Hi there.

In order for you to actually setup a firewall using IPTABLES, you should really know how to use IPTABLES. Even if i gave you a rule now, (i cant due to the fact that you have not provided any real information to setup this rule) it would not solve your problem. Whatever you do, do not just get a rule from someone and put it in. I think that you have no idea what so ever about IPTABLES, so i advise you to let someone setup that firewall who knows what he is doing. If you attempt to build that firewall, and have no idea about it, then you will be responsible for anything that happens from there onwards. Please please take my advice. Dont do anything foolish if you cant handle it. Take your time to learn networking, and iptables. Without at least these basics, you will never setup a firewall correctly. Once you think that you have learned something about networking and IPTABLES, then have a look at www.devil-linux.org for a sweet linux firewall which is based on IPTABLES. That firewall is a very powerfull one. All it needs to work is the network configuaration and the IPTABLES rules.

Cheers.