User's Manual

Configuration Guide of XGS-5240-Series
47-1
Chapter 47 802.1x Configuration
47.1 Introduction to 802.1x
The 802.1x protocol originates from 802.11 protocol, the wireless LAN protocol of I
EEE, which is designed to provide a solution to doing authentication when users acces
s 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 devic
e (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 enterpr
ise networks.
However, along with the boom of applications like mobile office and service operati
ng 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 acces
s 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 d
evices on the level of ports of LAN access devices. Only when the user devices conne
cted to the ports pass the authentication, can they access the resources in the LAN, ot
herwise, the resources in the LAN won’t be available.
47.1.1 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.