Ethernet issues! Please help. Problem with DNS cache.

Resolving Ethernet Connectivity and DNS Cache Issues on Windows 11

Experiencing persistent internet connectivity problems on a Windows 11 PC can be frustrating, especially when the issues are linked to Ethernet connections and DNS caching. If you’re facing similar challenges, detailed below are common symptoms, troubleshooting steps, and potential solutions to restore stable online access.

Symptoms Overview:
– Intermittent or no internet connection via Ethernet
– “Connection not private” error in Microsoft Edge
– Wi-Fi functioning on other devices but experiencing slow or limited connectivity on the affected PC
– Ethernet connection working on other devices or in different rooms
– Wi-Fi only functioning when Ethernet cable is disconnected

Common Troubleshooting Steps Undertaken:
1. Restarted the modem/router to resolve temporary network glitches.
2. Switched Ethernet cables to rule out faulty cables.
3. Flushed DNS cache to clear any corrupted DNS entries.
4. Attempted to toggle VPN connections, which were unsuccessful.
5. Reset network settings to restore default configurations.
6. Repeatedly restarted the PC to apply changes.
7. Ran Windows network troubleshooter, which did not identify issues.
8. Verified Ethernet driver is up-to-date.
9. Used command-line tools such as netsh int ip reset to reset TCP/IP stack.

Potential Causes and Solutions:

1. DNS Cache Corruption
   Corrupted DNS caches can lead to connectivity issues. Flushing the DNS cache is a good first step, but consider also manually renewing the IP address:

bash
ipconfig /release
ipconfig /renew
ipconfig /flushdns

1. Network Adapter and Driver Problems
   Even if the driver is up-to-date, reinstalling or resetting the network adapter can resolve underlying faults:

2. Disable and re-enable the Ethernet adapter via Network Settings.

3. Uninstall the Ethernet driver and restart your PC to allow Windows to reinstall the driver automatically.

4. Check Network Adapter Settings
   Ensure that the network adapter is configured correctly:

5. Set the DNS servers manually, for example, to Google’s DNS (8.8.8.8 and 8.8.4.4).

6. Disable any VPN or firewall temporarily to rule out interference.

7. Network Reset
   Perform a comprehensive network reset:

8. Open Settings > Network & Internet > Status.

9. Click on “Network reset” and follow prompts. Restart your PC afterward.

10. Hardware Inspection
    Given that Ethernet works on other devices, hardware issues are less likely, but double