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Firewall Builder is a GUI for easily creating iptables rules. These are my comments

You can get Firewall Builder (fwbuilder) at: http://www.fwbuilder.org.

Prequisites: You need sshd enabled on your DD-WRT software.

DD-WRT V24 & iptables-save

Added by --Ptruman 14:49, 2 June 2008 (CEST)

fwbuilder works with files created using iptables-save - which is NOT part of DD-WRT. If you download the ipkg iptables-utils which contains iptables-save & iptables-restore, you will find they do not work, and give you error messages such as these :

/jffs # iptables-save 
# Generated by iptables-save v1.3.3 on Wed May 14 09:04:13 2008 
*nat 
:PREROUTING ACCEPT [1791:460202] 
:POSTROUTING ACCEPT [9:1323] 
:OUTPUT ACCEPT [103:16861] 
Can't find library for match `tcp' 
-A PREROUTING -d 82.36.194.23 -p tcp /jffs/etc/iptables # 

However, V24 of DD-WRT has been modified to support iptables - although the iptables-save command is not present - however you can get it to work :)

Instructions :

1. Enable Journalling Flash File System
2. Run the following

cd /jffs/usr/bin
ln -s /usr/sbin/iptables ./iptables-save
cd /jffs
iptables-save > iptables.txt

You should now have a file called iptables.txt containing your firewall rules, which can you then use with fwbuilder :)

I found the above did not work but the following did... 

cd /jffs/usr/bin
ln -s /usr/sbin/iptables ./iptables-save
./iptables-save > /jffs/iptables.txt