PLANET XGS3-24042 - Manual (Page 519)

52-5
Identifier: to assist matching the Request and Response messages.
Length: the length of the EAP packet, covering the domains of Code, Identifier, Length and Data, in byte.
Data: the content of the EAP packet, depending on the Code type.
52.1.4 The Encapsulation of EAP Attributes
RADIUS adds two attribute to support EAP authentication: EAP-Message and Message-Authenticator. Please
refer to the Introduction of RADIUS protocol in “AAA-RADIUS-HWTACACS operation” to check the format of
RADIUS messages.
1. EAP-Message
As illustrated in the next figure, this attribute is used to encapsulate EAP packet, the type code is 79, String
domain should be no longer than 253 bytes. If the data length in an EAP packet is larger than 253 bytes, the
packet can be divided into fragments, which then will be encapsulated in several EAP-Messages attributes in
their original order.
Figure 52-6 the Encapsulation of EAP-Message Attribute
2. Message-Authenticator
As illustrated in the next figure, this attribute is used in the process of using authentication methods like EAP
and CHAP to prevent the access request packets from being eavesdropped. Message-Authenticator should
be included in the packets containing the EAP-Message attribute, or the packet will be dropped as an invalid
one.
Figure 52-7 Message-Authenticator Attribute
52.1.5 Web Authentication Proxy based on 802.1x
The authentication can either be started by supplicant system initiatively or by devices. When the device
detects unauthenticated users to access the network, it will send supplicant system EAP-Request/Identity
messages to start authentication. On the other hand, the supplicant system can send EAPOL-Start message
to the device via supplicant software.
802.1 x systems supports EAP relay method and EAP termination method to implement authentication with