Enabling L2TP over IPSec on Ubuntu 16.04

原文地址：http://blog.z-proj.com/enabling-l2tp-over-ipsec-on-ubuntu-16-04/

Ubuntu has stopped shipping L2TP over IPSec support for Ubuntu since Precise. A workaround for this exists usingnetwork-manager-l2tp.

First you must install the prerequisites:

sudo apt install \  intltool \  libtool \  network-manager-dev \  libnm-util-dev \  libnm-glib-dev \  libnm-glib-vpn-dev \  libnm-gtk-dev \  libnm-dev \  libnma-dev \  ppp-dev \  libdbus-glib-1-dev \  libsecret-1-dev \  libgtk-3-dev \  libglib2.0-dev \  xl2tpd \  strongswan  

Then build the network manager again:

git clone https://github.com/nm-l2tp/network-manager-l2tp.git  cd network-manager-l2tp  autoreconf -fi  intltoolize  

Make sure no errors have occurred.

Configure the build:

./configure \  --disable-static --prefix=/usr \  --sysconfdir=/etc --libdir=/usr/lib/x86_64-linux-gnu \  --libexecdir=/usr/lib/NetworkManager \  --localstatedir=/var \  --with-pppd-plugin-dir=/usr/lib/pppd/2.4.7

Make sure no errors occurred.

Then make it:

make  sudo make install  

Remove AppArmor settings for IPSec:

sudo apparmor_parser -R /etc/apparmor.d/usr.lib.ipsec.charon  sudo apparmor_parser -R /etc/apparmor.d/usr.lib.ipsec.stroke  

Replace x2ltpd with libpcap:

sudo apt remove xl2tpd  sudo apt install libpcap0.8-devwget https://github.com/xelerance/xl2tpd/archive/v1.3.6/xl2tpd-1.3.6.tar.gz  tar xvzf xl2tpd-1.3.6.tar.gz  cd xl2tpd-1.3.6  make  sudo make install  

Now restart your machine.

Network Manager should now have an option to use a L2TP VPN connection.