Which IEEE standard was originally designed for port-based network access control?

IEEE 802.1X is the standard specifically designed for port-based network access control. It provides an authentication mechanism to devices attempting to connect to a LAN or WLAN. This standard is significant in network security as it allows for controlled access by ensuring that only authenticated devices can use network resources. By using a process called the Extensible Authentication Protocol (EAP), 802.1X facilitates the implementation of secure access controls on network switches and wireless access points.

In contrast, the other IEEE standards listed serve different roles. IEEE 802.3 focuses on Ethernet networking, which deals with wired connections and defines standards for physical and data link layers of local area networks. IEEE 802.11 pertains to wireless networking technologies, primarily for establishing Wi-Fi connections. IEEE 802.15 defines standards for wireless personal area networks (WPANs), which are geared towards shorter-range communication, such as those used in Bluetooth devices. Each standard has its own purpose, but only IEEE 802.1X addresses port-based access control specifically within network security practices.