I figure there have to be some more network cable monkeys out there in our group. I'm looking to set up a box to monitor netflow and other data. My question... what are your favorite tools and why. Things I am hoping to get out of the program:
1) Free... I'm hoping here,

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2) Collect total bandwidth usage in graph form for time vs. bytes etc.
3) Be able to dig down to see individual IP in/out bound usage totals. In an ideal world, also support output of IP to IP connection monitoring. I'd like to see if any of my LAN is calling to China etc.
4) Anything else anyone knows of that sounds sexy in a monitoring tool.
Any tips and ideas on this subject would be most appreciated. I finally got my boss to submit to my claims of our needing network visibility, and that though I have had a fun time with nmap/wireshark and common sense... we could do with a full time monitoring system on our LAN here. Thanks guys!
Clay