PRTG Network Monitor 

Keep track of such resources in your network as LANs, WANs, servers, websites, and others. Enable automatic network detection and device assessment using thousands of sensors and receive alerts via email, push-notifications, or triggering HTTP requests.

PRTG Network Monitor is a powerful yet easy to use the powerful network monitoring solution that allows you to set up your complete network monitoring scenario within minutes. This incredible program runs with 10,000s of sensors offering automatic network discovery, device assessment and sensor configuration. What is more, the application features a highly interactive and customizable interface for optimized usability, making this task a breeze. Moreover, it includes more than 35 sensor types for comprehensive monitoring of small, medium and large networks such as WMI, PING, HTTP, SNMP, SMTP, POP3, FTP, and "Smart” sensors that e.g. automatically discover quad-core CPUs and and monitor them individually as well as the total CPU load. In addition to this, the integrated Webserver supports SSL security, multiple logins, user groups and an HTTP-based API for interfacing with other applications. All in all, if you are looking for a comprehensive and easy to use network monitoring solution, PRTG Network Monitor is perfect for you.