SCS-C02 Infrastructure Security Practice Question
A company is deploying a web application on EC2 instances behind an Application Load Balancer. The security team requires that all traffic between the ALB and the EC2 instances be encrypted. Which configuration should the engineer implement?
⚠ Common exam trap
It's easy for candidates to assume HTTPS on the listener alone is sufficient, overlooking that the target group protocol must also be HTTPS to encrypt traffic between the ALB and instances, not just between clients and the ALB.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Configure the ALB listener with HTTPS protocol and the target group with HTTPS protocol, and install SSL certificates on the EC2 instances.
It ensures end-to-end encryption between the ALB and EC2 instances. The ALB listener uses HTTPS to terminate client SSL/TLS, and the target group uses HTTPS to re-encrypt traffic to the instances, requiring SSL certificates on the EC2 instances to decrypt and re-encrypt. This satisfies the security requirement that all traffic between the ALB and EC2 instances be encrypted.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Configure the ALB listener with HTTP protocol and the target group with HTTP protocol, then use a security group to restrict traffic.
Why it's wrong here
HTTP on both listener and target group leaves ALB-to-instance traffic in plaintext; a security group filters source addresses and ports but performs no encryption. This configuration suits internal applications where the network is already trusted, not one where the security team mandates encryption in transit to the targets.
- ✗
Configure the ALB listener with HTTPS protocol and the target group with HTTP protocol.
Why it's wrong here
End-to-end encryption between ALB and instances requires the target group protocol set to HTTPS, so traffic is re-encrypted to the targets; leaving the target group on HTTP means the ALB-to-instance hop stays plaintext. HTTPS listeners are tempting because they secure client-to-ALB traffic, which is the correct choice when only edge encryption is needed.
- ✗
Configure the ALB listener with TCP protocol and the target group with TCP protocol, then install SSL certificates on the EC2 instances.
Why it's wrong here
A TCP listener forwards encrypted bytes without terminating TLS, so the ALB cannot inspect or route HTTP requests; installing certificates on instances encrypts traffic but forfeits layer-7 features and health checks. TCP passthrough suits non-HTTP protocols, not an HTTP web application needing host- or path-based routing.
- ✓
Configure the ALB listener with HTTPS protocol and the target group with HTTPS protocol, and install SSL certificates on the EC2 instances.
Why this is correct
End-to-end encryption requires TLS on both hops: an HTTPS listener terminates client TLS, while an HTTPS target group re-encrypts traffic to the instances. Installing certificates on the EC2 instances lets them present them, satisfying the requirement that ALB-to-instance traffic is encrypted.
Go deeper
Related to this question
About these practice questions
This SCS-C02 question is part of Courseiva's 1,205-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This SCS-C02 practice question is part of Courseiva's free Amazon Web Services certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the SCS-C02 exam.