Subnetting and IP addressing can be a daunting concept for beginners, especially when you are learning Networking concepts for the first time. Before starting with IP addressing and Subnetting concepts, it’s important to understand the fundamentals. And fundamentals start with Binary numbers.
Bit: A single bit that can either be 0 or 1
Byte: Eight bits (often called ‘Octet’)
To perform basic binary math, we will need a conversion chart, which looks like this:
Zeroes represent 8 bits and the number above is the decimal representation of the bits. Start from the right side with 1 and keep doubling it.
So what will 00000010 be in Decimal?
To determine the decimal equivalent of this binary sequence, place the conversion chart over these numbers.
Then add the corresponding numbers whose bit is 1 like so:
Hence 00000010 = 2 in Decimal.
Here’s another example: 10000010 = 128 + 2 = 130
If it’s all 1’s then 11111111 = 128 + 64 + 32 + 16 + 8 + 4 + 2 + 1 = 255 in Decimal
How to convert from Decimal to Binary?
So let’s say if we want to convert Decimal 154 to Binary.
For this we will use the same conversion chart, by adding the corresponding decimal numbers and see if the result of addition of two numbers is less than or equal to 154.
If the sum is greater than 154 then obviously it’s not a valid option and we put a 0 in its place. If the addition of two numbers is less than or equal to 154 then we put a 1 in its place.
The conversion chart is basically a Powers of two chart. Here’s how:
Hope you enjoyed this tutorial. Feel free to practice with any binary or decimal number you can think of.
In the next part, we are going to explore IP addressing.
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Subnetting Tutorial Part 2: Classful Subnetting
