Comments on: Ubuntu Linux Save / Restore Iptables Rules

By: budacsik

budacsik — Fri, 29 Jan 2010 07:29:22 +0000

Salvador:
You are right! Sorry for mistake.

(I’m sorry, but I can’t edit it.)

By: Salvador

Salvador — Fri, 29 Jan 2010 00:17:57 +0000

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

By: badwolf

badwolf — Fri, 10 Jul 2009 12:27:45 +0000

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.

By: budacsik

budacsik — Wed, 01 Jul 2009 10:14:17 +0000

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)

By: Joost

Joost — Fri, 26 Jun 2009 16:08:47 +0000

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).

By: Vivek Gite

Vivek Gite — Wed, 24 Jun 2009 15:45:27 +0000

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

@Michael, yes it works on all Linux distro.

Appropriate your posts!

By: Mike

Mike — Wed, 24 Jun 2009 15:23:12 +0000

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

By: Michael

Michael — Wed, 24 Jun 2009 14:40:52 +0000

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