T
he
Transmission Control Protocol/Internet Protocol (TCP/IP)
suite was created by the Department of Defense (DoD) to ensure and pre-
serve data integrity, as well as maintain communications in the event of
catastrophic war. If designed and implemented correctly, a TCP/IP network
can be a dependable and resilient one. In this chapter, I'll cover the protocols
of TCP/IP, and throughout this book, you'll learn how to create a marvelous
TCP/IP network--using Cisco routers, of course.
We'll begin by taking a look at the DoD's version of TCP/IP and then
compare this version and its protocols with the OSI reference model dis-
cussed in Chapter 1. Once you understand the protocols used at the various
levels of the DoD model, you'll learn about IP addressing and subnetting IP
network addresses.
IP addressing and subnetting isn't difficult; there is just a lot of material
to understand. I'm going to present it in a very detailed manner because that
will allow you to read each section over and over again until you feel you've
mastered that section of IP addressing.
Your assignment, if you choose to accept it--and you'd better, if you
want your Cisco certification--is to subnet IP addresses in your head. I can
take you to the promised land--just follow me!
TCP/IP and the DoD Model
T
he DoD model is basically a condensed version of the OSI model--
it's composed of four, instead of seven, layers:
Process/Application layer
Copyright ©2002 SYBEX, Inc., Alameda, CA
www.sybex.com