Category: Ubuntu

All Linux distributions are provided with a firewall solution of some form. In the case of Ubuntu, this takes the form of the Uncomplicated Firewall outlined in the previous chapter. This chapter will introduce a more advanced firewall solution available for Ubuntu in the form of firewalld. An Introduction to firewalld Originally developed for Red…

In the previous chapter, we looked at ports and services on an Ubuntu system. We also briefly looked at iptables firewall rules on Ubuntu, including the creation of a few very simple rules from the command line. In this chapter, we will look at a more user-friendly approach to iptables configuration using two tools named…

A firewall is a vital component in protecting an individual computer system or network of computers from external attack (typically from an internet connection). Any computer connected directly to an internet connection should ideally run a firewall to protect against malicious activity. Similarly, any internal network must have some form of firewall between it and…

It is difficult to envisage an Ubuntu system that does not have at least one network connection, and harder still to imagine how such an isolated system could be of much practical use. The simple fact is that Ubuntu is designed to provide enterprise-level services over network and internet connections. Therefore, a crucial part of…

The previous chapter explored the use of the Advanced Packaging Tool (APT) to install and update software packages on an Ubuntu system. In recent years a new package management system called Snap has been under development by the Ubuntu team at Canonical, Ltd. Although there are no official plans to replace APT entirely with Snap,…

It is highly unlikely that a newly installed Ubuntu system will contain all of the software packages necessary to perform the tasks for which it is intended. Even once all the required software has been installed, it is almost certain that newer versions of many of those packages will be released during the lifespan of…

To gain proficiency in Ubuntu system administration, it is essential to understand the concepts of systemd units with a particular emphasis on two specific types known as targets and services. This chapter provides a basic overview of the different systemd units supported by Ubuntu and how to configure the many services that run in the…

During the installation of Ubuntu, the installer created a root or superuser account and required that a password be configured. The installer also provided the opportunity to create a user account for the system. We should remember that Ubuntu is an enterprise-class, multi-user, and multitasking operating system. To use the full power of Ubuntu, therefore,…

An important part of learning to work with Ubuntu, and Linux distributions in general, involves gaining proficiency in working in the shell environment. While the graphical desktop environments such as GNOME included with Linux provide a user friendly interface to the operating system, in practice the shell environment provides far greater capabilities, flexibility and automation…

Although equipped with the latest Linux desktop environment, Ubuntu is very much a server operating system. As such, most Ubuntu deployments will be to remote physical servers or as cloud-based virtual machine instances. Invariably, these systems run without a keyboard, mouse, or monitor, with direct access only available via the command prompt over a network…