The correct answer is to deploy an Application Load Balancer in each public subnet across multiple AZs and a NAT Gateway per AZ. This combination ensures high availability across availability zones by allowing the ALB to distribute incoming traffic to healthy targets in any AZ, while a dedicated NAT Gateway in each AZ eliminates a single point of failure for outbound traffic from private subnets. On the AWS Certified Advanced Networking Specialty ANS-C01 exam, this scenario tests your understanding of how to architect resilient multi-AZ designs, specifically the trap of relying on a single NAT Gateway, which creates a bottleneck and failure risk. A common memory tip is to think of the ALB as the front door for inbound traffic and the NAT Gateway as the back door for outbound traffic—both must be replicated per AZ to maintain fault isolation. Remember: one per AZ keeps the outage at bay.
ANS-C01 Network Management and Operations Practice Question
This ANS-C01 practice question tests your understanding of network management and operations. 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 deploying a new application across multiple Availability Zones in a VPC. The application needs to be highly available and must handle traffic from both internal users and external customers. Which TWO options should the network team implement to meet these requirements? (Choose two.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Provision a NAT Gateway in each AZ for outbound connectivity from private subnets.
Option A is correct because an ALB can route traffic to targets across multiple AZs, providing high availability. Option C is correct because NAT Gateways in each AZ allow instances in private subnets to initiate outbound traffic to the internet while maintaining high availability. Option B is wrong because a single NAT Gateway in one AZ creates a single point of failure. Option D is wrong because a Network Load Balancer is for TCP/UDP traffic, but the question does not specify protocol requirements, and ALB is more common for HTTP applications. Option E is wrong because an Internet Gateway is a single point of failure only if the VPC has only one, but IGWs are highly available by design, but the question asks for actions to implement, and IGW is already present.
Key principle: Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Attach an Internet Gateway to the VPC.
Why it's wrong here
IGW is necessary but already assumed; not a specific action for HA.
✗
Use a Network Load Balancer to distribute traffic across AZs.
Why it's wrong here
NLB is for TCP/UDP, but ALB is typically used for HTTP applications.
✓
Provision a NAT Gateway in each AZ for outbound connectivity from private subnets.
Common exam trap: usable hosts are not the same as total addresses
Subnetting questions often tempt you into counting all addresses. In normal IPv4 subnets, the network and broadcast addresses are not usable host addresses.
Detailed technical explanation
How to think about this question
Subnetting questions test whether you can identify the network, broadcast address, usable range, mask and correct subnet. Slow down enough to calculate the block size correctly.
KKey Concepts to Remember
CIDR notation defines the prefix length.
Block size helps identify subnet boundaries.
Network and broadcast addresses are not usable hosts in normal IPv4 subnets.
The required host count determines the smallest suitable subnet.
TExam Day Tips
→Write the block size before choosing the subnet.
→Check whether the question asks for hosts, subnets or a specific address range.
→Do not confuse /24, /25, /26 and /27 host counts.
Key takeaway
Count usable hosts — not total addresses — and remember that the network and broadcast addresses are not available to hosts in standard IPv4 subnets.
Real-world example
How this comes up in practice
An e-commerce site experiences heavy traffic on Black Friday and near-zero traffic during off-peak weeks. Rather than provisioning permanent large VMs, the team uses auto-scaling groups that add capacity automatically under load and reduce it overnight. Questions like this test whether you understand elasticity, availability zones, and cloud compute scaling patterns.
What to study next
Got this wrong? Here's your next step.
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related ANS-C01 subnetting questions on CIDR, address ranges, and subnet selection.
Network Management and Operations — This question tests Network Management and Operations — CIDR notation defines the prefix length..
What is the correct answer to this question?
The correct answer is: Provision a NAT Gateway in each AZ for outbound connectivity from private subnets. — Option A is correct because an ALB can route traffic to targets across multiple AZs, providing high availability. Option C is correct because NAT Gateways in each AZ allow instances in private subnets to initiate outbound traffic to the internet while maintaining high availability. Option B is wrong because a single NAT Gateway in one AZ creates a single point of failure. Option D is wrong because a Network Load Balancer is for TCP/UDP traffic, but the question does not specify protocol requirements, and ALB is more common for HTTP applications. Option E is wrong because an Internet Gateway is a single point of failure only if the VPC has only one, but IGWs are highly available by design, but the question asks for actions to implement, and IGW is already present.
What should I do if I get this ANS-C01 question wrong?
Review block sizes, usable host formulas (2^n − 2), and how to find network and broadcast addresses for /24 through /30. Then practise related ANS-C01 subnetting questions on CIDR, address ranges, and subnet selection.
What is the key concept behind this question?
CIDR notation defines the prefix length.
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.