Introduction

A firewall acts as a guarded door controlling what type of network communication is allowed to enter or leave the computer or network. The firewall will only allow authorized communications to pass.

Firewalls can protect an area as small as a single computer, or as large as the entire campus network.

• IT Pros : If you are a network or system administrator who would like to place a subnetwork of machines into a certain protection category at the level of the campus firewalls, see the campus firewalls section below.
• Individuals: If you are an individual user who would like more information about how a personal firewall can help protect your computer from security compromise, see the personal firewalls section below.

Campus Firewalls

• Introduction to Campus Firewall Services
• Details about the firewall groups
  • Ports permitted through the Mostly Open and Mostly Closed group
  • Calculating network ranges for inclusion in a firewall group
  • Vulnerable ports blocked at the campus firewall
• How to join a campus firewall group
• Campus Firewall Service Level Definition

Personal firewalls

• Introduction to Personal Firewalls
• Commonly used personal firewalls:
  • Windows firewalls are built-in and automatically enabled by default.
  • Mac OS X firewalls are built-in but they are not enabled by default; you'll need to turn them on.