Click on the Mac logo and then System Preferences.
Click on Network in the Internet & Wireless section.
Click the + (plus) sign to create a new service.
Set the Interface as VPN, VPN Type as L2TP over IPSec and enter the Service Name (the preferred name, make sure it's something you can remember) and then click Create.
Enter Server Address as our server IP or Hostname, Account Name as your server access username and click Authentication Settings.
Enter your server access password in the Password field and the Shared Secret in small letters as "vpnconnected" then click OK.
Check Show VPN status in menu bar, click Advanced and check Send all traffic over VPN connection then click OK.
Click Apply and then Connect. Your Mac should now be connecting to our server through L2TP protocol. Click Disconnect to terminate the session.