Click on System Preferences…

Click on Network

Click on +

Select in the Interface: pulldown list VPN
And in the VPN Type: pulldown list L2TP over IPSec
Service Name: VPN Connection LION Click on Create

Click on Authentication Settings…

Leave Password field empty
And type the shared Secret you received in your mail. Click on OK

Enable Show VPN status in menu bar
Click on Advanced…

Select Send all traffic over VPN connection Click on OK

Click on Apply

Click on Connect VPN Connection LION in the menu bar

Fill in your credentials when you have choose the Push option in DUO and click OK For example, if you wanted to use a passcode to authenticate instead of Duo Push , you Should enter (don’t forget the comma after your password):

username: bob
password: *******,123456

If you wanted to use a Yubikey to authenticate instead of Duo Push , you should enter (don’t forget the comma after your password):

username: bob
password: *******,hold your finger on the yubikey