Operation Manual – 802.1x and System Guard
H3C S5100-SI/EI Series Ethernet Switches
Chapter 1 802.1x Configuration
1-5
04: Indicates that the packet is an EAPoL-encapsulated-ASF-Alert packet, which
is used to support the alerting messages of Alerting Standards Forum (ASF).
z
The Length field indicates the size of the Packet body field. A value of 0 indicates
that the Packet Body field does not exist.
z
The Packet body field differs with the Type field.
Note that EAPoL-Start, EAPoL-Logoff, and EAPoL-Key packets are only transmitted
between the supplicant system and the authenticator system. EAP packets are
encapsulated by RADIUS protocol to allow them successfully reach the authentication
servers. Network management-related information (such as alarming information) is
encapsulated in EAPoL-Encapsulated-ASF-Alert packets, which are terminated by
authenticator systems.
II. The format of an EAP packet
For an EAPoL packet with the value of the Type field being EAP-packet, its Packet body
field is an EAP packet, whose format is illustrated in
Figure 1-4
.
0
15
Code
Data
Length
7
Identifier
2
4
N
Figure 1-4
The format of an EAP packet
In an EAP packet:
z
The Code field indicates the EAP packet type, which can be Request, Response,
Success, or Failure.
z
The Identifier field is used to match a Response packet with the corresponding
Request packet.
z
The Length field indicates the size of an EAP packet, which includes the Code,
Identifier, Length, and Data fields.
z
The Data field carries the EAP packet, whose format differs with the Code field.
A Success or Failure packet does not contain the Data field, so the Length field of it is 4.
Figure 1-5
shows the format of the Data field of a Request packet or a Response
packet.
Figure 1-5
The format of the Data field of a Request packet or a Response packet
