TCP/IP Address and Subnetting – Part 1

This presentation is the first in four part series on TCP/IP Addressing Subnetting.

This is the first in the series of four videos on TCP/IP addressing and subnetting and it would be a brief introduction. One reason why people find this topic very difficult is because they don’t give attention to the basics. What I mean is that the first part is like a prerequisite and it has to do with a little mathematics (don’t get scared, it is really easy).
You need to learn the principles of converting binary to decimal. In one my computer programming articles, I talked about number bases.


The Basics

Computers on a network are assigned addresses known as IP Addresses. This addresses are made up of four parts, each part being 1byte in length.


A Word Network Address and Host Address
If you have a number of computers connected together, say 3 computers, it forms a networks ( as network of 3 computers. This network you created has an address called Network Address
In addition to that, each individual computers(also referred in the network has an address called Host Address. All these addresses are known as IP Address because they are based on the Internet Protocol.
This concepts is illustrated in the figure below


Remember that:

8bits = 1 byte

The IP addresses can be represented in Base 2 (Binary system)
The IP address can also be represented in Base 10 (Decimal system)

Either way, it is necessary to learn how to convert from decimal to binary and from binary to decimal.

Decimal to Binary conversion is highlighted in this video but decimal to binary conversion is discussed in another video.

So IP address could be something like:




Conversion From Binary to Decimal
Do not skip this part because, you’ll never be able to understand TCP/IP Addressing and subnetting if you don’t understand this conversion.
The fact is: If you know this conversion, then you will easily learn TCP/IP addressing and subnetting


Understanding Binary and Decimal
Binary numbers are based on two digits: 0 and 1
Decimal numbers are bases on 10 digits: 0 to 9 that is (0,1,2,3,4,5,6,7,8,9)

Example of binary numbers

  • 10101000 (8 bits)
  • 10110 ( 5bits)
  • 0010 ( 4 bits)

Bit stands for binary digit
Example of decimal numbers

  • 23
  • 8723
  • 234

Consider the binary number: 101010
It is made up of 6 bits.
Each of the bits in the number has a weight and the weight increases as you move from right to left.
The rightmost bit have a weight 1, the next have a weight of 2, the next 4 and so on.
This is illustrated below

To convert a binary number to decimal:
Step 1: Find the weights of all the binary digits
Step 2: Multiply each binary number with the corresponding weight
Step 3: Add the results.

The sum is the decimal equivalent

To convert 101010 to decimal, we would do something like this:
1 x 32 + 0 x 16 + 1 x 8 + 0 x 4 + 1 x 2 + 0 x 1

Exercise: Convert 111001 to decimal
Do this exercise and leave the answer in the comment below.


I hope this is very clear but you can also watch the video explanation on youtube on this link: TCP/IP Addressing, Part 1: Convert Binary To Decimal