Ubuntu16.04 Installing L2TP VPN

1. Installation

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

2. Download from Gitlab

git clone https://github.com/nm-l2tp/network-manager-l2tp.git

3. Running

CD NETWORK-MANAGER-L2TP    

Autoreconf-fi    
Intltoolize

./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    
sudo make install  

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

sudo apt remove xl2tpd    

sudo apt install libpcap0.8-dev  

wget 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    

4. After executing the above command: System Setup –> network –> add VPN–>L2TP