AWS Certified SysOps Administrator – Associate (legacy) — Question 300

A user has created a subnet in VPC and launched an EC2 instance within it. The user has not selected the option to assign the IP address while launching the instance. The user has 3 elastic IPs and is trying to assign one of the Elastic IPs to the VPC instance from the console. The console does not show any instance in the IP assignment screen. What is a possible reason that the instance is unavailable in the assigned IP console?

Answer options

• A. The IP address may be attached to one of the instances
• B. The IP address belongs to a different zone than the subnet zone
• C. The user has not created an internet gateway
• D. The IP addresses belong to EC2 Classic; so they cannot be assigned to VPC

Correct answer: D

Explanation

Elastic IP addresses allocated for the EC2-Classic platform are distinct from those allocated for a VPC and cannot be associated with VPC instances. To resolve this, the user must allocate a new Elastic IP specifically for use in a VPC. Other factors like Availability Zones or the presence of an Internet Gateway do not hide the instance from the console's assignment dropdown.