AZ-900 Describe Azure architecture and services Practice Question
Which Azure service enables accessing on-premises applications securely from anywhere without requiring VPN or changes to the network perimeter?
⚠ Common exam trap
Watch out — candidates often confuse Azure AD Application Proxy with Azure VPN Gateway, assuming that any secure remote access to on-premises resources requires a VPN tunnel, but the key differentiator is that Application Proxy works at the application layer (Layer 7) without network-level changes, while VPN Gateway operates at the network layer (Layer 3) and requires perimeter modifications.
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
✓
Azure AD Application Proxy
Azure AD Application Proxy enables secure remote access to on-premises web applications by publishing them through an external endpoint in Azure, without requiring a VPN or changes to the network perimeter. It works by establishing outbound connections from the on-premises Application Proxy connector to Azure AD, which then proxies user requests to the internal application, leveraging Azure AD for authentication and conditional 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.
- ✗
Azure VPN Gateway
Why it's wrong here
Azure VPN Gateway establishes encrypted IPsec site-to-site or point-to-site tunnels, extending a virtual network to remote users or branches. Users need to configure and connect a VPN client, and once connected they gain network-level access to on-premises resources; it doesn't offer per-application Azure AD integration like MFA or conditional access, nor does it provide seamless web app SSO without a distinct network session.
- ✓
Azure AD Application Proxy
Why this is correct
Azure AD Application Proxy publishes on-premises web applications to remote users via an outbound connector agent, so users access these apps using a single sign-on experience through Azure AD—with MFA and Conditional Access enforced before any request reaches the app. Because the connector initiates outbound connections to Azure, no inbound firewall ports are opened, and no VPN client is required; it is the correct service for VPN-free remote access to on-prem web apps.
- ✗
Azure Bastion
Why it's wrong here
Azure Bastion is a fully managed PaaS service deployed into a virtual network, offering secure HTML5-based RDP/SSH connections to Azure virtual machines without exposing public IPs. It targets VM management plane, not web applications, and doesn't provide identity-aware authentication to specific on-prem applications; it also doesn't integrate with Azure AD Application Proxy's outbound connector model.
- ✗
Azure Front Door
Why it's wrong here
Azure Front Door is a global Layer 7 load balancer that routes HTTP/HTTPS traffic across backends based on latency and priority, often used for public web applications with anycast. It cannot publish internal on-premises apps through an Azure AD identity boundary; it requires backends to be reachable via public or private endpoints and lacks the identity-aware pre-authentication that Application Proxy provides for application-specific access.
Go deeper
Related to this question
Learn chapter
Azure Regions and Geographies
Key term
User
A user is any person, system, or device that interacts with an IT service, resource, or identity system, typically authenticated through credentials and authorized to perform specific actions.
Key term
Conditional access
Conditional access is a security framework that evaluates signals like user location, device health, and risk level to grant or block access to resources in real time.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-900 practice question is part of Courseiva's free Microsoft 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 AZ-900 exam.