Before you can use your client computers or mobile devices as Mobile VPN with L2TP remote clients, you must configure and establish the L2TP connection on each client device. Many client operating systems include a native L2TP client. The steps to configure an L2TP connection are different for each client operating system.
For more information see:
For an iOS device, such as an iPhone or iPad, you have two configuration options:
If the instructions for your client operating system are not included here, see the documentation for your operating system for information about how to configure an L2TP VPN connection. For any L2TP VPN client, make sure the settings in the VPN client match the settings you configured on the XTM device.
About Mobile VPN with L2TP