3Com 4500 PWR 26-Port Configuration Manual page 348

Figure 28-3 The format of an EAPoL packet
In an EAPoL packet:
The PAE Ethernet type field holds the protocol identifier. The identifier for 802.1x is 0x888E.
The Protocol version field holds the version of the protocol supported by the sender of the EAPoL
packet.
The Type field can be one of the following:
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
The Length field indicates the size of th
Body field does not exist.
The Packet body field differs with the Type field.
Note that EAPoL-Start, EAPoL-Logof
supplicant system and the authenticator
a llow them successfully reach the authentication servers. Network management-related information
(such as alarming i nformation) is encapsulated in EAPoL-Encapsulated-ASF-Alert packets, which are
terminated by authenticator systems.
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
pack et, whose format
Figure 28-4 The format of an EAP packet
In an EAP packet:
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
et is an EAP-packet, which carries authentication information.
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
is illustrated in Figure 28-4
28-4
off packet, which sends logging off requests.
y packet, which carries key information.
ncapsulated-ASF-Alert packet, which is used to
.
onding Request packet.