Operation Manual – 802.1x 
Quidway S5600 Series Ethernet Switches-Release 1510  Chapter 1  
802.1x Configuration
 
Huawei Technologies Proprietary 
1-1 
Chapter 1  802.1x Configuration 
1.1  Introduction to 802.1x 
The 802.1x protocol (802.1x for short) was developed by IEEE802 LAN/WAN 
committee to address security issues of wireless LANs. It was then used in Ethernet as 
a common access control mechanism for LAN ports to address mainly authentication 
and security problems. 
802.1x is a port-based network access control protocol. It authenticates and controls 
devices requesting for access in terms of the ports of LAN access control devices. With 
the 802.1x protocol employed, a user-side device can access the LAN only when it 
passes the authentication. Those failing to pass the authentication are denied when 
accessing the LAN, as if they are disconnected from the LAN.  
1.1.1  Architecture of 802.1x Authentication 
802.1x adopts a client/server architecture with three entities: a supplicant system, an 
authenticator system, and an authentication server system, as shown in the following 
figure. 
Supplicant PAE
Supplicant system
Authentication 
server
Authentication 
server system
Services provided by 
authenticator
Authenticator PAE
Authenticator system
Port under 
control
Port not authorized
Port not 
Under 
control
LAN/WLAN
Supplicant PAE
Supplicant system
Authentication 
server
Authentication 
server system
Services provided by 
authenticator
Authenticator PAE
Authenticator system
Controlled port
Port not authorized
Uncontrolled
port
LAN/WLAN
Supplicant PAE
Supplicant system
Authentication 
server
Authentication 
server system
Services provided by 
authenticator
Authenticator PAE
Authenticator system
Port under 
control
Port not authorized
Port not 
Under 
control
LAN/WLAN
Supplicant PAE
Supplicant system
Authentication 
server
Authentication 
server system
Services provided by 
authenticator
Authenticator PAE
Authenticator system
Controlled port
Port not authorized
Uncontrolled
port
LAN/WLAN
 
Figure 1-1 Architecture of 802.1x authentication 
z  The supplicant system is an entity residing at one end of the LAN segment and is 
authenticated by the authenticator system connected to the other end of the LAN 
segment. The supplicant system is usually a user terminal device. An 802.1x 
authentication is initiated when a user launches client program on the supplicant 
system. Note that the client program must support the EAPoL (extensible 
authentication protocol over LANs).