The document discusses Internet Protocol (IP) which is used for addressing and routing in internet communication. There are two main versions of IP - IPv4 which uses 32-bit addresses written as four numbers between 0-255, providing about 4 billion possible addresses. IPv6 uses 128-bit addresses to support more devices as IPv4 addresses are running out. IP addresses identify devices and are split into host and network parts, with different IP address classes for small, medium and large networks. The document also provides methods to convert IP addresses between decimal and binary formats.

1. Internet Technology
Saman M. Almufti
Lecture 4

3. IP
• The Internet Protocol (IP) is one of the core protocols in the Network layer of the TCP/IP computer
connection model. It's used in all Internet communication to handle both addressing and routing.
• The protocol describes the use of IP addresses to uniquely identify Internet-connected devices. Just like
homes need mailing addresses to receive mail, Internet-connected devices need an IP address to receive
messages.
• When a computer sends a message to another computer, it must specify the recipient's IP address and also
include its own IP address so that the second computer can reply.

4. IP versions
Internet Protocol version 6
2001:0db8:0000:0042:0000:8a2e:0370:73
34
IPv6
Internet Protocol version 4
192.168.10.5
IPv4
There are two versions of the Internet Protocol in use today:

5. • Each IP address is split into 4 numbers, and each of those numbers can range
from 0 to 255:
[0-255].[0-255].[0-255].[0-255]
192.168.10.5
• We write those numbers in decimal, but the computer stores them in binary:
01010101 01010101 01010101 01010101
• Each number consists of 8 bits. That's why we often call them "octets."
• Each number can represent 28
• Overall, that's 232, possible values: 4,294,967,296 possible IPv4 addresses.

6. Parts in IP Address
It is comprised of two parts:
•Host: It uniquely identifies a device/machine in the
network that we can assign to each host.
•Network: It uniquely identifies the network and its class.
Subnet Mask
The meaning of Subnetting is separating the IP address into the

7. Class C address
IP Address ranges from 192 – 223 with a subnet mask of 255.255.255.0. It has 254 hosts on
each of the 2 million networks. This class address is most common and used in small business
and home networks. for example, 192.168.5.10.
Class D address
IP Address ranges from 224 -239 with no subnet mask. It is reserved for multicast groups.
for example, 224.0.0.5.
Class B address
The IP Address in Class B ranges from 128 – 191 with a subnet mask of 255.255.0.0.It
supports approx. 65,000 hosts over each of 16,000 networks. Used by medium and large-sized
networks in enterprises and organizations. for example, 130.5.4.77.
Class A address
The IP Address in this class ranges from 0 – 126 with a subnet mask of 255.0.0.0. It supports
approx.16 million hosts on each of 127 networks. Mostly used by Internet Service Providers
(ISP). for example, 10.50.13.40.
D
B
A
C
Class E address
IP Address ranges from 240 -255 with no subnet mask. It is reserved for future use, or research
and development purposes. for example, 241.0.0.1.
E

8. IP Classes Graph

9. Converting IP from Decimal to Binary
• In order to remember these values start with the number 1, go from right to left, and double that number
seven times.
• The key to this is that every single one of the values we put in that row are going to have either number
1 or number 0 assigned to it.
• To convert the IP address we will take that string of numbers and start from left to right this time.
• Compare the position value of first bit with the given number. If given number is greater than the
position value, write 0 in rough area of your worksheet. If given number is less than or equal to the
position value, write the position value.
• Add the position value of the second bit in whatever you written in first step and compare it with the
position value of the second bit. If sum is greater than the position value, skip the position value. If sum
is less than or equal to the position value, add the position value in sum.
128 64 32 16 8 4 2 1
IP: 66.130.10.2

10. Converting IP from Decimal to Binary
128 64 32 16 8 4 2 1
216=
58 =
212=
14=
Example: if we want to convert (216.58.212.14) to binary
1 1 0 1 1 0 0 0
0 0 1 1 1 0 1 0
1 1 0 1 0 1 0 0
0 0 0 0 1 1 0 0
11011000 00111010 11010100 00001100

11. IP Address