Bandwidth Measurement using Cisco Netflow

Netflow is great and handy to measure the amount of resources used in a typical Cisco network. Netflow comes with 3 versions: v1, v5 and v9. The most common version is v5. Recently, I have to justify for the amount of bandwidth upgrade for our Internet access - with a breakdown of the Internet application usage e.g. http, ftp, p2p etc. I configured the Internet router to keep pumping netflow data to a Netflow collector. I used an eval copy of PRTG network monitor (http://www.paessler.com/prtg)

The setup is amazingly simple:
On the router,
interface [WAN]
ip route-cache flow
ip flow-export version 5 peer-as
ip flow-export destination [Server IP] [UDP port]


Make sure that the Netflow collector is also configured with the matching server IP address and UDP port number. Few days later, I presented this chart to get my boss to agree on the bandwidth upgrade.