Nagios

Nagios provides complete monitoring of your entire IT infrastructure environment – including websites, DNS, servers, routers, switches, services, servers, workstations, and more. It enables organizations to identify and resolve IT infrastructure problems before they affect critical business processes. The Nagios Core Services Platform (CSP) is a proven open source monitoring tool and an enterprise-grade commercial monitoring solution. The CSP distribution contains a fully installed instance of both Nagios XI and Nagios Core, along with dozens of monitoring add-ons.