Centos – save and restore iptables

Linux command iptables can be used to make changes to Linux iptables. By default these changes are not reboot-safe and will get lost on reboot. Use these commands to save or restore iptables on Centos (Centos 6).

1. Install iptables service if not installed using:

   $ sudo yum install iptables
   $ sudo chkconfig iptables on
   $ sudo chkconfig ip6tables on
   

2. To save changes made to iptables

   $ sudo service iptables save
   iptables: Saving firewall rules to /etc/sysconfig/iptables:[  OK  ]
   $ sudo service ip6tables save
   $ sudo service ip6tables save
   ip6tables: Saving firewall rules to /etc/sysconfig/ip6table[  OK  ]
   

3. To save iptables changes to a temporary file and diff it with /etc/sysconfig/iptables. This may be useful to review what was changed before saving it.

   $ sudo iptables-save > /tmp/current.iptables
   $ sudo diff /tmp/current.iptables /etc/sysconfig/iptables
   $ sudo ip6tables-save > /tmp/current.ip6tables
   $ sudo diff /tmp/current.ip6tables /etc/sysconfig/ip6tables
   

4. To reload iptables data (this will undo any unsaved changes)

   $ sudo service iptables restart
   $ sudo service ip6tables restart