Cisco Netflow Network Usage Reports With RRDTool flow-tools FlowScan and CUFlow

I have been looking for resources on Netflow collection. This is one of the most thorough walk throughs I have seen. Cheaper than Crannog Software, and runs on FOSS platforms like GNU/Linux, FreeBSD and OpenBSD.

My NetFlow Reporting System - Dynamic Networks

How to build detailed Network Usage Reports using RRDTool, flow-tools, FlowScan, and CUFlow

This document is aimed at providing step by step instructions to build useful documentation and reports from NetFlow "flows" on Cisco routers. Other vendors have their own implementations of NetFlow. You should be able to use this document to build reports from those devices, but I am a Cisco expert, so this document assumes that you are using Cisco products.
Here's a list of what you will be able to do with this application:

• Build graphs showing network utilization, including break downs by router, protocol, service, and network/host groups.


• Build "top talker" reports for your network. These are EXTREMELY useful for just about everything.


• Track down users and computers that are abusing your network, including virus infections and DOS attacks.


• Impress the boss with colorful graphs! :-)