IPv6 Leak Test
This check shows the IP family observed for your request and compares DNS providers used for IPv4-only and IPv6-only test hostnames. These observations cannot independently confirm whether IPv6 traffic bypasses your VPN.
What Is an IPv6 Leak?
An IPv6 leak occurs when traffic intended to use a VPN instead leaves through a direct IPv6 connection. If your network supports IPv6, your VPN needs to route or block that traffic according to your intended configuration. IPv6 support and leak protection vary by provider, client and settings.
How Does This IPv6 Leak Test Work?
We generate two sets of unique DNS subdomains: one that only responds with IPv4 (A) records and one that only responds with IPv6 (AAAA) records. We compare the DNS providers observed by our authoritative server for each group and report the IP family observed for the result request. DNS lookups can occur even when a connection to the requested address fails, so this comparison does not establish IPv6 reachability or prove that traffic bypassed a VPN.
How to Fix IPv6 Leaks
- Check whether your VPN client routes IPv6 through the tunnel or blocks it.
- Enable the provider’s documented IPv6 leak protection where available.
- Verify that your kill-switch configuration covers both IPv4 and IPv6.
- Compare public addresses with the VPN connected and disconnected, using its expected exit addresses.
For detailed VPN configuration steps, read our guide: How to Prevent DNS Leaks.
Related Tools & Guides
- DNS Leak Test - inspect the DNS providers handling your test queries.
- WebRTC Leak Test - inspect addresses exposed through WebRTC.
- IP Lookup - check your public IPv4 and IPv6 addresses plus geolocation data.
Frequently Asked Questions
Does IPv6 leak testing work without IPv6 connectivity?
DNS observations may still be available. An IPv4 request does not prove that IPv6 connectivity is unavailable. Use the dual-stack IP check and compare results with your VPN connected and disconnected.
Do matching DNS providers prove my VPN carries IPv6?
No. Matching DNS providers does not establish that both traffic families use your VPN. Compare your observed public addresses with the VPN’s expected exit addresses and check its routing settings.
Should I disable IPv6 entirely?
Follow your VPN provider’s guidance. A client may tunnel IPv6 or deliberately block it. Changing adapter settings can affect other services; verify the resulting behavior rather than assuming this DNS comparison proves that IPv6 is blocked or protected.