XGS-5240-Series User Manual

Configuration Guide of XGS-5240-Series
47-5
 EAP-Packet (whose value is 0x00): the authentication information frame, used to c
arry EAP messages. This kind of frame can pass through the authenticator system
to transmit EAP messages between the supplicant system and the authentication
server system.
 EAPOL-Start (whose value is 0x01): the frame to start authentication.
 EAPOL-Logoff (whose value is 0x02): the frame requesting to quit.
 EAPOL-Key (whose value is 0x03): the key information frame.
 EAPOL-Encapsulated-ASF-Alert (whose value is 0x04): used to support the Alerting
messages of ASF (Alert Standard Forum). This kind of frame is used to encapsul
ate the relative information of network management such as all kinds of alerting inf
ormation, terminated by terminal devices.
Length: represents the length of the data, that is, the length of the “Packet Body”,
in byte. There will be no following data domain when its value is 0.
Packet Body: represents the content of the data, which will be in different formats
according to different types.
2. The Format of EAP Data Packets
When the value of Type domain in EAPOL packet is EAP-Packet, the Packet Body
is in EAP format (illustrated in the next figure).
Fig 3-4 the Format of EAP Data Packets
Code: specifies the type of the EAP packet. There are four of them in total: Reque
st（1）,Response（2）,Success（3）,Failure（4）.
 There is no Data domain in the packets of which the type is Success or Failure, a
nd the value of the Length domains in such packets is 4.
 The format of Data domains in the packets of which the type is Request and Res
ponse is illustrated in the next figure. Type is the authentication type of EAP, the c
ontent of Type data depends on the type. For example, when the value of the typ
e is 1, it means Identity, and is used to query the identity of the other side. When
the type is 4, it means MD5-Challenge, like PPP CHAP protocol, contains query
messages.