Firewall
A firewall is a gateway that limits access between networks in accordance with local security policy.
Your computer needs a firewall to protect it from unwanted and unsolicited network traffic to ensure the privacy of your personal information, prevent backdoor programs from monitoring your keystrokes, etc.
Windows:
- Windows Vista - Has a built-in firewall. Detailed Instructions

- Windows XP - Has a built-in firewall. Detailed Instructions

- Windows 2000 - Use McAfee Internet Security Suite
or Norton Personal Firewall 
Macintosh:
- Mac OS X 10.5 or later - Has a built-in firewall. Detailed Instructions

- Mac OS X 10.4 or earlier - Has a built-in firewall. Detailed Instructions

PDA:
- While firewalls for PDA's are not currently required for connection to the UCSD Network, UCSD ACS recommends Airscanner Mobile Firewall
(Free)
For more information, visit: http://www-ono.ucsd.edu/documentation/firewall/ 


