C H A P T E R 4
IP Addressing and Subnetting
In this chapter, you will learn about the concepts and mathematics that let you analyze IP addresses and subnets. IP addressing is the only major topic covered on both CCNA exams. To answer questions on either CCNA exam, you need to understand the structure of IP addresses, list the addresses in the same subnet, list the other subnets of that same network, identify the number of hosts in a subnet, and understand other information about addresses and subnets. This chapter describes the math and processes used to answer these questions.
The material in the “Foundation Topics” section of this chapter is an exact duplicate of the material from Chapter 12, “IP Addressing and Subnetting,” of my book CCNA INTRO Exam Certification Guide. If you bought both books and you have read Chapter 12 in the other book, the only thing new in this chapter is that some of the questions at the end of the chapter are different. So feel free to review the Q&A questions.
If you need work on IP subnetting and addressing, this chapter is meant for you. It is very thorough, and it is long because of the number of examples and because the text explains how to examine the topic of IP addressing from the same perspectives as the exam. But when you are finished, you should have a thorough understanding, as well as all the skills you need to answer questions well and quickly on either CCNA exam.
“Do I Know This Already?” Quiz
The purpose of the “Do I Know This Already?” quiz is to help you decide if you need to read the entire chapter. If you intend to read the entire chapter, you do not necessarily need to answer these questions now.
The ten-question quiz, derived from the major sections in the “Foundation Topics” section, helps you determine how to spend your limited study time.
98 Chapter 4: IP Addressing and Subnetting
Table 4-1 outlines the major topics discussed in this chapter and the “Do I Know This Already?” quiz questions that correspond to those topics.
Table 4-1 “Do I Know This Already?” Foundation Topics Section-to-Question Mapping
Foundations Topics Section |
Questions Covered in This Section |
|
|
Analyzing and Interpreting IP Addresses and Subnets |
1–10 |
|
|
CAUTION The goal of self-assessment is to gauge your mastery of the topics in this chapter. If you don’t know the answer to a question or you’re only partially sure of the answer, you should mark this question as wrong for purposes of the self-assessment. Giving yourself credit for an answer you guess correctly skews your self-assessment results and might give you a false sense of security.
1.Which of the following is the result of a Boolean AND between IP address 150.150.4.100 and mask 255.255.192.0?
a.1001 0110 1001 0110 0000 0100 0110 0100
b.1001 0110 1001 0110 0000 0000 0000 0000
c.1001 0110 1001 0110 0000 0100 0000 0000
d.1001 0110 0000 0000 0000 0000 0000 0000
2.If mask 255.255.255.128 were used with a Class B network, how many subnets could exist, with how many hosts per subnet, respectively?
a.a 256 and 256
b.a 254 and 254
c.a 62 and 1022
d.a 1022 and 62
e.a 510 and 126
f.a 126 and 510
“Do I Know This Already?” Quiz 99
3.If mask 255.255.255.240 were used with a Class C network, how many subnets could exist, with how many hosts per subnet, respectively?
a.16 and 16
b.14 and 14
c.12 and 12
d.8 and 32
e.32 and 8
f.6 and 30
g.30 and 6
4.Which of the following IP addresses are not in the same subnet as 190.4.80.80, mask 255.255.255.0?
a.190.4.80.1
b.190.4.80.50
c.190.4.80.100
d.190.4.80.200
e.190.4.90.1
f.10.1.1.1
5.Which of the following IP addresses is not in the same subnet as 190.4.80.80, mask 255.255.240.0?
a.190.4.80.1
b.190.4.80.50
c.190.4.80.100
d.190.4.80.200
e.190.4.90.1
f.10.1.1.1
100Chapter 4: IP Addressing and Subnetting
6.Which of the following IP addresses are not in the same subnet as 190.4.80.80, mask 255.255.255.128?
a.190.4.80.1
b.190.4.80.50
c.190.4.80.100
d.190.4.80.200
e.190.4.90.1
f.10.1.1.1
7.Which of the following subnet masks lets a Class B network allow subnets to have up to 150 hosts and up to 164 subnets?
a.255.0.0.0
b.255.255.0.0
c.255.255.255.0
d.255.255.192.0
e.255.255.240.0
f.255.255.252.0
g.255.255.255.192
h.255.255.255.240
8.Which of the following subnet masks let a Class A network allow subnets to have up to 150 hosts and up to 164 subnets?
a.255.0.0.0
b.255.255.0.0
c.255.255.255.0
d.255.255.192.0
e.255.255.240.0
f.255.255.252.0
g.255.255.255.192
h.255.255.255.240
“Do I Know This Already?” Quiz 101
9.Which of the following are valid subnet numbers in network 180.1.0.0 when using mask 255.255.248.0?
a.180.1.2.0
b.180.1.4.0
c.180.1.8.0
d.180.1.16.0
e.180.1.32.0
f.180.1.40.0
10.Which of the following are valid subnet numbers in network 180.1.0.0 when using mask 255.255.255.0?
a.180.1.2.0
b.180.1.4.0
c.180.1.8.0
d.180.1.16.0
e.180.1.32.0
f.180.1.40.0
The answers to the “Do I Know This Already?” quiz appear in Appendix A. The suggested choices for your next step are as follows:
■8 or less overall score—Read the entire chapter. This includes the “Foundation Topics,” “Foundation Summary,” and “Q&A” sections.
■9 or 10 overall score—If you want more review on these topics, skip to the “Foundation Summary” section and then go to the “Q&A” section. Otherwise, move to the next chapter.