Preface

This book is a practical guide to setting up Nagios, an open source network-monitoring tool. It is a system that checks whether hosts and services are working properly and notifies users when problems occur. The book covers the installation and configuring of Nagios 4 on various operating systems, with a focus on the Ubuntu Linux operating system. The book takes you through all the steps of compiling Nagios from source and installing and configuring advanced features such as redundant monitoring. It also mentions how to monitor various services, such as e-mail, WWW, databases, and file sharing. The book describes what SNMP is and how it can be used to monitor various devices. It also provides details of monitoring Windows computers. The book contains troubleshooting sections that aid you in case any problems arise while setting up Nagios functionalities. No previous experience with network monitoring is required, although it is assumed that you have a basic understanding of Unix systems. It also mentions examples to extend Nagios in JavaScript. The book also covers Nagios XI, a commercial offering built on top of the open source Nagios monitoring engine. It covers the basics of using Nagios XI as well as outlining the main differences between the open source version and the commercial product. When you finish this book, you'll be able to set up Nagios to monitor your network and will have a good understanding of what can be monitored.