TuxTraining

So you learned how to write your own iptables, unfortunately if you got it configured just the way you want and you reboot, your rules are lost. These few steps will correct that in no time.

First thing first, you want to save your iptables rule set.

sudo sh -c “iptables-save > /etc/iptables.rules

You will also want to save a backup of this ruleset in your home directory just in case the /etc/iptables.rules file gets over written.

pre-up iptables-save < /home/username/iptables.rules

Then modify the /etc/network/interfaces configuration file to apply the rules automatically. You will need to know the interface that you are using in order to apply the rules - if you do not know, you are probably using the interface eth0.
sudo vi /etc/network/interfaces

When in the file, search for the interface you found, and at the end of the network related lines for that interface, add the line:

pre-up iptables-restore < /etc/iptables.rules

You can also prepare a set of down rules and apply it automatically using the above steps, except add this to the end of the network lines:

post-down iptables-save -c > /etc/iptables.rules

A fully working example using both from above:

auto eth0

iface eth0 inet dhcp

pre-up iptables-restore < /etc/iptables.rules

post-down iptables-save -c > /etc/iptables.rules

Save the file, reboot your computer and do a iptables -L to check if the rules are what you set them to be.

Helpful Links 1 , 2 ,3, 4

Related Posts

• Beating Sandvine on Linux with iptables
• Time Based iptables rules with patch-o-matic extension
• The Ultimate SSH Security Tutorial
• Basics of iptables

Tags: iptables

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