What is Web Application Firewall?

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Azure Networking
Microsoft Azure for Solution Architects
AZ-104 Exam Preparation: Microsoft Azure Administrator
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1h 23m

This course will provide you with a foundational understanding of the different ways you can load balance traffic in Microsoft Azure. It includes guided walk-throughs from the Azure platform to give you a practical understanding of how to implement load balancing in your Azure environments.

We start by introducing the different types of load balancers, their components, and their use cases. You'll learn how to deploy a load balancer on Azure. Then we'll dive into Application Gateway and you'll learn about its features and components.
You'll also learn about Azure Front Door and how to create a Front Door instance.

We'll also take a look at Web Application Firewall, when it's used, and how to use it in conjunction with Application Gateway, Azure Front Door, and Azure CDN. Finally, you'll learn about Traffic Manager, how it works, and when to use it, as well as how to create a Traffic Manager profile.

Learning Objectives

  • Get a solid understanding of load balancing on Azure
  • Deploy a load balancer
  • Understand the features and components of Application Gateway and how to deploy it
  • Learn about Azure Front Door and how to create a Front Door instance
  • Learn about Web Application Firewall and how to deploy it on Application Gateway
  • Learn how to use Traffic Manager and how to create a Traffic Manager profile

Intended Audience

This course is intended for those who wish to learn about the different ways of performing load balancing in Azure.


To get the most out of this course, you should have a basic understanding of the Azure platform.


Welcome to web application firewall! In this lesson, I’m going to introduce you to the Azure web application firewall and what it offers.

Also known as WAF, the web application firewall in Azure offers a way to protect web applications from common vulnerabilities and exploits, like SQL injection attacks and cross-site scripting attacks.

While such attacks CAN be prevented within application coding, doing so is tedious and requires ongoing maintenance. The centralized protection that web application firewall offers vastly simplifies such protection – and it can often allow you to respond to threats far more quickly by patching known vulnerabilities instead of needing to secure every individual web application behind it.

The image on your screen depicts what a typical WAF solution looks like.

You can deploy web application firewall in conjunction with several different Azure services. It can be deployed with Azure Application Gateway, Azure Front Door, and with the Azure Content Delivery Network. The features of web application firewall can be customized for each service.

When used with Application Gateway, web application firewall offers protection for web applications against web vulnerabilities and attacks without any need for changes to the application code itself. You can even protect multiple applications simultaneously. As a matter of fact, you can host and protect up to 40 websites with web application firewall on a single instance of Application Gateway. The ability to create custom WAF policies allows you to use different policies for different sites.

The image on your screen depicts a typical WAF deployment with Application Gateway.

Just as it does when used with Application Gateway, web application firewall provides centralized protection against web threats when use with Azure Front Door. This type of global solution is deployed on edge locations on the Azure network around the world. Every incoming request to the Front Door is inspected at the edge of the network. This means attacks are prevented by WAF before they even enter your virtual network.

The image on your screen depicts a typical web application firewall deployment with Front Door.

When used with the Azure Content Delivery Network, the web application firewall can be used to protect web content itself. A global and centralized solution, WAF with the Azure CDN mitigates malicious attacks closer to their sources, rather than after they reach your network.

The image on your screen depicts a typical WAF deployment with Azure CDN.

So, to recap, web application firewall is designed to protect against various web threats, and it can be used with Application Gateway, Azure Front Door, and with the Azure Content Delivery Network. 

For more technical details on Web Application Firewall, visit the URL that you see on your screen.


About the Author
Thomas Mitchell
Learning Paths

Tom is a 25+ year veteran of the IT industry, having worked in environments as large as 40k seats and as small as 50 seats. Throughout the course of a long an interesting career, he has built an in-depth skillset that spans numerous IT disciplines. Tom has designed and architected small, large, and global IT solutions.

In addition to the Cloud Platform and Infrastructure MCSE certification, Tom also carries several other Microsoft certifications. His ability to see things from a strategic perspective allows Tom to architect solutions that closely align with business needs.

In his spare time, Tom enjoys camping, fishing, and playing poker.