Back in 2005 I used an old computer to build a Linux based firewall to protect my ADSL internet connection. I remember it being a bit of a learning curve, but I eventually got it all working excellently. It was an IPTABLES based firewall built using FWBuilder. This system has worked very well. Recently I needed to make some major configuration changes so I decided to build a new Firewall using Ubuntu Server 11.04.

I modified the FWBuilder files to reflect changes in the network IP addresses and then installed it on the new server. It all works fine with one exception. The use of DCC from IRC is not working now.

So I looked further into the original configuration and found this information.

The Linux kernel is 2.4.29
I found the following code in /etc/rc.d/rc.local
Code:
IRC_PORTS="ports=6665,6666,6667,6668,6669,7000,7001"


/sbin/modprobe ip_conntrack_irc $IRC_PORTS
/sbin/modprobe ip_nat_irc $IRC_PORTS
. /etc/guardian.fw
/etc/guardian.fw is the file containing the IPTABLES commands to set up the rules.

I have searched in vain on the internet for instructions on loading ip_conntrack_irc and ip_nat_irc modules. As far as I can tell Netfilter is included with Ubuntu 11.04. But clearly something is missing. An "lsmod" on the new system shows lots of nf_ modules loaded. I made the inference that most ip_ modules had been renamed to nf_

So my question is two fold?


  1. Are there any extra modules I should be loading?
  2. Where is the correct place to place the code to load those modules and to execute the firewall script?

Any help would be much appreciated.