With today’s network professionals needing deeper forensic details such as mac address, VLAN, etc., it is even easier to understand that the NetFlow protocol needed to evolve. As NetFlow matured, the need for a dynamic flow technology capable of exporting anything began to become more evident
This document explains what you get with NetFlow v5 and the enhancements brought about with NetFlow v9 which is the basis for the proposed standard called IPFIX. For several reasons explained below, NetFlow v9 is the export of choice. The biggest reason is templates and the ability to work with them makes for the best NetFlow solutions.
Below table illustrates the major differences between Netflow v5 and v9 –