Question 240 of 510
Security ArchitecturemediumMultiple ChoiceObjective-mapped

Quick Answer

The correct choice is to deploy an IPsec VPN with certificate-based authentication and integrate with a RADIUS server for role-based access control. This solution directly meets all requirements because IPsec provides both encryption and integrity protection for the data tunnel, while certificate authentication leverages the company’s internal PKI to verify each remote user’s identity without relying on pre-shared keys. The RADIUS integration is critical for enforcing IP-based network access control: after the VPN gateway authenticates the user via certificate, it queries the RADIUS server to retrieve the user’s role, which then dynamically restricts access to specific internal subnets. On the CompTIA SecurityX CAS-004 exam, this scenario tests your understanding of how to combine authentication, encryption, and authorization into a cohesive remote access architecture. A common trap is choosing a solution that provides strong encryption but lacks role-based subnet filtering, such as a simple TLS VPN without RADIUS. Remember the mnemonic “CERT-RADIUS” to link certificate-based IPsec with role-based access via RADIUS.

CAS-004 Security Architecture Practice Question

This CAS-004 practice question tests your understanding of security architecture. 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 security architect is designing a secure remote access solution for a global workforce. The company requires that all remote connections be authenticated using certificates issued by the company's internal PKI, and that the connection be encrypted and integrity-protected. Additionally, the solution must support IP-based network access control to restrict access to specific internal subnets based on the user's role. Which of the following should the architect recommend?

Question 1mediummultiple choice
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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

Deploy an IPsec VPN with certificate-based authentication and integrate with a RADIUS server for role-based access control.

Option D is correct because an IPsec VPN with certificate-based authentication satisfies the requirement for encrypted, integrity-protected connections using the company's internal PKI. Integrating with a RADIUS server enables role-based IP access control, allowing the VPN gateway to restrict access to specific internal subnets based on the user's role, which aligns with the need for IP-based network access control.

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.

  • Deploy SSH tunneling with certificate-based authentication and configure iptables rules on the bastion host.

    Why it's wrong here

    SSH tunnels are for port forwarding, not full IP routing; iptables rules are complex and not scalable.

  • Deploy an SSL/TLS VPN using client certificates and rely on the VPN client to enforce access policies.

    Why it's wrong here

    SSL VPNs are application-layer and typically cannot enforce IP subnet restrictions; policy enforcement is server-side.

  • Deploy a RDP gateway with certificate authentication and restrict access via group policies.

    Why it's wrong here

    RDP is for remote desktop sessions, not general network access; group policies cannot restrict IP subnets dynamically.

  • Deploy an IPsec VPN with certificate-based authentication and integrate with a RADIUS server for role-based access control.

    Why this is correct

    IPsec provides network-layer access, RADIUS can enforce subnet restrictions based on user role.

    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 choose SSL/TLS VPN (Option B) because it is commonly associated with certificate authentication, but they overlook the critical requirement for IP-based network access control enforced by the server, not the client.

Detailed technical explanation

How to think about this question

IPsec VPNs operate at Layer 3, encapsulating entire IP packets, which allows the VPN gateway to apply access control lists (ACLs) based on the user's RADIUS-supplied role attributes (e.g., Filter-ID or Cisco AV-pair). The RADIUS server can return a Framed-Filter or vendor-specific attribute that dynamically installs ACLs on the VPN concentrator, restricting the user's traffic to specific subnets. In contrast, SSL/TLS VPNs often rely on client-side split-tunneling or application-layer proxies, which are less granular for IP-based controls and can be bypassed.

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 junior network technician can log in to a core router but cannot reach the enable prompt or configuration mode. The AAA server is authenticating the login — but the authorisation policy only grants privilege level 1, not 15. Authentication (who you are) is working; authorisation (what you can do) is not.

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.

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FAQ

Questions learners often ask

What does this CAS-004 question test?

Security Architecture — This question tests Security Architecture — Read the scenario before looking for a memorised answer..

What is the correct answer to this question?

The correct answer is: Deploy an IPsec VPN with certificate-based authentication and integrate with a RADIUS server for role-based access control. — Option D is correct because an IPsec VPN with certificate-based authentication satisfies the requirement for encrypted, integrity-protected connections using the company's internal PKI. Integrating with a RADIUS server enables role-based IP access control, allowing the VPN gateway to restrict access to specific internal subnets based on the user's role, which aligns with the need for IP-based network access control.

What should I do if I get this CAS-004 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.

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Last reviewed: Jun 11, 2026

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This CAS-004 practice question is part of Courseiva's free CompTIA 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 CAS-004 exam.