16.4. Storing iptables Information

Rules created with the iptables command are stored in memory. If the system is restarted after setting up iptables rules, they will be lost. In order for netfilter rules to persist through system reboot, they need to be saved. To do this, log in as root and type:

/sbin/service iptables save

This executes the iptables init script, which runs the /sbin/iptables-save program and writes the current iptables configuration to the /etc/sysconfig/iptables. This file should only be readable by root.

The next time the system boots, the iptables init script will reapply the rules saved in /etc/sysconfig/iptables by using the /sbin/iptables-restore command.

While it is always a good idea to test a new iptables rule before committing it to the /etc/sysconfig/iptables file, it is possible to copy iptables rules into this file from another system's version of this file. This provides a quick way to distribute sets of iptables rules to multiple machines.

	Important
	If distributing the /etc/sysconfig/iptables file to other machines, type /sbin/service iptables restart for the new rules take effect.