Frequently Asked Questions about Firewalls

• What is a firewall?
• How do I know if I already have a firewall installed?
• What is the firewall program's default configuration?
• What should I do when my firewall program displays a security alert?

What is a firewall?

A firewall protects your computer from undesired network access or self-spreading worms that infiltrate your computer through open network ports.

For more detailed information, see http://www.howstuffworks.com/firewall.htm.

How do I know if I already have a firewall installed?

On a computer running the Windows XP, Vista, or Windows 7 operating system, go to the Start menu to see if you have a firewall installed.

On a computer running the Mac OS X 10.4, 10.5, 10.6, or 10.7 operating system, go to the Apple menu. Choose System Preferences and then Security. On the Security screen, click the Firewall tab to see if you have the firewall activated.

What is the firewall program's default configuration?

The firewall program's default security level is set to medium. The medium protection setting prevents harmful programs from hacking into your computer by blocking unused ports, and asks for permission each time an ActiveX or Java applet attempts to run.

ITS recommends a medium-level setting for most users.

Getting Help

For other questions, please contact the Customer Support Center at 213-740-5555 or send an email to consult@usc.edu.