Custom VPC and CIDR Block
Explore how to design custom VPCs by planning CIDR blocks, selecting availability zones, and configuring public and private subnets. Understand IP address ranges and subnet types to build secure and highly available AWS networks.
A VPC is crucial to deploying and managing resources securely within AWS Regions. We can have a maximum of five VPCs in an AWS Region, including a default one.
Planning IP range for the VPC
Let’s consider an organization with offices worldwide. For now, we are planning connectivity for only one AWS Region, us-east-1. To create our own VPC, we need to take care of the following:
IP addresses range for the VPC
Number of availability zones to span the VPC
Private and public subnets and their IP ranges
When we create a VPC we need to define the CIDR block for our VPC. From the networking point of view, all the resources we create in a VPC must take IP addresses from this CIDR block. Below are a few important points to consider when defining the CIDR block:
A maximum of five CIDR blocks are allowed per VPC
A CIDR block can have a minimum size of
/28...