Build a Local DNS in an Afternoon to Stop ISP Snooping

Understanding the Role of Your Internet Service Provider (ISP)

Your Internet Service Provider (ISP) serves as the initial gateway between you and the internet. Every time you connect, your ISP receives a wealth of information, including domain names, IP addresses, connection timestamps, and any unencrypted HTTP traffic. While this is standard practice, it can raise concerns about privacy and security, especially if you value your online activities remaining confidential.

Many people assume that using a reliable Virtual Private Network (VPN) is the sole solution for protecting their online privacy. However, there's another effective approach: setting up a local DNS. This method offers an additional layer of control and security without the need for complex configurations or subscriptions.

What Is DNS and Why Does It Matter?

The Domain Name System (DNS) acts as a translator, converting human-readable website addresses into computer-readable IP addresses. This process is essential for navigating the internet. By default, DNS requests are sent in plain text, which means your ISP can see the websites you visit. This lack of encryption poses potential risks, as your browsing habits could be tracked over time.

In addition to privacy concerns, DNS can also be manipulated. In some regions, failed DNS lookups might redirect users to ad-filled pages or even malicious sites. This highlights the importance of securing your DNS settings to protect against these threats.

Local DNS vs. ISP Snooping

When you type a website address into your browser, the first step involves a DNS server query to translate the name into an IP address. This request is typically sent in plain text, and unless you have a hardened configuration like DNS-over-HTTPS (DoH) or DNS-over-TLS (DoT), your ISP is likely to handle the response. As a result, your ISP maintains logs of the websites you access.

This metadata can reveal a lot about your online behavior, including your work hours, medical interests, hobbies, and more. Moreover, DNS snooping isn't just a privacy issue; it can also lead to unwanted redirects or blocked domains, depending on regional policies.

Taking Control with a Local DNS Configuration

Setting up a local DNS allows you to take control of how your DNS requests are handled. Instead of relying on your ISP's default settings or third-party providers like Google or Cloudflare, you can run a small DNS service on your own machine. This gives you the ability to decide how your requests are processed.

With a local DNS, you can either resolve requests yourself by querying authoritative servers directly or forward them to a trusted resolver. However, it's important to note that without encrypted DNS protocols like DoH or DoT, your requests may still be visible to your ISP or upstream resolver.

This level of control enables you to apply caching and custom rules to block specific sites from your kids' devices or speed up access to frequently visited domains. You can even add a hosts file to block known trackers, enhancing your overall browsing experience.

DNS vs. VPN: Understanding the Differences

While both DNS and VPNs contribute to online privacy, they serve different purposes. A VPN encrypts your entire internet traffic, including DNS lookups, and routes your traffic through a secure tunnel. This not only hides your IP address but also protects your identity from the websites you visit.

On the other hand, a local DNS primarily focuses on how lookups are resolved. It does not hide your activity from network observers or your ISP, nor does it provide encryption or anonymity. Therefore, while a VPN offers comprehensive privacy and identity protection, a local DNS provides flexibility and control. They can complement each other, but it's crucial to understand their distinct roles.

Setting Up a Free Local DNS on Windows 11

If you're looking for a practical and free solution, setting up a local DNS on Windows 11 is a viable option. Here's a simple guide:

1. Download Acrylic DNS Proxy from the Mayakron website and install it using the default options. Acrylic is lightweight and doesn't require complex configurations.
2. Open the Control Panel network connections settings, right-click on your active connection (Wi-Fi or Ethernet), and choose Properties.
3. Select Internet Protocol Version 4 (TCP/IPv4) and click Properties. Choose "Use the following DNS server addresses" and set your Preferred DNS server to 127.0.0.1. This ensures Windows sends DNS lookups to Acrylic running locally.
4. Set Quad9 as the upstream resolver by launching Acrylic, clicking File, then Open Acrylic Configuration, and entering the following parameters:
5. Primary Server Address: 9.9.9.9
6. Primary Server Port: 53
7. Secondary Server Address: 149.112.112.112
8. Secondary Server Port: 53

Quad9 is an excellent choice for its active blocking of malicious domains. To further enhance your security, consider adding a free hosts file or filter lists to block known ad/tracker domains.

Benefits of a Local DNS Setup

This setup offers several advantages, including faster DNS resolution times due to cached queries. It also allows you to customize your DNS experience, making it more efficient and secure. While a local DNS won't prevent your ISP from seeing the IP addresses you connect to, pairing it with an encrypted DNS or a recommended VPN service can provide comprehensive protection for your online activities.