DNS over HTTPS (DoH) is a protocol that encrypts your DNS queries, improving your privacy and security online. However, you might encounter errors when configuring or using DoH. This guide will help you troubleshoot common issues and get your DoH connection working smoothly.
DoH errors manifest in various ways, including slow internet speeds, website unavailability, or specific error messages in your browser or operating system. The underlying causes are often related to:
Double-check the DoH server address you're using. Common servers include Cloudflare (https://cloudflare-dns.com/dns-query), Google (https://dns.google/dns-query), and Quad9 (https://dns.quad9.net/dns-query). Ensure you've entered the address correctly in your browser settings, operating system settings, or router settings.
Temporarily disable any firewalls, proxies, or VPNs to see if they're interfering with DoH. If disabling them resolves the issue, configure your firewall or proxy to allow DoH traffic (usually on port 443). For VPNs, check if they offer DoH compatibility or switch to a different VPN provider.
This error often indicates a problem with DNS resolution. It can be caused by incorrect DoH server settings, network issues, or a problem with the DoH server itself.
Use an online DNS checker tool to test if the DoH server is working correctly. If the server is down, try a different DoH server.
Restart your computer, router, and modem to clear any temporary network glitches.
Ensure DoH is enabled in your browser settings. Some browsers have built-in support, while others might require extensions. For operating system settings, check your network configuration to ensure DoH is correctly configured.
Make sure your browser, operating system, and network drivers are up to date. Outdated software can sometimes contain bugs that affect DoH functionality.
If one DoH provider consistently gives you issues, try switching to another like Cloudflare, Google, or Quad9. This can help determine if the problem is with your specific provider or a broader network issue.
If you've tried all the above steps and still can't resolve the issue, contact your ISP. They might be blocking DoH or have other network issues affecting your connection.
For more advanced users, you can use command-line tools like nslookup or dig to troubleshoot DNS resolution problems directly. You can also check your router's logs for any errors related to DoH.