Hardening your Ubuntu Server (Ubuntu 20.04) The Complete Guide (Ubuntu 20.04) The Complete Guide

Chroot your Ubuntu Server
Extreme Hardening
This book focuses its attention on securing your Linux Ubuntu server 20.04. Linux has become one of the most used Operating system, if not the most used, across the world and all over the Internet.
Most web servers run Apache or Nginx on Linux, a lot of MTAs also run Postfix or Sendmail and they both run on Linux. With the advent of broadband, more and more home users are setting up their web servers and leaving it always connected to the Internet, this require special attention with the seciurity of your system.
A few years ago (about 15) years, I had set up a Linux router for my Internet at home, I left the default configuration, I mean wide open, just because a) I did not want to spend too much time making it secure (I did not think anyone would have an interest in my router) b) I was lazy c) I did not care much. So the story goes, my Internet became slow, and I started to investigate the issue. I managed to track the slowness to my Linux router; it had been targeted, by multiple requests and attempts to break in, trying the root password. I examined the /var/log/messages log, and there were 200000 failed attempts to log in to my router, which sparked my desire to become an expert in Cyber Security, this is to show that we all need to take security seriously.