VPC, subnets, and gateways

15 min · Module 3

A VPC is your isolated network. Subnets are AZ-scoped. Public subnets route to an Internet Gateway; private subnets often use a NAT Gateway for egress. Security groups are stateful; NACLs are stateless subnet firewalls.

Example / notes

# Typical three-tier VPC
# public-a / public-b     → ALB, (optional) bastion, NAT
# private-app-a/b         → ASG instances
# private-db-a/b          → RDS subnet group
# IGW on VPC · NAT in public · route tables per tier

Practice in Lab: /lab/scenarios/three-tier/

Well-Architected Framework →

Modules in this track

2. Accounts, IAM & shared responsibility
- Shared responsibility model
- IAM users, roles, and policies
3. VPC & Well-Architected basics
- VPC, subnets, and gateways
- Well-Architected Framework