Why Validate Your VPN Tunnel?
A VPN client that reports a connected state is not evidence of a sealed tunnel. Encrypted routing depends on every egress path — DNS, IPv6, and peer discovery — resolving through the same interface the tunnel controls. The diagnostics on this page verify that assumption end to end.
DNS resolution outside the tunnel
Operating systems often retain resolver bindings from the underlying interface after a tunnel is established. When that happens, name resolution traverses your ISP's recursive resolvers even though the transport is encrypted, restoring full ISP visibility over browsing metadata. A DNS leak check confirms the resolver endpoints observed by authoritative nameservers match the provider's advertised DNS infrastructure, not your access network.
Public IP and routing path integrity
IP masking is only effective when every outbound flow is bound to the tunnel interface. Split-tunnel misconfiguration, IPv6 fall-through, and transient tunnel degradation during network handoff can restore the origin address without any client-side indication. Comparing the resolved public address and ASN against the expected exit node establishes that the routing path has not silently reverted.
WebRTC and application-layer bypass
The browser's WebRTC stack enumerates host and server-reflexive ICE candidates independently of the system routing table. Without an explicit blockade, remote peers can observe local RFC1918 addresses and the public IP of the underlying interface, defeating the tunnel at the application layer. A WebRTC leak test enumerates the same candidate pool a peer would see and flags any address that originates outside the VPN interface.
Continuous verification, not one-time checks
Tunnel state changes with every network transition — Wi-Fi to cellular handoff, sleep and wake, DHCP lease renewal. Any of these events can trigger short intervals of tunnel degradation during which traffic exits the underlying interface. Treat these diagnostics as a checklist to run after each material change to your network posture, not a one-time acceptance test.
