|top| Free Netflow Monitor May 2026

interface GigabitEthernet0/1 ip flow ingress ip flow egress flow exporter MY_EXPORTER destination 192.168.1.100 (Your monitor’s IP) transport udp 2055 source Loopback0

On pfSense/OPNsense: Services > NetFlow > Enable + set collector IP. On Ubiquiti UniFi: System > Advanced > NetFlow Export (IP + Port 2055). Before you build a whole stack, point your router’s NetFlow export to a laptop running ntopng in a Docker container : free netflow monitor

The security investigation tools. You can drill from “High UDP traffic” straight into a flow grid, apply a filter for “Deny” actions, and pivot to a geo-map. No other free tool matches its threat-hunting workflow. interface GigabitEthernet0/1 ip flow ingress ip flow egress

flow monitor MY_MONITOR record netflow ipv4 original-input exporter MY_EXPORTER apply a filter for “Deny” actions