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This chapter is from the book

This chapter is from the book

CCENT ICND1 100-105 Exam Cram, 3rd EditionCCENT ICND1 100-105 Exam Cram, 3rd Edition

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This chapter is from the book

This chapter is from the book

CCENT ICND1 100-105 Exam Cram, 3rd EditionCCENT ICND1 100-105 Exam Cram, 3rd Edition

Learn More Buy

Topic: Describe the need for private IPv4 addressing

CramSaver

  1. List the Class A private address space.

    _________

  2. List the Class B private address space.

    _________

  3. List the Class C private address space.

    _________

Answers

  1. 10.0.0.0 to 10.255.255.255

  2. 172.16.0.0 to 172.31.255.255

  3. 192.168.0.0 to 192.168.255.255

The designers of IPv4 created private address space to help alleviate the depletion of IPv4 addresses. This address space is not routable on the public Internet. This address space can be used as needed inside corporations. This address space would then be translated using Network Address Translation (NAT) to allow access to and through the public Internet. Of course, this is why you tend to see the same addresses used in homes today (typically in the 192.168.1.X range). Table 2.4 shows you the private address space.

TABLE 2.4 The IPv4 Private Address Ranges

Address Class

Range of Private Addresses

A

10.0.0.0 to 10.255.255.255

B

172.16.0.0 to 172.31.255.255

C

192.168.0.0 to 192.168.255.255

ExamAlert

Clearly a skill you must possess is to memorize these ranges. Although it is normally not important to memorize Request for Comment numbers, the RFC that defined these ranges is so famous you should know it. The above ranges are often termed RFC 1918 addresses.

CramQuiz

  1. What technology permits many private addresses to communicate on the public Internet?

    cir.jpg A. SMTP

    cir.jpg B. POP3

    cir.jpg C. SNMP

    cir.jpg D. NAT

  2. Which of the following is not a private address?

    cir.jpg A. 10.10.10.1

    cir.jpg B. 12.34.100.1

    cir.jpg C. 172.16.1.10

    cir.jpg D. 192.168.1.10

  3. What famous RFC defined the private use only IP address space?

    cir.jpg A. RFC 2020

    cir.jpg B. RFC 2191

    cir.jpg C. RFC 2001

    cir.jpg D. RFC 1918

CramQuiz Answers

  1. D is correct. Network Address Translation permits these private addresses to communicate.

  2. B is correct. 12.X.X.X is part of the public IP address space.

  3. D is correct. RFC 1918 defined the private address space.

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