In this chapter, you’ll learn how to install and configure Nagios to monitor network services, host processes, and hardware. Nagios is so flexible it would take a couple of books to detail everything it can do, so we’re going to focus on the most common functions to build a good foundation that will let Nagios grow as your network grows.
In this chapter, you will learn how to:
Monitor services like HTTP, SSH, name services, and mail services
Monitor system processes and hardware usage
Receive alerts when there are problems
Why Nagios, when the FOSS world offers a multitude of good network monitors? You could probably choose one with a coin toss and be happy with it. Nagios’ strength is its modular design, which permits the greatest flexibility and room for growth. The grunt work is done with plug-ins. You may use or modify the official Nagios plug-ins, try some of the many third-party plug-ins, or write your own. Plug-ins make Nagions future-proof; for example, as more devices become SNMP-aware, you may wish to add or write SNMP plug-ins.