Addressing the Network – IPv4 - ECED Mansoura B addresses represent 25% of the total IPv4 unicast address space. ... Addressing the Network – IPv4

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

ITE PC v4.0

Chapter 1 1

IP-V4 Addressing

Network Fundamentals – Chapter 6

ITE PC v4.0

Chapter 1 2 © 2007 Cisco Systems, Inc. All rights reserved. Cisco Public

Objectives

1. convert between 8-bit binary and decimal numbers.

2. classful/classless addressing & Subnet mask

3. calculate the appropriate addressing components.

Network / Broadcast Addresses

4. Types of addresses in an IPv4 network

5. ANDING Process.

ITE PC v4.0


IP Addressing Structure Describe the dotted decimal structure of a binary IP

address and label its parts

ITE PC v4.0


The anatomy of an IPv4 address

ITE PC v4.0


IPv4 Addresses An IP address has two parts:

network number

host number

Which bits refer to the network number?

Which bits refer to the host number?

ITE PC v4.0


Dividing the Network and Host Portions

Subnet Mask

Used to define the:

Network portion

Host portion

32 bits

Contiguous set of 1’s followed by a contiguous set of 0’s

1’s: Network portion

0’s: Host portion

11111111111111110000000000000000

ITE PC v4.0


Dividing the Network and Host Portions

Expressed as:

Dotted decimal

Ex: 255.255.0.0

Slash notation or prefix length

/16 (the number of one bits)

11111111.11111111.00000000.00000000

Dotted decimal: 255 . 255 . 0 . 0

Slash notation: /16

ITE PC v4.0


IPv4 Addresses

Newer technology - Classless IP Addressing

The subnet mask determines the network portion and the host portion.

Value of first octet does NOT matter (older classful IP addressing)

Hosts and Classless Inter-Domain Routing (CIDR).

Classless IP Addressing is what is used within the Internet and in most internal networks.

Older technology - Classful IP Addressing (later)

Value of first octet determines the network portion and the host portion.

Used with classful routing protocols like RIPv1.

The Cisco IP Routing Table is structured in a classful manner (CIS 82)

ITE PC v4.0


Classful IP Addressing

When an organization received an IP network address, that address was associated with a “Class”, A, B, or C.

This is known as Classful IP Addressing

The first octet of the address determined what class the network belonged to and which bits were the network bits and which bits were the host bits.

There were no subnet masks.

It was not until 1992 when the IETF introduced CIDR (Classless Interdomain Routing), making the address class meaning less.

This is known as Classless IP Addressing.

ITE PC v4.0


Class A addresses

Network Host Host Host

First octet is between 0 – 127, begins with 0

Number

between 0 - 127

8 bits 8 bits 8 bits

With 24 bits available for hosts,

there a 224 possible addresses.

That’s 16,777,216 nodes!

There are 126 class A addresses.

0 and 127 have special meaning and are not used.

16,777,214 host addresses, one for network address and one for broadcast address.

Only large organizations such as the military, government agencies, universities, and large corporations have class A addresses.

For example ISPs have 24.0.0.0 and 63.0.0.0

Class A addresses account for 2,147,483,648 of the possible IPv4 addresses.

That’s 50 % of the total unicast address space, if classful was still used in the Internet!

Default Mask: 255.0.0.0 (/8)

ITE PC v4.0


Class B addresses

Network Network Host Host


Number

between

128 - 191

8 bits 8 bits



That’s 65,536 nodes!

There are 16,384 (214) class B networks.

65,534 host addresses, one for network address and one for broadcast address.

Class B addresses represent 25% of the total IPv4 unicast address space.

Class B addresses are assigned to large organizations including corporations (such as Cisco, government agencies, and school districts).

Default Mask: 255.255.0.0 (/16)

ITE PC v4.0


Class C addresses

Network Network Network Host


Number

between

192 - 223

8 bits



That’s 256 nodes!

There are 2,097,152 possible class C networks.

254 host addresses, one for network address and one for broadcast address.

Class C addresses represent 12.5% of the total IPv4 unicast address space.

Default Mask: 255.255.255.0 (/24)

ITE PC v4.0


IPv4 Address Classes

Class D Addresses

A Class D address begins with binary 1110 in the first octet.

First octet range 224 to 239.

Class D address can be used to represent a group of hosts called a host group, or multicast group.

Class E Addresses First octet of an IP address begins with 1111

Class E addresses are reserved for experimental purposes and should not be used for addressing hosts or multicast groups.

