AZ-900 Describe Azure architecture and services Practice Question
A global e-commerce company has deployed its web application in two Azure regions: West US and East US. The company wants to automatically route end users to the region that provides the lowest latency, and if an entire region becomes unavailable, gracefully redirect all traffic to the remaining healthy region. Which Azure service should the company use?
⚠ Common exam trap
Watch out — candidates often confuse Azure Traffic Manager (DNS-based, global, multi-region) with Azure Load Balancer (regional, Layer 4) or Azure Front Door (global, Layer 7 with advanced features), failing to recognize that Traffic Manager is the simplest and most cost-effective service for DNS-level latency routing and regional failover without requiring HTTP/HTTPS traffic inspection.
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 Traffic Manager
Azure Traffic Manager is a DNS-based traffic load balancer that routes incoming DNS requests to the endpoint with the lowest latency based on the user's geographic location. It also supports automatic failover: if an entire region becomes unavailable, Traffic Manager detects the endpoint health probe failure and redirects all traffic to the remaining healthy region, meeting the company's requirements.
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 Load Balancer
Why it's wrong here
Azure Load Balancer is a region-scoped, Layer 4 (TCP/UDP) service that distributes traffic among healthy virtual machines or instances within a single Azure region, typically for high availability of backend pools. It does not provide DNS-based global routing, cannot steer users to the lowest-latency region, and has no mechanism to fail over across regions. Because the scenario requires cross-region latency-based routing for a global e-commerce application, Azure Load Balancer is fundamentally unsuitable regardless of its health probes and load-balancing rules.
When this WOULD be correct
A company needs to distribute incoming traffic among virtual machines in the same Azure region for high availability and scalability, with no requirement for global routing or latency-based steering.
- ✗
Azure Application Gateway
Why it's wrong here
Azure Application Gateway is a regional web traffic load balancer that operates at Layer 7 (HTTP/HTTPS). It can route traffic based on URL path or host headers within a region, but it does not support cross-region latency-based routing or region failover.
When this WOULD be correct
A company needs to load balance HTTP(S) traffic within a single Azure region, with requirements for SSL offloading, cookie-based session affinity, or URL path-based routing. For example, distributing web requests across multiple virtual machines in the same region while offloading SSL encryption.
- ✓
Azure Traffic Manager
Why this is correct
Azure Traffic Manager is a DNS-based traffic load balancer that works at the global level. It can route users to the endpoint with the lowest latency (performance routing) and automatically fail over to a different region if the primary endpoint is unhealthy.
- ✗
Azure Front Door
Why it's wrong here
Azure Front Door is tempting because it provides global HTTP/HTTPS load balancing, latency-based routing, and health probes for failover, directly addressing the scenario's requirements for web applications. However, its primary purpose extends to application acceleration, WAF, and CDN capabilities, operating at Layer 7. For a scenario focused purely on DNS-based global traffic distribution to the lowest latency region and failover across entire regions, a DNS-based service is generally the more direct and appropriate solution.
When this WOULD be correct
Azure Front Door would be correct if the question required global load balancing with advanced features like SSL termination, URL-based routing, web application firewall (WAF), and acceleration for web applications, and the company needed to route traffic based on the fastest response time with additional security and performance optimizations.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The AZ-900 exam frequently reuses these exact scenarios with slightly different constraints.
✓Azure Traffic ManagerCorrect answer▾
Why this is correct
Azure Traffic Manager is a DNS-based traffic load balancer that works at the global level. It can route users to the endpoint with the lowest latency (performance routing) and automatically fail over to a different region if the primary endpoint is unhealthy.
✗Azure Load BalancerWrong answer — click to see why▾
Why this is wrong here
Azure Load Balancer distributes traffic within a single region at the transport layer (TCP/UDP) and does not perform global routing based on latency or cross-region failover.
★ When this WOULD be the correct answer
A company needs to distribute incoming traffic among virtual machines in the same Azure region for high availability and scalability, with no requirement for global routing or latency-based steering.
Why candidates choose this
Candidates may confuse load balancing with global traffic routing, assuming 'load balancer' implies any traffic distribution, including across regions.
✗Azure Application GatewayWrong answer — click to see why▾
Why this is wrong here
Azure Application Gateway is a regional load balancer for HTTP(S) traffic with features like SSL termination and URL-based routing, but it cannot route traffic across Azure regions or provide global latency-based routing and regional failover.
★ When this WOULD be the correct answer
A company needs to load balance HTTP(S) traffic within a single Azure region, with requirements for SSL offloading, cookie-based session affinity, or URL path-based routing. For example, distributing web requests across multiple virtual machines in the same region while offloading SSL encryption.
Why candidates choose this
Candidates may confuse Application Gateway's layer 7 capabilities (HTTP routing) with global traffic routing, or assume its 'gateway' name implies cross-region functionality.
✗Azure Front DoorWrong answer — click to see why▾
Why this is wrong here
Azure Front Door is a global load balancer that provides application acceleration and SSL offloading, but it operates at Layer 7 (HTTP/HTTPS) and is designed for web applications with specific routing rules, not for simple latency-based global routing across regions. Traffic Manager is the correct choice because it provides DNS-based traffic routing with latency and priority profiles, which directly meets the requirement for automatic latency-based routing and regional failover.
★ When this WOULD be the correct answer
Azure Front Door would be correct if the question required global load balancing with advanced features like SSL termination, URL-based routing, web application firewall (WAF), and acceleration for web applications, and the company needed to route traffic based on the fastest response time with additional security and performance optimizations.
Why candidates choose this
Candidates may confuse Azure Front Door with Traffic Manager because both can perform global routing and failover, but Front Door offers more features, leading them to assume it is always the better choice without considering the specific requirement for simple latency-based routing without Layer 7 processing.
Analysis generated from the official AZ-900blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Go deeper
Related to this question
Learn chapter
Azure Regions and Geographies
Key term
Azure Traffic Manager
Azure Traffic Manager is a DNS-based traffic load balancer that directs incoming web traffic to the most appropriate endpoint based on performance, priority, geographic location, or a weighted distribution method.
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.
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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.