iptables -A INPUT -i eth0 -m state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -i eth0 -p icmp -m icmp --icmp-type echo-request -m hashlimit --hashlimit-name echo_requests --hashlimit 1/minute --hashlimit-burst 1 --hashlimit-mode srcip -j ACCEPT
iptables -P INPUT DROP