The Nagios Plugins package offers a large variety of checks that can be performed to monitor your infrastructure. Whether you are an administrator of an IT company managing a large network, or just want to monitor a small server room, these plugins will allow you to check the majority of the services that you are currently using.

In this chapter, you learned how the plugins report status to Nagios using standard output and exit codes. You also learned about the Nagios Plugins project and the standard options for all the plugins within the package.

We also covered the generic communication plugins for checking remote host connectivity using ping as well as generic TCP and UDP checking plugins.

The chapter also described how to perform checks of standard networking protocols, such as e-mail, FTP, DHCP, website checking as well as Nagios process information.

You also learned about checking various databases and how it can also be used for monitoring the propagation of data to slave databases.

The chapter also covered information about monitoring disk and swap space as well as monitoring system resources and processes.

You also learned how to monitor additional operations, such as APT package management status and UPS and LM sensors. You also learned about using third-party plugins in Nagios.

The next chapter will cover how to create Nagios configuration so that it can be used for monitoring both small and large infrastructure. It also will cover advanced configuration options, such as dependencies, custom variables, inheriting, and flapping.