Adblock DNS: Options and Setup

Adblock DNS provides a powerful, network-wide solution for filtering unwanted content, advertisements, and tracking scripts before they even reach your devices. Unlike browser extensions, DNS-based adblocking operates at a fundamental network layer, offering comprehensive protection across all devices connected to your network, from laptops and smartphones to smart TVs and IoT gadgets. This article delves into the core concepts of Adblock DNS, explores popular options, and provides a practical guide for setting up these solutions to enhance your digital privacy, security, and browsing experience.

Understanding DNS and Adblocking Fundamentals

At its core, the Domain Name System (DNS) acts as the internet’s phonebook, translating human-readable domain names (like example.com) into machine-readable IP addresses (like 192.0.2.1). When you type a website address into your browser, your device sends a DNS query to a DNS resolver, which then returns the corresponding IP address.

DNS-based adblocking leverages this process by using specialized DNS resolvers. These resolvers maintain extensive blocklists of known domains associated with advertising networks, trackers, malware, and other undesirable content. When your device requests a domain on one of these blocklists, the Adblock DNS resolver does not return the legitimate IP address. Instead, it typically returns a non-routable IP address (like 0.0.0.0 or a local server address) or simply refuses to resolve the domain. This effectively prevents your device from connecting to the ad server, blocking the content before it can load.

The primary advantage of this approach over traditional browser-based adblockers is its system-wide coverage. Once configured on a router or a central server, every device on that network benefits from the filtering without requiring individual software installations. This also often results in reduced resource consumption on client devices and can even improve page load times by preventing unnecessary data transfers.

Key Adblock DNS Options

When considering Adblock DNS, you generally have two main approaches: utilizing public DNS resolvers that offer adblocking features or setting up a self-hosted DNS blocker within your own network.

Public DNS Resolvers with Adblocking

Public DNS resolvers are services operated by third parties that provide DNS resolution to anyone. Many of these now offer enhanced features, including built-in ad and malware blocking. This approach is the easiest to implement and requires minimal technical expertise or ongoing maintenance.

AdGuard DNS: A popular choice, AdGuard DNS offers free public DNS servers specifically designed for ad and tracker blocking. They provide both “Default” and “Family protection” servers, with the latter also blocking adult content. AdGuard DNS also supports encrypted DNS protocols like DNS over HTTPS (DoH) and DNS over TLS (DoT), enhancing privacy by encrypting your DNS queries.
NextDNS: NextDNS provides a highly customizable DNS filtering service. Users can create a free account to configure specific blocklists, whitelist/blacklist domains, view analytics, and apply parental controls. It supports DoH, DoT, and DNS over HTTP/3 (DoH3), offering robust privacy and security features. NextDNS operates globally with a vast network, ensuring low latency.

The main benefit of public resolvers is their simplicity. You simply configure your devices or router to use their DNS server addresses, and the blocking starts immediately. The trade-off is that you delegate trust to a third-party provider for your DNS queries and have less granular control over the blocking compared to self-hosted solutions.

Network diagram with devices connecting to a cloud DNS server — Photo by David Pupăză on Unsplash

Self-Hosted DNS Blockers

For those seeking maximum control, customization, and data privacy, self-hosting an Adblock DNS solution is the preferred route. These solutions typically run on a dedicated device within your local network, such as a Raspberry Pi, a virtual machine, or a Docker container.

Pi-hole

Pi-hole is arguably the most well-known self-hosted DNS sinkhole. It acts as a DNS server for your network, routing requests through its blocklists.

Features: Pi-hole offers a sleek web interface for managing blocklists, viewing query logs, and whitelisting/blacklisting domains. It provides detailed statistics on blocked queries and clients. It can also act as a DHCP server for your network.
Setup: Typically installed on a Raspberry Pi, it can also run on various Linux distributions or in a Docker container. The installation script automates most of the process.
Pros: Extremely powerful, high degree of customization, open-source, large community support. It keeps all DNS query data local to your network.
Cons: Requires a dedicated device (even a low-power one), initial setup can be more involved than public resolvers, and ongoing maintenance (updates) is necessary.

AdGuard Home

AdGuard Home is another robust self-hosted DNS blocker, developed by the same team behind AdGuard DNS and browser extensions.

Features: Similar to Pi-hole, AdGuard Home provides a web interface for management, blocklist configuration, and statistics. A key differentiator is its native support for DoH and DoT as both upstream and downstream protocols, making it easier to secure DNS traffic within your network and to external resolvers. It also offers more advanced filtering rules and can handle DNS-level content filtering beyond just ads.
Setup: Can be installed on a wide range of devices (Raspberry Pi, NAS, Windows, macOS, Linux) or run in Docker. Its installation is often simpler than Pi-hole for some platforms.
Pros: Modern interface, built-in DoH/DoT server capabilities, flexible filtering rules, active development.
Cons: Similar to Pi-hole, it requires a dedicated host and some technical know-how for setup and maintenance.

While both Pi-hole and AdGuard Home serve a similar purpose, AdGuard Home is often praised for its more modern interface and native support for encrypted DNS protocols, making it a strong contender for those prioritizing advanced privacy features.

Setting Up Adblock DNS

The setup process varies depending on whether you choose a public resolver or a self-hosted solution.

Public DNS Resolver Setup

This involves changing the DNS server settings on your router or individual devices.

