Microsoft Network Access ProtectionAbbreviated as NAP, Microsoft's Network Access Protection is a policy-enforcement platform built into the Microsoft Windows Vista and Windows Server Code Name "Longhorn" operating systems, NAP allows you to better protect network assets by enforcing compliance with system health requirements. With Network Access Protection, you can create customized health policies to validate computer health before allowing access or communication, automatically update compliant computers to ensure ongoing compliance, and optionally confine noncompliant computers to a restricted network until they become compliant.
In October 2006, Cisco and Microsoft formally announced interoperability between the Cisco Network Admission Control (NAC) and Microsoft Network Access Protection (NAP) solutions. Interoperability will be supported with the release of NAP in the future version of Windows Server which is scheduled to be available in the second half of 2007. The interoperability architecture allows customers to deploy both NAC and NAP incrementally or concurrently.
See also Cisco Network Admission Control (NAC).
Also see Webopedia's "Did You Know... All About Network Access Controls".