What equipment is needed to set up a hardware firewall?
Chances are you may have one already. In the early days of Internet’s reach into schools and businesses, many did not consider what they were opening themselves to by getting connected. Every machine got a registered public IP address, visible to the whole world. Some went about it more cautiously, deploying dedicated machines (usually cheap clones) with dual NICs as hardware firewalls. Usually they ran on some flavor of Linux, which often required the services of a Linux consultant. In a short time, tiny mini-systems such as those by Qube, and small appliance boxes with a Linux kernel embedded in firmware, became available for the purpose at lower prices. Meanwhile, RFC (Request for Comment) document #1918 established formal ranges of IP addresses to be used “behind a firewall” in private networks, starting in 1996. Those addresses are not routable on the public Internet. http://en.wikipedia.org/wiki/Private_network Fundamentally, what a firewall does is block traffic that originates
