This SCS-C02 practice question tests your understanding of infrastructure security. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 security engineer runs the iptables command on an EC2 instance in a VPC. The instance has a security group that allows all outbound traffic and inbound SSH from 0.0.0.0/0, HTTP from 0.0.0.0/0, and HTTPS from 0.0.0.0/0. A user from IP 203.0.113.5 tries to connect to the instance over HTTP. What will happen?
The connection succeeds because the security group allows HTTP.
Why wrong: Security groups are stateful but iptables can override.
The connection succeeds because iptables allows HTTP from anywhere.
Why wrong: Iptables only allows HTTP from 10.0.0.0/16.
The connection is dropped by iptables.
Iptables drops the packet because the source IP is not in the allowed range.
The connection is dropped by the security group.
Why wrong: Security group allows HTTP from anywhere.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
The connection is dropped by iptables.
The iptables command shown in the exhibit (not provided here but implied to have a default DROP or REJECT policy on the INPUT chain, or a specific rule that drops HTTP traffic) overrides the security group's permissive rules. Security groups act as a virtual firewall at the instance level, but iptables operates within the instance's OS kernel netfilter framework and is evaluated after the security group. Since iptables drops the HTTP connection, the packet is discarded before reaching the application, regardless of the security group allowing HTTP from 0.0.0.0/0.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
The connection succeeds because the security group allows HTTP.
Why it's wrong here
Security groups are stateful but iptables can override.
The connection succeeds because iptables allows HTTP from anywhere.
Why it's wrong here
Iptables only allows HTTP from 10.0.0.0/16.
The connection is dropped by iptables.
Why this is correct
Iptables drops the packet because the source IP is not in the allowed range.
Related concept
Read the scenario before looking for a memorised answer.
The connection is dropped by the security group.
Why it's wrong here
Security group allows HTTP from anywhere.
Common exam traps
The trap here is that candidates assume security groups are the only firewall layer and forget that iptables rules within the instance can override them, leading them to incorrectly choose option A or B.
Detailed technical explanation
In AWS, security groups are stateful and evaluated before the instance's OS firewall (iptables/nftables). However, iptables rules are processed by the kernel's netfilter framework after the security group has already permitted the packet. A common subtlety is that iptables can be used to implement host-based access controls that are more granular than security groups, such as rate limiting or geo-blocking. In a real-world scenario, an engineer might use iptables to restrict HTTP access to a specific CIDR range even if the security group allows all inbound HTTP, creating a defense-in-depth layer.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
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.
Visual reference
What to study next
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Practise SCS-C02 questions linked to Threat Detection and Incident Response.
Practise SCS-C02 questions linked to Security Logging and Monitoring.
Practise SCS-C02 questions linked to Identity and Access Management.
Practise SCS-C02 questions linked to Management and Security Governance.
Practise SCS-C02 questions linked to Infrastructure Security.
Practise SCS-C02 questions linked to Data Protection.
Practise SCS-C02 questions linked to SCS-C02 fundamentals.
Practise SCS-C02 questions linked to SCS-C02 scenario.
Practise SCS-C02 questions linked to SCS-C02 troubleshooting.
Practice this exam
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Infrastructure Security — This question tests Infrastructure Security — Read the scenario before looking for a memorised answer..
The correct answer is: The connection is dropped by iptables. — The iptables command shown in the exhibit (not provided here but implied to have a default DROP or REJECT policy on the INPUT chain, or a specific rule that drops HTTP traffic) overrides the security group's permissive rules. Security groups act as a virtual firewall at the instance level, but iptables operates within the instance's OS kernel netfilter framework and is evaluated after the security group. Since iptables drops the HTTP connection, the packet is discarded before reaching the application, regardless of the security group allowing HTTP from 0.0.0.0/0.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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: Jul 4, 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.