This chapter covers the following exam topics:
1.0 Network Fundamentals
1.3 Compare physical interface and cabling types
1.3.a Single-mode fiber, multimode fiber, copper
1.3.b Connections (Ethernet shared media and point-to-point)
Welcome to the first chapter in your study for CCNA! This chapter begins Part I, which focuses on the basics of networking.
Networks work correctly because the various devices and software follow the rules. Those rules come in the form of standards and protocols, which are agreements of a particular part of how a network should work. However, the sheer number of standards and protocols available can make it difficult for the average network engineer to think about and work with networks—so the world of networking has used several networking models over time. Networking models define a structure and different categories (layers) of standards and protocols. As new standards and protocols emerge over time, networkers can think of those new details in the context of a working model.
You can think of a networking model as you think of a set of architectural plans for building a house. A lot of different people work on building your house, such as framers, electricians, bricklayers, painters, and so on. The blueprint helps ensure that all the different pieces of the house work together as a whole. Similarly, the people who make networking products, and the people who use those products to build their own computer networks, follow a particular networking model. That networking model defines rules about how each part of the network should work, as well as how the parts should work together so that the entire network functions correctly.
Today, TCP/IP rules as the most pervasive networking model in use. You can find support for TCP/IP on practically every computer operating system (OS) in existence today, from mobile phones to mainframe computers. Every network built using Cisco products today supports TCP/IP. And not surprisingly, the CCNA exam focuses heavily on TCP/IP. This chapter uses TCP/IP for one of its main purposes: to present various concepts about networking using the context of the different roles and functions in the TCP/IP model.
Note that most chapters cover topics about some specific CCNA exam topic. However, this chapter does not. Instead, it describes background information about the TCP/IP model and ideas you need to know about so you can better understand the detail included in CCNA.
Take the quiz (either here or use the PTP software) if you want to use the score to help you decide how much time to spend on this chapter. The letter answers are listed at the bottom of the page following the quiz. Appendix C, found both at the end of the book as well as on the companion website, includes both the answers and explanations. You can also find both answers and explanations in the PTP testing software.
Table 1-1 “Do I Know This Already?” Foundation Topics Section-to-Question Mapping
Foundation Topics Section | Questions |
Perspectives on Networking | None |
TCP/IP Networking Model | 1–4 |
Data Encapsulation Terminology | 5–6 |
1. Which of the following protocols are examples of TCP/IP transport layer protocols? (Choose two answers.)
2. Which of the following protocols are examples of TCP/IP data-link layer protocols? (Choose two answers.)
3. The process of HTTP asking TCP to send some data and making sure that it is received correctly is an example of what?
4. The process of TCP on one computer marking a TCP segment as segment 1 and the receiving computer then acknowledging the receipt of TCP segment 1 is an example of what?
5. The process of a web server adding a TCP header to the contents of a web page, followed by adding an IP header and then adding a data-link header and trailer, is an example of what?
6. Which of the following terms is used specifically to identify the entity created when encapsulating data inside data-link layer headers and trailers?
Answers to the “Do I Know This Already?” quiz:
1 D and F
2 A and G
3 B
4 B
5 A
6 D