AWS Certified Solutions Architect – Professional SAP-C01 – Question160

IAM Secure and Scalable is an organization which provides scalable and secure SAAS to its clients. They are planning to host a web server and App server on AWS VPC as separate tiers. The organization wants to implement the scalability by configuring Auto Scaling and load balancer with their app servers (middle tier) too.
Which of the below mentioned options suits their requirements?

A. Since ELB is internet facing, it is recommended to setup HAProxy as the Load balancer within the VPC.
B. Create an Internet facing ELB with VPC and configure all the App servers with it.
C. The user should make ELB with EC2-CLASSIC and enable SSH with it for security.
D. Create an Internal Load balancer with VPC and register all the App servers with it.

Correct Answer: D

Explanation:

Explanation: The Amazon Virtual Private Cloud (Amazon VPC) allows the user to define a virtual networking environment in a private, isolated section of the Amazon Web Services (AWS) cloud. The user has complete control over the virtual networking environment. Within this virtual private cloud, the user can launch AWS resources, such as an ELB, and EC2 instances. There are two ELBs available with VPC: internet facing and internal (private) ELB. For internal servers, such as App servers the organization can create an internal load balancer in their VPC and then place back-end application instances behind the internal load balancer. The internal load balancer will route requests to the back-end application instances, which are also using private IP addresses and only accept requests from the internal load balancer.
Reference: http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGui…