A computer system in a network that is fortified against illegal entry and attack, because it is exposed to the outside world (the Internet). Bastion hosts are used for services such as Web site hosting, mail, DNS lookups and FTP transfer and are located on the public side of a perimeter net (DMZ). The name comes from medieval fortresses built with bastions, which were projections out from the wall that enabled more men to gather behind in order to shoot their arrows.
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DMZ
(DeMilitarized Zone) A middle ground between an organization's trusted internal network and an untrusted, external network such as the Internet. Also called a "perimeter network," the DMZ is a subnetwork (subnet) that may sit between firewalls or off one leg of a firewall. Organizations typically place their Web, mail and authentication servers in the DMZ. DMZ is a military term that refers to the area between two enemies. See bastion host and firewall.
In computer networks, a DMZ (demilitarized zone) is a computer host or small network inserted as a "neutral zone" between a company's private network and the outside public network. It prevents outside users from getting direct access to a server that has company data. (The term comes from the geographic buffer zone that was set up between North Korea and South Korea following the UN "police action" in the early 1950s.) A DMZ is an optional and more secure approach to a firewall and effectively acts as a proxy server as well.
In a typical DMZ configuration for a small company, a separate computer (or host in network terms) receives requests from users within the private network for access to Web sites or other companies accessible on the public network. The DMZ host then initiates sessions for these requests on the public network. However, the DMZ host is not able to initiate a session back into the private network. It can only forward packets that have already been requested.
Users of the