nProbe is a stand-alone program to listen on a network interface and generate NetFlow packets based on the traffic it sees. You will still need a collector (such as ntop for flow-tools) to collect the NetFlow packets and store or process them. nProbe is licensed under the GPL, but is not currently available for public download. (You will need to know the appropriate username and password to download the distribution file for this package.) Please see the "nProbe Availability" section of for more information. A binary i386 package of the demonstration version of nProbe (limited to exporting 1000 flows) is available here: http://luca.ntop.org/demo/nProbe/1.3.1/nprobe-1.3.1-netbsd-i386.tgz