owner-nanog@merit.edu wrote on 10/30/2007 04:59:05 PM:

> 2.  Open Source Tools that you use or would recommend (I know the
> obvious smokeping, mrtg, nagios).

As mentioned, you can get alot of network information from netflow. There are several open-source options. One such for netflow collection/analysis is 'flow-tools' with 'FlowViewer'.

http://www.splintered.net/sw/flow-tools (original development)
http://code.google.com/p/flow-tools (active fork)

http://ensight.eos.nasa.gov/FlowViewer

Joe