Traffic monitoring - help needed

Hello,

i would like to monitor the traffic (bandwith usage, traffic type…) on my Mikrotik router.
As far as i know, i have to enable traffic-flow feature and set up a server running an analysis software.
Ntop looks very good, however - if i got it right - ntop/ntopng is not free anymore?

So, the question ist:
What free software can you recommend that can be run on a raspberry pi?
Or is it possible to install an old/free version of ntop?

Thanks
ubimikro

I’ve used NFSen before. It’s Linux based, so if nothing else you should be able to compile it for your pi.