Question

A software development company has hundreds of amazon ec2 instances with multiple application load balancers (albs) across multiple aws regions. the public applications hosted in their ec2 instances are accessed on their on-premises network. the company needs to reduce the number of ip addresses that it needs to regularly whitelist on the corporate firewall device. which of the following approach can be used to fulfill this requirement?

A. Create a AWS Lambda function to keep track of the IPs for all the ALBs in different Regions. Keep refreshing this list.
B. Set up a Network Load Balancer (NLB) with Elastic IPs. Register the private IPs of all the ALBs as targets to this NLB.
C. Launch AWS Global Accelerator and create endpoints for all the Regions. Register all the ALBs in different Regions to the corresponding endpoints.
D. Set up an Amazon EC2 instance, assign an Elastic IP to this EC2 instance, and configure the instance as a proxy to forward traffic to all the ALBs

Answer 1

The software development company can reduce the number of IP addresses that it regularly whitelists by using AWS Global Accelerator, which provides static IPs that serve as a fixed entry point to the public applications hosted on amazon ec2 instances behind ALBs in multiple AWS regions.

Step-by-step explanation:

The company can address the challenge of reducing the number of IP addresses it needs to whitelist on the corporate firewall by using AWS Global Accelerator. AWS Global Accelerator allows you to use static IP addresses as a fixed entry point to your applications hosted in various AWS regions, which integrates well with HTTP/HTTPS applications behind Application Load Balancers (ALBs).

Option C is the correct choice: Launch AWS Global Accelerator and create endpoints for all the Regions. By registering all the ALBs in different Regions to the corresponding endpoints, traffic is efficiently routed to the nearest application endpoint. This not only can help in reducing the number of IP addresses but also improves the performance and reliability of the user access to the applications.

Options A, B, and D are not as efficient or practical as AWS Global Accelerator for this particular use case. Lambdas (Option A) would create unnecessary overhead, NLB with Elastic IPs (Option B) does not target the cross-region aspect directly and an EC2 instance as a proxy (Option D) introduces a single point of failure and potential performance bottleneck.