Securing Your Linux Mint Connection: A Comprehensive Guide to DNS over HTTPS (DoH)

DNS over HTTPS (DoH) is a method of encrypting your DNS queries, protecting your privacy and improving security. Unlike traditional DNS, which sends your requests in plain text, DoH encrypts them using HTTPS, making it more difficult for eavesdroppers and malicious actors to monitor your online activity. This guide will walk you through setting up DoH on your Linux Mint system.

Why Use DNS over HTTPS on Linux Mint?

Using DoH offers several key advantages:

Enhanced Privacy: Your DNS queries are encrypted, preventing your internet service provider (ISP) and others from seeing which websites you visit.
Improved Security: Encryption protects against DNS spoofing and other attacks that can redirect you to malicious websites.
Faster Resolution (Potentially): Some DoH providers offer faster DNS resolution than traditional DNS servers.
Circumvention of Censorship (Potentially): DoH can help bypass some forms of internet censorship.

Important Note:

While DoH enhances privacy and security, it's crucial to choose a reputable DoH provider. A compromised or malicious provider could potentially intercept your traffic. Research different providers and select one with a strong reputation for security and privacy.

Setting up DoH on Linux Mint

There are several ways to configure DoH on Linux Mint, depending on your network manager and preferences:

1. Using NetworkManager (Recommended):

Most Linux Mint users utilize NetworkManager for network configuration. This method is generally the easiest and most integrated.

Open the Settings menu and select Network.
Select your active network connection (Wi-Fi or Ethernet).
Click the IPv4 or IPv6 settings (depending on your preference).
Look for an option to specify DNS servers. This might be labeled differently depending on your NetworkManager version.
Instead of specifying IP addresses, enter the address of your chosen DoH provider. For example, for Cloudflare's DoH, you would enter: https://cloudflare-dns.com/dns-query
Important: You might need to add a port if your selected provider requires it. For example some providers might require port 443.
Save your changes. Your network connection will likely reconnect automatically.

2. Modifying the `/etc/resolv.conf` File (Not Recommended):

This method is generally discouraged because `/etc/resolv.conf` is often dynamically managed by NetworkManager or systemd-resolved. Modifying it directly might cause conflicts and lead to network issues. Only consider this if NetworkManager doesn't provide DoH options or you have a specific reason for manual configuration.

3. Using systemd-resolved (Advanced):

Systemd-resolved is a DNS resolver that integrates well with systemd. You can configure it to use DoH by editing its configuration file. This method requires more technical knowledge. Consult the systemd-resolved documentation for specific instructions.

Choosing a DoH Provider

Several reputable providers offer DoH services. Some popular options include:

Cloudflare (https://cloudflare-dns.com/dns-query): A widely used and respected provider.
Google Public DNS (https://dns.google/): Another popular choice with a strong reputation.
Quad9 (https://dns.quad9.net/dns-query): Focuses on security and privacy.
CleanBrowsing (https://doh.cleanbrowsing.org/dns-query): Offers various filtering options.

Research each provider and choose the one that best suits your needs and privacy preferences.

Verifying DoH is Working

After configuring DoH, you can verify it's working by using tools like `dig` or `nslookup`. These command-line tools allow you to query DNS servers and see if your requests are being sent over HTTPS.

For example, you can use the following command to query Google's DNS server using DoH:

dig @dns.google.com google.com +tls

If DoH is configured correctly, you should see the results using TLS encryption.

By following these steps, you can significantly enhance the security and privacy of your Linux Mint system by implementing DNS over HTTPS.