1 iptables -t filter -A INPUT -m hbh --hbh-len 5 -j ACCEPT
2 iptables -t filter -A INPUT -m hbh --hbh-len ! 7 -j DROP
3 iptables -t filter -A INPUT -m hbh --hbh-opts 4:5 -j REJECT
4 iptables -t filter -A INPUT -m hbh --hbh-opts 6:7,8:9,10:11 -j ACCEPT
