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An old Cisco ASA 5540, PRTG and Netflow V9 sensor



Hello PRTG team.
So, yesterday i've upgraded my PRTG installation from v17.3.33.2830 to and ran into a trouble.

Can't make PRTG to accept Netflow flows from our old Cisco ASA 5540.

So, what i've tried so far:

- Rebuilt all settings from zero, on PRTG, also on ASA.
- Used wireshark to check that flows are actually arriving to PRTG.
- Used Paessler's Netflow V9 Tester to check if flows aren't mailformed and decoded.
- Enabled storing stream data in sensor's settings to see if PRTG is perceiving them.

What i've got:
- Flows are coming (seeing it in wireshark).
- Flows aren't mailformed and are decoded (seeing it in Netflow tester).
- Flows ARE NOT perceived by PRTG (stream data .csv is empty, has only headers).

I could present wireshark dumps as well as screenshots of the netflow tester and stored stream data .csv

My e-mail is: [email protected]

asa cisco netflow

Created on Mar 31, 2022 1:06:49 PM

Last change on Apr 1, 2022 10:37:11 AM by  Felix Wiesneth [Paessler Support]

1 Reply



Hello Kiryl
Thanks for reaching us,
There are multiple things to check on the capture, on the sensor settings, and on the device. It could be something as simple as a timestamp not properly configured or something really complicated.
Since this would require deep analysis I would kindly suggest opening a Support ticket and attaching all the information mentioned above for further analysis.
Please make reference to this KB article. Cheers

Created on Apr 6, 2022 12:36:14 AM by  Luis Quesada (Paessler Technical Support)

Disclaimer: The information in the Paessler Knowledge Base comes without warranty of any kind. Use at your own risk. Before applying any instructions please exercise proper system administrator housekeeping. You must make sure that a proper backup of all your data is available.