AWS VPC Edge Routing Guide Part 3: How Packets Actually Flow Inside a VPC — IGW, NAT Gateway, Route Tables, Security Group vs NACL
The four components (IGW, NAT GW, Route Table, SG vs NACL) that decide where packets go inside a VPC and where they get blocked. The real difference between Public and Private subnets, NAT Gateway mechanics, Route Table evaluation order, the decisive split between stateful and stateless firewalls, and the common anti-patterns. The final post in the AWS VPC Edge Routing Guide series.