How to estimate NetFlow flows per second(FPS) from specific device?

NetFlow flows per second of a device can be found using CLI using show command. The command can vary depending on the vendor and firmware OS running.

For example, the steps for CIsco IOS is as follows -

  1. Log on to the device
  2. Execute clear ip flow stats in the CLI prompt
  3. Wait the some time, may be 15 min or more
  4. Run show ip cache flow after the appropriate time elapses.

Another example on Ruckus Device,

Log on to the device
2. Execute clear statistics in the CLI prompt
3. Wait the some time, may be 15 min or more
4. Run show sflow after the appropriate time elapses.

There are instance where customer is not able to provide such vital information. In such cases, SapphireIMS encourages to use SapphireIMS NetFlow module on trial basis for few days to arrive upon accurate flows per second across all the devices. Once FPS is arrived, SapphireIMS team will suggest on license details and appropriate hardware needed. Please follow below steps to find the FPS -

  1. Access URL: http://localhost:9200/_cat/indices to see elastic search data. Pick 4 sample where size is more (last column is size) and index name contains NetFlow. Each index refers to one day data.
  2. Go to Performance > NetFlow > Raw Data page.
  3. In time scale select custom time and select one day duration based on sample selected in #1. Click on search.
  4. Note down number of flows appearing in grid (this is flows per day).
  5. Convert it to flows per second using : Flows per second = (Flows per day)/24/60/60;
  6. Repeat steps 3-5 for all 4 samples and take average of 4 sample. That is the resultant number of flows per second.