Securing Your Network with RouterOS: A Comprehensive Guide to DNS over HTTPS (DoH)

DNS over HTTPS (DoH) is a privacy-enhancing protocol that encrypts DNS queries, preventing your internet service provider (ISP) and potential eavesdroppers from seeing which websites you visit. This guide details how to configure DoH on your MikroTik RouterOS devices, significantly improving your network's security and privacy.

Why Use DNS over HTTPS with RouterOS?

Traditional DNS queries are sent in plain text, making them vulnerable to interception and manipulation. With DoH, your DNS requests are encrypted using HTTPS, ensuring confidentiality and integrity. The benefits include:

• Increased Privacy: Your ISP and others cannot see your browsing history.
• Improved Security: Protects against DNS spoofing and other attacks that target unencrypted DNS traffic.
• Enhanced Censorship Resistance: DoH can help bypass some forms of DNS censorship.
• Centralized Management: Configure DoH at the router level, protecting all devices on your network.

Configuring DoH on RouterOS

RouterOS offers several ways to implement DoH. The most common and recommended method involves using the built-in DNS proxy functionality along with a DoH resolver. Here's a step-by-step guide:

1. Choosing a DoH Resolver

Several reputable providers offer public DoH services. 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
• CleanBrowsing: (Requires selecting a specific family filter; check their website for the appropriate URL)

Consider the privacy policy and security practices of each provider before making your selection.

2. Configuring the DNS Proxy in RouterOS

Access your RouterOS device via Winbox or the command-line interface. Navigate to IP > DNS. You'll need to create a new DNS proxy entry. The crucial settings are:

• Address: Leave this blank. RouterOS will use the DoH URL.
• Server: Enter the URL of your chosen DoH resolver (e.g., https://cloudflare-dns.com/dns-query).
• Allowed-clients: Specify which interfaces or IP addresses should use this DoH proxy. all for all interfaces. /ip address list 192.168.1.0/24 for a specific subnet.
• Protocol: doh

Save the configuration. You might need to specify a different port if your chosen DoH resolver doesn't use the standard port 443. However most providers use 443, so this should not be required.

3. Setting the DNS Server

Next, configure your network interfaces to use the newly created DNS proxy. Under IP > Interfaces, select your interface (e.g., your LAN interface). Go to the DNS tab. You should specify the address of the newly created DNS proxy. This address will likely be something like 192.168.1.1 or whatever is the IP address of your RouterOS device. You can find this address under IP > Addresses

4. Verification

After saving your configuration, verify that DoH is working correctly. Use a tool like `dig` (available on most Linux systems) or an online DoH test website to check if your queries are being sent over HTTPS.

Troubleshooting

If you encounter issues, ensure that:

• Your RouterOS device has a stable internet connection.
• The DoH resolver URL is correctly entered.
• The firewall rules aren't blocking DoH traffic (ensure port 443 is open and allowed).
• Allowed-clients are correctly configured.

Advanced Configurations

For more advanced users, you can explore using alternative methods, such as custom scripts or using a more advanced DNS server configuration to offer even more granular control.

Implementing DoH on your RouterOS device enhances the security and privacy of your network. By following these steps, you can significantly improve your online experience and protect your data.