CIDR blocks and IP addressing in AWS - Mini Project: Build & Apply

CIDR Blocks and IP Addressing in AWS VPC

📖 Scenario: You are setting up a simple AWS Virtual Private Cloud (VPC) for a small company. The company wants to create a network with a specific IP address range using CIDR blocks. You will create the VPC and define its CIDR block, then add a subnet with a smaller CIDR block inside the VPC.

🎯 Goal: Build an AWS VPC with a CIDR block of 10.0.0.0/16 and add a subnet inside it with a CIDR block of 10.0.1.0/24. This will help the company organize its network and control IP addressing.

📋 What You'll Learn

Create a VPC with the exact CIDR block 10.0.0.0/16

Create a subnet inside the VPC with the exact CIDR block 10.0.1.0/24

Use AWS CloudFormation syntax for resource definitions

Name the VPC resource MyVPC and the subnet resource MySubnet

💡 Why This Matters

🌍 Real World

Setting up a VPC with proper CIDR blocks is essential for organizing network IP addresses in AWS cloud environments.

💼 Career

Cloud engineers and architects often create and manage VPCs and subnets using CIDR blocks to control network segmentation and security.

1

Create the VPC with CIDR block

Create a resource called MyVPC of type AWS::EC2::VPC with the property CidrBlock set to "10.0.0.0/16".

AWS

# Your code here to create MyVPC with CIDR block 10.0.0.0/16

Need a hint?

Use the Resources section and define MyVPC with the correct type and CIDR block.

2

Add a subnet CIDR block variable

Add a parameter called SubnetCIDR with the default value "10.0.1.0/24" to hold the subnet's CIDR block.

AWS

Resources:
  MyVPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: "10.0.0.0/16"

# Your code here to add SubnetCIDR parameter with default 10.0.1.0/24

Need a hint?

Use the Parameters section to define SubnetCIDR as a string with the default value.

3

Create the subnet using the CIDR parameter

Create a resource called MySubnet of type AWS::EC2::Subnet. Set its VpcId to reference MyVPC and its CidrBlock to use the parameter SubnetCIDR.

AWS

Parameters:
  SubnetCIDR:
    Type: String
    Default: "10.0.1.0/24"

Resources:
  MyVPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: "10.0.0.0/16"

# Your code here to create MySubnet with VpcId referencing MyVPC and CidrBlock from SubnetCIDR

Need a hint?

Use !Ref to reference the VPC and the subnet CIDR parameter.

4

Add a tag to the subnet for identification

Add a Tags property to MySubnet with a tag that has Key set to Name and Value set to MySubnet.

AWS

Parameters:
  SubnetCIDR:
    Type: String
    Default: "10.0.1.0/24"

Resources:
  MyVPC:
    Type: AWS::EC2::VPC
    Properties:
      CidrBlock: "10.0.0.0/16"
  MySubnet:
    Type: AWS::EC2::Subnet
    Properties:
      VpcId: !Ref MyVPC
      CidrBlock: !Ref SubnetCIDR
      # Your code here to add Tags with Key Name and Value MySubnet

Need a hint?

Tags are a list of key-value pairs under the Tags property.