tailieunhanh - Lecture TCP-IP protocol suite (3/e): Chapter 5 - Behrouz Forouzan

Chapter 5 - IP addresses: Classless addressing. When you finish this chapter, you should: Understand the concept of classless addressing, be able to find the first and last address given an IP address, be able to find the network address given a classless IP address, be able to create subnets from a block of classless IP addresses, understand address allocation and address aggregation. | Chapter 5 Objectives Upon completion you will be able to: IP Addresses: Classless Addressing Understand the concept of classless addressing Be able to find the first and last address given an IP address Be able to find the network address given a classless IP address Be able to create subnets from a block of classless IP addresses Understand address allocation and address aggregation TCP/IP Protocol Suite VARIABLE-LENGTH BLOCKS In classless addressing variable-length blocks are assigned that belong to no class. In this architecture, the entire address space (232 addresses) is divided into blocks of different sizes. The topics discussed in this section include: Restrictions Finding the Block Granted Block TCP/IP Protocol Suite Figure Variable-length blocks TCP/IP Protocol Suite Which of the following can be the beginning address of a block that contains 16 addresses? a. c. Example 1 Solution Only two are . | Chapter 5 Objectives Upon completion you will be able to: IP Addresses: Classless Addressing Understand the concept of classless addressing Be able to find the first and last address given an IP address Be able to find the network address given a classless IP address Be able to create subnets from a block of classless IP addresses Understand address allocation and address aggregation TCP/IP Protocol Suite VARIABLE-LENGTH BLOCKS In classless addressing variable-length blocks are assigned that belong to no class. In this architecture, the entire address space (232 addresses) is divided into blocks of different sizes. The topics discussed in this section include: Restrictions Finding the Block Granted Block TCP/IP Protocol Suite Figure Variable-length blocks TCP/IP Protocol Suite Which of the following can be the beginning address of a block that contains 16 addresses? a. c. Example 1 Solution Only two are eligible (a and c). The address is eligible because 32 is divisible by 16. The address is eligible because 80 is divisible by 16. TCP/IP Protocol Suite Which of the following can be the beginning address of a block that contains 256 addresses? Example 2 Solution In this case, the right-most byte must be 0. As we mentioned in Chapter 4, the IP addresses use base 256 arithmetic. When the right-most byte is 0, the total address is divisible by 256. Only two addresses are eligible (b and c). TCP/IP Protocol Suite Which of the following can be the beginning address of a block that contains 1024 addresses? a. c. Example 3 Solution In this case, we need to check two bytes because 1024 = 4 × 256. The right-most byte must be divisible by 256. The second byte (from the right) must be divisible by 4. Only one address is eligible (c). TCP/IP Protocol Suite