Configuring DNS over HTTPS (DoH) on Linux Mint: A Comprehensive Guide

DNS over HTTPS (DoH) enhances your privacy and security by encrypting your DNS queries. This guide provides a detailed walkthrough of configuring DoH on your Linux Mint system, covering various methods and troubleshooting steps.

Understanding DNS over HTTPS

Traditional DNS queries are sent in plain text, making them vulnerable to eavesdropping and manipulation. DoH encapsulates these queries within HTTPS, providing encryption and protecting your browsing activity from prying eyes. This is particularly beneficial on public Wi-Fi networks.

Methods for Configuring DoH on Linux Mint

There are several ways to enable DoH on Linux Mint. We'll cover the most common and user-friendly approaches:

1. Using NetworkManager (Recommended for most users)

NetworkManager is a powerful tool that manages your network connections. Many Linux Mint users will find this the easiest method.

Open the Network Connections application (usually found in the system settings).
Select your active network connection (e.g., Wi-Fi or Ethernet).
Click on the IPv4 or IPv6 settings tab (depending on your preference).
Look for an option to manually specify DNS servers. The exact wording might vary slightly depending on your NetworkManager version.
Enter the DoH address of your chosen provider. Popular options include:

https://cloudflare-dns.com/dns-query (Cloudflare)
https://dns.google/dns-query (Google)
https://doh.opendns.com/dns-query (OpenDNS)

Important: You'll likely need to specify the port number (usually 443) as well, depending on your NetworkManager version. The correct format might be https://cloudflare-dns.com/dns-query#443 or similar. Experiment if necessary.
Save the changes and reconnect to your network.

2. Modifying the `/etc/resolv.conf` file (Advanced users)

Warning: Directly editing `/etc/resolv.conf` is generally discouraged, as it's often managed dynamically by NetworkManager. This method might be overwritten upon reboot or network changes. Proceed with caution.

This method requires using a DNS resolver that supports DoH. You would typically install such a resolver (like `dnsmasq`) and configure it to use your chosen DoH provider. This is a more advanced process and requires more technical knowledge.

3. Using systemd-resolved (More robust solution)

Systemd-resolved is a modern DNS resolver that's gaining popularity. It provides a more reliable and robust way to manage DoH compared to directly editing `/etc/resolv.conf`. You can configure it through a configuration file or command-line tools. The specifics depend on your Linux Mint version and systemd-resolved configuration.

Troubleshooting

If you encounter issues, check the following:

Verify the DoH address and port number you've entered are correct.
Restart your network service: sudo systemctl restart networking
Check your firewall settings to ensure they're not blocking port 443.
Ensure your system's time is synchronized correctly.
Test your DNS resolution using tools like dig or nslookup.

Choosing a DoH Provider

Select a DoH provider that aligns with your privacy preferences and security requirements. Research the privacy policies of different providers before making a choice.

This guide offers a starting point for configuring DoH on Linux Mint. Further research might be needed depending on your specific setup and chosen DoH provider.