AZ-305 Design infrastructure solutions Practice Question
You are designing a highly available architecture for a web application that runs on Azure VMs. The solution must distribute incoming traffic across multiple VMs in an availability set. Which TWO Azure components should you include? (Choose two.)
⚠ Common exam trap
Many candidates confuse the regional, layer-4 Azure Load Balancer with the global, layer-7 Azure Front Door or Application Gateway, or mistakenly think Traffic Manager can distribute traffic within a single region, when it is designed for cross-region DNS-based routing.
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 Load Balancer
Azure Load Balancer (A) is correct because it distributes incoming traffic across multiple VMs in an availability set at the transport layer (TCP/UDP), providing high availability by rerouting traffic away from failed instances. An availability set (D) is required to ensure VMs are placed in different fault domains and update domains, protecting against hardware failures and planned maintenance. Together, they form the core of a highly available architecture for VMs within a single Azure region.
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 this is correct
Azure Load Balancer is a layer 4 (TCP/UDP) load balancer that distributes traffic to virtual machines in a backend pool within the same Azure region. It uses health probes to detect VM availability and automatically routes traffic only to healthy instances, providing regional high availability. Because the scenario only requires distributing web traffic across VMs in one region, Load Balancer meets the requirement without introducing unnecessary global or application-layer complexity.
- ✗
Azure Traffic Manager
Why it's wrong here
Azure Traffic Manager is a DNS-based global traffic router that directs clients to endpoints across different Azure regions, using methods like priority or performance. It does not inspect or forward individual TCP/UDP connections, so it cannot distribute web traffic among VMs within a single regional backend pool. It is designed for global failover and cross-region load balancing, not regional VM load balancing.
- ✗
Azure Front Door
Why it's wrong here
Azure Front Door is a global, layer 7 application delivery network that routes HTTP/HTTPS traffic to the fastest available backend across regions, with capabilities like URL path-based routing, TLS termination, and web application firewall. It operates at the global edge and is not intended to distribute connections among VMs within a single regional VNet. For a single-region web tier, Front Door adds unnecessary global acceleration and application-layer features.
- ✓
Availability Set
Why this is correct
An Availability Set is a VM placement configuration that distributes virtual machines across multiple fault domains and update domains within an Azure datacenter, protecting against hardware failures and planned maintenance. It ensures that at least one VM remains available during outages but does not provide any traffic distribution or load balancing. In this architecture, an Availability Set works alongside Azure Load Balancer to maximize VM uptime, but it cannot replace the load-balancing function.
- ✗
Azure Application Gateway
Why it's wrong here
Azure Application Gateway is a layer 7 load balancer that provides advanced HTTP(S) routing, such as URL path-based routing, cookie-based session affinity, TLS termination, and a built-in web application firewall. It can distribute traffic to VMs, but it is designed for scenarios requiring application-layer intelligence and protection. If the architecture does not need these HTTP-specific features, the simpler layer 4 Load Balancer is the appropriate choice for regional VM traffic distribution.
Go deeper
Related to this question
About these practice questions
One of 795 original AZ-305 practice questions on Courseiva, each with a full explanation and wrong-answer analysis — not exam dumps or protected exam content. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This AZ-305 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-305 exam.