Iptables

See [1] for a quick guide.

Setting iptables to be saved on stop and restart

The configuration for iptables lives in /etc/sysconfig/iptables-config. Set the following parameters to 'yes':

IPTABLES_SAVE_ON_STOP="yes"
IPTABLES_SAVE_ON_RESTART="yes"

(You can see what these parameters do in the /etc/init.d/iptables script.)