TUN creates a virtual network interface and changes routes, so desktop systems may require administrator access and mobile platforms usually require VPN authorization. After verifying the installer source, grant only the permission requested by the current system, close conflicting tools, and create TUN again. If authorization succeeds but networking fails, inspect DNS and routing.
Is VPN authorization, a network extension, or administrator access missing?
Use the system prompt to distinguish VPN authorization, a network extension, driver installation, and administrator access. Check whether a second VPN/TUN tool occupies the virtual adapter.
- Does the system prompt you to install a network extension, driver, or VPN configuration?(See Download and Installation FAQ)
- Is another VPN or TUN tool already running?
- Is security software blocking the virtual adapter?
- Do the client logs show permission denied?
Close other networking tools, then authorize TUN again
- Verify that the client source is trustworthy before granting permission(See Security FAQ)
- Close other VPN, proxy-client, or virtual-adapter tools and retry
- On Windows, try launching once as administrator
- On macOS, allow the network extension or background service in System Settings
Do not grant system-level network access to a client from an unknown source
Multiple VPN/TUN tools can overwrite each other's routes
After granting permission, verify that DNS and rules are correct