Save current iptables settings using command iptables-save. We save it to /etc/network/iptables.v4.rules
iptables-save > /etc/network/iptables.v4.rules
Last we configure our box to restore it upon booting up the network interface.
Configure your network interface file /etc/network/interfaces
nano /etc/network/interfaces
#under
iface eth0 inet static
....
pre-up iptables-restore < /etc/network/iptables.v4.rules
tadaaa! short and sweet!