A firewall is a hardware or software network security device that sits at the juncture between two networks to control what information is allowed to pass between those networks. Usually, the two networks are an organization's internal network and the Internet. A firewall's primary role in information security is to protect computers on the internal network from intentional attacks that aim to:

• exploit well-known security holes that may exist on computers on the network
• flood a computer or the entire campus network with bad information, effectively shutting the network down (also called a Denial-of-Service, or DoS, attack).

So a firewall greatly reduces the risk of outside attacks corrupting information, compromising confidentiality or denying service. It DOES NOT protect computers on the network against viruses sent in email attachments or through web downloads and file transfers from removable media such as USB and Firewire drives.

In 2009, HSU established a "closed border configuration" firewall which:

• balances the openness of the Internet with the need to protect the privacy and integrity of University information and services
• reduces the threat of attacks that can deny service to campus computer users
• minimizes the ability of unauthorized individuals to launch attacks against others on the Internet using campus computers.