- A
Change the VPC CIDR to a non-overlapping range such as 172.16.0.0/16.
Why wrong: VPC CIDR cannot be changed after creation; you would need to recreate the VPC.
- B
Create a more specific route in the VPC route table for the on-premises network that is within the 10.0.0.0/8 range but not overlapping with the VPC's subnets.
More specific routes take precedence, so traffic to specific on-premises prefixes will go via VPN even if the VPC CIDR is a superset.
- C
Use a NAT gateway to translate the VPC's IP addresses to a different IP range when communicating with on-premises.
Why wrong: NAT is for outbound internet traffic, not for resolving IP overlap in VPN connections.
- D
Use AWS Transit Gateway with a network overlay to encapsulate traffic.
Why wrong: Transit Gateway does not provide IP overlay; it uses standard routing.
ANS-C01 Network Implementation Practice Question
This ANS-C01 practice question tests your understanding of network implementation. 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 has a VPC with a CIDR of 10.0.0.0/16 and needs to connect to an on-premises network using AWS Site-to-Site VPN. The on-premises network uses 10.0.0.0/8. The company wants to ensure that traffic to on-premises from VPC does not overlap with VPC's own CIDR. Which action should be taken?
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
Create a more specific route in the VPC route table for the on-premises network that is within the 10.0.0.0/8 range but not overlapping with the VPC's subnets.
Option B is correct because creating a more specific route (e.g., 10.0.0.0/8 with a longer prefix than the VPC's /16) in the VPC route table allows traffic destined for the on-premises network to be directed through the VPN, while the VPC's own /16 CIDR remains local. AWS uses the most specific route that matches the destination IP, so a route with a longer prefix (e.g., /8) will not override the local /16 route for VPC-internal traffic, preventing overlap.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Change the VPC CIDR to a non-overlapping range such as 172.16.0.0/16.
Why it's wrong here
VPC CIDR cannot be changed after creation; you would need to recreate the VPC.
- ✓
Create a more specific route in the VPC route table for the on-premises network that is within the 10.0.0.0/8 range but not overlapping with the VPC's subnets.
- ✗
Use a NAT gateway to translate the VPC's IP addresses to a different IP range when communicating with on-premises.
- ✗
Use AWS Transit Gateway with a network overlay to encapsulate traffic.
Why it's wrong here
Transit Gateway does not provide IP overlay; it uses standard routing.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume overlapping CIDRs are impossible to route and immediately choose to change the VPC CIDR (Option A), but AWS allows overlapping ranges as long as more specific routes are used to direct traffic correctly.
Detailed technical explanation
How to think about this question
AWS VPC route tables follow the longest prefix match (LPM) rule, where a route with a more specific (longer) prefix takes precedence over a less specific (shorter) one. In this scenario, the VPC's local route for 10.0.0.0/16 is automatic and cannot be overridden, but a static route for 10.0.0.0/8 (which is less specific) will only match traffic outside the /16 range, effectively directing on-premises traffic through the VPN while keeping VPC-internal traffic local. This is a common pattern when using overlapping CIDRs with VPNs, as long as the on-premises network uses a larger aggregate range.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
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
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
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
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Network Implementation — study guide chapter
Learn the concepts, then practise the questions
- →
Network Implementation practice questions
Targeted practice on this topic area only
- →
All ANS-C01 questions
1,705 questions across all exam domains
- →
AWS Certified Advanced Networking Specialty ANS-C01 study guide
Full concept coverage aligned to exam objectives
- →
ANS-C01 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related ANS-C01 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Management and Operations practice questions
Practise ANS-C01 questions linked to Network Management and Operations.
Network Security, Compliance and Governance practice questions
Practise ANS-C01 questions linked to Network Security, Compliance and Governance.
Network Design practice questions
Practise ANS-C01 questions linked to Network Design.
Network Implementation practice questions
Practise ANS-C01 questions linked to Network Implementation.
ANS-C01 fundamentals practice questions
Practise ANS-C01 questions linked to ANS-C01 fundamentals.
ANS-C01 scenario practice questions
Practise ANS-C01 questions linked to ANS-C01 scenario.
ANS-C01 troubleshooting practice questions
Practise ANS-C01 questions linked to ANS-C01 troubleshooting.
Practice this exam
Start a free ANS-C01 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 ANS-C01 question test?
Network Implementation — This question tests Network Implementation — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Create a more specific route in the VPC route table for the on-premises network that is within the 10.0.0.0/8 range but not overlapping with the VPC's subnets. — Option B is correct because creating a more specific route (e.g., 10.0.0.0/8 with a longer prefix than the VPC's /16) in the VPC route table allows traffic destined for the on-premises network to be directed through the VPN, while the VPC's own /16 CIDR remains local. AWS uses the most specific route that matches the destination IP, so a route with a longer prefix (e.g., /8) will not override the local /16 route for VPC-internal traffic, preventing overlap.
What should I do if I get this ANS-C01 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
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
More ANS-C01 practice questions
- A financial services company has a VPC with a public subnet and a private subnet. EC2 instances in the private subnet ne…
- A company is designing a network security architecture for a multi-account environment using AWS Transit Gateway. The se…
- A company is using AWS Direct Connect to connect its on-premises network to AWS. The company wants to encrypt all traffi…
- A company uses AWS Transit Gateway to connect multiple VPCs and on-premises networks via AWS Site-to-Site VPN. The secur…
- A company runs a web application on EC2 instances behind an Application Load Balancer (ALB). The application must be acc…
- A global e-commerce company uses a hub-and-spoke network topology with a transit VPC in us-east-1. Each spoke VPC has an…
Last reviewed: Jul 4, 2026
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.