Network Monitoring Tools

[Kooty]

We have a very small environment, 20 or less servers across 4 geographically spread locations. All connected via a MPLS WAN with T1 speeds. I want to monitor/alert on the following items:
Up/Down status on servers(including individual services would be a huge bonus)
Windows Event log errors
Disk space utilization – trends
Non server hardware alive status(routers, switches etc…)
Custom alerts(ping, batch file etc..)

I can't invest much right now, so freeware is the best. The solution needs to be a standalone app that is not hosted by a 3rd party.

Suggestions?

We are currently playing with spiceworks. Seems to be a lot of advertising going on and I don't feel comfortable my info isn't being sent offsite.

Thanks!!

John

[Kooty]

Also forgot to add, all Win Srvr 2003, Exchange etc...

[GhOsTzZ]

check this 1 too if you want http://www.networkuptime.com/tools/enterprise/ and try google ur requests maybe you'll find something out there..

[thewebhostingdi]

List of almost all the famous network monitoring tools with feature comparison is available at wikipedia:

http://en.wikipedia.org/wiki/Comparison_of_network_monitoring_systems

Personally, I have used PandoraFMS and it was working fine including your requirement. As slowly you invest time in it, it will help you beyond your imagination and expectations, like sending alerts using SMS, Flexible monitoring timing etc.