Notes on Virtual Private Cloud

Linux clouds mostly…

This is going to be ever updating blog. I will try create a zapier or something so that these notes will keep on sync with my GitHub.

What is Virtual Private Cloud or Virtual Private Network or you can insert your cloud provider keyword…?

VPC/VPN is a network which is not connected to the internet.

Also, I will be using VPC and VPN interchangeably.

Best analogy: Consider it as an island like Australia/SriLanka which is not connected to any any other country. Same is VPC.

I will be using AWS to show how to create a simple VPC.

Without wasting any time. Let’s create a simple VPC.

Assuming you have an account with AWS, let’s try to create it.

Steps to follow:

1. Login to your aws account.
2. Once you log in, you will be redirected to your dashboard. Mine looks like this.

3. Click on VPC. You will get following screen.

You can see that AWS already gave you default VPC. Let’s not use it for now. So rename it to DO NOT USE.

==========DO NOT DELETE IT=========

Otherwise you will be needing to raise a support ticket to AWS and it will be a nightmare.

Now, you can see an orange button on top right. Click on it, you will be able to create VPC.

Once you enter create VPC screen, it will look something like this.

You can give any name tag but important part here is IPv4 CIDR.

So we are going to talk about it a bit.

CIDR stands for Classless Inter-Domain Routing. It is a method for allocating IP addresses and for IP routing that was introduced in the 1990s to address the limitations of the original classful network design.

You can read about it more in this RFC: https://datatracker.ietf.org/doc/html/rfc1918

You can use this tool to visualize CIDR: https://cidr.xyz/

We will go with AWS provided CIDR. Remember, greater the number after slash(/) less IP address we will get.

You can use this beautiful tool to get the generalized formula by looking the source code: https://github.com/yuvadm/cidr.xyz

For the demo purpose, I don’t need so many IP addresses. I will select greater number.

This is what I selected.

You can see that I can have 256 usable IP addresses except two which are CIDR BASE IP and BROADCAST IP. Which means I can alot these IP address range to 254 different objects or machines or interface that take IP address.

Here I created my first VPC.

There are a lot of grammatical mistakes in this tutorial since I am not writing with the help of any third party tool so suggestions to edit are welcome.

I am doing the cloud seminar by CloudGenius.

Here is the link for the course

cloudgenius.app

Thank You!!!