I am in need and I would like to see if anyone can help me find my solution.

I have a personal LAN. with 31 computers.
Many run windows and some run linux and bsd.

I have one (1) connection to the internet.

I want to have a computer or appliance or something (i dont know what it is yet)
that will sit infront of the internet and monitor.

and I want it to show me real time what is happening with my entire connection to the internet.

I want it to show me if a windows computer is secretly communicating with mircrosoft,
I want it to show me incoming connections, I want it to show me what ip is going to what ip.
Real time.

and as an addition to that, if it could do any of the following it would be cool, but not nessacary:

Caching streaming video and audo from the internet so that I can save it to a file.
Caching of live updates.
ablility to block the secret communications that my computers might be making to the internet. -spyware, -microsoft monitroing what dvd's I watch and mp3's i listen to.. etc etc.

Please help me.
I want as much info as I can get, Ill leave this question up for a while so I get maximum feedback.

Jon.

For the monitoring side of things I would use ntop to get a general usage monitor. MRTG is also pretty good for bandwidth graphs.

To see the live connections you could use an iptables log rule and "tail -f /path/to/log" to view it live. For a slightly more graphical representation iftop is pretty good too.

For caching you will probably be best with squid and using it along with iptables for blocking urls and hosts.