Guide

Following these below steps to install Drush 8 (Ubuntu and MacOS):

The current version of Drush 8 when I writing this article is 8.2.1

1. Choose the latest version of Drush 8 in the below link: 

https://github.com/drush-ops/drush/releases

You can choose v8.2.2 and download the drush.phar. You can use the bellow command line to download it:

wget https://github.com/drush-ops/drush/releases/download/8.2.1/drush.phar

Note: to use the wget command line, you need to install it first.

When I searched a solution for connecting through VPN with L2TP/IPSec on Ubuntu (I used Ubuntu 18.04 at this time), I found this article and kept it in my note.

Just as a followup to the great information you provided, thought I'd give people a complete set of steps I took to get this working on Ubuntu GNOME 17.04: