AWS Certified SysOps Administrator – Associate (legacy) — Question 310

A user has configured ELB with two EBS backed instances. The user has stopped the instances for 1 week to save costs. The user restarts the instances after 1 week. Which of the below mentioned statements will help the user to understand the ELB and instance registration better?

Answer options

• A. There is no way to register the stopped instances with ELB
• B. The user cannot stop the instances if they are registered with ELB
• C. If the instances have the same Elastic IP assigned after reboot they will be registered with ELB
• D. The instances will automatically get registered with ELB

Correct answer: D

Explanation

When EBS-backed EC2 instances registered with an ELB are stopped, the ELB retains them in its configuration but reports their status as OutOfService. Once the instances are restarted, the ELB automatically detects that they are running again and resumes routing traffic to them without requiring manual reregistration. This behavior is independent of whether the instances use Elastic IPs or dynamic public IPs.