I recently changed my PC dns to free Level 3 DNS because I just don’t like using the standard BT DNS servers.
I opted for Level 3 as the servers were benchmarked top from my location in the UK – tested with GRC DNS Benchmark.
This tool is now paid – I think $10 for the new V2 or you can use V1 free but that is years old and less reliable.
I started receiving the error:
net::ERR_CERT_AUTHORITY_INVALIDIt would prevent me from visiting some sites, including Proton VPN, NordVPN and others. I couldn’t figure it out.
After testing the pages with NordVPN desktop app I realised it was the DNS.
I switched to DNS4EU and tested the unrestricted IPV4 and IPV6, and now I have no issues – simple fix.
Change the DNS in Ethernet IP DNS settings, then save and run CMD via start menu as Administrator and run command:
ipconfig /flushdns