19.1

Chap:04Chap:04

IP AddressingIP Addressing

19.2

IntroductionIntroduction

A computer somewhere in the world needs to communicate with another computer some where else in the world

computers communicate through the Internet

The packet (data) transmitted by the sending computer may pass through several LANs or WANs before reaching the destination computer.

19.3

Conti...Conti...

For this level of communication, we need a global addressing scheme

we called this IP Addressing (Internetwork Protocol /logical addressing)

19.4

What is IP Address ?What is IP Address ?

IP Address—internet protocol A 32 bit address that is used to uniquely identify a computer on a network

Or we can say ip is a numerical label which assigned to each computer for communication

19.5

What is a Protocol?

A set of rules that enable two devices to connect and transmit data to one another. Protocols determine how data are transmitted between computing devices and over networks. They define issues such as error control and data compression methods. The protocol determines the following: type of error checking to be used, data compression method (if any), how the sending device will indicate that it has finished a message and how the receiving device will indicate that it has received the message. Internet protocols include TCP/IP (Transfer Control Protocol/Internet Protocol), HTTP (Hypertext Transfer Protocol), FTP (File Transfer Protocol), and SMTP (Simple Mail Transfer Protocol).

19.6

IP version

Ip have two version

1)Ipv4

2)Ipv6

IPV4 is 32 bits

ipv6 is 128 bits

In IPv4 an address consists of 32 bits which limits the

address space to 4294967296 (232

) possible unique addresses.

IPv4 reserves some addresses for special purposes such as

private networks (~18 million addresses) or multicast addresses

(~270 million addresses).

19.7

Ipv4 classes

Class 1st Octet Decimal range

Host ID,Network ID

A 1--126 N.H.H.HB 128--191 N.N.H.HC 192---223 N.N.N.HD 224—239 Reserved for

multicasting E 240—254 Used for research

19.8

Identifies the network

where the computer sitsuniquely identifies the

computer on its network

19.9

19.10

IPv4 ADDRESSESIPv4 ADDRESSES

An An IPv4 address IPv4 address means Internetwork Protocl version 4 means Internetwork Protocl version 4 Adresses Adresses

IPv4 address is IPv4 address is 32-bit32-bit long long

It uniquely defines the connection of a device (for It uniquely defines the connection of a device (for example, a computer or a router) to the Internetexample, a computer or a router) to the Internet

Means Two devices on the Internet can neverhave the same IP address at the same time.

19.11

An IPv4 address is 32 bits long.

Note

19.12

ADDRESS SpaceADDRESS Space

An address space is the total number of addresses used IP

If IP uses N bits to define an address

the address space is 2N because each bit can IPv4 uses 32-bit addresseswhich means that the address space is 232 or4,294,967,296 (more than 4 billion)

19.13

The address space of IPv4 is 232 or 4,294,967,296.

Note

19.14

NotationsNotations

•There are two ways of notations to show an IPv4 address:

1. Binary Notation 2. Dotted Decimal Notation.

19.15

1. Binary Notations1. Binary Notations

•the IPv4 address is displayed as 32 bits

•Each octet is often referred to as a byte.

•The following is an example of an IPv4 address in binary notation:

01110101 10010101 00011101 00000010

19.16

Change the following IPv4 addresses from binary notation to dotted-decimal notation.

Example

SolutionWe replace each group of 8 bits with its equivalent decimal number and add dots for separation.

19.17

2.Dotted-Decimal Notation

•To make useful and easier to read, IP addresses are written in decimal form •decimal point (dot) separating the bytes. •The following is the dotted-decimal notation of the above address:

117.149.29.2

19.18

Change the following IPv4 addresses from dotted-decimal notation to binary notation.

Example 19.2

SolutionWe replace each decimal number with its binary equivalent

19.19

Figure 19.1 Dotted-decimal notation and binary notation for an IPv4 address

19.20

Find the error, if any, in the following IPv4 addresses.

Example

19.21

Solutiona. There must be no leading zero (045).b. There can be no more than four numbers.c. Each number needs to be less than or equal to 255.d. A mixture of binary notation and dotted-decimal notation is not allowed.

19.22

Classes of IP AddressingClasses of IP Addressing

•IPv4 addressing is divided into 5 classes

•Class-A: •Class-B: •Class-C: •Class-D:•Class-E:

Class-AClass-A

•This is first class of IP addressing•It is 32 bit long•It has two parts

• Netid part (8 bits)•Hostid Part (24 bits)

Netid.Hostid.Hostid.Hostid

•Range for Netid: 0-127•Range for Hostid: 0-255

Class-BClass-B

•This is second class of IP addressing•It is 32 bit long•It has two parts

• Netid part (16 bits)•Hostid Part (16 bits)

Netid.Netid.Hostid.Hostid

•Range for Netid: 128-191•Range for Hostid: 0-255

Class-CClass-C

•This is third class of IP addressing•It is 32 bit long•It has two parts

• Netid part (24 bits)•Hostid Part (8 bits)

Netid.Netid.Netid.Hostid

•Range for Netid: 192-223•Range for Hostid: 0-255

Class-DClass-D

•This is Fourth class of IP addressing

•It is 32 bit long

•Used for Multicasting

•Range for Netid: 224-239

Class-EClass-E

•This is Fifth class of IP addressing

•It is 32 bit long

•Reserved by Company for its own Purpose

•Range for Netid: 240-255

19.28

Subnet Mask:

•Subnet Mask is used to identify the network of an IP address

•Default Sunbet Masks for :•Class-A: 255.0.0.0•Class-B: 255.255.0.0•Class-C: 255.255.255.0

19.29

•End of Chap