Restore iptables after reboot
iptables-save > /etc/iptables.conf
Add to eth0 in /etc/network/interfaces
pre-up iptables-restore < /etc/iptables.conf
Drop example
iptables -A INPUT -p tcp -m tcp --dport 111 -j DROP iptables -A INPUT -p udp -m udp --dport 111 -j DROP