Ubuntu Linux Save / Restore Iptables Rules

by on June 24, 2009 · 8 comments· LAST UPDATED June 24, 2009

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I want to make changes to an iptables configuration. How to do I Save and Restore an iptables Configuration in Ubuntu Linux server?

If you want to make changes to an iptables configuration, it is always good idea to save the current configuration by typing the following commands:
$ sudo -s
$ iptables-save > /root/working.iptables.rules

Now, you can make any changes using command line.

To restore it use the command iptables-restore, enter:
# iptables-restore < /root/working.iptables.rules

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{ 8 comments… read them below or add one }

1 Michael June 24, 2009 at 2:40 pm

Thanks for the tip!
Not only useful for Ubuntu users!

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2 Mike June 24, 2009 at 3:23 pm

Thanks

Here’s another little tip. If you add a shebang line to the top of the saved iptables file like “#!/usr/bin/env iptables-restore” and make it executable (chmod +x) you can then just execute the saved firewall rules like so ./my-firewall

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3 nixCraft June 24, 2009 at 3:45 pm

@Mike, Excellent tip. I never thought about it.

@Michael, yes it works on all Linux distro.

Appropriate your posts!

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4 Joost June 26, 2009 at 4:08 pm

Be carefull if you change your iptables file remotely (via ssh). A mistake might lock you out.
In that case it is safer to use iptables-apply. It changes the iptables, but gives you a prompt to confirm the change. If the change locked you out, it will revert to the previous ruleset.
So change the /root/working.iptables.rules file, and use:

iptables-apply -t 15 /root/working.iptables.rules

You have 15 seconds to accept the change.
Only works on newer versions of iptables (Ubuntu jaunty in my case).

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5 budacsik July 1, 2009 at 10:14 am

tip:
iptables auto on/off

1.)
Run in terminal the next command:
sudo iptables-save > /etc/iptables.rules

2.) Edit /etc/network/interfaces file and add this two line to interface configuration:
pre-up iptables-restore /etc/iptables.rules

To sum:

auto eth1
iface eth1 inet static
address 192.168.2.1
network 255.255.255.0
broadcast 192.168.2.255
pre-up iptables-restore /etc/iptables.rules

3.) Save and test (reboot)

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6 badwolf July 10, 2009 at 12:27 pm

One other way of safeguarding yourself when you modify iptables via ssh is (before you start fiddling around ;-) )to set a cron job to reset the firewall rules every say 15 minutes. That way you only have to wait at most 15 minutes to get back into your machine. Don’t forget to disable the cron job when you are finished. This presumes that you have root/sudo access to be able to set the cron and run iptables-restore as super user.
Thanks for the info.

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7 Salvador January 29, 2010 at 12:17 am

budacsik:

You made a little mistake in the line:
pre-up iptables-restore /etc/iptables.rules

it must be:
pre-up iptables-restore < /etc/iptables.rules

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8 budacsik January 29, 2010 at 7:29 am

Salvador:
You are right! Sorry for mistake.

(I’m sorry, but I can’t edit it.)

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