Section 4. Understanding TCP/IP

TCP/IP was created by the Defense Advanced Research Projects Agency (DARPA) to run as the protocol for the ARPANET in 1974. TCP/IP is the most widely used protocol suite in the world today. It is the protocol suite used on the Internet, and most network operating systems (NOS) require TCP/IP to run to communicate with other nodes. TCP/IP is the protocol suite you will encounter the most as a network engineer. You must thoroughly understand TCP/IP and know how it works.

As you can tell by its name, TCP/IP is a suite of protocols, with its major protocols being TCP and IP. TCP provides reliable delivery, and IP provides network addressing and routing.

Currently, two versions of IP exist: IP version 4 (IPv4) and IP ...

Get Cisco CCNA Routing and Switching 200-120: Flash Cards and Exam Practice Pack now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.