Webspace Sponsored by:

Version 0.0.0 @ 03:55/08.07.2000

Decomposition of an IP Packet

Bits used per field:
0....... 8....... 16...... 24......
(<--------32-bits-wide-------->)
Vers
HLen
8Bit-Tos
16-Bit-Total-Len
16-Bit-Identifi.
Flg
Fragment-Offs
8Bit-Ttl
Protocol
Header-Checksum-
32-Bit-Src-IP-Address-For-Packet
32-Bit-Dst-IP-Address-For-Packet
-----------Options(?)-----------
--------data/payload(?)---------

The above is an example of an IP Header. Rows 1 through 5 are commonly used, and when options are included in the header, then rows 1 through 6 or more depending upon how many 32-bit option words are used by special options. The payload contained is the encapsulated data from the upper layer. (For example, a TCP, or UDP packet from the Transport Layer may be coming down to the Network Layer to be included in an outgoing IP address.)

This ends the brief preview of an IP packet.

Comments and/or suggestions for this?: Email me at: dugan@passwall.com
Attempts have been made to make the tables appear as they should for LYNX users by forcing a common field width for fields being used by padding them with other printable characters. This is meant to allow for LYNX users to see the tables much like the Netscape and other web browser worlds might show them. However, from personal experience, some versions of LYNX still manage to munge the tables, making them use up several pages. It seems to be a problem with how earlier versions of LYNX dealt with tables, but the problem has not been entirely isolated.
Some have asked why this collection of on-line documents is so lacking of graphic content. To them I answer: faster downloads. Many of these pages are smaller than some pictures on many commercial web sites. You do not come here to look at my pictures. You come here to read content. Also, LYNX users benefit from this, and by using ALL text, people with ADA issues are able to use speech recognition software on the text to hear the words.
Copyright (C) 1999, 2000, 2001, 2002 by Michael Egan: All rights reserved.
A Special License: No part of this document may be used for profit without the consent of the author Michael Egan in writing. Content may be duplicated for retransmission for non-profit purposes as long as the copyright and license remain included in their entirety. The content is provided "as-is" and I take no responsibility on the content's truthfulness or consistency. Errors may exist in these documents, but acting upon these errors is left up to the reader to verify by a third party that will take responsibility for fact verification. When notified of errors or inconsistencies, attempts will be made to rectify the errors.
In plan English this is meant to do many things: This copyright is meant to exist so that others may not profit from this work as published in paper form, or by duplicating the content to place advertisements over it and generate income. It is also meant to exist to prevent people from publishing this work as their own and receiving profit from this process on research they did not perform. It is not meant to stop a professor from running off copies to use in their classes for their students. It is also not meant to stop the student from printing up copies for their own education. How depressing it would be to find your work published in book form without your permission, or compensation. Another reason for this Copyright is to limit the effect of the mistakes I have made within this document before I was able to complete it. It would be even sadder to notice my mistakes in print and criticized before I could resolve them. Eventually, after I finish this work, I may retain copyright, but eliminate the license.