iptables rules revert on Ubuntu

Question

I'm using iptables on Ubuntu 10.04 and whenever I set iptables rules they will revert after a while. I set them with iptables -I INPUT or iptables -D INPUT and they work immediately and I see them in iptables -L INPUT but after a while the rules revert.

I even exported the rules

iptables-save > /etc/firewall.conf

I even created a script /etc/network/if-up.d/iptables

#!/bin/sh
iptables-restore < /etc/firewall.conf

and I even checked firewall.conf and it has the rules I want in it.

So why would iptables be reverting?

UPDATE:

I found this in /etc/cron.daily/apf

#!/bin/bash
/etc/apf/apf -f >> /dev/null 2>&1
/etc/apf/apf -s >> /dev/null 2>&1

Would this be flushing the iptables rules?

Answer 1

The wiki page references feisty etc. so may be out of date but I would guess its still relevant:

https://help.ubuntu.com/community/IptablesHowTo#Configuration%20on%20startup suggests that NetworkManager may be the culprit...

https://help.ubuntu.com/community/IptablesHowTo#Configuration%20on%20Startup%20for%20NetworkManager then suggests how to get NetworkManager to play nice.

Answer 2

I'm not familiar with apf, but it's easy enough to check if that's the culprit. Remove it from cron.

I'd also do something like grep -ri --color iptables /etc and also check /var/log/messages and /var/log/syslog for anything that could be doing this.