Setup IPTABLES untuk Keamanan

Syn-flood protection

Force SYN packet check

iptables –A INPUT –p tcp ! --syn –m state --state NEW –j DROP

Force Fragments packets check

iptables –A INPUT –f –j DROP

XMAS packets

iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP

Drop all NULL packets

iptables -A INPUT -p tcp --tcp-flags ALL NONE -j DROP

Once system is secured, test your firewall with nmap or hping2 command:
# nmap -v -f FIREWALL-IP
# nmap -v -sX FIREWALL-IP
# nmap -v -sN FIREWALL-IP
# hping2 -X FIREWALL-IP