Microsoft released its first firewall, the Internet Connection Firewall (ICF), for the desktop when it released Windows XP. Most users were not even aware that ICF came with Windows XP because it was turned off by default. Not until SP2 for XP did users become aware of the desktop firewall. SP2 brought what is now referred to as the Windows Firewall. The Windows Firewall that came with SP2 allowed network administrators to use Active Directory Group Policies to configure them. Group Policies had numerous configurations that you could use with the Windows Firewall, such as specifying which applications or ports to open and whether connections to those resources must be secure.

Windows XP with SP2 brought about significant and needed changes in securing the desktop with the Windows Firewall. Windows Vista has taken this even further by introducing the Windows Firewall with Advanced Security. The Windows Firewall in Vista is a stateful, authenticating firewall that provides more granular rules. It can block both incoming and outgoing traffic. It fully supports IPv6, is capable of using location-aware profiles, enforces network service hardening, and provides integrated IPSec protection. In this section, we will examine how to configure and manage the Windows Firewall with IPSec. Table 8.1 is a feature comparison of the Windows firewalls from SP2 of XP and Vista.