Argus, the network Audit Record Generation and Utilization System. The Argus Project is focused on developing network activity audit strategies and prototype technology to support Network Operations, Performance and Security Management. If you look at packets to solve problems, or you need to know what is going on in your network, right now or way back then, you should find Argus a useful tool.
Platform:Windows/Linux;License: GNU General Public License v2
Reference: https://www.qosient.com/argus/