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VPN switches protocols? What to test

Check whether a VPN protocol switch is normal, compare what changes, and test for IPv6 or WebRTC leaks before you adjust the connection.

Daniel HayesHardware tests Tests 4 min read

Your VPN disconnects, reconnects, or quietly changes protocols, and you are not sure whether your traffic is still protected. A protocol switch can be an automatic fallback, but a new connection can also change your apparent IP address or briefly interrupt the tunnel.

Use the VPN Leak Test to check for IPv6 or WebRTC IP leaks while the VPN is connected. It cannot tell you which protocol is active, so compare the VPN app's connection details with the test results.

Test after a protocol switch

  1. Open the VPN Leak Test while your VPN is connected. Keep the VPN on for the whole check.
  2. Note the protocol and server or location shown in your VPN app. If the app says it is choosing automatically, note that too.
  3. Run the leak check and record whether it reports an IPv6 or WebRTC leak. Also note the time and whether you are on Wi-Fi or mobile data.
  4. If the VPN switches protocols on its own, wait for the connection to settle, then run the check again. Compare the results, and note whether the server or location changed too.
  5. If your VPN app lets you choose a protocol, test one option at a time on the same network and server location. Wait for each connection to settle before checking it.

For a useful comparison, change only one thing at a time. If the app reconnects to a different server, the public IP can change even if the protocol is working properly. A change in IP address alone does not prove that your real address leaked.

What the result means

No IPv6 or WebRTC leak is reported

The test did not detect your real IP address through those two routes during that check. The VPN may still have other privacy or connection issues, and this result does not identify the protocol or prove that every kind of traffic is protected. Check the VPN app's connection details to confirm which protocol it says it is using.

An IPv6 or WebRTC leak is reported

Your real IP may be visible through that route while the VPN is on. Confirm the VPN is connected, run the test again, and check that you did not switch networks during the test. If the result repeats, avoid sensitive activity until you have checked the VPN's leak protection settings or contacted its support.

IPv6 and WebRTC are different ways a browser can communicate. For more detail on IPv6 checks, see how to check VPN leaks on a dual-stack connection.

The result changes after the VPN reconnects

A new server, a different network, or a brief interruption during reconnection can change what the test sees. Repeat the check with the same network and server location if possible. The test can reveal an IP leak, but it cannot show whether your VPN app changed protocols or exactly when a tunnel dropped.

How to reduce unwanted switching

  1. Check the protocol setting in the VPN app. Look for a connection, protocol, or advanced setting. The label and available choices vary by provider. If you need a consistent connection, try selecting one supported protocol instead of automatic selection, then test again.
  2. Check whether the network changed. Moving between Wi-Fi and mobile data, waking a laptop, or changing access points can make the VPN reconnect. On a phone, check whether the switch happens when you leave Wi-Fi coverage or when battery saving is enabled.
  3. Review the VPN profile in your system settings. In Windows 11, go to Settings › Network & internet › VPN. On macOS, go to System Settings › VPN. On iPhone, go to Settings › General › VPN & Device Management. On Android, go to Settings › Network & internet › VPN, though the wording can vary by device. These screens help you inspect system-managed VPN connections; protocol choices may still be controlled in the VPN app.
  4. Update the VPN app. Install an update from the source you normally use, then restart the app and reconnect. An outdated app can have trouble reconnecting after an operating system or network change.
  5. Try another supported protocol or server. A network may block or interrupt one protocol. Test a different option offered by your provider, or choose another server location, then check again. A new server can give you a different public IP without indicating a leak.
  6. Check the connection over time. If the switch repeats, note the time, network, protocol, and server each time. This can help distinguish a recurring Wi-Fi or mobile-data interruption from a problem limited to one protocol. For a longer check of interruptions, see why an unstable VPN tunnel can look like packet loss.

What the browser test cannot tell you

A browser-based leak check does not read the VPN app's protocol setting, inspect all traffic from your device, or prove complete anonymity. It checks specific IP exposure routes, including IPv6 and WebRTC. The VPN app is the source to consult for its active protocol and connection status.

If the VPN drops completely during a switch, a test run after reconnection may not capture the brief interruption. Use the app's connection log, if available, and note whether a website or call continued working during the change.

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