Azure Load Balancer vs Other Load Balancing Services
A company has an application running on Azure VMs across multiple availability zones to protect against data center failures. They need to distribute incoming traffic evenly across all VMs in a single region. Which Azure load balancing solution should they use?
Quick Answer
The answer is Azure Load Balancer. This is correct because Azure Load Balancer operates at Layer 4 of the OSI model, routing TCP and UDP traffic based on IP address and port, making it ideal for distributing incoming traffic evenly across healthy VM instances in a backend pool without inspecting application-layer data. By deploying VMs across multiple availability zones within a single region, the Load Balancer ensures high availability and even load distribution even if an entire zone fails. On the AZ-900 exam, this question tests your understanding of which service handles regional, zone-resilient traffic distribution versus global or application-layer solutions like Traffic Manager or Application Gateway. A common trap is choosing Traffic Manager for regional load balancing, but remember: Traffic Manager works at the DNS level for global traffic, while Azure Load Balancer is the correct choice for distributing traffic evenly across VMs within a single region. Memory tip: "Layer 4 for regional, Layer 7 for app-level, DNS for global."
⚠ Common exam trap
Candidates often confuse Azure Load Balancer (Layer 4, regional) with Azure Traffic Manager (DNS-based, global) or Azure Front Door (Layer 7, global), leading candidates to pick a global solution when the requirement is for regional traffic distribution.
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 operates at Layer 4 (TCP/UDP) and distributes incoming traffic across healthy VM instances in the backend pool. By deploying VMs across multiple availability zones within a single region, the Load Balancer can route traffic evenly to all zone-resilient VMs, providing high availability and load distribution without application-layer inspection.
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 operates at layer 4, distributing TCP/UDP flows across VMs within a single region and across availability zones. This matches the requirement for even regional traffic distribution, unlike zone-redundant Application Gateway or Traffic Manager, which serve different scopes.
- ✗
Azure Application Gateway
Why it's wrong here
Application Gateway operates at layer 7 for HTTP and HTTPS routing, and its zone-redundant SKUs do not provide the layer 4 distribution across zone-spread VMs described. It is tempting because it balances web traffic, and would be correct when URL-path or host-based routing and web application firewall protection are required.
When this WOULD be correct
Azure Application Gateway would be correct in a scenario where the company needs to route traffic based on URL paths (e.g., /images to one pool, /api to another), perform SSL offloading, or require Web Application Firewall (WAF) capabilities to protect against web attacks. For example: 'A company runs a web application that requires SSL termination and URL-based routing to different backend pools.'
- ✗
Azure Traffic Manager
Why it's wrong here
Traffic Manager is a DNS-based global traffic distributor, so it routes users to endpoints across regions rather than balancing connections among VMs inside one region. It is tempting because it does provide load distribution, but its axis is geographic DNS routing, not per-connection regional balancing.
When this WOULD be correct
A company has web applications deployed in multiple Azure regions (e.g., East US and West Europe) and needs to route user traffic to the closest region for low latency and high availability. Azure Traffic Manager would be the correct solution for global traffic distribution based on performance or geographic location.
- ✗
Azure Front Door
Why it's wrong here
Azure Front Door operates at layer 7 as a global HTTP content delivery and application acceleration service, distributing requests across regions rather than evenly across VMs within a single region. It is tempting because it performs load balancing, but its scope is global edge routing, not regional VM distribution.
When this WOULD be correct
A company has a global web application deployed in multiple Azure regions and needs to provide fast, secure, and scalable access to users worldwide. They require global load balancing with SSL offload, path-based routing, and web application firewall (WAF) capabilities. Azure Front Door would be the correct solution.
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 Load BalancerCorrect answer▾
Why this is correct
Azure Load Balancer operates at layer 4, distributing TCP/UDP flows across VMs within a single region and across availability zones. This matches the requirement for even regional traffic distribution, unlike zone-redundant Application Gateway or Traffic Manager, which serve different scopes.
✗Azure Application GatewayWrong answer — click to see why▾
Why this is wrong here
Azure Application Gateway is a Layer 7 load balancer that provides HTTP/HTTPS traffic management, URL-based routing, and SSL termination, but it is not designed for simple Layer 4 traffic distribution across VMs in multiple availability zones. The question requires distributing incoming traffic evenly across VMs at the network level, which is the function of Azure Load Balancer.
★ When this WOULD be the correct answer
Azure Application Gateway would be correct in a scenario where the company needs to route traffic based on URL paths (e.g., /images to one pool, /api to another), perform SSL offloading, or require Web Application Firewall (WAF) capabilities to protect against web attacks. For example: 'A company runs a web application that requires SSL termination and URL-based routing to different backend pools.'
Why candidates choose this
Candidates may confuse Application Gateway as a general load balancer because it also distributes traffic, but they overlook that it operates at Layer 7 and is specialized for web traffic, not for simple network-level load balancing across VMs.
✗Azure Traffic ManagerWrong answer — click to see why▾
Why this is wrong here
Azure Traffic Manager operates at the DNS level to distribute traffic across different regions, not within a single region. It cannot balance traffic evenly across VMs in the same region because it relies on DNS resolution and does not route based on real-time load.
★ When this WOULD be the correct answer
A company has web applications deployed in multiple Azure regions (e.g., East US and West Europe) and needs to route user traffic to the closest region for low latency and high availability. Azure Traffic Manager would be the correct solution for global traffic distribution based on performance or geographic location.
Why candidates choose this
The name 'Traffic Manager' suggests it manages traffic distribution, leading candidates to assume it can handle load balancing within a region, but it is actually a global DNS-based traffic router.
✗Azure Front DoorWrong answer — click to see why▾
Why this is wrong here
Azure Front Door is a global load balancer that operates at Layer 7 (HTTP/HTTPS) and routes traffic across regions, not within a single region. It does not distribute traffic evenly across VMs in one region across availability zones.
★ When this WOULD be the correct answer
A company has a global web application deployed in multiple Azure regions and needs to provide fast, secure, and scalable access to users worldwide. They require global load balancing with SSL offload, path-based routing, and web application firewall (WAF) capabilities. Azure Front Door would be the correct solution.
Why candidates choose this
Candidates may confuse Azure Front Door's global capabilities with regional load balancing, or think that its advanced features (like WAF and SSL termination) are needed for the simple traffic distribution described in the question.
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
Availability Zones and Region Pairs
Key term
Availability
Availability is the measure of how often a system or service is operational and accessible when needed, typically expressed as a percentage of uptime.
Key term
Region
A region is a distinct geographic location where a cloud provider operates multiple data centers that are connected by low-latency networks and provide cloud services.
About these practice questions
This AZ-900 question is part of Courseiva's 983-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
Same concept, more angles
1 more way this is tested on AZ-900
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. A company deploys a web application on Azure Virtual Machines across multiple availability zones within a single region. They need to distribute incoming network traffic across these VM instances to ensure high availability. Which Azure service should they use?
easy- ✓ A.Azure Load Balancer
- B.Azure Application Gateway
- C.Azure Traffic Manager
- D.Azure Front Door
Why A: Azure Load Balancer is the correct choice because it operates at Layer 4 (TCP/UDP) and distributes incoming traffic across healthy virtual machines within a single region, including across availability zones. It provides high availability by automatically routing traffic only to healthy VM instances based on health probes, and it supports both public and internal load balancing scenarios.
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.