DNS Logging & User Tracking

TL;DR

Yes, DNS servers can log user requests for commercial use (tracking website access). However, it’s complex. Public DNS providers often do this for security and analytics, but privacy regulations like GDPR limit how they can use the data without consent. Running your own DNS server gives you more control, but also more responsibility regarding data protection.

Understanding DNS Logging

DNS (Domain Name System) translates website names (like google.com) into IP addresses (like 142.250.185.142). Every time you visit a website, your device asks a DNS server to do this translation. This creates a log of which websites users are accessing.

Can DNS Servers Log Requests?

1. Yes, they can. Most DNS servers technically *can* record these requests (called DNS queries). The information logged typically includes:
   • The domain name requested (e.g., google.com)
   • Your IP address (identifying your internet connection)
   • Timestamps (when the request was made)
   • Sometimes, the DNS server used by the requester
2. Why log? DNS logs are useful for:
   • Security: Identifying malicious websites and preventing access.
   • Analytics: Understanding website traffic patterns (for the DNS provider).
   • Troubleshooting: Diagnosing network issues.
   • Commercial tracking: Building user profiles for targeted advertising or other purposes.

Public DNS Providers & Logging

Popular public DNS providers like Google Public DNS (8.8.8.8, 8.8.4.4) and Cloudflare DNS (1.1.1.1) do log queries, but they anonymize or aggregate the data to protect privacy.

• Google: Logs are retained for a limited time (typically around 30-60 days) and used for security improvements and service performance analysis.
• Cloudflare: Offers options like 1.1.1.1 with enhanced privacy features, including shorter log retention periods.

However, even anonymized data can potentially be re-identified under certain circumstances.

Running Your Own DNS Server

1. More Control: If you run your own DNS server (e.g., using BIND9, PowerDNS, or Unbound), you have complete control over logging.
2. Logging Configuration: You decide what to log and how long to retain the data. For example, with BIND9, you can configure logging in named.conf:

   options {
      directory "/var/cache/bind";
      logging {
         channel querylog {
            file "query.log" versions 3 size 5m;
            severity dynamic;
         };
         category queries {
             querylog; 
         };
      };
   };

3. Privacy Responsibility: Running your own server means you are legally responsible for complying with privacy regulations (like GDPR, CCPA) if you collect personal data.
4. Software Choices:
   • BIND9: A widely used and powerful DNS server.
   • PowerDNS: Another popular option known for its flexibility.
   • Unbound: A validating, recursive DNS resolver focused on security and privacy.

Privacy Regulations & Consent

Regulations like GDPR (in Europe) require explicit consent before collecting and using personal data, including DNS queries.

• GDPR: If you are tracking users’ website access for commercial purposes within the EU, you must:
  • Obtain informed consent from users.
  • Provide a clear privacy policy explaining how the data is collected and used.
  • Allow users to access, rectify, and erase their data.
• CCPA (California): Similar requirements apply in California.

How Users Can Protect Their Privacy

1. Use a privacy-focused DNS provider: Cloudflare (1.1.1.1) and others offer enhanced privacy features.
2. Use a VPN: A Virtual Private Network encrypts your internet traffic, hiding your IP address from the DNS server.
3. Use DNS over HTTPS (DoH): Encrypts DNS queries to prevent eavesdropping.
   • Most modern browsers support DoH. Enable it in your browser settings.