Question 1,648 of 1,705
Network DesignhardMultiple ChoiceObjective-mapped

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 has deployed an application in a VPC with public and private subnets. The application uses an Amazon RDS for MySQL database in a private subnet. To meet security requirements, the database must not be accessible from the internet. The application team needs to connect to the database for maintenance using SSH over a bastion host. Which architecture is the most secure?

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

Bastion host in a public subnet with a security group allowing SSH from the corporate IP range, and database security group allowing MySQL from the bastion host's security group

Option D is the most secure architecture because it restricts SSH access to the bastion host from only the corporate IP range, and the database security group allows MySQL (port 3306) traffic solely from the bastion host's security group. This ensures the database is never directly exposed to the internet and only accepts connections from the bastion, which itself is locked down to authorized corporate IPs. The use of security group referencing (instead of IP-based rules) provides dynamic, scalable access control that automatically applies to any instances with the bastion's security group.

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.

  • Bastion host in a public subnet with the same security group as the database, allowing SSH from the corporate IP range and MySQL from the bastion

    Why it's wrong here

    Using the same security group for both is less granular and not recommended.

  • Bastion host in a public subnet with a security group allowing SSH from 0.0.0.0/0, and database security group allowing MySQL from the bastion host's security group

    Why it's wrong here

    Allowing SSH from 0.0.0.0/0 is insecure.

  • Connect to the database directly using a Site-to-Site VPN without a bastion host

    Why it's wrong here

    While VPN is secure, the question specifies using SSH over a bastion host.

  • Bastion host in a public subnet with a security group allowing SSH from the corporate IP range, and database security group allowing MySQL from the bastion host's security group

    Why this is correct

    This is secure and follows best practices.

    Related concept

    Read the scenario before looking for a memorised answer.

Common exam traps

Common exam trap: answer the scenario, not the keyword

The trap here is that candidates often confuse security group referencing with IP-based rules, or they mistakenly think that allowing SSH from 0.0.0.0/0 is acceptable because the bastion host is the only entry point, ignoring the increased attack surface and the principle of least privilege.

Detailed technical explanation

How to think about this question

Under the hood, security group referencing in AWS allows you to specify another security group as a source in an inbound rule, which resolves to the private IP addresses of all instances associated with that source group. This is more secure than using IP-based CIDR blocks because it automatically adapts to instance scaling and avoids exposing the database to any other IPs. In a real-world scenario, if the bastion host is terminated and recreated with a new private IP, the security group reference continues to work without manual rule updates, whereas an IP-based rule would break connectivity.

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 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.

Visual reference

192.168.1.0 /24 256 addresses (254 usable) 192.168.1.0 /25 Subnet A 128 addr (126 usable) 192.168.1.128 /25 Subnet B 128 addr (126 usable) Borrowing 1 bit from host portion creates 2 subnets (/25)

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.

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.

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 — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Bastion host in a public subnet with a security group allowing SSH from the corporate IP range, and database security group allowing MySQL from the bastion host's security group — Option D is the most secure architecture because it restricts SSH access to the bastion host from only the corporate IP range, and the database security group allows MySQL (port 3306) traffic solely from the bastion host's security group. This ensures the database is never directly exposed to the internet and only accepts connections from the bastion, which itself is locked down to authorized corporate IPs. The use of security group referencing (instead of IP-based rules) provides dynamic, scalable access control that automatically applies to any instances with the bastion's security group.

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 →

How Courseiva writes practice questions · Editorial policy

Keep practising

More ANS-C01 practice questions

Last reviewed: Jul 4, 2026

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.

Loading comments…

Sign in to join the discussion.

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.