Monitoring Network Traffic

Hello All!

I'm working on installing a network monitor in my network. Does anyone know of are how to install a network tap? Years ago at one of my companies I used to work. I installed one, but it was pre-built. The machine cost like $3k. It contained 2 special network cards and some special software to capture the traffic. We used 2 of them for upstream and downstream traffic. The log files the Proprietary software spit out where HUGE! The company was call Genetron, Network General, today it's Network Associates.

I'd like to build one for home use and keep an eye out on what people are doing and where and why. Read this link you'll find out why? Linux software only.

2 Modems ?

Now where should I install the tap before my firewall or afterwards. If I install it before, I'll be able to capture and detect OSPF traffic. The sad thing is this is for my WIRED network this doesn't include my WIFI clients. That is another BEAST in itself.

Additional reading: http://en.wikipedia.org/wiki/Network_tap, http://en.wikipedia.org/wiki/Ospf