Router-Level Configuration (Recommended):
- Access your router’s administration interface (usually via a web browser, e.g., 192.168.1.1).
- Navigate to the WAN, Internet, or DHCP/DNS settings.
- Locate the DNS server fields and replace any existing entries with the primary and secondary IP addresses provided by your chosen Adblock DNS service (e.g., AdGuard DNS: 94.140.14.14, 94.140.15.15).
- Save changes and reboot your router. All devices connected to your network will now use the Adblock DNS.
- Note: Some routers may not allow custom DNS settings or may revert to ISP DNS.
Device-Level Configuration:
- Windows: Go to Network & Internet settings, change adapter options, right-click your active connection, select Properties, then Internet Protocol Version 4 (TCP/IPv4) and manually enter DNS server addresses.
- macOS: System Settings > Network > Wi-Fi/Ethernet > Details > DNS, then add the new DNS servers.
- Android: Wi-Fi settings, long-press network, Modify network, Advanced options, change IP settings to Static, then input DNS servers. For Android 9+, you can also configure Private DNS (DoT) under Network & internet settings.
- iOS: Wi-Fi settings, tap i next to your network, Configure DNS, Manual, then add the new DNS servers. For iOS 14+, you can install configuration profiles for DoH/DoT.

Self-Hosted Setup (Pi-hole/AdGuard Home)

This guide outlines general steps, as specific commands may vary based on your operating system and chosen software.

Prepare Your Host Device:
- Install your preferred operating system (e.g., Raspberry Pi OS Lite for a Raspberry Pi).
- Ensure the device has a static IP address on your local network. This is crucial for its role as a DNS server.
- Update the system: sudo apt update && sudo apt upgrade -y
Install the Adblocker:
- For Pi-hole:
```
curl -sSL https://install.pi-hole.net | bash
```
  The automated installer will guide you through selecting network interfaces, setting up upstream DNS providers, and choosing blocklists. Note the admin password displayed at the end of installation.
- For AdGuard Home:
```
curl -s -S -L https://raw.githubusercontent.com/AdGuardTeam/AdGuardHome/master/scripts/install.sh | sh -s -- -v
```
  After installation completes, access the web interface at http://[your-device-ip]:3000 to complete the initial setup wizard.
Configure Your Network:
- Pi-hole: Access the admin interface at http://[your-device-ip]/admin using the password from installation.
  - Navigate to Settings > DNS to configure upstream DNS providers (e.g., Cloudflare, Google DNS).
  - Under Settings > Blocklists, you can add custom blocklists or use the default ones.
  - Configure your router to use the Pi-hole’s IP address as its primary DNS server (same method as configuring public DNS resolvers).
- AdGuard Home: Complete the setup wizard in your browser:
  - Set the admin interface port (default 3000 can be changed).
  - Create an admin username and password.
  - Configure listening interfaces and ports for DNS queries.
  - Select upstream DNS servers and enable DoH/DoT if desired.
  - Update your router’s DNS settings to point to the AdGuard Home device’s IP address.
Enable DHCP (Optional):
- Both Pi-hole and AdGuard Home can act as DHCP servers, automatically assigning IP addresses to devices while also setting themselves as the DNS server. This is an alternative to manually configuring your router’s DNS settings. Enable this in the respective admin interfaces if your router supports disabling its DHCP server.

Testing Your Adblock DNS Setup

After configuring your Adblock DNS, it’s essential to verify it’s working correctly.

Check DNS Resolution: Use nslookup or dig to confirm your device is using the new DNS server.
```
nslookup google.com
# or
dig google.com
```
The server address in the response should match your Adblock DNS server’s IP (for self-hosted) or the public resolver’s IP.
Visit Test Websites: Navigate to ad-heavy websites and observe if ads are blocked. You can also visit specific test pages:
- https://ads-blocker.com/testing/ - Shows which ad types are blocked.
- Try loading known ad-serving domains directly (e.g., doubleclick.net). If your Adblock DNS is working, these should fail to load or return a blocked page.
Query Logs: Self-hosted solutions provide detailed query logs in their admin interfaces.
- Pi-hole: Navigate to Query Log to see all DNS queries, including which were blocked.
- AdGuard Home: Go to Query Log to view and filter DNS requests and blocks. These logs are invaluable for troubleshooting issues where legitimate sites are blocked or identifying unexpected network traffic.

Troubleshooting Common Issues

Even with proper setup, you may encounter occasional hiccups.

Legitimate Sites Blocked: If a website or service isn’t functioning correctly, check your query logs to see if essential domains are being blocked. Add these to your whitelist.
- In Pi-hole: Whitelist section in the admin panel.
- In AdGuard Home: Filters > Custom filtering rules, add rules like @@||example.com^.
Slow DNS Resolution: If you experience slower internet speeds after implementing Adblock DNS:
- Ensure your self-hosted device is not under-powered or overloaded.
- Try different upstream DNS providers for better performance and reliability.
- Check network connectivity between your devices and the DNS server.
Devices Not Using Adblock DNS: Some devices (especially smartphones with data connections or VPNs) may bypass your network DNS settings.
- For smartphones, configure DNS manually in Wi-Fi settings or use a VPN with custom DNS options.
- Smart TVs and IoT devices may require individual DNS configuration if they have hardcoded DNS settings.
DNS Leaks: If using a VPN, ensure your VPN is configured to use your Adblock DNS or that the VPN provider doesn’t override DNS settings, causing DNS leaks that bypass your filtering.

Conclusion

Implementing Adblock DNS, whether through a public resolver or a self-hosted solution like Pi-hole or AdGuard Home, provides robust, network-wide protection against ads, trackers, and malicious domains. Public resolvers offer ease of use with minimal setup, while self-hosted options grant maximum control, privacy, and customization. By following the setup steps outlined in this guide, configuring your network appropriately, and understanding how to test and troubleshoot your installation, you can significantly enhance your browsing experience, improve network security, and protect the privacy of all devices on your network. As the digital landscape evolves, DNS-level filtering remains a powerful and efficient first line of defense in maintaining a cleaner, safer, and faster internet experience.