Every app loses connectivity
Routes or DNS were rewritten. Disable TUN, then check whether another VPN is competing for the default route.
Network feature
What TUN mode does and when to use it
TUN covers traffic the system proxy misses. Here is what it changes and which permissions it needs.
Content reviewed · Nov 3, 2026
Who it is for
People whose apps ignore the system proxy, or who need every request from the device to go through the client.
Prerequisites
- The client and core support TUN
- The normal system proxy already works
- Administrator or VPN permission is available
Usage steps
- 1
TUN captures traffic that bypasses the system proxy: some games, terminal commands, and requests inside containers.
- 2
Confirm the system proxy works first, otherwise you cannot tell which layer broke.
- 3
Enabling it asks for permission: administrator on Windows, network extension on macOS, VPN on Android.
- 4
If connectivity dies, turn TUN off, return to proxy mode, then check routes and DNS one at a time.
Common issues
Expecting a speed boost
TUN does not make things faster; it widens what gets captured. Speed depends on nodes and routes.
Next step
If TUN breaks connectivity, read the TUN troubleshooting guide.
Read next：Client will not start: troubleshooting order