Symptoms
- A device plugged into one specific port gets no connection
- Port's light doesn't turn on when a cable is plugged in
- Device works fine when moved to a different port on the same router
- All wired devices lose connection at once
Likely causes
- CommonA single Ethernet port has failedIndividual ports can fail from electrical surges or simple wear while the rest of the router works fine.
- CommonFaulty Ethernet cableA damaged cable is often mistaken for a port problem.
- PossibleDevice's own network adapter or port issueThe problem may be with the connected device rather than the router.
- PossibleRouter-wide hardware or firmware issueIf every port fails at once, the cause is more likely the router itself rather than one component.
What to do
- Try a different Ethernet cable in the same port to rule out a bad cable.
- Move the same device and cable to a different port on the router to see if the problem follows the port or the device.
- Try connecting a different device to the suspect port to confirm whether it's the port or the original device at fault.
- Restart the router, since a port can occasionally stop responding until a reboot.
- Check the router's admin page for that port's status (some routers show per-port link status), and check for a stuck 'disabled' setting.
- If only one port has failed, simply use a different port going forward or add a small Ethernet switch to regain the lost port's functionality.
- If all ports have failed simultaneously, the router likely needs replacement rather than a single-port repair.
Tools and parts
- Spare Ethernet cable
Small Ethernet switchSearch: “5 port ethernet switch”
Replacement routerSearch: “home wifi router”
When to call a pro
Not usually needed; a failed port can typically be worked around with a switch or a different port without professional help.
Safety
Generally low risk
Generally low risk for a careful person. Stop if anything looks different from what this guide describes.