A feature which blocks internet access when FREEDOME VPN connection is disrupted or being established.
F-Secure FREEDOME VPN includes a killswitch feature to prevent accidental leakage of traffic to the internet.
Should the VPN connection between the FREEDOME VPN client and the server drop for any reason, for example due to a short network outage or while changing from one FREEDOME VPN site to another, the FREEDOME VPN killswitch will notice this. Depending on the settings, it may block the network traffic until the connection to the FREEDOME VPN backend has been established again. In this scenario, only the mandatory network traffic is allowed. In other words, apart from the OpenVPN or IPSEC protocol itself, only the traffic that is required to establish the VPN connection, such as DNS and DHCP, is allowed.
If the user turns off FREEDOME VPN, it will not trigger the killswitch feature. Instead, the network traffic will work normally but naturally not protected by FREEDOME VPN.
There are minor differences in how the killswitch works on different operating systems.
On Android devices, the killswitch feature is turned ON by default.
However, if there is a captive portal in the network (for example a hotel WiFi with a login page) and FREEDOME VPN detects it, the killswitch works differently depending on the Android version in use. On Android 6.0 and newer, the traffic will be allowed only to the captive portal and after the authentication, to the FREEDOME VPN backends. Because of the limitations in Android versions 4 and 5, the killswitch will start working only after FREEDOME VPN has detected that the captive portal authentication has been completed.
Note: Android version 4.4.2 has an unavoidable bug which allows traffic to leak briefly outside the VPN tunnel during the VPN connection phase regardless of the killswitch setting.
Note: Some Huawei devices running on Android 8 and 8.1 have a firmware bug that in some rare cases may cause a momentary traffic leak outside the VPN tunnel during the VPN connection phase regardless of the killswitch setting.