CCNA CHAPTER 2 BY jetarvind kumar madhukar

Release 16/07/2009 Jetking Infotrain Ltd.

IP Addressing

Chapter 2


Chapter Objectives

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


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


TCP/IP Stack

TCP/IP stack has four layers

Application

Transport Internet

NetworkInterface

TCP/IP


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


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)


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


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


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


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


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 Values

128 0 0 16 0 4 0 0


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


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


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


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


IP Subnetting


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


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.


Problem

Finding IP address range for each subnet


Suggested Solution

Find IP address range for each subnet


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


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


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


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


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


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


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


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


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

Education

CCNA CHAPTER 2 BY jetarvind kumar madhukar