An introduction to 802.1x
Many Ethernet and Wi-Fi Local Area Networks (LAN) in enterprises use 802.1x to verify the user credentials before authorizing them to access the network. 802.1x defines a flexible set of protocols that support various forms of user authorization and authentication and can be used at scale.
Two recent blog posts provide an introduction to these protocols that are suitable to networking students. The first part describes the basics while the second part explores the formats of the packets that are exchanged using Wireshark.