CCNA Cisco Certified Network Associate Study Guide - FTP Server

The Transmission Control Protocol/Internet Protocol (TCP/IP)
suite was created by the Department of Defense (DoD) to ensure and
preserve 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 protocols with the OSI reference model discussed
in Chapter 1. After you have an understanding of the protocols used at the
various levels of the DoD model, it will be time to learn about IP addressing.
This chapter also covers subnetting an IP network address.
IP addressing and subnetting is not difficult; there is just a lot of material
to understand. I will present it in a very detailed manner, which will allow
you to read each section over and over again until you feel you have mastered
that section of IP addressing.
TCP/IP and the DoD Model
The DoD model is a condensed version of the OSI model. It is comprised
of four, instead of seven, layers:
� The Process/Application layer
� The Host-to-Host layer
� The Internet layer
� The Network Access layer