We installed Flexible NetFlow V9 on our router(Cisco 877 with recent IOS) which is running VPN IPsec. We inputted the important configuration that would export the traffic which was monitored to the PRTG. When we view the cache flow in the router, data is populated in the Source IP,Destination IP, Source Port, Destination Port, Protocol and Bytes columns. We installed the NetFlow V9 sensor on our PRTG server and inputted the configuration settings that would connect the router and the PRTG. When we view the toplist option for the sensor, it shows data in the Source IP, Destination IP and the Bytes columns but all zeros value is populated for the Source Port, Destination Port, Protocol .These zero value did not show in the cache in the router( i.e. the router is showing the actual associated ports for the traffic and the protocol). A screenshot of the result is shown below for the PRTG toplist .
We have tried resetting the router several times but get the same results. What would be your recommended router configuration and your recommended PRTG settings.? Do you know if there is any Known Issues with regards to only 0s showing up for the port and protocol columns.