Question 478 of 510
Security ArchitecturemediumMultiple ChoiceObjective-mapped

Quick Answer

The answer is to implement an externalized authorization management system using a Policy Decision Point (PDP) and a Policy Enforcement Point (PEP) at the application gateway. This approach enables centralized policy enforcement across multiple identity providers by decoupling authentication from authorization, allowing the PEP to intercept every access request and query the PDP for a dynamic decision based on user attributes like role, location, and device posture, regardless of whether the user authenticates through Active Directory, a cloud IdP, or self-registration. On the CompTIA SecurityX CAS-004 exam, this scenario tests your understanding of how to unify access control in a heterogeneous identity environment—a common trap is assuming that a federation server (like SAML) or a simple proxy alone can handle authorization, when in fact they only manage authentication. Remember the key distinction: authentication verifies *who* you are, while authorization determines *what* you can do, and only a dedicated PDP/PEP architecture can abstract that logic from multiple IdPs. Memory tip: think “PEP talks, PDP decides”—the PEP enforces at the gate, the PDP makes the call.

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 multinational corporation is deploying a new application that will be accessed by employees, partners, and customers. The security architecture must support single sign-on (SSO) across different identity providers (IdPs) while maintaining strict access control based on user attributes such as role, location, and device posture. The company uses Active Directory for employees, a cloud IdP for partners, and self-registration for customers. The architect needs to design a centralized policy enforcement point that can evaluate access requests from multiple IdPs and enforce dynamic access policies before granting access to the application.

Which of the following is the BEST architectural approach?

Clue words in this question

Noticing these words before you look at the options changes how you read each choice.

  • Clue: "best"

    Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

Question 1mediummultiple choice
Read the full NAT/PAT explanation →

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

Implement an externalized authorization management system (e.g., OAuth 2.0 with OpenID Connect) using a policy decision point (PDP) and a policy enforcement point (PEP) at the application gateway

A Policy Enforcement Point (PEP) integrated with a Policy Decision Point (PDP) can abstract authentication from authorization, allowing unified policy regardless of IdP. Option A is wrong because relying on each IdP for authorization leads to policy fragmentation. Option B is wrong because a SAML federation server handles authentication but not authorization. Option D is wrong because a proxy alone does not provide the policy decision capabilities.

Key principle: Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.

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 a SAML/WS-Federation federation server that authenticates users and then passes the identity to the application for authorization

    Why it's wrong here

    The federation server handles authentication but the application must still implement authorization logic; no centralized policy enforcement.

  • Have each IdP enforce its own access policies and pass the authorization decision via SAML assertions

    Why it's wrong here

    This leads to inconsistent policies and does not provide a centralized view.

  • Configure a reverse proxy to authenticate users from any IdP and pass their identity to the application

    Why it's wrong here

    A reverse proxy can handle authentication but not fine-grained attribute-based authorization.

  • Implement an externalized authorization management system (e.g., OAuth 2.0 with OpenID Connect) using a policy decision point (PDP) and a policy enforcement point (PEP) at the application gateway

    Why this is correct

    This separates authentication from authorization, allows centralized attribute-based policy, and works across IdPs.

    Clue confirmation

    The clue word "best" in the question point toward this answer.

    Related concept

    Authentication checks who the user is.

Common exam traps

Common exam trap: authentication is not authorization

Logging in proves the user can authenticate. It does not automatically mean the user is allowed to enter privileged or configuration mode. Watch for AAA authorization, privilege level and command authorization details.

Detailed technical explanation

How to think about this question

This kind of question is testing the difference between identity and permission. A user may successfully log in to a router because authentication is working, but still fail to enter configuration mode because authorization is missing, misconfigured or mapped to a lower privilege level.

KKey Concepts to Remember

  • Authentication checks who the user is.
  • Authorization controls what the user is allowed to do after login.
  • Privilege levels affect access to EXEC and configuration commands.
  • AAA, TACACS+ and RADIUS can separate login success from command access.

TExam Day Tips

  • Do not assume successful login means full administrative access.
  • Look for words such as cannot enter configuration mode, privilege level, authorization or command access.
  • Separate login problems from permission problems before choosing the answer.

Key takeaway

Authentication proves identity; authorization controls what that identity can do after login. Both must work for full privileged access.

Real-world example

How this comes up in practice

A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.

What to study next

Got this wrong? Here's your next step.

Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related CAS-004 questions on access control and AAA configuration.

Related practice questions

Related CAS-004 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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FAQ

Questions learners often ask

What does this CAS-004 question test?

Security Architecture — This question tests Security Architecture — Authentication checks who the user is..

What is the correct answer to this question?

The correct answer is: Implement an externalized authorization management system (e.g., OAuth 2.0 with OpenID Connect) using a policy decision point (PDP) and a policy enforcement point (PEP) at the application gateway — A Policy Enforcement Point (PEP) integrated with a Policy Decision Point (PDP) can abstract authentication from authorization, allowing unified policy regardless of IdP. Option A is wrong because relying on each IdP for authorization leads to policy fragmentation. Option B is wrong because a SAML federation server handles authentication but not authorization. Option D is wrong because a proxy alone does not provide the policy decision capabilities.

What should I do if I get this CAS-004 question wrong?

Review Cisco AAA concepts — authentication, authorization, and accounting. Study privilege levels (0–15), command authorization under TACACS+, and how RADIUS differs. Then practise related CAS-004 questions on access control and AAA configuration.

Are there clue words in this question I should notice?

Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.

What is the key concept behind this question?

Authentication checks who the user is.

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Last reviewed: Jun 24, 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.