In this book, we will learn about the concepts that are required to manage real Linux-based networks. The goal is to help the reader grow from a beginner or an intermediate-level Linux user, to someone who can manage and support real Linux-based networks. The book starts with a couple of introductory chapters, in which the reader will set up their environment and then refresh some basics that will serve as the foundation for the rest of the book. From there, more advanced topics will be covered with useful examples, which the reader will be able to follow along with gaining valuable hands on practice.
During this journey, we will cover the tasks that a network administrator will typically perform on the job such as installing Linux, setting up DHCP, sharing files, IP addressing, monitoring resources, and so on. These examples are covered for not one but two popular distributions, Debian and CentOS. Since these two are very popular distributions in the enterprise, the reader will be well prepared to manage networks based on one distribution or the other (and also the countless other distributions based on them).
Finally, the last few chapters will cover the best practices to prevent intrusions and attacks and also troubleshooting to assist you when things go wrong.
Chapter 1, Setting up Your Environment, covers the process of setting up your lab environment for use in this book. Installing Debian and CentOS is covered, along with the pros and cons of using virtual machines.
Chapter 2, Revisiting Linux Network Basics, refreshes the reader on core Linux concepts that provide a foundation for the rest of the book such as TCP/IP, hostname resolution, and the IP and net tools suites.
Chapter 3, Communicating Between Nodes via SSH, covers all things SSH. In this chapter, we take a look at how to use SSH and how to set up an OpenSSH server to allow other nodes to connect. The scp command is also covered, allowing us to transfer files from one machine to another.
Chapter 4, Setting up a File Server, covers both Samba and NFS. Here, we'll discuss when it's appropriate to use one over the other, as well as the configuring and mounting these shares.
Chapter 5, Monitoring System Resources, deals with the monitoring of resources on our Linux systems such as inspecting free disk space, checking available memory, rotating logs, and viewing journal logs.
Chapter 6, Configuring Network Services, is all about the services that make our network come together. Topics such as DHCP and DNS servers are covered here. NTP is also thrown in for good measure.
Chapter 7, Hosting HTTP Content via Apache, covers Apache, which is currently the most used web server software in the world. Here, we'll not only install Apache, but we'll configure it and manage the modules as well. The virtual hosts are also covered.
Chapter 8, Understanding Advanced Networking Concepts, takes the reader to the next level by discussing more advanced topics such as subnetting, Quality of Service, redundancy in DHCP and DNS, and many more.
Chapter 9, Securing Your Network, deals with hardening our systems in order to prevent unauthorized access. Here, we'll cover iptables, fail2ban, SELinux, and much more.
Chapter 10, Troubleshooting Network Issues, rounds up our journey with some troubleshooting tips you can use if you run into problems.