Configuring DNS over HTTPS (DoH) in KDE Plasma: A Comprehensive Guide

DNS over HTTPS (DoH) enhances your privacy and security by encrypting your DNS queries. This guide explains how to configure DoH in various ways within the KDE Plasma desktop environment.

Understanding DNS over HTTPS

Traditional DNS queries are sent in plain text, making them vulnerable to eavesdropping and manipulation. DoH encrypts these queries using HTTPS, preventing third parties from seeing your browsing activity. This improves your privacy by protecting your DNS queries from your ISP and other network observers. It also offers potential security benefits, as it makes it harder for attackers to perform DNS spoofing or cache poisoning attacks.

Methods for Configuring DoH in KDE Plasma

There are several ways to enable DoH in KDE Plasma, each with its own advantages and disadvantages:

1. System-Wide Configuration (Recommended):

This method configures DoH for all applications on your system. The best approach depends on your network manager:

Using NetworkManager (Most Common): NetworkManager often provides a graphical interface to set DoH. Look for settings within your network connection configuration (usually accessible through the system tray or System Settings). The specific location varies depending on your distribution and NetworkManager version, but look for options related to "DNS" or "IPv4/IPv6 Settings." You should find a field to enter a custom DNS server address. Use a DoH address like https://cloudflare-dns.com/dns-query or https://dns.google/dns-query.
Using systemd-resolved (For advanced users): If you use systemd-resolved as your DNS resolver, you can edit the /etc/systemd/resolved.conf file. Add or modify the following lines, replacing the example with your preferred DoH provider's address. Remember to reload systemd-resolved afterward using sudo systemctl restart systemd-resolved.

[Resolve] 
DNS=https://dns.google/dns-query
DNSOverTLS=yes

Warning: Incorrectly configuring /etc/systemd/resolved.conf can disrupt your network connectivity. Back up the file before making any changes.

2. Application-Specific Configuration:

Some applications allow you to configure their own DNS settings. Check the application's preferences or settings for options related to DNS or proxies. This is useful if you want to use DoH for only specific applications without affecting the entire system.

3. Using a Custom DNS Client:

Applications like DNScrypt or AdGuardHome provide more advanced features and control over your DNS settings, including DoH support. These often involve installing and configuring a separate application, then pointing your system's DNS settings to them.

Choosing a DoH Provider

Several reputable providers offer DoH services. Consider factors such as privacy policy, performance, and location when selecting a provider. Popular options include:

Cloudflare (1.1.1.1): https://cloudflare-dns.com/dns-query - Known for its speed and focus on privacy.
Google Public DNS: https://dns.google/dns-query - Widely used and reliable.
Quad9: https://dns.quad9.net/dns-query - Focuses on security and blocking malicious domains.

Note: Always check the privacy policy of your chosen DoH provider to understand how they handle your data.

Troubleshooting

If you encounter issues after configuring DoH, try the following:

Verify your DoH address: Double-check that you've entered the correct DoH server address.
Restart your network services: Restarting your network manager or systemd-resolved might be necessary.
Check your firewall: Ensure your firewall isn't blocking DoH traffic (port 443).
Consult your distribution's documentation: For more specific instructions, refer to your Linux distribution's documentation.

By following these steps, you can successfully enable DoH in your KDE Plasma environment and enjoy enhanced privacy and security.