802.1x: Port Security for Network Communications
Secure access to virtually any network port (wired or wireless) with 802.1x.
The 802.1x protocol is actually not a wireless protocol at all. It describes a method for port authentication that can be applied to nearly any network connection, whether wired or wireless.
Just when you thought you knew every IEEE spec relating to wireless, suddenly 802.1x appeared on the scene. The full title of 802.1x is “802.1x: Port Based Network Access Control.” Interestingly enough, 802.1x wasn’t originally designed for use in wireless networks; it is a generic solution to the problem of port security. Imagine a college campus with thousands of Ethernet jacks scattered throughout libraries, classrooms, and computer labs. At any time, someone could bring their laptop on campus, sit down at an unoccupied jack, plug in, and instantly gain unlimited access to the campus network. If network abuse by the general public were common, it might be desirable to enforce a policy of port access control that permitted only students and faculty to use the network.
This is where 802.1x fits in. Before any network access (to Layer 2 or above) is permitted, the client (the supplicant, in 802.1x parlance) must authenticate itself. When first connected, the supplicant can only exchange data with a component called the authenticator. This in turn checks credentials with a central data source (the Authentication Server), typically a RADIUS server or other existing user ...