Generic Routing Encapsulation - Packet Header

Packet Header

A GRE packet header structure is represented in the diagram below.

Bits 0–4 5–7 8–12 13–15 16–31
C R K S s Recur Flags Version Protocol Type
Checksum (optional) Offset (optional)
Key (optional)
Sequence Number (optional)
Routing (optional)

Read more about this topic:  Generic Routing Encapsulation

Famous quotes containing the word packet:

    The captain was a duck
    With a packet on his back,
    And when the ship began to move
    The captain said, Quack! Quack!
    Mother Goose (fl. 17th–18th century. I saw a ship a-sailing (l. 13–16)