Compiled by Aaron W from Spiceworks, here are 13 free network monitoring tools that will help you detect when your network is down — and hopefully help you prevent it from going down in the first place.
- Microsoft Network Monitor
- Nagios
- OpenNMS
- Spiceworks Network Monitor
- Spiceworks Connectivity Dashboard
- PRTG Network Monitor
- The Dude
- Zabbix
- Zenoss Core
- Icinga
- Pandora FMS
- WireShark
- Observium
There are definitely more out there, but this is an excellent list of tools Aaron compiled.
One more tool I have come across for monitoring is the Agentless monitor. I have used it for database monitoring and it worked great. It is a pure web based solution with easy to use UI and free for use. Find more about this tool at http://www.appperfect.com/products/agentless-monitor.php