jNetMap

jNetMap helps you to keep an eye on you network. You can draw a graphical representation of your network, and jNetMap will periodically check if the devices are still up or a service is still running.

You can also set up E-mail notifications or let jNetMap execute a script when a device goes down or comes up again.
Additionally, you may attach notes to a device, initiate an RDP/VNC/SSH connection to a device and much more.