AWS (Amazon Web Services) Certification Practice Exam

What is the main benefit of using a NAT Gateway in a public subnet?

1. It secures traffic between instances

2. It ensures that operating system updates can occur

3. It enhances the speed of data transfers

4. It allows for public access to all private resources

The correct answer is: It ensures that operating system updates can occur

The main benefit of using a NAT Gateway in a public subnet is that it allows instances in a private subnet to initiate outbound traffic to the internet while preventing unsolicited inbound traffic from the internet. This capability is crucial for enabling instances to access external services, such as downloading operating system updates and software patches, without exposing them to direct internet access. When instances in a private subnet need to perform updates or retrieve packages from the internet, they route their traffic through the NAT Gateway. The NAT Gateway acts as an intermediary, sending requests to the internet and receiving the necessary data back to pass on to the private instances. This setup maintains the security of the private instances while ensuring they can stay updated and functional. The other choices, while they may touch on aspects related to NAT Gateways and networking, do not encapsulate the core purpose of a NAT Gateway in a public subnet as effectively as the ability to allow operating system updates. Options related to security, speed, and public access do not accurately reflect the NAT Gateway's primary function in managing outbound traffic from private subnets.