Linux Security Basics and Beyond: Unit 3

Overview

This course is designed for aspiring Linux security administrators who are eager to enhance their skills in safeguarding systems and networks. In this course, you will delve into the world of firewalls, exploring tools like UFW, firewalld, and nftables, each offering unique capabilities for robust protection. You'll gain hands-on experience in configuring and managing these firewalls, ensuring your systems are shielded from unauthorized access. Additionally, you'll learn the practice of securing SSH connections, a critical skill for remote system administration. By the end of this course, you will have a solid understanding of firewall technologies and SSH security, empowering you to implement a multi-layered defense strategy with confidence.

Syllabus

Firewalls and SSH Security

This module introduces firewalls, which are used to permit or deny traffic to and from a computer or network. It covers different types of Linux-based firewalls and the meaning behind zero trust mindsets. You will learn about UFW, an uncomplicated firewall and the trade-offs in security that can be associated with ease-of-use firewalls. You'll learn about firewalld, a functional front-end firewall tool that offers increased security. You also learn about nftables and the nft command, currently the most powerful firewalling tool in Linux. Finally, you'll learn how to harden a secure shell server using keys and locking down the SSHD_config file, as well as why incorporating SSH security to firewalling is a critical security step and how to do it.