DNS over HTTPS (DoH) enhances your network's privacy and security by encrypting DNS queries, preventing eavesdropping and manipulation. This guide provides a detailed walkthrough of configuring DoH on your NixOS system, covering various approaches and troubleshooting common issues.
NixOS, known for its declarative configuration and reproducibility, provides an ideal environment for implementing DoH securely and consistently. By configuring DoH at the system level, you ensure all applications benefit from the enhanced privacy and security it offers. Traditional DNS queries are sent in plain text, making them vulnerable to interception and modification. DoH mitigates this risk by encrypting the communication between your system and the DNS resolver.
There are several ways to configure DoH in NixOS, ranging from simple modifications to your existing configuration to leveraging more advanced networking features. We'll explore the most common and effective approaches:
While you *can* directly modify `/etc/resolv.conf`, this is generally not recommended for NixOS. This file is managed by NixOS and changes will likely be overwritten upon the next configuration update. This method lacks the robustness and repeatability that NixOS provides.
systemd-resolved is a powerful service that manages DNS resolution. Configuring DoH through this service provides a cleaner and more integrated approach. You can achieve this by adding the following to your configuration.nix file within the networking.dns section:
{ config, pkgs, ... }: {
networking.dns = {
nameservers = [ "1.1.1.1" ]; # Example: Cloudflare's DNS
dnssec = true;
systemd-resolved.Domains = [ "example.com" ]; #Example of adding domain to resolve
systemd-resolved.DNSOverHTTPS = true;
systemd-resolved.DNSOverHTTPSProvider = "cloudflare-dns.com"; # Or your preferred provider
};
}Remember to replace "1.1.1.1" and "cloudflare-dns.com" with your preferred DNS provider's IP address and DoH URL respectively. Popular options include Cloudflare (1.1.1.1), Google Public DNS (8.8.8.8), and Quad9 (9.9.9.9). You will need to find the appropriate DoH URL for your chosen provider.
For advanced users, creating a custom network configuration offers greater control. This allows for fine-grained management of your network interfaces and DNS settings. This method often involves creating a custom network.nix file within your NixOS configuration.
Example (Illustrative, adjust to your specific needs):
{ config, pkgs, ... }: {
networking.interfaces.eth0.useDHCP = true;
networking.interfaces.eth0.dns = [ { address = "1.1.1.1"; useDoH = true; dohUrl = "https://cloudflare-dns.com/dns-query"; } ];
}systemd-resolved logs for errors. Check your firewall settings to ensure that outbound connections to the DoH provider are allowed.configuration.nix file for syntax errors. Use nixos-rebuild switch to apply changes and restart the necessary services.While DoH enhances privacy, it's crucial to choose a reputable DNS provider. Consider the provider's privacy policy and security practices. Also, ensure that your chosen DoH provider supports DNSSEC for added security against DNS spoofing.
Implementing DoH on your NixOS system significantly strengthens your network security and privacy. By using the methods outlined above and following best practices, you can enjoy the benefits of encrypted DNS resolution while maintaining the reliability and reproducibility that NixOS offers. Remember to adapt the configurations to your specific needs and chosen DNS provider.