Two Installation Methods
Two ways of installing and configuring the Linux software are described here:
- Method 1 — Use a standard Linux distribution — such as Red Hat or Caldera OpenLinux — and configure it yourself.
- Method 2 — Use a Linux router distribution that runs from a floppy disk and is mostly preconfigured.
Advantages and disadvantages accompany both of these approaches. The advantages to method 1 are that you can use the latest Linux kernel and that the packet filtering is done with ipchains, the most advanced packet-filtering mechanism that is currently available on Linux. An even more advanced system called netfilter will be available with the next Linux kernel (2.4). If you've set up your firewall using method 1, you will be able to upgrade your system to netfilter; this is not an option if you use method 2.
The disadvantage to using this approach, however, is that it requires more work to set up a standard Linux distribution, and you probably won't get any additional advantages for the extra investment of time and effort. The firewall used in method 2 is already configured, which means that you'll spend less time setting it up. You also won't learn very much about Linux.
The advantage of using method 2 is that it is easy to install and run. Also, if you are using an older computer such as an Intel-compatible 486, this is the best choice. Installing the newest Linux versions on an older computer can be a challenge, even for an experienced user.
The disadvantage is that this second method is based on an older Linux kernel that uses ipfwadm. Ipfwadm has fewer features, does not support packet redirection, and does not allow use of protocols other than TCP, UDP, or ICMP. This can mean that videoconferencing and Internet telephony may not be accessible through this type of firewall without the addition of special modules (which may or may not be available). However, if you simply need a standard firewall system for your home, you probably do not need to make use of these protocols. You'll still have access to everything you'll need on the Internet.