the ONT. This is probably a bad cable or loose connection. Check the Ethernet cord that connects your router to the ONT. 


  • ONT or Optical Network Terminal -- This is the device where the fiber connects. It is usually installed in your basement or mounted to the wall. The ONT is a small white box, about 4inches square and has 3 ports--a port to receive the fiber,  a Gigabit Ethernet port to connect your router and a third port to connect power.
  • ROUTER -- The router is the device in your home that creates your Wi-Fi network. The Router is connected to the ONT via an Ethernet cable.
  • Ethernet -- The cord that connects the ONT to the Router. You can also connect your wired devices to the router via Ethernet cords.

The following conditions can cause the Ethernet between your ONT and Router to drop:

  • Loose connection - Try unplugging the Ethernet cord and reconnecting. Push the cord into the jack firm enough to hear a "click" 
  • Damaged cable - A visibly crimped, bent or chewed cable should be replaced. Bending a patch cord harsh enough can cause the small wires inside the cord to be damaged and lose electrical signal. Replace the patch cords if damage is suspected.
  • Damaged ethernet jack - If your home was wired with an ethernet jack, remove the cable and look inside the jack. There are 8 small pins that should run parallel and not show any visible damage. If pins are bent or crooked, the jack should be replaced.  Check around the jack for visible damage. 
  • Failing router or ONT - If there is no other explanation, it is possible the ONT or router is malfunctioning. Call LightSpeed to replace the ONT and/or replace your router to confirm


ONT Lights:

  • The ONT also has the following lights: POWER, PON, LOS, ALARM, LAN. All lights can flash, that is totally normal. 
    • The POWER light will be GREEN when the ONT is plugged in and powered on. If the power light is not green, it means the ONT is powered off or 
    • The PON light will be SOLID GREEN if the ONT is connected to the LightSpeed network. The PON light will FLASH when it is attempting to connect. It will flash for a few moments, then go solid green. If the PON light is OFF, call LightSpeed for assistance.
    • LOS light should remain off at all times. If the LOS light is on, contact LightSpeed for help.
    • ALARM light should remain off at all times other than a) it will flash red when we are sending you a software update, or b) it will be solid red when the fiber link is down. If the Alarm light is blinking, please do nothing unless it lasts more than 10 minutes. If the Alarm light is solid red, contact LightSpeed for help.
    • LAN light should be GREEN when the Ethernet cord is connected to both your ONT and router. If the LAN light is off, that means your Ethernet connection has dropped or is disconnected. A rapidly flashing green light is fine. 

Here are some examples:


The following image shows a good working install. This is a customer install in a single family home when the fiber jack and ONT is installed in the basement. An ethernet jack is installed near the ONT. The other side of that ethernet cable is usually in the living room, wherever the router was installed. 



The following image is a good working install in a studio apartment, where there is no basement. A fiber jack was installed on the wall and this customer chose to mount their ONT on the wall. There was no furniture present at the time, so the router is also on the floor (not customary.)  The ONT is connected directly to the router via an ethernet patch cord.



The following image shows a damaged ethernet cord. This customer thought their Lightspeed service was dropping, when in reality the ethernet cord was just damaged causing their router to lose connection to the ONT about 50 times per day. The problem was resolved by replacing the ethernet cord and moving the ONT away from the fiber jack to avoid creasing the cable again.




The following image illustrates a damaged ethernet cable. The cable was bent to severely and caused the customer to experience numerous ethernet drops throughout the day. To the customer, it appeared their Lightspeed service was dropping. in reality, it was just their router losing connection to the ONT due to a damaged ethernet cord. Replacing the cord solved the problem.


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