Installation notes for ipsec support
Notes derived from here
Update and upgrade beforehand.
sudo apt-get update
sudo apt-get upgrade
Add a repository to apt with the command (I didn't and it worked
sudo add-apt-repository ppa:nm-l2tp/network-manager-l2t
Install it
sudo apt-get install network-manager-l2tp network-manager-l2tp-gnome
Then log out and log back in.