Chapter 42 802.1X Configuration; Introduction To 802.1X; The Authentication Structure Of 802.1X - Planet WGSW-52040 Configuration Manual

Chapter 42 802.1x Configuration

42.1 Introduction to 802.1x

The 802.1x protocol originates from 802.11 protocol, the wireless LAN protocol of IEEE, which
is designed to provide a solution to doing authentication when users access a wireless LAN.
The LAN defined in IEEE 802 LAN protocol does not provide access authentication, which
means as long as the users can access a LAN controlling device (such as a LAN Switch), they
will be able to get all the devices or resources in the LAN. There was no looming danger in the
environment of LAN in those primary enterprise networks.
However, along with the boom of applications like mobile office and service operating networks,
the service providers should control and configure the access from user. The prevailing
application of WLAN and LAN access in telecommunication networks, in particular, make it
necessary to control ports in order to implement the user-level access control. And as a result,
IEEE LAN/WAN committee defined a standard, which is 802.1x, to do Port-Based Network
Access Control. This standard has been widely used in wireless LAN and ethernet.
"Port-Based Network Access Control" means to authenticate and control the user devices on
the level of ports of LAN access devices. Only when the user devices connected to the ports
pass the authentication, can they access the resources in the LAN, otherwise, the resources in
the LAN won't be available.

42.1.1 The Authentication Structure of 802.1x

The system using 802.1x has a typical Client/Server structure, which contains three entities
(as illustrated in the next figure): Supplicant system, Authenticator system, and Authentication
server system.
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