What Is a DNS Leak? Complete Diagnostic & Prevention Guide

What Is a DNS Leak?

When you connect to a Virtual Private Network (VPN), your internet traffic is routed through an encrypted tunnel. However, if your operating system mistakenly sends DNS translation queries to your ISP's default resolver instead of the VPN's private DNS server, a DNS Leak occurs.

---

Why DNS Leaks Destroy Online Anonymity

Even if your IP address appears to be in another country, a DNS leak reveals:

• Every website domain you visit to your local ISP.
• Your approximate physical region and ISP routing server.

---

How to Fix and Prevent DNS Leaks

1. Enable DNS Leak Protection in Your VPN App: Most modern VPN clients include a native toggle to block non-VPN DNS traffic.
2. Manually Assign Encrypted DNS: Set your operating system DNS to 1.1.1.1 (Cloudflare) or 9.9.9.9 (Quad9).
3. Disable Teredo / Smart Multi-Homed Resolution on Windows: Prevents Windows from querying secondary network adapters.

Verify your connection with WhatsMyDevice IP Check and WebRTC Leak Test.