What is CIDR in AWS

Question

I’m setting up a VPC in AWS and need to use CIDR. What is it, and how does it work?

Answer 1

Let me explain CIDR (Classless Inter-Domain Routing) in simple terms, along why CIDR is used in AWS.

CIDR is a way to assign IP addresses more flexibly. You know how every device on the internet—like your computer, phone, or server—has an IP address, which is like a unique ID? Well, CIDR helps allocate these IP addresses efficiently. Instead of assigning IP addresses one by one or in strict blocks, CIDR allows for grouping IP addresses together, making it easier for organizations to manage networks without wasting addresses.

With CIDR, networks can be divided or expanded as needed, which is useful for keeping things organized and for data to travel efficiently. So, it's like a smarter way of handing out and managing addresses across the internet!

Why CIDR is used in AWS:

• Efficient IP Allocation: CIDR helps AWS allocate IP addresses more flexibly and efficiently, avoiding wastage by allowing customized IP ranges.

• Subnetting Flexibility: CIDR enables the division of a VPC into smaller subnets for better organization and management of network resources.

• Scalability: CIDR allows for easy scaling of network infrastructure by adding or adjusting IP address ranges as needed.