#!/bin/sh
echo "0" > /proc/sys/net/ipv4/ip_forward
iptables -F
iptables -X
iptables -Z
for i in `cat /proc/net/ip_tables_names`
  do 
   iptables -F -t $i 
   iptables -X -t $i 
   iptables -Z -t $i 
 done

iptables -P INPUT ACCEPT
iptables -P OUTPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -N syn-flood
iptables -A INPUT -i eth0 -p tcp --syn -j syn-flood
iptables -A syn-flood -m limit --limit 1/s --limit-burst 4 -j RETURN
iptables -A syn-flood -j DROP
# Make sure NEW tcp connections are SYN packets
iptables -A INPUT -i eth0 -p tcp ! --syn -m state --state NEW -j DROP 
iptables -t nat -A POSTROUTING -s 192.168.10.0/255.255.255.0 -o eth0 -j MASQUERADE
iptables -A FORWARD -m state --state NEW -i eth1 -j ACCEPT
iptables -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A FORWARD -m state --state NEW,INVALID -i eth0 -j DROP
iptables -A INPUT -i lo -j ACCEPT
echo 7 > /proc/sys/net/ipv4/ip_dynaddr
echo "1" > /proc/sys/net/ipv4/ip_forward