Addressing the Network – IPv4skj3443.weebly.com/uploads/2/3/3/1/23318904/chapter_6_ipv4... · Addressing the Network – IPv4 ... Given an IPv4 address, ... Converting 8-bit binary

© 2007 Cisco Systems, Inc. All rights reserved. Cisco Public 1 Version 4.0

Addressing the Network – IPv4

Network Fundamentals – Chapter 6

2 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public

Objectives Explain the structure IP addressing and demonstrate the ability

to convert between 8-bit binary and decimal numbers.

Given an IPv4 address, classify by type and describe how it is used in the network.

Explain how addresses are assigned to networks by ISPs and within networks by administrators.

Determine the network portion of the host address and explain the role of the subnet mask in dividing networks.

Given IPv4 addressing information and design criteria, calculate the appropriate addressing components.

Use common testing utilities to verify and test network connectivity and operational status of the IP protocol stack on a host.


IP Addressing Structure Inside the devices, digital logic is applied for

interpretation of the address

Human – 32 bits is difficult to interpret + remember

IPv4 addresses are easier to remember, write, and verbally communicate than strings of 32 bits.

Separating the 32 bits - into bytes.

Represented as dotted decimal


IP Addressing Structure Each byte of the binary pattern, called an octet, is

separated with a dot.

Ex. 10101100000100000000010000010100

Expressed in dotted decimal as : 172.16.4.20


IP Addressing Structure IPv4 addresses have two parts:

•the network portion and

• the host portion

Most significant bits, or high-order bits, represents the network address.

Two addresses above would be on the same logical network.


IP Addressing Structure

Host portion determines the number of hosts within the network.

To assign a unique address to 200 hosts -use the entire last octet.

8 bits = 256 different bit patterns can be achieved.


IP Addressing Structure Converting 8-bit binary to decimal.

Mathematical basis of a numbering system called positional notation.

A digit represents different values depending on the position it occupies.

Value of the digit multiplied by the power of the base, or radix - the position the digit occupies.


IP Addressing Structure Converting 8-bit binary to decimal


IP Addressing Structure Converting 32 bits IP Address




IP Addressing Structure Converting 32 bits IP Addresses




IP Addressing Structure Exercise

00001011?


IP Addressing Structure Decimal to 8-bit binary








IP Addressing Structure Converting decimal to 8-bit binary- practice

11010001


Addressing Types of Communication

In IPv4 network, the hosts can communicate in one of three different ways



Unicast

Most common in CS and P2P



Broadcast

Using Broadcast Address

Two types:

Directed Broadcast – Broadcast is sent to all hosts on a specific network/nonlocal

Limited Broadcast - Broadcast is sent to all hosts on local network



Multicast

Only to selected set of hosts




IPv4 Addresses Three types of addresses in the network:

• Network address: A special address that refers to the network

• Cannot be assign to a device, only reference to a network

• The lowest address in IPv4 address range

• Broadcast address: A special address used to send data to all hosts in the network

• The highest address in IPv4 address range

• Host addresses: The unicast addresses assigned to the end devices in the network


IPv4 Addresses


IPv4 Addresses

172.16.4.127

Host Address: Network Address: Broadcast Address:


IPv4 Addresses Network prefix

When an IPv4 network address is expressed, a prefix length added to the network address.

This prefix length is the number of bits in the address that gives the network portion.

Written in slash format. That is a forward slash (/) followed by the number of network bits.

Example, in 172.16.4.0 /24, the /24 is the prefix length.

•The first 24 bits are the network address.

•The remaining 8 bits, the last octet, are the host portion.


IPv4 Addresses Network prefix

Network not always assigned a /24 prefix

Depends on the number of hosts on the network

28=256, 27=128…


IPv4 Addresses Determine the network, broadcast and host addresses

for a given address and prefix combination

172.16.4.35/24

Type of Address Last octet in

binary

Last octet in

decimal

Full address in

decimal

Network 00000000 0 172.16.4.0

Broadcast 11111111 255 172.16.4.255

First Useable Host

Address

00000001 1 172.16.4.1

Last Useable Host

Address

11111110 254 172.16.4.254


IPv4 Addresses Exercise

Determine the network, broadcast and host addresses for a given address and prefix combination

144.83.250.97/25

Type of Address Last octet in

binary

Last octet in

decimal

Full address in

decimal

Network

Broadcast

First Useable Host

Address

Last Useable Host

Address

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Addressing the Network – IPv4skj3443.weebly.com/uploads/2/3/3/1/23318904/chapter_6_ipv4... · Addressing the Network – IPv4 ... Given an IPv4 address, ... Converting 8-bit binary