IPv6 Leak Test: What It Is, How to Detect It, and How to Fix It
IPv6 Leak Test: What It Is, How to Detect It, and How to Fix It
What Is IPv6 and Why Does It Matter for Privacy?
IPv6 (Internet Protocol version 6) is the successor to IPv4, designed to solve the address exhaustion problem. IPv6 provides 340 undecillion addresses — a number so large that every atom on Earth could have its own IP address with addresses to spare. For the strategic overview of where IPv6 leaks fit among DNS, WebRTC, and other privacy threats, see our complete privacy tools guide.
From a privacy perspective, IPv6 introduces a significant concern: IPv6 addresses can be uniquely tied to your hardware. While IPv4 addresses are typically shared among many users, some IPv6 address configurations embed your device's MAC address or use persistent identifiers that follow you across networks.
What Is an IPv6 Leak?
An IPv6 leak occurs when you are connected to a VPN that handles IPv4 traffic but does not tunnel IPv6 traffic. Your device continues to send IPv6 traffic directly to your ISP, bypassing the VPN. The result: your real IPv6 address is visible to any website that checks for it.
How to Test for IPv6 Leaks
Use SpeedIQ's built-in IPv6 leak test. Connect to your VPN, then run the test. If your real IPv6 address appears, you have a leak.
How to Fix IPv6 Leaks
- Enable IPv6 leak protection in your VPN: Most reputable VPN clients have an option to block IPv6 when connected.
- Disable IPv6 on your device: On Windows, go to Network Adapter settings and uncheck IPv6. On macOS, disable IPv6 in Network preferences.
- Use a VPN that supports IPv6 tunneling: Some VPNs route IPv6 traffic through the VPN tunnel, preventing leaks entirely.
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