802.1x features the ability to authenticate a machine during the system boot of that machine. This machine authentication happens prior to dynamic IP address assignment and prior to port-based user authentication. Machine-based authentication supports only Windows machines because the machine name is authenticated against an Active Directory server. Microsoft’s support for specific EAP types enables 802.1x to support machine authentication for multiple EAP types. An overview and details about the variety of EAP types that are supported in Cisco 802.1x are provided later in this chapter in the "EAP" section.