802.1X authentication (port-based, multiple supplicant)

This feature introduces port-based 802.1X authentication and support for multiple supplicant mode. 802.1X provides network edge security, protecting Ethernet LANs from unauthorized user access. 802.1X authentication works by using an authenticator port access entity (the switch) to block all traffic to and from a supplicant (end device) at the port until the supplicant's credentials are presented and matched on the authentication server (a RADIUS server). When authenticated, the switch stops blocking traffic and opens the port to the supplicant.