AWS Certified Solutions Architect – Professional SAP-C01 – Question164

An organization is having an application which can start and stop an EC2 instance as per schedule. The organization needs the MAC address of the instance to be registered with its software. The instance is launched in EC2-CLASSIC.
How can the organization update the MAC registration every time an instance is booted?

A.
The organization should write a boot strapping script which will get the MAC address from the instance metadata and use that script to register with the application.
B. The organization should provide a MAC address as a part of the user data. Thus, whenever the instance is booted the script assigns the fixed MAC address to that instance.
C. The instance MAC address never changes. Thus, it is not required to register the MAC address every time.
D. AWS never provides a MAC address to an instance; instead the instance ID is used for identifying the instance for any software registration.

Correct Answer: A

Explanation:

Explanation: AWS provides an on demand, scalable infrastructure. AWS EC2 allows the user to launch On- Demand instances. AWS does not provide a fixed MAC address to the instances launched in EC2-CLASSIC. If the instance is launched as a part of EC2VPC, it can have an ENI which can have a fixed MAC. However, with EC2-CLASSIC, every time the instance is started or stopped it will have a new MAC address. To get this MAC, the organization can run a script on boot which can fetch the instance metadata and get the MAC address from that instance metadata. Once the MAC is received, the organization can register that MAC with the software.
Reference: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AESDG-chapter-in…