iptables2

*filter

:INPUT DROP [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:syn-flood - [0:0]
-A syn-flood -p tcp -m limit --limit 3/sec --limit-burst 6 -j RETURN
-A syn-flood -j REJECT --reject-with icmp-port-unreachable
-A INPUT -i lo -j ACCEPT
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 443 -j ACCEPT
-A INPUT -p icmp -m limit --limit 100/sec --limit-burst 100 -j ACCEPT
-A INPUT -p icmp -m limit --limit 1/sec --limit-burst 10 -j ACCEPT
-A INPUT -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -j syn-flood
-A INPUT -p tcp --syn -m limit --limit 12/s --limit-burst 24 -j ACCEPT  
-A INPUT -m limit --limit 5/min -j LOG --log-prefix "iptables denied: " --log-level 7
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A OUTPUT -j ACCEPT
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -p tcp -m tcp --tcp-flags FIN,SYN,RST,ACK SYN -m limit --limit 20/sec --limit-burst 200 -j ACCEPT
-A FORWARD -p icmp -m icmp --icmp-type 8 -m limit --limit 1/sec -j ACCEPT
-A FORWARD -p tcp --syn -m limit --limit 1/s -j ACCEPT  
-A FORWARD -f -m limit --limit 100/sec --limit-burst 100 -j ACCEPT
-A INPUT -j DROP
-A FORWARD -j DROP

COMMIT