ITE PC v4.0


Fill in the information…

1. 192.168.1.3 Class ________ Default Mask:_____________________

Network: _____________________ Broadcast: _____________________

Hosts: _____________________ through _____________________



Hosts: _____________________ through _____________________



Hosts: _____________________ through _____________________

ITE PC v4.0


Fill in the information…

1. 192.168.1.3 Class C Default Mask: 255.255.255.0

Network: 192.168.1.0 Broadcast: 192.168.1.255

Hosts: 192.168.1.1 through 192.168.1.254

2. 1.12.100.31 Class A Default Mask: 255.0.0.0


Hosts: 1.0.0.1 through 1.255.255.254

3. 172.30.77.5 Class B Default Mask: 255.255.0.0


Hosts: 172.30.0.1. through 172.30.255.254

ITE PC v4.0


Class C Default Mask: 255.255.255.0 Network: 192.168.1.0

Class A Default Mask: 255.0.0.0 Network: 1.0.0.0

Class B Default Mask: 255.255.0.0 Network: 172.30.0.0

Class separates network from host bits

The Class determines the Base Network Mask!

1. 192.168.1.3

2. 1.12.100.31

3. 172.30.77.5

ITE PC v4.0


Know the classes! (Write this out)

First First Network Host

Class Bits Octet Bits Bits

A 0 0 – 127 8 24

B 10 128 - 191 16 16

C 110 192 - 223 24 8

D 1110 224 – 239

E 1111 240 -

ITE PC v4.0


IP addressing crisis

Address Depletion

Internet Routing Table Explosion

ITE PC v4.0


Classless IP Addressing

The subnet mask determines the network portion and the host portion.

Value of first octet does NOT matter (older classful IP addressing)

Classless IP Addressing is what is used within the Internet and in most internal networks.

IP Add.======= 172.16.2.5

Subnet mask=== 255.255.255.0

Subnet== 172.16.2.0

Is not the default mask

ITE PC v4.0


Example 1

Network Address: 192.168.1.0

Subnet Mask: 255.255.255.0

192.168.1.0

Network Host

Network Address in binary:

11000000.10101000.00000001.00000000

Subnet Mask in binary:

11111111.11111111.11111111.00000000

Prefix Length: /24

ITE PC v4.0


Example 2


Subnet Mask: 255.0.0.0

172.0.0.0

Network Host


10101100.00000000.00000000.00000000

Subnet Mask in binary:

11111111.00000000.00000000.00000000

Prefix Length : /8

ITE PC v4.0


Example 3


Subnet Mask: 255.255.0.0

172.0.0.0

Network Host


10101100.00000000.00000000.00000000 Subnet

Mask in binary:

11111111.11111111.00000000.00000000

Prefix Length: /16

ITE PC v4.0


Subnet Masks – Your Turn!

Underline the network portion of each address:

Network Address Subnet Mask

172.0.0.0 255.0.0.0

172.16.0.0 255.255.0.0

192.168.1.0 255.255.255.0

192.168.0.0 255.255.0.0

192.168.0.0 255.255.255.0

10.1.1.0 /24

10.2.0.0 /16

10.0.0.0 /16

What is the other portion of the address?

ITE PC v4.0


Subnet Masks – Your Turn! Underline the network portion of each address:

Network Address Subnet Mask

172.0.0.0 255.0.0.0

172.16.0.0 255.255.0.0

192.168.1.0 255.255.255.0

192.168.0.0 255.255.0.0

192.168.0.0 255.255.255.0

10.1.1.0 /24

10.2.0.0 /16

10.0.0.0 /16

What is the other portion of the address?

Host portion for host addresses


ITE PC v4.0

Chapter 1 25

Network / Broadcast Addresses


ITE PC v4.0


Types of addresses in an IPv4 network Name the three types of addresses in the network and

describe the purpose of each type

ITE PC v4.0


Network / Broadcast Addresses - Network address :

the first IP address in it which all host part bits = 0

- Broadcast address:

the last IP address in the network which all host part bits = 1

no. of host bits

- other addresses are host addresses = 2 - 2

-Here are some examples:

Class Network Address Broadcast Address

A 12.0.0.0 12.255.255.255

B 172.16.0.0 172.16.255.255

C 192.168.1.0 192.168.1.255

ITE PC v4.0


Types of Addresses

Network address - The address by which we refer to the network

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

Host addresses - The addresses assigned to the end devices in the network

Network

Addresses have

all 0’s in the host

portion.

ITE PC v4.0


Types of Addresses




Broadcast

Addresses have

all 1’s in the host

portion.

ITE PC v4.0


Types of Addresses




Host Addresses

can not have all

0’s or all 1’s in the

host portion.

