I'm currently looking for network monitoring off our production network uplink but it runs on fiber optics cable. My peek throughput is around 150mb/s to 200mb/s. Can Netprobe handle that amount of traffic and what kind of hardware I'm looking into in order to support it.
Network Probe should be able to handle approximately 70-100.000 packets per second. To do some memory/performance tests, start it from command line with the "-loadtest" parameter, and give us the results. As long as the traffic is not very diversified, it should run very well without memory problems.
I recommend at least a 2 GHz CPU with 1 GB of RAM. We've done successfully tests on both RedHat, Fedora and FreeBSD on medium scaled networks, but it does not matter which distribution you choose (but from my personal point of view I would recommend Fedora Core with a 2.6 kernel).
Network Probe is primarly used to monitor traffic between local segments and the Internet. Your WAN is not very likely using over 150-200 Mbit/s, so Network Probe should work very well for that purpose.