Quick Answer
The answer is a security group rule blocking inbound SSH traffic. This is the most likely cause because the EC2 instance is confirmed to be in a running state, which eliminates issues like the instance being stopped or terminated, and the AWS CLI output shows no indication of a misconfigured query. When an instance is running but unreachable over SSH, the problem almost always lies in the network layer—specifically, a missing or overly restrictive inbound rule on the security group for port 22, or less commonly, a network ACL that denies the traffic. On the AWS Certified Solutions Architect Professional SAP-C02 exam, this scenario tests your ability to distinguish between compute state issues and network configuration problems, a common trap where candidates overlook security groups after seeing a healthy instance state. Remember the memory tip: “Running doesn’t mean reachable—check the port 22 rule first.”
This SAP-C02 practice question tests your understanding of continuous improvement for existing solutions. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. 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.
Refer to the exhibit. A solutions architect runs the AWS CLI command to check the state of an EC2 instance. The output shows the instance is running. However, the application team reports that the instance is unreachable over SSH. What is the MOST likely cause?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
The CLI command is querying the wrong instance
Why wrong: The query is for the first reservation and instance.
A security group rule blocks inbound SSH traffic
Security groups control inbound traffic.
The instance is in a 'stopped' state
Why wrong: The state is 'running'.
The instance does not have EBS optimization enabled
Why wrong: EBS optimization does not affect SSH.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
A security group rule blocks inbound SSH traffic
Option C is correct. The instance state is 'running', so it's not stopped or terminated. The issue is likely a security group or network ACL blocking SSH. Option A is wrong because the instance is running. Option B is wrong because the instance ID is not shown but the query is correct. Option D is wrong because EBS optimization does not affect network connectivity.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
The CLI command is querying the wrong instance
Why it's wrong here
The query is for the first reservation and instance.
A security group rule blocks inbound SSH traffic
Why this is correct
Security groups control inbound traffic.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Static NAT maps one inside address to one outside address.
The instance is in a 'stopped' state
Why it's wrong here
The state is 'running'.
The instance does not have EBS optimization enabled
Why it's wrong here
EBS optimization does not affect SSH.
Common exam traps
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Detailed technical explanation
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
A healthcare organisation deploys an application with a public-facing web tier and a private database tier. The database subnet has no public IP and only accepts connections from the web tier's security group. Questions like this test whether you can design cloud network isolation using VNets/VPCs, subnets, and security group rules.
What to study next
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related SAP-C02 NAT questions on configuration and troubleshooting.
Continuous Improvement for Existing Solutions — study guide chapter
Learn the concepts, then practise the questions
Continuous Improvement for Existing Solutions practice questions
Targeted practice on this topic area only
All SAP-C02 questions
1,746 questions across all exam domains
AWS Certified Solutions Architect Professional SAP-C02 study guide
Full concept coverage aligned to exam objectives
SAP-C02 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise SAP-C02 questions linked to Design Solutions for Organizational Complexity.
Practise SAP-C02 questions linked to Design for New Solutions.
Practise SAP-C02 questions linked to Continuous Improvement for Existing Solutions.
Practise SAP-C02 questions linked to Accelerate Workload Migration and Modernization.
Practise SAP-C02 questions linked to SAA-C03 VPC.
Practise SAP-C02 questions linked to SAA-C03 S3 lifecycle policy questions.
Practise SAP-C02 questions linked to SAA-C03 RDS Multi-AZ questions.
Practise SAP-C02 questions linked to SAA-C03 IAM policy.
Practise SAP-C02 questions linked to SAA-C03 Route 53 failover questions.
Practise SAP-C02 questions linked to SAA-C03 CloudFront.
Practise SAP-C02 questions linked to SAA-C03 NAT gateway questions.
Practise SAP-C02 questions linked to SAA-C03 VPC endpoint questions.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Continuous Improvement for Existing Solutions — This question tests Continuous Improvement for Existing Solutions — Static NAT maps one inside address to one outside address..
The correct answer is: A security group rule blocks inbound SSH traffic — Option C is correct. The instance state is 'running', so it's not stopped or terminated. The issue is likely a security group or network ACL blocking SSH. Option A is wrong because the instance is running. Option B is wrong because the instance ID is not shown but the query is correct. Option D is wrong because EBS optimization does not affect network connectivity.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related SAP-C02 NAT questions on configuration and troubleshooting.
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Static NAT maps one inside address to one outside address.
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
Last reviewed: Jun 20, 2026
This SAP-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 SAP-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.