This is a straightforward shell script with alternate JAVA application to regularly monitor your hosts and let you know via GUI or email if they go down. The app can be run in a simple GUI or via the command line.
jnetscan is a simple java network utility, it allows you to scan networks, find reachable hosts , opened ports and sheared resources, with additional functions (ping, trace route, netstat, send message, ...)
multi-protocol, multi-host, graphical ping utility, used to ensure a set of hosts are up and running and providing the expected services. traditional ICMP echo along with status of http, smtp, pop, etc.