OpManager is a network monitoring software that can automatically discover your network, group your devices into intuitive maps, monitor devices in real-time and alert instantaneously on failure. It serves as a complete network monitoring solution by providing complete fault and performance functionality across your WAN and LAN infrastructure.
OpManager automatically discovers your Routers, Switches, Servers, Printers and other networked devices. OpManager speeds up the discovery process by building up a list of possibly active devices by reading ARP tables, but at the same time does a complete ping sweep to ensure that none of the devices are left undetected. OpManager also discovers services (like HTTP etc.) running on a device. It normally takes under 2 minutes for OpManager to discover a Class C network.
As soon as OpManager detects a problem it can notify administrators via email or SMS. OpManager's network monitoring functionality also includes running of external programs, system commands or playing an audio file. More on Alerting & Fault Monitoring