My PC's Ethernet connection worked normally until last night, but this morning Windows still says it is connected while no websites or internet-dependent apps will load. Wi-Fi works on my phone, and I have already tried driver checks, updates, network resets, reconnecting the cable, different router ports, and verifying the IP configuration. The Ethernet port briefly changed from one green light to green and orange, then returned to its usual two green lights, but the internet still does not work. The connection also reports its normal link speed. What other troubleshooting steps could identify whether the problem is the cable, router, Windows, DNS, or the network adapter?
4 Answers
The Ethernet link light only proves that the PC and router have negotiated a physical connection; it does not prove that internet traffic is working. In an elevated Command Prompt, run `ipconfig /all`, then ping the router’s default gateway, followed by `ping 1.1.1.1` or `ping 8.8.8.8`. If those work, run `nslookup www.google.com`. A successful DNS lookup but failed browser connections would point away from basic DNS and toward Windows filtering, a proxy, firewall, VPN, or browser configuration.
Make sure your phone is actually using the router’s Wi-Fi rather than cellular data. If other devices work through the router, try power-cycling the modem and router completely. If the phone only works over cellular, the issue may be the router’s internet connection, firewall, hardware, or an ISP service problem. A hotspot test for the PC is useful as well.
Check the adapter and docking-station or Ethernet-adapter software if you are using anything between the PC and router. Confirm that the network adapter has a valid MAC address and that the adapter firmware or utility is current. A failed USB-C dock or Ethernet adapter can still show link lights while preventing usable network traffic.
Try connecting the PC directly to the router with a known-good Ethernet cable, even if the current cable looks fine. Cable failures are uncommon but possible. If you can, boot the computer from a Linux live USB. If Ethernet works there, the problem is probably within Windows or its network configuration; if it fails there too, investigate the router, cable, or ISP connection. You can also test the PC through your phone’s hotspot to help separate a computer problem from a router or ISP problem.
The adapter reports the normal connection speed, and the DNS lookup returned IP addresses. Websites and apps still fail, so I may need to check for a proxy, VPN, firewall rule, or another Windows-level issue.