"And let’s face it, a firewall isn’t something you
can choose to use anymore; a firewall is your first line of
defense, and a critical one at that.
"So where is the appeal of creating your own firewall system?
Take a look at some of the many extra features available in a
do-it-yourself firewall. While such a firewall system would be
self-contained, require a fair amount of storage, run on
over-powered hardware, and consume more electricity than a simple
appliance, the benefits still far outweigh the drawbacks.
"For one, there is a higher degree of reliability. Running on a
full computer system makes it infinitely upgradeable. It can be
extended to do more than just shuffle packets back and forth. You
can turn a simple firewall into a full intrusion detection system.
You can analyze and track bandwidth usage. It can be a VPN end
point, a Web proxy, DHCP and DNS server, load balancer, handle
automatic failover, and provide great diagnostic tools."