On OS X, there's an option for L2TP/IPSec VPN in network connections where it lets you enter an IP Address, Username, Password, and Shared Secret.
I downloaded Strongswan in Ubuntu, but do not see any place to put a Shared Secret, Username, or Password. There are boxes to select a file for certificate and private key (I do not have these files nor do I know how to get them).
How can I just manually enter the information I need to connect over VPN?