- A
The EC2 instances are not running a web server listening on port 443.
Why wrong: The question states the app runs on EC2, but if it were not listening, the health check would fail for that reason, but the certificate issue is more specific.
- B
The ALB is configured to verify the certificate on the backend instances, and the self-signed certificate is not trusted.
ALB by default verifies backend certificates; self-signed certs cause health check failure.
- C
The security group for the EC2 instances does not allow inbound traffic from the ALB on the health check port.
Why wrong: The security group allows port 443, which is the health check port if using HTTPS.
- D
The target group health check is configured to use the same port as the traffic port (443), but the health check path is incorrect.
Why wrong: While a wrong path can cause failure, the likely issue is certificate verification.
SCS-C02 ALB target group HTTPS protocol Practice Question
This SCS-C02 practice question tests your understanding of infrastructure security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: aLB target group HTTPS protocol. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A company is deploying a new web application on AWS. The application runs on EC2 instances behind an Application Load Balancer (ALB). The security team requires that all traffic between the ALB and the EC2 instances be encrypted using TLS. The ALB uses a certificate from AWS Certificate Manager (ACM). The EC2 instances are Linux-based and have a self-signed certificate installed. The security engineer configured the ALB target group to use HTTPS on port 443, and the EC2 security group allows inbound traffic on port 443 from the ALB security group. However, when testing, the application returns a 502 Bad Gateway error. The ALB health checks are failing. What is the likely cause?
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
The ALB is configured to verify the certificate on the backend instances, and the self-signed certificate is not trusted.
The ALB can be configured to verify the backend certificate when establishing TLS connections. By default, this verification is disabled, but it can be enabled via a target group attribute. In this scenario, the security team requires encrypted traffic between ALB and EC2, and they configured the target group to use HTTPS. If the target group has certificate verification enabled (e.g., via a mutual authentication policy), the ALB will check that the backend certificate is trusted. The self-signed certificate on the EC2 instances is not trusted by the ALB, causing the TLS handshake to fail. This leads to the health checks failing and the ALB returning 502 Bad Gateway errors. The other options are less likely because the question states health checks are failing; if the web server were not running or the security group were misconfigured, the health check would also fail but the specific mention of a self-signed certificate points to certificate verification as the root cause.
Key principle: ALB target group HTTPS protocol
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The EC2 instances are not running a web server listening on port 443.
Why it's wrong here
The question states the app runs on EC2, but if it were not listening, the health check would fail for that reason, but the certificate issue is more specific.
- ✓
The ALB is configured to verify the certificate on the backend instances, and the self-signed certificate is not trusted.
Why this is correct
ALB by default verifies backend certificates; self-signed certs cause health check failure.
Related concept
ALB target group HTTPS protocol
- ✗
The security group for the EC2 instances does not allow inbound traffic from the ALB on the health check port.
Why it's wrong here
The security group allows port 443, which is the health check port if using HTTPS.
- ✗
The target group health check is configured to use the same port as the traffic port (443), but the health check path is incorrect.
Why it's wrong here
While a wrong path can cause failure, the likely issue is certificate verification.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Candidates often assume that ALB never validates backend certificates. However, ALB can be configured to verify backend certificates, and not updating the trust store with a self-signed or custom CA certificate will cause health checks to fail.
Detailed technical explanation
How to think about this question
Treat this as a scenario question. Identify the problem, the constraint, and the best action. Then compare each option against those facts.
KKey Concepts to Remember
- ALB target group HTTPS protocol
- Backend certificate validation
- 502 Bad Gateway
- Health check with HTTPS
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
ALB target group HTTPS protocol
Real-world example
How this comes up in practice
A company's IT admin needs to give a contractor read-only access to production logs without sharing account credentials. Using role-based access control (RBAC) and temporary scoped permissions — not a permanent shared password — is the correct pattern. Questions like this test whether you can apply least-privilege access across cloud identity services.
What to study next
Got this wrong? Here's your next step.
Review aLB target group HTTPS protocol, then practise related SCS-C02 questions on the same topic to reinforce the concept.
- →
Infrastructure Security — study guide chapter
Learn the concepts, then practise the questions
- →
Infrastructure Security practice questions
Targeted practice on this topic area only
- →
All SCS-C02 questions
1,748 questions across all exam domains
- →
AWS Certified Security Specialty SCS-C02 study guide
Full concept coverage aligned to exam objectives
- →
SCS-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related SCS-C02 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Threat Detection and Incident Response practice questions
Practise SCS-C02 questions linked to Threat Detection and Incident Response.
Security Logging and Monitoring practice questions
Practise SCS-C02 questions linked to Security Logging and Monitoring.
Identity and Access Management practice questions
Practise SCS-C02 questions linked to Identity and Access Management.
Management and Security Governance practice questions
Practise SCS-C02 questions linked to Management and Security Governance.
Infrastructure Security practice questions
Practise SCS-C02 questions linked to Infrastructure Security.
Data Protection practice questions
Practise SCS-C02 questions linked to Data Protection.
SCS-C02 fundamentals practice questions
Practise SCS-C02 questions linked to SCS-C02 fundamentals.
SCS-C02 scenario practice questions
Practise SCS-C02 questions linked to SCS-C02 scenario.
SCS-C02 troubleshooting practice questions
Practise SCS-C02 questions linked to SCS-C02 troubleshooting.
Practice this exam
Start a free SCS-C02 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this SCS-C02 question test?
Infrastructure Security — This question tests Infrastructure Security — ALB target group HTTPS protocol.
What is the correct answer to this question?
The correct answer is: The ALB is configured to verify the certificate on the backend instances, and the self-signed certificate is not trusted. — The ALB can be configured to verify the backend certificate when establishing TLS connections. By default, this verification is disabled, but it can be enabled via a target group attribute. In this scenario, the security team requires encrypted traffic between ALB and EC2, and they configured the target group to use HTTPS. If the target group has certificate verification enabled (e.g., via a mutual authentication policy), the ALB will check that the backend certificate is trusted. The self-signed certificate on the EC2 instances is not trusted by the ALB, causing the TLS handshake to fail. This leads to the health checks failing and the ALB returning 502 Bad Gateway errors. The other options are less likely because the question states health checks are failing; if the web server were not running or the security group were misconfigured, the health check would also fail but the specific mention of a self-signed certificate points to certificate verification as the root cause.
What should I do if I get this SCS-C02 question wrong?
Review aLB target group HTTPS protocol, then practise related SCS-C02 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
ALB target group HTTPS protocol
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Keep practising
More SCS-C02 practice questions
- A company uses AWS Organizations with multiple accounts. The security team wants to enforce that all Amazon S3 buckets a…
- A company is designing a multi-tier web application on AWS. The web tier must be accessible from the internet, but the a…
- A company is migrating a legacy application to AWS. The application requires two-way communication between the web serve…
- A security engineer is troubleshooting connectivity issues between an Amazon EC2 instance in a VPC and an on-premises se…
- A security engineer is reviewing the SQS queue policy shown in the exhibit. The queue is subscribed to an SNS topic in t…
- A company uses AWS Organizations with multiple accounts. The security team wants to ensure that all IAM users in the pro…
Last reviewed: Jun 20, 2026
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.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.