IP Addressing lecture computer network.pptx

This explains Ip addresses, their versions, classes and few divisions

1. Computer Networks Muhammad Shahid Khan Department of Computer Science COMSATS University Islamabad, Wah Campus The slides are adapted from the publisher’s material Data Communications and Networking by Behrouz A. Forouzan, 5 th edition Data and Computer Communications by William Stallings, 8 th Edition Computer Networking: A Top- Down Approach by J F Kurose, K W Ross, 6 th Edition Computer Networks, b y L. Peterson, and B. Davie, 5 th edition IP Addresses

2. 2 Outline IP address a number identifying a computer or another device on the Internet Classful IP addressing

3. IPv4 ADDRESSES An IPv4 address is a 32- bit address that uniquely and universally defines the connection of a device (for example, a computer or a router) to the Internet. 3

4. Change the following IPv4 addresses from dotted-decimal notation to binary notation. Example Solution We replace equivalent. 4 each decimal number with its binary

5. Change the following IPv4 addresses from dotted-decimal notation to binary notation. Example Solution We replace equivalent. each decimal number with its binary 5

6. Change the following IPv4 addresses from binary notation to dotted- decimal notation. Example Solution We replace each group of 8 bits with its equivalent decimal number and add dots for separation. 6

7. Find the error, if any, in the following IPv4 addresses. Example Solution a. 7

8. Find the error, if any, in the following IPv4 addresses. Example Solution There must be no leading zero (045). There can be no more than four numbers. Each number needs to be less than or equal to 255. A mixture of binary notation and dotted- decimal notation is not allowed. 8

9. Hierarchy in Addressing A 32- bit IPv4 address is hierarchical, but divided only into two parts. The first part of the address, called the prefix , defines the network; the second part of the address, called the suffix , defines the node (connection of a device to the Internet). Figure shows the prefix and suffix of a 32- bit IPv4 address. The prefix length is n bits and the suffix length is (32 - n ) bits. 18. 9

10. Classful Addressing When the Internet started, an IPv4 address was designed with a fixed-length prefix, but to accommodate both small and large networks, three fixed- length prefixes were designed instead of one (n = 8, n = 16, and n = 24). The whole address space was divided into five classes (class A, B, C, D, and E), as shown in Figure below. This scheme is referred to as classful addressing. Although classful addressing belongs to the past, it helps us to understand classless addressing, discussed later. 18. 10

11. Classful Addressing 18. 11

12. Find the class of each address. 0000001 00001011 00001011 11101111 110 00001 10000011 00011011 11111111 14 .23.120.8 252 .5.15.111 Solution a. 12 Example

13. Find the class of each address. 0000001 00001011 00001011 11101111 110 00001 10000011 00011011 11111111 14 .23.120.8 252 .5.15.111 Solution The first bit is 0. This is a class A address. The first 2 bits are 1; the third bit is 0. This is a class C address. The first byte is 14; the class is A. The first byte is 252; the class is E. 13 Example