My workplace has a Windows network with about 60 PCs running Windows 7. I'm in the process of configuring a Linux-based monitoring server that will be running Nagios and Cacti. I also have access to a cloud-based VPS running Ubuntu.
I'd like to use the VPS to monitor the monitoring server and issue an alert if the monitoring server goes down. As it stands now, the monitoring server will not be visible outside the LAN, and I don't want to make any changes to the firewall. My thought is to have the monitoring server continuously ping the VPS. If the pinging stops, the VPS will send me an alert via email.
I've done some Googling, but I can't find any information about a way to issue an alert when a server stops receiving pings from another machine.
I'm a Linux newbie, and any help would be appreciated. Thanks!