The correct answer is to apply a service control policy (SCP) that denies ec2:AttachInternetGateway at the root level of AWS Organizations. This works because SCPs act as a centralized permission guardrail, allowing you to deny internet gateway attachment across all accounts in the organization by targeting the specific API action, regardless of any IAM policies applied at the account level. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this question tests your understanding of how SCPs enforce preventive controls at the organization root or OU level, a common trap being that candidates mistakenly think IAM roles or network ACLs can block this attachment—they cannot, as IAM is per-account and security groups or NACLs only filter traffic, not resource creation. A useful memory tip: think of SCPs as the "master deny switch" for API actions across your entire AWS Organization, so for blocking internet gateways, remember "SCP stops the attach."
ANS-C01 Network Security, Compliance and Governance Practice Question
This ANS-C01 practice question tests your understanding of network security, compliance and governance. 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.
A company uses AWS Organizations to manage multiple accounts. The security team wants to ensure that no VPC in any account can have an internet gateway attached. Which option meets this requirement?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Apply a service control policy (SCP) that denies ec2:AttachInternetGateway at the root level.
Option D is correct because a service control policy (SCP) can be applied to the root or OUs to deny the ec2:AttachInternetGateway action. Option A is wrong because IAM roles are per-account and not centrally enforced. Option B is wrong because security groups do not control internet gateway attachments. Option C is wrong because network ACLs do not control internet gateway attachments.
Key principle: ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Create an IAM policy that denies ec2:AttachInternetGateway and attach it to each account's admin role.
Why it's wrong here
IAM policies are per-account and can be bypassed by users with full admin access.
✗
Use security groups to block traffic from internet gateways.
Why it's wrong here
Security groups filter traffic at the instance level, not the VPC level.
✓
Apply a service control policy (SCP) that denies ec2:AttachInternetGateway at the root level.
Why this is correct
SCPs centrally control permissions for all accounts in the organization and can deny the action.
Related concept
Standard ACLs match source addresses.
✗
Use network ACLs to block traffic from internet gateways.
Why it's wrong here
Network ACLs are stateless and can block traffic but do not prevent attachment of internet gateways.
Common exam traps
Common exam trap: ACLs stop at the first match
ACLs are processed top to bottom. The first matching entry wins, and an implicit deny usually exists at the end.
Detailed technical explanation
How to think about this question
ACL questions test precision: source, destination, protocol, port and direction. A generally correct ACL can still fail if it is applied on the wrong interface or in the wrong direction.
KKey Concepts to Remember
Standard ACLs match source addresses.
Extended ACLs can match source, destination, protocol and ports.
The first matching ACL entry is used.
There is usually an implicit deny at the end.
TExam Day Tips
→Check inbound versus outbound direction.
→Read the ACL from top to bottom.
→Look for a broader permit or deny above the intended line.
Key takeaway
ACLs process entries top to bottom and stop at the first match. Entry order and interface direction matter as much as the permit or deny statement.
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 ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related ANS-C01 ACL questions on filtering logic and placement.
Network Security, Compliance and Governance — This question tests Network Security, Compliance and Governance — Standard ACLs match source addresses..
What is the correct answer to this question?
The correct answer is: Apply a service control policy (SCP) that denies ec2:AttachInternetGateway at the root level. — Option D is correct because a service control policy (SCP) can be applied to the root or OUs to deny the ec2:AttachInternetGateway action. Option A is wrong because IAM roles are per-account and not centrally enforced. Option B is wrong because security groups do not control internet gateway attachments. Option C is wrong because network ACLs do not control internet gateway attachments.
What should I do if I get this ANS-C01 question wrong?
Review ACL processing order, placement rules (standard near destination, extended near source), and inbound vs outbound direction. Study wildcard masks and implicit deny. Then practise related ANS-C01 ACL questions on filtering logic and placement.
What is the key concept behind this question?
Standard ACLs match source addresses.
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 →
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.
This ANS-C01 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 ANS-C01 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.