My wired connection worked normally until last night, but this morning Windows still says Ethernet is connected while no websites or internet-dependent apps will load. Wi-Fi works normally on my phone. I've already checked drivers and updates, restarted networking, unplugged and reconnected the cable, tried different router ports, reviewed the IP configuration, and worked through the usual basic and intermediate troubleshooting steps. The Ethernet port briefly changed from one green light to green and orange, then returned to its usual two green lights, but the problem remained. Windows reports the expected connection speed, and DNS lookup returns IP addresses, yet browsers and applications still cannot connect. I'm trying to determine whether the cable, router, network adapter, DNS, or another software setting is responsible.
4 Answers
Try connecting the PC directly to the router with a different Ethernet cable, even if the current cable looks fine. Cable failures are uncommon unless the cable was damaged, but swapping it removes one variable. You can also boot the computer from a Linux live USB. If networking works there, the hardware and router are probably fine and the issue is somewhere in Windows. If it fails there too, investigate the router, cable, or internet service.
Use an elevated Command Prompt and work through the connection in layers. Run `ipconfig /all` and note the default gateway, then ping the gateway address. After that, try `ping 1.1.1.1` or `ping 8.8.8.8`. If those work, test DNS with `nslookup www.google.com`. Since the connection is negotiating at the normal speed and DNS is returning addresses, the next suspects are a firewall, proxy, VPN, browser-specific issue, or another Windows networking filter rather than the physical link.
Make sure the phone is actually using the router’s Wi-Fi rather than cellular data. Turn mobile data off temporarily and confirm that internet access still works. If Wi-Fi continues working, test the PC through the phone’s hotspot. That can help determine whether the PC’s Ethernet adapter or Windows configuration is the problem. Also power-cycle the modem, router, and PC completely.
If the Ethernet adapter is connected through a dock or USB adapter, check that the adapter is detected correctly and that its hardware address appears in Windows. Dock firmware or driver problems can make the link light look normal while traffic still fails. Updating the dock or adapter firmware may fix it; if possible, test the PC’s built-in Ethernet port directly instead.
The port shows connected at its usual speed, and the DNS lookup returned Google addresses, but browsers and internet apps still fail. I may be misunderstanding some of the command-line output, though, so I’ll compare the gateway and ping results next.