We are running Nagios for server monitoring, but are kicking around the idea of setting up a second instance from outside the network to check for connectivity issues outside the network. Is there a way to get a single Nagios instance to use multiple machines for a test? For example, we set up Nagios on nagios.domain.com to run the WebUI and do checking, and have nagios-child.domain.com just run checks.
I'd like to have nagios.domain.com and nagios-child.domain.com run a ping test against mysite.com and alert me if either one is down. Is this possible with Nagios or any other monitoring system?