Network binding is the act of assigning an app, service, or socket to a specific network interface or route, such as Wi‑Fi, cellular, or a VPN tunnel. Instead of letting the operating system choose the “best” path, binding forces traffic to use the selected network path.
In cyber security, binding matters because it can enforce trust boundaries or accidentally weaken them. A VPN client may bind protected traffic to the tunnel interface so requests stay inside the encrypted path. But a misconfigured app, platform bug, or bypass rule can bind some connections to the underlying physical interface and expose the device’s real IP address. Attackers may also abuse binding to route traffic around monitoring controls, while defenders test it to confirm that sensitive apps cannot escape the VPN or other policy-enforced network.