H3C S5500-SI Series, Руководство по эксплуатации

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1-4
Figure 1-3 EAPOL frame format
z
PAE Ethernet type: Protocol type. It takes the value 0x888E.
z
Protocol version: Version of the EAPOL protocol supported by the EAPOL frame sender.
z
Type: Type of the EAPOL frame. Table 1-1 lists the types that the device currently supports.
Table 1-1 Types of EAPOL frames
Type Description
EAP-Packet (a value of 0x00)
Frame for carrying authentication information, present between
a device and the authentication server.
A frame of this type is repackaged and transferred by RADIUS
to get through complex networks to reach the authentication
server.
EAPOL-Start (a value of 0x01)
Frame for initiating authentication, present between a client and
a device.
EAPOL-Logoff (a value of 0x02) Frame for logoff request, present between a client and a device.
z
Length: Length of the data, that is, length of the Packet body field, in bytes. If the value of this field
is 0, no subsequent data field is present.
z
Packet body: Content of the packet. The format of this field varies with the value of the Type field.
EAP Packet Format
An EAPOL frame of the type of EAP-Packet carries an EAP packet in its Packet body field. The format
of the EAP packet is shown in Figure 1-4 .
Figure 1-4 EAP packet format
0 15
Code
Data
Length
7
Identifier
2
4
N
z
Code: Type of the EAP packet, which can be Request, Response, Success, or Failure.
An EAP packet of the type of Success or Failure has no Data field, and has a length of 4.
An EAP packet of the type of Request or Response has a Data field in the format shown in Figure 1-5 .
The Type field indicates the EAP authentication type. A value of 1 represents Identity, indicating that the
packet is for querying the identity of the client. A value of 4 represents MD5-Challenge, which
corresponds closely to the PPP CHAP protocol.