Port-based authentication is a network access control concept in which a particular device is evaluated before being permitted to communicate with other devices located on the network. 802.1X Port-Based Authentication examines how this concept can be applied and the effects of its application to the majority of computer networks in existence today. 802.1X is a standard that extends the Extensible Authentication Protocol (EAP) over a Local Area Network (LAN) through a process called Extensible Authentication Protocol Over LANs (EAPOL). The text presents an introductory overview of port-based authentication including a description of 802.1X port-based authentication, a history of the standard and the technical documents published, and details of the connections among the three network components. It focuses on the technical aspect of 802.1X and the related protocols and components involved in implementing it in a network. The book provides an in-depth discussion of technology, design, and implementation with a specific focus on Cisco devices. Including examples derived from the 802.1X implementation, it also addresses troubleshooting issues in a Cisco environment. Each chapter contains a subject overview. Incorporating theoretical and practical approaches, 802.1X Port-Based Authentication seeks to define this complex concept in accessible terms. It explores various applications to todays computer networks using this particular network protocol.