HOWTO: Menghindari Port Scanner dari Hacker

di bagian filter:

/ip firewall filter
add chain=input protocol=tcp psd=21,3s,3,1 action=add-src-to-address-list address-list="port scanners" address-list-timeout=2w comment="Port scanners to list " disabled=no
(Chain ini dipakai untuk mendaftar ip ke black-list address list)

Chain selanjutnya untuk mendeteksi apakah ada indikasi aktifitas port scanner:

add chain=input protocol=tcp tcp-flags=fin,!syn,!rst,!psh,!ack,!urg
action=add-src-to-address-list address-list="port scanners"
address-list-timeout=2w comment="NMAP FIN Stealth scan"

add chain=input protocol=tcp tcp-flags=fin,syn
action=add-src-to-address-list address-list="port scanners"
address-list-timeout=2w comment="SYN/FIN scan"

add chain=input protocol=tcp tcp-flags=syn,rst
action=add-src-to-address-list address-list="port scanners"
address-list-timeout=2w comment="SYN/RST scan"

add chain=input protocol=tcp tcp-flags=fin,psh,urg,!syn,!rst,!ack
action=add-src-to-address-list address-list="port scanners"
address-list-timeout=2w comment="FIN/PSH/URG scan"

add chain=input protocol=tcp tcp-flags=fin,syn,rst,psh,ack,urg
action=add-src-to-address-list address-list="port scanners"
address-list-timeout=2w comment="ALL/ALL scan"

add chain=input protocol=tcp tcp-flags=!fin,!syn,!rst,!psh,!ack,!urg
action=add-src-to-address-list address-list="port scanners"
address-list-timeout=2w comment="NMAP NULL scan"

jika ada tanda tanda dari kejadian di atas, maka harus didrop scanning IPnya pakai perintah ini:

add chain=input src-address-list="port scanners" action=drop comment="dropping port scanners" disabled=no

sumber : okto_2005