Somewhat similar here: https://bugs.launchpad.net/ubuntu/+source/l2tp-ipsec-vpn/+bug/1187390
L2TP bugs are not new. Look at this: http://www.kabatology.com/04/10/how-to-install-l2tpipsec-vpn-on-ubuntu/
tldr, you cannot use L2TP for about a year now with current ubuntu packages.
Somewhat similar here: https:/ /bugs.launchpad .net/ubuntu/ +source/ l2tp-ipsec- vpn/+bug/ 1187390
L2TP bugs are not new. Look at this: http:// www.kabatology. com/04/ 10/how- to-install- l2tpipsec- vpn-on- ubuntu/
tldr, you cannot use L2TP for about a year now with current ubuntu packages.