difference between netflow and port mirroring

[Ranjna Aggarwal]

what is the difference between netflow and port mirroring? and when to use which one?

[mcowger]

Netflow provides information about the data flowing across a port to a monitoring system.

port mirror COPIES the actual data flowing across a port to another port.

[rickardnobel]

Ranjna Aggarwal wrote:

and when to use which one?

You use port mirroring to troubleshoot network issues and copy some traffic into a destination where you typically will have Wireshark or similar tool running.

The most easy way is to install the network analyze tool into the VM you want to troubleshoot, but you might not always want or even be allowed to install new code into a production VM. Being able to listen and capture the traffic from the outside is great in such cases.