- A
Use a single NAT Gateway in one Availability Zone for internet access
Why wrong: A single NAT Gateway creates a single point of failure; deploy one per AZ.
- B
Use VPC endpoints for Amazon S3 to reduce internet dependency
Why wrong: VPC endpoints do not improve inter-instance communication fault tolerance.
- C
Configure the Auto Scaling group to launch instances in multiple Availability Zones
Auto Scaling across AZs automatically replaces failed instances and maintains capacity.
- D
Use a single Network Load Balancer in one Availability Zone
Why wrong: A single NLB in one AZ is a single point of failure; use cross-zone load balancing.
- E
Deploy EC2 instances evenly across three Availability Zones
Distributing instances across AZs ensures availability if one AZ fails.
ANS-C01 Network Design Practice Question
This ANS-C01 practice question tests your understanding of network design. 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 is designing a network architecture for a critical application that requires high availability and fault tolerance. The application will be deployed on EC2 instances in an Auto Scaling group across three Availability Zones. The instances must be able to communicate with each other across AZs. Which TWO design decisions improve the fault tolerance of the application? (Choose TWO.)
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
Configure the Auto Scaling group to launch instances in multiple Availability Zones
Options B and D are correct. Option B is correct because distributing instances across three AZs ensures that the application survives an AZ failure. Option D is correct because Auto Scaling across AZs automatically replaces failed instances. Option A is wrong because a single NAT Gateway is a single point of failure. Option C is wrong because a single NLB in one AZ is a single point of failure. Option E is wrong because VPC endpoints do not improve fault tolerance for inter-instance communication.
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
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Use a single NAT Gateway in one Availability Zone for internet access
- ✗
Use VPC endpoints for Amazon S3 to reduce internet dependency
Why it's wrong here
VPC endpoints do not improve inter-instance communication fault tolerance.
- ✓
Configure the Auto Scaling group to launch instances in multiple Availability Zones
Why this is correct
Auto Scaling across AZs automatically replaces failed instances and maintains capacity.
Related concept
Static NAT maps one inside address to one outside address.
- ✗
Use a single Network Load Balancer in one Availability Zone
Why it's wrong here
A single NLB in one AZ is a single point of failure; use cross-zone load balancing.
- ✓
Deploy EC2 instances evenly across three Availability Zones
Why this is correct
Distributing instances across AZs ensures availability if one AZ fails.
Related concept
Static NAT maps one inside address to one outside address.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
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
How to think about this question
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.
KKey Concepts to Remember
- Static NAT maps one inside address to one outside address.
- PAT allows many inside hosts to share one public address using ports.
- Inside local and inside global describe the private and translated addresses.
- NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
- Identify inside and outside interfaces first.
- Check whether the scenario needs static NAT, dynamic NAT or PAT.
- Do not confuse NAT matching ACLs with normal packet-filtering intent.
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
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
What to study next
Got this wrong? Here's your next step.
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 ANS-C01 NAT questions on configuration and troubleshooting.
- →
Network Design — study guide chapter
Learn the concepts, then practise the questions
- →
Network Design 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 Design — This question tests Network Design — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: Configure the Auto Scaling group to launch instances in multiple Availability Zones — Options B and D are correct. Option B is correct because distributing instances across three AZs ensures that the application survives an AZ failure. Option D is correct because Auto Scaling across AZs automatically replaces failed instances. Option A is wrong because a single NAT Gateway is a single point of failure. Option C is wrong because a single NLB in one AZ is a single point of failure. Option E is wrong because VPC endpoints do not improve fault tolerance for inter-instance communication.
What should I do if I get this ANS-C01 question wrong?
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 ANS-C01 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
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
More ANS-C01 practice questions
- 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 global e-commerce company uses a hub-and-spoke network topology with a transit VPC in us-east-1. Each spoke VPC has an…
- A company is designing a multi-VPC architecture in the same region. The VPCs need to communicate with each other using p…
- A company is deploying an application that requires low-latency communication between EC2 instances in two different AWS…
Last reviewed: Jun 20, 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.