AWS Certified Advanced Networking Specialty Practice Exam

To improve response times for web access in a private subnet, what change should be made to the NAT instance?

1. Increase the instance size of the NAT

2. Replace the NAT instance with a NAT gateway

3. Add more NAT instances in the same subnet

4. Disable outbound traffic from instances

The correct answer is: Replace the NAT instance with a NAT gateway

Replacing the NAT instance with a NAT gateway is a valid approach to improve response times for web access in a private subnet. NAT gateways are a managed service that is designed to provide better performance and availability compared to NAT instances. They can scale automatically to accommodate varying levels of traffic, which helps improve response times due to their ability to handle bursts of outbound traffic more efficiently than a NAT instance. NAT gateways also offer higher throughput limits and are not subject to the same resource constraints as EC2 instances running as NAT. They eliminate the need for administrative overhead involved in managing instance types, scaling, and maintenance, thereby allowing for improved reliability and reduced latency when instances in the private subnet need access to the internet. While increasing the instance size of the NAT might provide some improvement, it may not be as effective as switching to a NAT gateway, which is specifically designed for this purpose. Adding more NAT instances could also help but introduces additional complexity and management. Disabling outbound traffic from instances would limit functionality and is not a viable solution for improving access.