You should have a Nagios Core 4.0 or newer server running with a few hosts and services configured already, and you should have found an appropriate plugin that is to be installed to solve a particular monitoring need. Your Nagios Core server should have Internet connectivity to allow you to download the plugin directly from the website.
In this example, we'll use
check_rsync, which is available on the Web at https://exchange.nagios.org/directory/Plugins/Network-Protocols/Rsync/check_rsync/details.
This particular plugin is quite simple, consisting of a single Perl script with only very basic dependencies. If you want to install this script as an example, the server will also need to have a Perl interpreter installed, for example, in
This example will also...