Deploying Your Own Internal DNS-over-HTTPS Server in 2024: A Comprehensive Guide

The demand for enhanced privacy and security on internal networks is constantly growing. DNS-over-HTTPS (DoH) offers a significant improvement over traditional DNS, encrypting DNS queries to protect sensitive data from eavesdropping and manipulation. This guide will walk you through setting up your own internal DoH server in 2024, offering greater control and security within your organization's infrastructure.

Why Deploy an Internal DoH Server?

• Enhanced Privacy: Encrypt DNS queries to prevent unauthorized observation of browsing activity within your network.
• Improved Security: Protect against DNS spoofing and other attacks that exploit vulnerabilities in traditional DNS.
• Centralized Control: Manage DNS resolution policies and configurations from a single point.
• Bypass External DoH Services: Maintain control over your DNS data and avoid reliance on third-party providers.
• Compliance: Meet regulatory requirements that necessitate heightened data security and privacy.

Choosing the Right Software

Several excellent open-source options are available for building your own DoH server. Popular choices include:

• dnsmasq: A lightweight and versatile DNS forwarder that can be configured to support DoH. It's a good choice for smaller networks or those requiring minimal configuration.
• coredns: A more advanced and feature-rich DNS server written in Go. It offers greater flexibility and scalability, suitable for larger and more complex environments.
• unbound: A validating, recursive, and caching DNS resolver. It emphasizes security and can be configured for DoH.

Step-by-Step Guide (using dnsmasq as an example):

This guide provides a basic setup using dnsmasq. Adapt the steps for other software based on their respective documentation.

1. Installation:

Install dnsmasq on your chosen server. The exact command will depend on your operating system (e.g., sudo apt-get install dnsmasq on Debian/Ubuntu, brew install dnsmasq on macOS).

2. Configuration:

Configure dnsmasq to listen on HTTPS and forward DNS queries to your internal or external upstream DNS servers. A sample configuration file (/etc/dnsmasq.conf) might look like this:

interface=eth0  # Replace with your network interface
listen-address=192.168.1.100  # Replace with your server's IP address
port=0
user=nobody
group=nogroup
#Enable DoH
listen-address=:::8443
bind-dynamic
no-resolv
dns-forward-max=1500
#Upstream DNS server
server=8.8.8.8
server=8.8.4.4
#Specify your TLS certificate and key
tls-cert=/etc/dnsmasq/server.crt
tls-private-key=/etc/dnsmasq/server.key

3. Certificate Generation:

Generate a self-signed TLS certificate and key. For production environments, use a trusted Certificate Authority (CA) to issue certificates. You can use OpenSSL for self-signed certificate generation.

openssl req -x509 -newkey rsa:4096 -nodes -keyout /etc/dnsmasq/server.key -out /etc/dnsmasq/server.crt -days 365 -subj "/C=US/ST=YourState/L=YourCity/O=YourOrganization/CN=your.internal.domain"

4. Client Configuration:

Configure your clients (desktops, laptops, mobile devices) to use your internal DoH server. This typically involves setting the DNS server address in your network settings to the IP address and port of your DoH server (e.g., 192.168.1.100:8443). Some operating systems and browsers might require additional configuration.

5. Testing and Monitoring:

Thoroughly test your DoH setup to ensure proper functionality and performance. Monitor the server's logs for any errors or issues.

Security Considerations:

Implementing strong security measures is crucial:

• Use a strong password and regularly update the server software.
• Employ a firewall to restrict access to the DoH server.
• Use a trusted CA-signed certificate in a production environment.
• Regularly audit server logs for suspicious activity.