ABSTRACT
A host-based firewall is a firewall soft-ware package that runs on a preexisting server or client machine. Given that a host-based firewall runs on a server or client machine, host-based firewalls offer greater functionality than network-based firewalls, even including internal fire-walls that are dedicated to protecting a single machine. Host-based firewalls can be divided into two categories: stand-alone and agent-based. Stand-alone firewalls are independent of other network devices in the sense that their configuration is managed on the machine itself. While host-based firewalls are not designed to interfere with Trojan horses that do not send or receive network connections, they can be quite effective in blocking net-work traffic to or from an unauthorized application when configured properly. Indeed, in one sense, host-based firewalls have an advantage over anti-virus software. Host-based firewalls are often associated with Windows platforms, given the history and evolution of personal firewall software.
