8. Previous knowledge and system requirements

1. Very important: You must know how to use the iptables package as a user, such as how to create or list rules and user chains. You do not need to be a firewall expert, but you should know how to use iptables fluently.

2. You have to have kernel sources installed in your system, in /usr/src/linux as usual.

   I am using a 2.4.16 kernel in a SuSE 7.1 Linux environment. You need 2.4.x kernel code to follow this HOWTO, preferably kernel 2.4.16 . For SuSE you can get the kernel sources at ftp://ftp.gwdg.de/pub/linux/suse/ftp.suse.com/suse/i386/update .

3. You have to know how to compile the kernel if you have to update your kernel version. After activating the netfilter options using make menuconfig , you must compile and install the kernel as usual.

4. Reboot your new kernel using init 6 . Ensure that you backup a copy of your previous kernel in lilo in case you encounter a problem and need to retrace your steps.

5. Be sure that your new 2.4.x kernel is running fine. To install iptables-1.2.6 you will need to patch the kernel again (and re-compile and install it), and it is better if you follow the previous two steps to ensure that your kernel is running right before applying new iptables patches.