DNS leaks, IPv6 leaks and Tor
What DNS and IPv6 leaks are, how to check for one without naming a test site, what ForestVPN publishes about its apps, and a VPN compared with Tor.
A leak is traffic or a lookup that leaves your device by the ordinary network instead of the tunnel.
How it works
DNS. Before a device connects to a website it asks a resolver to turn the name into an address. A DNS leak is when those lookups go to the resolver of the network you are on, usually your internet provider's, instead of through the tunnel. The resolver then sees the names you look up, even though the pages themselves travel inside the tunnel.
IPv6. An IPv6 leak is IPv6 traffic that leaves by the ordinary network because the tunnel carries only IPv4. It needs an IPv6 route outside the tunnel.
How to check for a DNS leak. Connect, then open a DNS leak test page from a source you trust and run its test. The page lists the resolvers it saw. If they belong to your internet provider or the network you are on, the lookups are leaving outside the tunnel. If they belong to the VPN's side, they are not. This page does not name a test site, because it does not endorse one.
What ForestVPN publishes. ForestVPN keeps no record of the names you look up: there is no field anywhere for them. It publishes no DNS leak test result for its apps and makes no promise about one. If a test shows your provider's resolver while ForestVPN is connected, write to support with a support code.
What it does not do
- A test page is one observation. A clean result on one test, on one network, on one day, does not prove it will be clean on another.
- It does not stop a leak by itself. If the device resolves names outside the tunnel, a tunnel that carries traffic still leaves those lookups visible.
- A VPN is not Tor. They are different tools with different trade-offs. A VPN moves your trust from your network to the VPN's operator, so the operator matters. Tor sends traffic through several relays run by other people, so no single relay sees both who you are and where you are going. ForestVPN does not claim to replace Tor, publishes no comparison with it, and makes no ranking claim. Which one fits depends on what you need to hide, and from whom.
- Neither makes you anonymous to a site you sign in to.