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Do I need to use a separate port for each Netflow sensor?



In general does each Netflow sensor need to receive data on a different TCP port? We have multiple routers with multiple interfaces and we are setting each interface on each router to send Netflow traffic to the same probe but each on a different TCP port. This means we will have about 30 different ports used for Netflow traffic. If we have a Router with two interfaces then I assume we have to enable Netflow on both interfaces and then have it sent to our probe.

multiple-sensors multiple-tcp-ports netflow prtg

Created on Jun 16, 2010 8:12:02 PM

Last change on Jun 18, 2010 6:29:01 AM by  Daniel Zobel [Product Manager]

2 Replies



If you want to differ traffic for the individual devices then each device should send on a different port.

If you want to receive NetFlow data from all interfaces you need to configure this on the device.

Created on Jun 17, 2010 4:57:36 AM by  Aurelio Lombardi [Paessler Support]

Last change on Jun 18, 2010 6:31:52 AM by  Daniel Zobel [Product Manager]



I've noticed that PRTG does not pay attention to the Netflow exporter IP or the source interface. It only identifies individual streams by TCP listener port number. I like this because it allows me to aggregate all of my netflow traffic by having all routers sending to the same port. This makes it quite easy to track a single client's data usage across all of our internet feeds for monthly bills (I think our accounting dept likes PRTG more than we do these days).

If you need to uniquely identify each NDE router interface, then each interface needs to be sending to a unique TCP port.

Created on Jun 21, 2010 2:33:46 PM

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