Although the L2TP/IPsec VPN protocols were primarily developed by Microsoft and Cisco, there are open source alternatives that work well in Linux. L2TP/IPsec is an older VPN protocol but it is still quite popular despite the Snowden revelations that the NSA may have deliberately weakened the protocol. It supports various encryption ciphers and is built-in to Microsoft Windows and many routers.
If you want to use L2TP/IPsec on Linux you are probably going to need to install a few extra packages. I wrote this tutorial on Linux Mint 17.3 Cinnamon desktop edition, but it should be very similar for other flavors of Linux, and I will discuss these as well. Plenty of screenshots are included below.
Ted Parvu
My hacking career began at age 12, when my father brought home a Sinclair ZX-81 computer kit and a lifelong fascination with computing was born. I became a privacy and security advocate after learning of the US Government's criminal investigation against Phil Zimmermann. Years later I found myself in Silicon Valley being paid to hack Phil's PGP code. I soon tired of the rat race and moved to the Northwoods of Minnesota where I have over 2 million acres of protected wilderness to roam. Here I indulge in my passions for wilderness and technology and as an advocate for computer security and privacy.