AWS Certified Solutions Architect – Professional SAP-C01 – Question228

An organization has developed an application which provides a smarter shopping experience. They need to show a demonstration to various stakeholders who may not be able to access the in premise application so they decide to host a demo version of the application on AWS. Consequently, they will need a fixed elastic IP attached automatically to the instance when it is launched.
In this scenario which of the below mentioned options will not help assign the elastic IP automatically?

A.
Write a script which will fetch the instance metadata on system boot and assign the public IP using that metadata.
B. Provide an elastic IP in the user data and setup a bootstrapping script which will fetch that elastic IP and assign it to the instance.
C. Create a controlling application which launches the instance and assigns the elastic IP based on the parameter provided when that instance is booted.
D. Launch instance with VPC and assign an elastic IP to the primary network interface.

Correct Answer: A

Explanation:

Explanation: EC2 allows the user to launch On-Demand instances. If the organization is using an application temporarily only for demo purposes the best way to assign an elastic IP would be: Launch an instance with a VPC and assign an EIP to the primary network interface. This way on every instance start it will have the same IP Create a bootstrapping script and provide it some metadata, such as user data which can be used to assign an EIP Create a controller instance which can schedule the start and stop of the instance and provide an EIP as a parameter so that the controller instance can check the instance boot and assign an EIP The instance metadata gives the current instance data, such as the public/private IP. It can be of no use for assigning an EIP.
Reference:
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AESDG-chapter-in…