IP Addressing

IP Addressing

Chapter 2

Chapter 2 2

Chapter Objectives

Explain TCP/IP protocol stack Explain IP addressing Discuss IP subnetting Plan IP addressing

Chapter 2 3

Recall

Physical and the Logical topology are the two types of topologies

LAN, MAN and WAN are the different types of networks used

Hierarchical model includes three layers, core layer, distribution layer and the access layer

Application layer, presentation layer, session layer, transport layer, network layer, data link layer and the physical layer are the different layers of the OSI model

Chapter 2 4

TCP/IP Stack

TCP/IP stack has four layers

Application

Transport Internet

NetworkInterface

TCP/IP

Chapter 2 5

Application Layer

Application layer clubs the functionality of application, presentation, and session layers of the OSI model

Protocols that function at the application layer include Hyper Text Transfer Protocol (HTTP) Simple Network Management Protocol (SNMP) File Transfer Protocol (FTP) Telnet

Chapter 2 6

Transport Layer

Layer is responsible for source-to-destination delivery of the entire message

Ensures that the entire message arrives at the destination computer

Protocols that function in the transport layer include TCP User Datagram Protocol (UDP)

Chapter 2 7

Internet Layer

Layer allows routing of data over the network Protocols that function in the network layer include

Address Resolution protocol (ARP) - ARP provides a method for finding the Media Access Control (MAC) address of the host computer from its IP address

Reverse Address Resolution Protocol (RARP) - RARP provides a method for finding the IP address of the host computer from the MAC address

Chapter 2 8

Internet Control Message Protocol (ICMP) ICMP functions at the network layer of Internet

Protocol The protocol reports errors related to the delivery of

IP packets within a network ICMPs generate the following four messages

Destination Unreachable message Echo request message Redirect message Time exceeded message

Chapter 2 9

IP Addressing IP address is a 32-bit binary number that is unique for each

device IP address is converted to a decimal format to make them

readable for the humans Within the network, the IP address is interpreted in a binary

format consisting of 0 and 1 IP address of 10010100101000101001010010101011, it is

split into 4 octets such as 10010100 10100010 10010100 10101011

Chapter 2 10

IP Addressing

To convert the bits to a decimal format, right most bit in the octet has the least value of 20. This value goes on increasing towards the left

Bits 1 0 0 1 0 1 0 0

Values 27 = 128 26 = 64 25 = 32 24 = 16 23 = 8 22 = 4 21 = 2 20 = 1

Chapter 2 11

IP Addressing You need to multiply the bits with its corresponding value in the table

Bits 1 0 0 1 0 1 0 0

Values 27 = 128 26 = 64 25 = 32 24 = 16 23 = 8 22 = 4 21 = 2 20 = 1

Multiplied

Values128 0 0 16 0 4 0 0

Chapter 2 12

IP Addressing

The equivalent decimal value for the octet will be the addition of all the multiplied values

For the octet 10010100, the decimal value will be 128+0+0+16+0+4+0+0 = 148

So the IP address of the machine will be 148.162.148.171

Chapter 2 13

Classification of IP Addresses

CLASSES

Class A

1-126

Class B

128 - 191

Class C

192 -223

Class D

224-239

Class E

240 - 255

Chapter 2 14

IP Address Components

A network number denotes the network segment to which the device is connected

A host number specifies the address of the device in the network segment. Host numbers are the numbers between the network number and the directed broadcast number

Chapter 2 15

Subnet Mask

Subnet mask is used to identify the network bits and host bits in the IP address

A subnet mask always has a series of consecutive 1s followed by consecutive 0s

A subnet mask cannot start with the bit 0 or ending with the bit 1

Chapter 2 16

IP Subnetting

Chapter 2 17

Algorithm to determine the number of hosts and subnets Identify the IP address structure Determine the number of network bits based on the

class of the IP address Determine the number of host bits based on the

number of 0s in the mask Determine the number of host bits using the formula,

32 – (network bits + host bits) Calculate the number of subnets using the formula,

2subnet bits – 2 Calculate the number of hosts in each subnet using

the formula, 2host bits – 2

Chapter 2 18

Case Study

The Blue Diamond Steel organization located in Gujarat is granted an IP address 220.56.64.0 by Internet Assigned Numbers Authority (IANA). The company requires five different subnets for its Finance, Business Development, Software Management, Project Management and Detailing departments. The network administrator Robert needs to design the subnets for the company.

Chapter 2 19

Problem

Finding IP address range for each subnet

Chapter 2 20

Suggested Solution

Find IP address range for each subnet

Chapter 2 21

Variable Length Subnet Mask (VLSM) VLSM allows you to use different masks for each

subnet Classful protocols such as Routing Information

Protocol version 1 (RIPv1) and IGRP do not support VLSM

Advantages of VLSM include Efficient use of IP addressing Route summarization

Chapter 2 22

Route Summarization

Advantages of route summarization include: Reduction in the size of routing table, memory

requirement and time for processing Reduction in the size of updates and bandwidth

requirement Detection of networking problems that ensures

proper routing of the packets to the destination

Chapter 2 23

VLSM Design

A VLSM design ensures efficient use of available IP addresses as well as more-efficient routing update communication using hierarchical IP addressing

Design criteria that affect the functioning of the VLSM technology include Total subnets required currently Total subnets that may be required in the future Number hosts on the largest subnet currently Number of hosts that may be required on the

largest subnet in future

Chapter 2 24

Planning IP Addressing

Planning IP addressing include Identifying Network and Host Requirements Calculating Subnet Masks Identifying Network Addresses Identifying Directed Broadcast Addresses Identifying Host Addresses

Chapter 2 25

Summary - I

TCP/IP is a protocol suite that allows data transfer between network devices

The Application layer clubs the functionality of application, presentation, and session layers of the OSI model

The transport layer is responsible for source-to-destination delivery of the entire message

The network layer allows routing of data over the network The data-link layer allows the source computer to add

meaningful bits to the data packet so that the destination computer identifies it

Chapter 2 26

Summary - II

Every device that is connected to the network using the TCP/IP protocol requires an IP Address

The IP address is a 32-bit number that is unique for each device The IP address is converted to a decimal format to make them

readable for the human eye The 32-bit binary IP address is represented as 4 octets, each

consisting of 8 bits Every IP address consists of two parts, the network, and the host

number The network number identifies the network segment and the host

number identifies the actual device

Chapter 2 27

Summary - III

Host numbers are the numbers between the network number and the directed broadcast number

Subnetting refers to the process of grouping a definite number of devices

A subnet mask allows us to identify the network number and the host number of an IP address

A subnet mask contains 32 bits similar to IP addresses and is represented in a decimal form separated by periods

Chapter 2 28

Summary - IV

In a binary format, the bit 1 in the subnet mask represents the network number and the bit 0 represents the host number

A subnet mask always has a series of consecutive 1s followed by consecutive 0s

The higher order bits are always reserved for subnetting

The boolean AND operation enables us to identify the subnet number in an IP address

The directed broadcast address specifies all host addresses on the particular network

Chapter 2 29

Summary - V

You can calculate network and host requirements using the following formulae: 2X = > number of networks, where X refers to

number of subnet bits 2Y – 2 = > hosts on largest segment, where Y

represents the host bits. X + Y <= total host bits

Variable Length Subnet Mask (VLSM) allows you to use different masks for each subnet to prevent the wastage of address space