MikroTik supports exporting NetFlow traffic data via /ip traffic-flow, which can be read using free or paid software.
This guide shows you how to setup ntop (a free option) on a fresh CentOS 6 (or RedHat) install and assumes you have setup a CentOS 6 server that has a connection to the internet.
Continue reading Installing ntop on CentOS 6/Redhat with NetFlow