Figure 28-3
The format of an EAPoL packet
z
The Type field can be one of the following:
et is an EAP-packet, which carries authentication information.
off packet, which sends logging off requests.
y packet, which carries key information.
ncapsulated-ASF-Alert packet, which is used to
g Standards Forum (ASF).
e Packet body field. A value of 0 indicates that the Packet
f, and EAPoL-Key packets are only transmitted between the
system. EAP packets are encapsulated by RADIUS protocol to
llow them successfully reach the authentication servers. Network management-related information
nformation) is encapsulated in EAPoL-Encapsulated-ASF-Alert packets, which are
The format of an EAP packet
pack
is illustrated in
Figure 28-4
In an EAPoL packet:
z
The PAE Ethernet type field holds the protocol identifier. The identifier for 802.1x is 0x888E.
z
The Protocol version field holds the version of the protocol supported by the sender of the EAPoL
packet.
00: Indicates that the pack
01: Indicates that the packet is an EAPoL-start packet, which initiates the authentication.
02: Indicates that the packet is an EAPoL-log
03: Indicates that the packet is an EAPoL-ke
04: Indicates that the packet is an EAPoL-e
support the alerting messages of Alertin
z
The Length field indicates the size of th
Body field does not exist.
z
The Packet body field differs with the Type field.
Note that EAPoL-Start, EAPoL-Logof
supplicant system and the authenticator
a
(such as alarming i
terminated by authenticator systems.
For an EAPoL packet with the value of the Type field being EAP-packet, its Packet body field is an EAP
et, whose format
.
Figure 28-4
The format of an EAP packet
packet:
z
z
onding Request packet.
In an EAP
The Code field indicates the EAP packet type, which can be Request, Response, Success, or
Failure.
The Identifier field is used to match a Response packet with the corresp
28-4