L2TP VPN on OS X El Capitan
1.) To configure a L2TP VPN connection in OS X 10.11, access the “System Preferences…”
2.) Select the “Network” icon to access the network connections.
3.) Select the “+” button in the bottom left corner of the “Network” window to add a new connection.
4.) Select “VPN” for the interface type. Select “L2TP over IPSec” for the VPN Type. Name the network connection accordingly, for easy recognition. Select “Create” to create the new connection.
5.) Enter the IP address of the VPN server you will be connecting to in the “Server Address” area and your username in the “Account Name” area. Select “Authentication Settings” to setup your user authentication credentials.
6.) Enter your user account password in the “Password” area. Enter the “shared secret password” for the connection in the “Shared Secret” area, you may obtain this from your network administrator.