I would like to know, wich Monitoring Tools are out there. I currently have Tested:
Nagios (I know how to operate it, and works great) - Great for Service Monitoring
Cacti (It never worked) - But it would be a great tool to poll The same data as Nagios but in MRTG Graphs.
MRTG (Sucessfully Installed) - Great Bandwith Reporting Tool.
Now, are there any other tools?
Check out Nessus and Snort. They are mostly used to secure networks, but never bad to learn to use them.
I actualy know someone on the devel team from nagios, its an incredable product, i love it. I ran it at home for fun, and plan on trying to get it running at work.