Netgear Router Not Recognizing an Ethernet Cable: Fixes

First, work out which connection is failing

“Not recognizing an Ethernet cable” can mean two different things, and the fix depends on which one you have:

1. The router’s Internet (WAN) port does not detect the cable from the modem. The router may show no internet and the Internet light may stay off or show a warning color (see how to fix a red light on a Netgear router).
2. A device plugged into a LAN port is not detected. A computer may say “network cable unplugged,” or Ethernet may not appear in its network connections, even though Wi-Fi works.

The checks below cover both. The general approach is to change one thing at a time: the cable, the port, the device, then the power.

Quick checks

1. Reseat the cable

Unplug both ends, then push each one in until it clicks. A cable that is not fully seated is a surprisingly common cause. Look for a bent or broken clip on the plug.

2. Make sure it is in the right port

The cable from your modem or fiber box belongs in the router’s Internet/WAN port. Devices belong in the numbered LAN ports. See the WAN port on a router and LAN ports on a router if you are unsure which is which.

3. Swap the cable

Try a different cable you know works. Cables can fail internally even when they look fine, especially old, kinked or very cheap ones. Cat5e or Cat6 is suitable for typical home use.

4. Try a different port and a different device

• Move the cable to another LAN port on the router.
• Plug the same cable and device into another router or switch, if you have one.
• Try a different computer on the same port.

If the problem follows the device, the fault is with the device. If it follows the port, the router port may be faulty. Many routers show a light for each LAN port when a link is established, so check whether it lights up.

Power cycle the network

Power cycling clears many temporary faults:

1. Turn off and unplug the modem and router.
2. Wait about 30 seconds.
3. Plug in and turn on the modem, and wait a couple of minutes for it to fully start.
4. Turn the router on and wait for its lights to settle.
5. Test again.

If the modem is a combined unit from your ISP, restart that and check your ISP’s guidance for any wait times.

If the modem cable isn’t detected at the router

• Confirm the modem has its own connection by checking its lights, or by connecting a computer directly to it if your ISP allows.
• Some modems need a restart before they will talk to a new device. Power cycle the modem with the router connected.
• Check whether your ISP ties service to a specific device and requires a registration step.
• Look at the Internet port light on the router. If it never lights at all with a known-good cable and a working modem, the port may be faulty. Netgear’s support pages describe a loopback test for checking a port, so search for your model’s instructions.

If a computer says the cable is unplugged

On Windows:

1. Check Device Manager. Right-click Start, open Device Manager, and look under Network adapters for your Ethernet adapter. If it has a warning icon or is missing, try enabling it, updating its driver, or restarting the computer.
2. Check Network Connections. Open the old network connections view (type ncpa.cpl into Start) and see whether Ethernet is disabled. If so, right-click and enable it.
3. Run the network troubleshooter in Settings under Network & internet.
4. Update or reinstall the driver through Device Manager or from the PC maker’s website. If Wi-Fi works, you can download the driver on the same machine.
5. Check power-saving settings. In the adapter’s properties, some options let Windows turn the device off to save power. Disabling that may help.

On a Mac, look at Network settings for the Ethernet entry, and try a different adapter or dongle if your Mac uses one.

Why Wi-Fi works but Ethernet doesn’t

Wi-Fi and Ethernet use different hardware on your computer, so one can work while the other fails. A failed network adapter, a disabled adapter, a missing driver or a bad cable can all affect only the wired side. That is why swapping the cable and testing another device are useful.

Other things to try

• Update the router firmware. Log in to the admin page and check for an update, or use Netgear’s support site for your model. Our guide on how to tell if your router needs an update explains what to look for.
• Reset the router as a last resort. A factory reset erases your settings, including the Wi-Fi name and password, so only do it after the checks above and note your settings first. It usually involves holding the recessed Reset button for several seconds, and the exact timing is in your model’s manual. Our walkthrough on how to factory reset a Netgear Nighthawk shows the full process.
• Check the cable run. Very long or damaged cable runs can cause problems. See router too far for Ethernet.
• Check for adapters, splitters or couplers in the path and try bypassing them.

When to contact support

If a known-good cable, a different port, a different device and a power cycle all fail, the router port or the device’s network card is probably faulty. Contact Netgear support, or your ISP if they provided the equipment. Have your model number ready. If you are unsure where to find it, see how to identify your router’s components.