Installing and configuring fail2ban

In this recipe, we will learn how to implement additional security measures for protecting the SSH server with a package called fail2ban. This is a tool that serves to protect a variety of services including SSH, FTP, SMTP, Apache, and many more against unwanted visitors. It works by reading log files for patterns based on failed login attempts and deals with the offending IP addresses accordingly. Of course, you may have already hardened your SSH server or another service on a direct application level, but it is the purpose of this recipe to show that, when faced with the possibility of Brute Force Attacks, an added layer of protection is always useful.

Getting ready

To complete this recipe, you will require a working installation of the CentOS 7 operating system with root privileges, a console-based text editor of your choice, and a connection to the Internet in order to download additional packages. In addition to this, it will be assumed that YUM is...