Build and Validate a Production-Ready AWS VPC with IPAM, Regional NAT Gateway, and Elastic Beanstalk

In this build session, we take AWS networking from design to validation. We start with a full IP address management plan using AWS IPAM, then use that plan to build a production-style VPC from the ground up. Instead of randomly creating CIDR blocks, public subnets, private subnets, and route tables, we design the network intentionally so it can scale across regions, environments, accounts, and future workloads. This time, we go beyond planning. We provision a full AWS VPC using IPAM-managed CIDRs, create public and private subnets across multiple Availability Zones, configure routing, attach the required gateways, and use the new Regional NAT Gateway pattern for outbound internet access from private workloads. To validate the entire network design, we deploy an Elastic Beanstalk application with an Application Load Balancer in the public subnets and EC2 instances running in private subnets behind an Auto Scaling Group. By the end of this session, the IPAM plan becomes a real working AWS network. 🧱 What We Built ➜ AWS IPAM with a structured pool hierarchy ➜ Root pool from RFC1918 address space ➜ Regional pools for scalable multi-region network planning ➜ Environment pools for prod, nonprod, shared, and reserved workloads ➜ Client VPC pool sized at /16 ➜ Subnet-level pools for private workloads, public workloads, private endpoints, and reserved space ➜ A production-style VPC using IPAM-allocated CIDRs ➜ Public subnets across multiple Availability Zones ➜ Private subnets across multiple Availability Zones ➜ Internet Gateway for public subnet internet access ➜ Regional NAT Gateway for private subnet outbound access ➜ Route tables for public and private traffic flow ➜ Application Load Balancer in public subnets ➜ Elastic Beanstalk environment deployed into the custom VPC ➜ Auto Scaling Group launching EC2 instances into private subnets 🔍 What We Covered ✅ Why AWS IPAM should be planned before creating VPCs ✅ How poor CIDR planning leads to overlap, peering issues, and future rework ✅ How to organize IP space by region, environment, VPC, and subnet purpose ✅ Why separating public, private, endpoint, and reserved subnet pools matters ✅ How to create a VPC using IPAM instead of hardcoded CIDRs ✅ How public subnets route traffic through an Internet Gateway ✅ How private subnets get outbound internet access through a Regional NAT Gateway ✅ How to validate subnet design using Elastic Beanstalk ✅ How an ALB can sit in public subnets while application instances stay private ✅ How this design supports scalable, production-ready AWS networking 🧩 Why This Matters Most AWS networking challenges begin with early design decisions. People create a VPC quickly, pick a random CIDR, add a few subnets, and move on. That works for a lab, but it becomes painful when you need multiple environments, multiple regions, Transit Gateway, VPC peering, hybrid connectivity, shared services, or client/account isolation. AWS IPAM helps turn IP address space into a managed cloud resource. Regional NAT Gateway simplifies the outbound path for private workloads. Elastic Beanstalk gives us a practical way to test whether the network actually works. This session connects all of them together: IPAM for planning. VPC for network foundation. Regional NAT Gateway for private outbound access. Elastic Beanstalk for real application validation. This is how you build AWS networking on purpose. — Build with Brainyl