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.

Nagios offers many plugins for monitoring network-aware applications. These include generic TCP and UDP checks — whether a service is accepting connections or not, as well as more complex checks — whether POP3 service accepts a specific username and password. These also include database monitoring checks for commonly-used database servers. Network-based checks can be used to monitor all of the hosts within your network from a single Nagios server. This makes them much easier to be set up.

Another type of check commands are plugins that return information on local resources — such as CPU usage, disk space, or patches that need to be installed. These plugins...