ITE PC v4.0


Bringing it all together

Broadcast IP Address

Convert these addresses and masks to Binary (to be used later)

Network: 10.1.1.0 00001010.00000001.00000001.00000000

Mask: /24 11111111.11111111.11111111.00000000

Bcast: 10.1.1.255 00001010.00000001.00000001.11111111

Network: 10.2.0.0 00001010.00000010.00000000.00000000

Mask: /16 11111111.11111111.00000000.00000000

Bst:10.2.255.255 00001010.00000010.11111111.11111111

Network 10.0.0.0 00001010.00000000.00000000.00000000

Mask: /16 11111111.11111111.00000000.00000000

Bcast10.0.255.255 00001010.00000000.11111111.11111111

ITE PC v4.0


Range of hosts – Your Turn! Network Address Subnet Mask Broadcast Address

172.0.0.0 255.0.0.0 172.255.255.255

172.0.0.1 through 172.255.255.254

172.16.0.0 255.255.0.0 172.16.255.255

172.16.0.1 through 172.16.255.254

192.168.1.0 255.255.255.0 192.168.1.255

192.168.1.1 through 192.168.1.254

192.168.0.0 255.255.0.0 192.168.255.255

192.168.0.1 through 192.168.255.254

192.168.0.0 255.255.255.0 192.168.0.255

192.168.0.1 through 192.168.0.254

ITE PC v4.0


Range of hosts – Your Turn!

Network Address Subnet Mask Broadcast Address

10.1.1.0 /24 10.1.1.255

10.1.1.1 through 10.1.1.254

10.2.0.0 /16 10.2.255.255

10.2.0.1 through 10.2.255.254

10.0.0.0 /16 10.0.255.255

10.0.0.1 through 10.0.255.254

ITE PC v4.0


Subnet Masks: Non-Natural Boundaries Subnet masks do not have to end on natural octet boundaries

172.1.16.0 10101100.00000001.00010000.00000000

255.255.240.0 11111111.11111111.11110000.00000000

172.1.16.1 10101100.00000001.00010000.00000001

172.1.16.2 10101100.00000001.00010000.00000010

172.1.16.3 10101100.00000001.00010000.00000011

…

172.1.16.255 10101100.00000001.00010000.11111111

172.1.17.0 10101100.00000001.00010001.00000000

172.1.17.1 10101100.00000001.00010001.00000001

…

172.1.31.254 10101100.00000001.00011111.11111110

ITE PC v4.0


Subnet Masks: Non-Natural Boundaries Subnet masks do not have to end on natural octet boundaries

172.1.16.0 10101100.00000001.00010000.00000000

255.255.240.0 11111111.11111111.11110000.00000000

172.1.16.1 10101100.00000001.00010000.00000001

…

172.1.31.254 10101100.00000001.00011111.11111110

172.1.31.255 10101100.00000001.00011111.11111111

(broadcast)

Number of hosts: 212 – 2 = 4,096 – 2 = 4,094 hosts

ITE PC v4.0


Subnet Masks: Non-Natural Boundaries

Subnet masks do not have to end on natural octet boundaries

192.168.1.0 11000000.10101000.00000001.00000000

255.255.255.224 11111111.11111111.11111111.11100000

192.168.1.1 11000000.10101000.00000001.00000001

192.168.1.2 11000000.10101000.00000001.00000010

192.168.1.3 11000000.10101000.00000001.00000011

…

192.168.1.29 11000000.10101000.00000001.00011101

192.168.1.30 11000000.10101000.00000001.00011110

192.168.1.31 11000000.10101000.00000001.00011111

(broadcast)

ITE PC v4.0


Subnet Masks: Non-Natural Boundaries

Subnet masks do not have to end on natural octet boundaries

192.168.1.0 11000000.10101000.00000001.00000000

255.255.255.224 11111111.11111111.11111111.11100000

192.168.1.1 11000000.10101000.00000001.00000001

…

192.168.1.30 11000000.10101000.00000001.00011110

192.168.1.31 11000000.10101000.00000001.00011111

(broadcast)

Number of hosts: 25 – 2 = 32 – 2 = 30 hosts

ITE PC v4.0


Given------------ IP Add. &subnet mask

Determine -----the network ID which this IP belongs.

------the broadcast IP Add. Of the network.

----the range of usable IP Addresses.

