DNS over HTTPS (DoH) enhances the privacy and security of your DNS lookups by encrypting the communication between your device and the DNS resolver. However, simply using DoH doesn't guarantee everything is working correctly. This guide will walk you through various methods to verify that DoH is indeed active and functioning as intended.
Traditionally, DNS queries were sent over UDP or TCP in plain text, making them vulnerable to eavesdropping and manipulation. DoH encrypts these queries using HTTPS, preventing third parties from seeing your DNS requests (e.g., what websites you're visiting). This improves your online privacy and security by protecting against DNS spoofing and censorship.
There are several ways to verify that DoH is working correctly:
Most modern browsers support DoH. Check your browser's settings to see if DoH is enabled and which resolver it's using. The specific location of this setting varies depending on the browser (e.g., in Chrome, it might be under Privacy and security -> Security -> Use secure DNS). Look for options like "Secure DNS" or "DNS over HTTPS".
Numerous online tools can perform DNS lookups and indicate whether DoH is being used. These tools often show the protocol used for the query (e.g., HTTPS). Simply enter a domain name and check the results. Some popular options include:
dig (available on most Linux/macOS systems) or nslookup.When using dig, look for the presence of "HTTPS" in the output to confirm DoH usage. For example:
dig example.com +trace +dnssecThe output should show the protocol used for each query. If it uses DoH you will likely see something like `HTTPS` in the output.
Advanced users can leverage network monitoring tools like Wireshark or tcpdump to capture and inspect network traffic. By filtering for HTTPS traffic destined to your chosen DNS resolver, you can verify that your DNS queries are indeed encrypted.
If you're using a custom DNS resolver (e.g., Cloudflare's 1.1.1.1 or Google's 8.8.8.8), check its documentation or settings to confirm that DoH is enabled and properly configured. This often involves specifying the DoH endpoint in your operating system's network settings or your browser settings.
While not directly verifying DoH, using a tool like SSL Labs' SSL Server Test can help indirectly confirm the HTTPS connection to your DNS resolver. This is useful for verifying the secure nature of the DoH connection, though it doesn't directly show that DNS queries are being made via DoH.
If you're having trouble verifying DoH, consider the following troubleshooting steps:
By employing these verification methods and troubleshooting steps, you can confidently confirm that DoH is working correctly, ensuring your DNS lookups are private and secure.