What is this?

This knowledgebase contains questions and answers about PRTG Network Monitor and network monitoring in general.

Learn more

PRTG Network Monitor

Intuitive to Use. Easy to manage.
More than 500,000 users rely on Paessler PRTG every day. Find out how you can reduce cost, increase QoS and ease planning, as well.

Free Download

Top Tags

View all Tags

Netflow data from Fortigate not seperated



We have several Fortigates, All send their Netflow data to a Probe. When adding the Netflow sensor to an interface of one of those devices, it will show the data of all netflow data that has been send to the Probe. I only want to see the traffic of that single interface.

netflow sensor traffic

Created on Sep 26, 2017 9:48:58 AM

4 Replies




thank you for the KB-Post. If you already have separate Netflow Sensors (one for each firewall), and all are listening on the same UDP port, the traffic will be added up. You can filter per firewall then by using the "Sender IP"-Field on each Firewall, and enter the IP of the sending firewall on each Netflow Sensor. Please be aware though, that this will not filter backwards / historic data entries.

best regards

Created on Sep 27, 2017 10:23:56 AM by  Torsten Lindner [Paessler Support]



Unfortunately that doesn't work, as soon as I enter the source IP (which is the same as the interface I added the sensor to) and add the sender IP in the Netflow part on the Fortigate, I don't get any data at all.... I'm now seperating the data by sending it to different ports, but that's not an ideal situation if you have more then 50 devices. Looking in the history of the KB, this was already a problem in 2010, so I can't understand why it isn't solved yet. In solarwinds this isn't a problem....

Created on Sep 27, 2017 11:36:21 AM



If a sensor doesn't show any data, after a Sender IP is entered, it means it doesn't get any data from the entered IP. Which sender IP do you enter? Can you share some screenshots? Please use the Netflow-Tester to verify that the entered Sender-IP is correct.

Created on Sep 27, 2017 3:46:37 PM by  Torsten Lindner [Paessler Support]



Hi, I will be on holiday for the next three weeks, so I will come back on this afterwards.

Created on Sep 28, 2017 1:41:10 PM

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.