ITE PC v4.0


Calculating network, hosts, and broadcast addresses

ITE PC v4.0


Determine if this IP is network address or host address or broadcast address 172.16.5.0/23

Solution :

- subnet mask = 255.255.254.0

- interesting octet is 254

- hop count = 256 – 254 = 2

- The first subnet is 172.16.0.0/23

- The second subnet is 172.16.2.0/23

- The third subnet is 172.16.4.0/23

- The fourth subnet is 172.16.6.0/23

So 172.16.5.0/23 is a host address

172.16.5.0/23

ITE PC v4.0


- Which IP address should be assigned to PC B ?

A . 192.168.5.5

B . 192.168.5.32

C . 192.168.5.40

D . 192.168.5.63

E . 192.168.5.75

192.168.5.33/27

?

A

B

Answer : C

ITE PC v4.0


- Given the choices below, which address represents a unicast address?

Answer : E

A . 224.1.5.2

B . FFFF. FFFF. FFFF.

C . 192.168.24.59/30

D . 255.255.255.255

E . 172.31.128.255/18


ITE PC v4.0

Chapter 1 43

Types of addresses in an IPv4 network


ITE PC v4.0


Unicast, multicast, broadcast - types of communication

difference between limited B.C & directed B.C?

ITE PC v4.0


Reserved IPv4 address ranges

Identify the address ranges reserved for these special purposes in the IPv4 protocol

ITE PC v4.0


multicast address range

multicast address range is subdivided into different types of addresses:

reserved link local addresses(224.0.0.0 to 224.0.0.255 )

globally scoped addresses. (224.0.1.0 to 238.255.255.255)

administratively scoped addresses (239.0.0.0/8)

(limited scope addresses.)

ITE PC v4.0


Private Addresses

The private address blocks are:

10.0.0.0 to 10.255.255.255 (10.0.0.0 /8)

172.16.0.0 to 172.31.255.255 (172.16.0.0 /12)

192.168.0.0 to 192.168.255.255 (192.168.0.0 /16)

With services to translate private addresses to public addresses, hosts on a privately addressed network can have access to resources across the Internet.

Public Addresses These addresses are designed to be used in the

hosts that are publicly accessible from the Internet.

ITE PC v4.0


Public and private address

ITE PC v4.0


Special IPv4 addresses Describe the purpose of several special addresses

ITE PC v4.0


Special IPv4 addresses

Network and Broadcast Addresses

Default Route

Loopback

Link-Local Addresses

These addresses can be automatically assigned to the local host by the operating system in environments where no IP configuration is available

TEST-NET Addresses

Unlike the experimental addresses, network devices will accept these addresses in their configurations.

ITE PC v4.0


Planning to address the network Explain the importance of using a structured process to

assign IP addresses to hosts and the implications for choosing private vs. public addresses

ITE PC v4.0


Static or dynamic addressing for end user devices

Explain how end user devices can obtain addresses either statically through an administrator or dynamically through DHCP

ITE PC v4.0


Who assigns the different addresses

Internet Assigned Numbers Authority (IANA)

Registration companies are called Regional Internet Registries (RIRs)

ITE PC v4.0


ISP’s Identify different types of ISPs and their roles in

providing Internet connectivity

•The primary advantages for customers of Tier 1 ISPs are reliability and speed.

• Tier 2 ISPs generally focus on business customers.

• Tier 3 ISPs is the retail and home markets in a specific locale.

ITE PC v4.0


ISP’s

ITE PC v4.0


Overview of IPv6 Identify several changes made to the IP protocol in

IPv6 and describe the motivation for migrating from IPv4 to IPv6.

ITE PC v4.0


Simpler header -E IP v.6 packet is simpler than IP v.4. (no fragmentation field).

ITE PC v4.0


Ipv6 features

Large address space

No need for NAT/PAT

IPsec.

Transition tools

Header improvements


ITE PC v4.0

Chapter 1 59

ANDING Process.


ITE PC v4.0


Determine the network portion of the host address and the role of the subnet mask The prefix and the subnet mask are different ways of

representing the same thing - the network portion of an address.

ITE PC v4.0


ANDing- What is in our network?

Use the subnet mask and ANDing process to extract the network address from the IP address.

ITE PC v4.0


Determine the network portion of the host address and the role of the subnet mask Routers use ANDing to determine an acceptable route

for an incoming packet.

ITE PC v4.0


Determine the network portion of the host address and the role of the subnet mask An originating host must determine if a packet should

be sent directly to a host in the local network or be directed to the gateway.

ITE PC v4.0


Summary

ITE PC v4.0


Documents

Addressing the Network – IPv4 - ECED Mansoura B addresses represent 25% of the total IPv4 unicast address space. ... Addressing the Network – IPv4