IP Header
Byte |
Bit |
0 |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
0 |
IP Version |
Hdrlen |
TOS |
Datagram (or fragment) length |
4 |
Identification |
r |
D |
M |
Fragment offset |
8 |
TTL |
Protocol |
Checksum |
12 |
Source |
16 |
Destination |
TCP Header (follows IP header)
Byte |
Bit |
0 |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
20 |
Source port |
Destination port |
24 |
Sequence number |
28 |
Acknowledgement number |
32 |
Hdrlen |
(reserved) |
U |
A |
P |
R |
S |
F |
Window size |
36 |
Checksum |
Urgent pointer |
UDP Header (follows IP header)
Byte |
Bit |
0 |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
20 |
Source port |
Destination port |
24 |
Datagram (or fragment) length |
Checksum |
Checksum pseudo-header (used during checksum calculation)
Byte |
Bit |
0 |
4 |
8 |
12 |
16 |
20 |
24 |
28 |
0 |
Source |
4 |
Destination |
8 |
zero |
Protocol |
Datagram (or fragment) length |
$Id: tcpheader.html 14 2004-03-15 22:29:45Z mnadler $