TCP/IP Tutorial and Technical Overview - IBM Redbooks

Figure 23-13 shows the EAP Request/Authentication or EAP Request/PEAP
packet. A value of 1 in the Code field of the EAP header indicates that it is an
EAP-Request packet. A value of 25 in the Type field of the EAP header indicates
that it is an EAP-Request/PEAP packet.
Figure 23-13 EAP-Request/PEAP packet
EAP success packet
Figure 23-14 depicts the format of an EAP-Success packet.
(Bytes)
Destination
address
6 6 2 1 1 2 1 1 2 (Bytes)
Source
address
Type
0x888E
Protocol
version
1
Figure 23-14 EAP-Success packet format
Packet
type
0
Packet body
length
4
Figure 23-15 on page 902 shows the sniffer trace for the EAP-Success packet.
The value of the Packet type field in the 802.1x header is 0, which indicates that it
is an EAP packet. A value of 3 for the Code field in the EAP header indicates that
it is an EAP-Success packet. Note that there is not a Data field for this packet.
Therefore, the Packet body length value in the 802.1x or EAPOL header is 4
excluding the Ethernet and 802.1x headers. Similarly, the value of the Length
field in the EAP header is 4, which just includes the EAP header.
Code
3
Identifier Length
4
Ethernet Header 802.1x/EAPOL Header EAP Header
Chapter 23. Port based network access control 901