AWS (Amazon Web Services) Certification Practice Exam

Where is a NAT Gateway typically placed within a VPC?

1. Inside a private subnet only

2. Within a public subnet

3. At the edge of the VPC

4. In a designated management subnet

The correct answer is: Within a public subnet

A NAT Gateway is typically placed within a public subnet of a Virtual Private Cloud (VPC). This configuration allows it to communicate with the internet while also enabling instances in private subnets to connect to the internet for updates, patches, and other services without exposing those instances directly to incoming internet traffic. By situating the NAT Gateway in a public subnet, it is assigned a public IP address, allowing it to serve as a bridge for outbound traffic. Instances in private subnets that need to access external resources can route their traffic through the NAT Gateway. This placement is essential to maintain the security posture of the private subnet while providing access to necessary resources on the internet. Other options like placing the NAT Gateway inside a private subnet would prevent it from accessing the internet entirely since private subnets do not have a public IP or direct internet connectivity. Similarly, placing it at the edge of the VPC or in a designated management subnet does not align with the NAT Gateway's primary function, which necessitates public internet access.