> /ip firewall filter
> add action=drop chain=input comment="port scanners" src-address-list="port scanners"
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp psd=21,3s,3,1
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp tcp-flags=fin,!syn,!rst,!psh,!ack,!urg
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp tcp-flags=fin,syn
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp tcp-flags=syn,rst
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp tcp-flags=fin,psh,urg,!syn,!rst,!ack
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp tcp-flags=fin,syn,rst,psh,ack,urg
> add action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w chain=input protocol=tcp tcp-flags=!fin,!syn,!rst,!psh,!ack,!urg