IPT="/sbin/iptables" IFOUT="em1" $IPT -P INPUT DROP $IPT -P OUTPUT DROP $IPT -P FORWARD DROP # Block Fragments $IPT -A INPUT -i $IFOUT -f -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Fragments Packets" $IPT -A INPUT -i $IFOUT -f -j DROP # Block bad stuff $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags ALL FIN,URG,PSH -j DROP $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags ALL ALL -j DROP $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags ALL NONE -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "NULL Packets" $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags ALL NONE -j DROP # NULL packets $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags SYN,RST SYN,RST -j DROP $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags SYN,FIN SYN,FIN -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "XMAS Packets" $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags SYN,FIN SYN,FIN -j DROP #XMAS $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags FIN,ACK FIN -m limit --limit 5/m --limit-burst 7 -j LOG --log-level 4 --log-prefix "Fin Packets Scan" $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags FIN,ACK FIN -j DROP # FIN packet scans $IPT -A INPUT -i $IFOUT -p tcp --tcp-flags ALL SYN,RST,ACK,FIN,URG -j DROP # Allow full outgoing connection but no incomming stuff $IPT -A INPUT -i $IFOUT -m state --state ESTABLISHED,RELATED -j ACCEPT $IPT -A OUTPUT -o $IFOUT -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT $IPT -A INPUT -i $IFOUT -p tcp --dport 22 -j ACCEPT