Securing Your Raspberry Pi with DNS over HTTPS (DoH): A Comprehensive Guide

DNS over HTTPS (DoH) is a method of encrypting DNS queries, enhancing your privacy and security. This guide provides a comprehensive walkthrough of setting up DoH on your Raspberry Pi, covering various methods and considerations.

Why Use DNS over HTTPS on Your Raspberry Pi?

Using DoH on your Raspberry Pi offers several key advantages:

• Increased Privacy: Your DNS queries are encrypted, preventing your ISP and other potential eavesdroppers from seeing which websites you visit.
• Improved Security: DoH protects against DNS spoofing and other attacks that could redirect you to malicious websites.
• Enhanced Performance: Some DoH providers offer faster DNS resolution times.

Choosing a DoH Provider

Several reputable DoH providers exist, each with its own strengths and weaknesses. Popular choices include:

• Cloudflare: https://cloudflare-dns.com/dns-query
• Google Public DNS: https://dns.google/dns-query
• Quad9: https://dns.quad9.net/dns-query
• OpenDNS: https://doh.opendns.com/dns-query

Consider factors like privacy policies, performance in your region, and security features when selecting a provider.

Methods for Setting Up DoH on Raspberry Pi

1. Modifying Your Network Manager Configuration (Recommended for Desktop Environments)

This method is generally suitable for desktop environments like Raspberry Pi OS with a graphical interface. The exact steps might vary slightly depending on your desktop environment and network manager (NetworkManager is common). Generally, you'll need to access your network settings, find the active connection, and add the DoH server address to the DNS configuration.

Note: Consult your desktop environment's documentation for specific instructions. The process typically involves adding the DoH URL under advanced settings within the network configuration.

2. Using `systemd-resolved` (Recommended for Server Environments and headless setups)

systemd-resolved is a powerful DNS resolver integrated into systemd. It's ideal for server environments and headless Raspberry Pi setups. You can configure it to use DoH by editing the /etc/systemd/resolved.conf file:

sudo nano /etc/systemd/resolved.conf

Add or modify the following line, replacing the placeholder with your chosen DoH URL:

DNSOverHTTPS=yes
DNSOverHTTPSAddress=YOUR_DOH_SERVER_URL

Save the file, then restart systemd-resolved:

sudo systemctl restart systemd-resolved

3. Using a Custom DNS Client (Advanced Users)

For advanced users, manually configuring a DNS client like dnsmasq or bind provides granular control but requires more technical expertise. This involves setting up the client, configuring it to use DoH, and potentially modifying your network configuration to use the custom DNS client.

Verification and Troubleshooting

After configuring DoH, verify its functionality using tools like dig or online DoH checkers. Check the DNS resolution, look for encrypted communication (HTTPS), and make sure your requests are reaching the chosen DoH provider.

Troubleshooting common issues might involve checking your network configuration, ensuring systemd-resolved (or your chosen DNS client) is running correctly, and verifying the DoH URL's accuracy.

Conclusion

Implementing DoH on your Raspberry Pi significantly improves security and privacy. Choose the method that best suits your technical expertise and setup, selecting a reputable DoH provider for optimal results. Remember to verify the configuration and address any issues that may arise.