How does a kill switch for a VPN work?

Your VPN kill switch, when enabled, continuously monitors your VPN connection and looks for changes in your IP address or network status.When it detects a change in either status, the kill switch will immediately activate and prevent internet access.The kill switch will continue to monitor your VPN connection even if you reconnect to a VPN server or the VPN tunnel automatically reestablishes itself.
Kill switches for VPNs come in two varieties:some that operate at the application level and others at the system level.
You can select which applications on your device to kill in the event of a VPN disconnect with an application-level kill switch.Even though some applications will be blocked, any others that are connected but you didn't kill will stay connected and could put you in danger.You have some flexibility with an application-level kill switch, but you need to be careful about which apps you include or exclude.Because it shuts down all network traffic on your device at the system level whenever it detects that the VPN tunnel has failed, a system-level kill switch is the better option overall.
While ExpressVPN only provides a system-level kill switch, some VPNs, like NordVPN, provide both an application-level and a system-level kill switch.Although ExpressVPN's Network Lock kill switch is enabled by default, not all VPNs include kill switches.You can activate the kill switch in your VPN client by going to the settings section if it is not enabled by default.