Testing NetFlow Export Configurations. Our NetFlow Testers are small programs that simply dump the data of all NetFlow packets that a computer receives from a Cisco router. This can be useful when debugging bandwidth monitoring configurations based on Cisco´s NetFlow protocol (both v5 and v9). First the NetFlow protocol must be enabled and configured on the router. The router must be given the IP address of the computer running NetFlow tester so that the UDP data packets with NetFlow data are sent to this computer.

Just follow these simple instructions:

1. Download Paessler Netflow Tester. Netflow5Tester.exe for testing NetFlow version 5 and Netflow9Tester.exe for testing NetFlow version 9.
2. Enter the IP and port number that you have configured as NetFlow packet target in your Cisco Router. Usually selecting "Any IP" should work, in some cases the IP must be explicitly selected.
3. Click on "Start".
4. You should now see a line in the logfile for each packet the computer receives. Each line shows the time, NetFlow version, number of flows and the IP of a packet (Note: You need NetFlow v5 for PRTG Traffic Grapher; PRTG Network Monitor supports both NetFlow v5 and v9). NetFlow5Tester only: Enable "Show Flow Data instead of packet data" to also show the corresponding flow data. If you do not see any activity then the system does not receive any NetFlow data (e.g. due to misconfiguration of the router or a firewall blocking the packets, etc.).