EAPOL PDU EAPOL

An EAPOL frame — a four-octet header and the packet body it describes.

Reading a capture

Carried inside an ordinary Data frame, not a management frame. That is worth pausing on: the exchange that establishes encryption travels as user data, in a frame whose Protected bit is necessarily zero, because the keys that would protect it are what the exchange is for.

Subfields

• Protocol Version — Which revision of 802.1X the sender implements.
• Packet Type — What kind of EAPOL packet this is.
• Packet Body Length — Octets of packet body following this field.

Where it sits

EAPOL PDU

• Open in the explorer — Four-way handshake message 1
• Open in the explorer — Four-way handshake message 2
• Open in the explorer — Four-way handshake message 3
• Open in the explorer — Four-way handshake message 4

Accuracy

Clause

IEEE 802.1X-2020 §11.3

Verified

Not verified against the standard. Treat this as a claim, not a fact.