This page is written as generic. Please note this as you will need to rewrite these instructions for your own operating system and type of firewall.
Now you will need to get your preferred type of firewall package installed. The best types of software firewalls are found for the UNIX world, which include IPFW and IPF for BSD, iptables and ipchains for Linux.
The BSD firewall packages come preinstalled and can be loaded by modifying /etc/rc.conf. You can compile the firewall into the kernel if using other options like IPDIVERT. l In Linux, you will need to find the packages (iptables or ipchains) and install them using the rpm commands.
You can follow these steps to install the firewall:
- Put the needed entried into /etc/rc.conf.
- Modify /etc/rc.firewall with the needed rules.
- You are now done. Please test your setup.
Note: for special options like divert or forwarding, you will need to recompile the firewall into your kernel so it can support the divert packet types.