Layout of an IP Version 4 (IPV4) packet

0

4

8

12

16

20

24

31

Version

Header Len

Diff. Serv

Total Length incl. Header

Identification

Flags (3 bits)

Fragment Offset (13 bits)

Time to Live

Protocol

Header Checksum

Source IP Address

Destination IP Address

Options up to 40 bytes max

Padding