TP-Link TL-SL5428E User Guide - Page 178

X Timer, Supplicant system timer Supplicant Timeout

Page 178 highlights

the RADIUS server through the switch. (The encryption is irreversible.) 6. The RADIUS server compares the received encrypted password (contained in a RADIUS Access-Request packet) with the locally-encrypted password. If the two match, it will then send feedbacks (through a RADIUS Access-Accept packet and an EAP-Success packet) to the switch to indicate that the supplicant system is authorized. 7. The switch changes the state of the corresponding port to accepted state to allow the supplicant system access the network. And then the switch will monitor the status of supplicant by sending hand-shake packets periodically. By default, the switch will force the supplicant to log off if it can not get the response from the supplicant for two times. 8. The supplicant system can also terminate the authenticated state by sending EAPOL-Logoff packets to the switch. The switch then changes the port state from accepted to rejected. (2) EAP Terminating Mode In this mode, packet transmission is terminated at authenticator systems and the EAP packets are mapped into RADIUS packets. Authentication and accounting are accomplished through RADIUS protocol. In this mode, PAP or CHAP is employed between the switch and the RADIUS server. This switch supports the PAP terminating mode. The authentication procedure of PAP is illustrated in the following figure. Supplicant System EAP Switch RADIUS Authentication Server EAPOL-Start EAP-Request/Identity EAP-Response/Identity EAP-Request EAP-Response RADIUS-Access-Request EAP-Success RADIUS-Access-Accept Figure 13-21 PAP Authentication Procedure In PAP mode, the switch encrypts the password and sends the user name, the randomly-generated key, and the supplicant system-encrypted password to the RADIUS server for further authentication. Whereas the randomly-generated key in EAP-MD5 relay mode is generated by the authentication server, and the switch is responsible to encapsulate the authentication packet and forward it to the RADIUS server. ¾ 802.1X Timer In 802.1 x authentication, the following timers are used to ensure that the supplicant system, the switch, and the RADIUS server interact in an orderly way: (1) Supplicant system timer (Supplicant Timeout): This timer is triggered by the switch after the switch sends a request packet to a supplicant system. The switch will resend the request packet to the supplicant system if the supplicant system fails to respond in the specified timeout period. 170

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170
the RADIUS server through the switch. (The encryption is irreversible.)
6.
The RADIUS server compares the received encrypted password (contained in a RADIUS
Access-Request packet) with the locally-encrypted password. If the two match, it will then
send feedbacks (through a RADIUS Access-Accept packet and an EAP-Success packet) to
the switch to indicate that the supplicant system is authorized.
7.
The switch changes the state of the corresponding port to accepted state to allow the
supplicant system access the network. And then the switch will monitor the status of
supplicant by sending hand-shake packets periodically. By default, the switch will force the
supplicant to log off if it can not get the response from the supplicant for two times.
8.
The supplicant system can also terminate the authenticated state by sending EAPOL-Logoff
packets to the switch. The switch then changes the port state from accepted to rejected.
2
EAP Terminating Mode
In this mode, packet transmission is terminated at authenticator systems and the EAP packets are
mapped into RADIUS packets. Authentication and accounting are accomplished through RADIUS
protocol.
In this mode, PAP or CHAP is employed between the switch and the RADIUS server. This switch
supports the PAP terminating mode. The authentication procedure of PAP is illustrated in the
following figure.
Figure 13-21 PAP Authentication Procedure
In PAP mode, the switch encrypts the password and sends the user name, the
randomly-generated key, and the supplicant system-encrypted password to the RADIUS server for
further authentication. Whereas the randomly-generated key in EAP-MD5 relay mode is generated
by the authentication server, and the switch is responsible to encapsulate the authentication
packet and forward it to the RADIUS server.
¾
802.1X Timer
In 802.1 x authentication, the following timers are used to ensure that the supplicant system, the
switch, and the RADIUS server interact in an orderly way:
1
Supplicant system timer (Supplicant Timeout):
This timer is triggered by the switch
after the switch sends a request packet to a supplicant system. The switch will resend the
request packet to the supplicant system if the supplicant system fails to respond in the
specified timeout period.
Switch
EAPOL
-
Start
EAP-Request/Identity
EAP-Request
RADIUS-Access-Request
RADIUS-Access-Accept
EAP-Success
EAP-Response/Identity
EAP-Response
EAP
RADIUS
Supplicant System
Authentication Server