Packet formats
EAP packet format
Figure 21 shows the EAP packet format.
Figure 21: EAP packet format
Code—Type of the EAP packet. Options include Request (1), Response (2), Success (3), or Failure (4).
Identifier—Used for matching Responses with Requests.
Length—Length (in bytes) of the EAP packet. The EAP packet length is the sum of the Code, Identifier, Length, and Data fields.
Data—Content of the EAP packet. This field appears only in a Request or Response EAP packet. The Data field comprises the request type (or the response type) and the type data. Type 1 (Identify) and type 4 (MD5-challenge) are two examples for the type field.
EAPOL packet format
Figure 22 shows the EAPOL packet format.
Figure 22: EAPOL packet format
PAE Ethernet type—Protocol type. It takes the value 0x888E for EAPOL.
Protocol version—The EAPOL protocol version used by the EAPOL packet sender.
Type—Type of the EAPOL packet. Table 5 lists the types of EAPOL packets supported by Hewlett Packard Enterprise implementation of 802.1X.
Table 5: Types of EAPOL packets
Value | Type | Description |
|---|---|---|
0x00 | EAP-Packet | The client and the network access device uses EAP-Packets to transport authentication information. |
0x01 | EAPOL-Start | The client sends an EAPOL-Start message to initiate 802.1X authentication to the network access device. |
0x02 | EAPOL-Logoff | The client sends an EAPOL-Logoff message to tell the network access device that it is logging off. |
Length—Data length in bytes, or length of the Packet body. If packet type is EAPOL-Start or EAPOL-Logoff, this field is set to 0, and no Packet body field follows.
Packet body—Content of the packet. When the EAPOL packet type is EAP-Packet, the Packet body field contains an EAP packet.