Azure Front Door: Secure, high performance Content Delivery


Azure Front Door: Secure, high performance Content Delivery

During the last few months, we have been developing a project for a client in which we had to cover various needs in the Azure architecture of their corporate website.

In this case, the main premise was to have a WAF (Web Application Firewall), but what about the content? What elements do we have to improve the delivery of content and thus improve the user experience with the web?

Basically, we had two Azure services:

  • Azure Gateway
  • Azure Front Door

Initially, it may seem that the choice between Azure Application Gateway and Azure Front Door is a trivial one.

Azure Application Gateway is widely known due to its wider adoption and longer market presence. However, we concluded that Azure Front Door was the more appropriate choice. Its feature set and specific functionalities convinced us that it was the ideal solution for our case.

Why was it the option we chose for this particular case?

In the following, we will explain in detail the reasons that led us to do so.

Azure Front Door is a service offered by Microsoft Azure that has the function of managing traffic flow and distributing content in web applications and cloud services. Its design focuses on addressing three fundamental aspects in this type of applications:

  • Improves performance: It works a number of features together to optimise content delivery, reduce latency and improve user experience.
  • Improves availability: By leveraging geographic redundancy, intelligent routing, fault detection and mitigation, and protection against attacks. These capabilities ensure continuous and reliable availability of your application or service to end users.
  • Enhanced Security: Offers comprehensive DDoS attack protection, managed SSL/TLS certificates, advanced authentication and authorisation, content filtering, and an integrated Web Application Firewall. These features combine to mitigate security risks, protect web applications and services, and ensure data confidentiality, integrity and availability.

front door Features

Now, let’s dive into the details to explore the features it offers:

1. Intelligent Routing

Front Door uses intelligent routing to direct requests to nearby, low-latency endpoints. This maximizes application performance by minimizing distance and potential network bottlenecks. As a result, users experience a noticeable improvement in application loading speed, contributing to a smoother and more satisfying experience.

2. Global Load Balancing

Integral and crucial function in optimizing load distribution in multi-instance application environments. It refers to the ability to distribute load efficiently. Optimizing the performance, availability, and scalability of applications in multi-instance environments. By ensuring a balanced distribution of requests, greater efficiency in the use of resources and an improved user experience are achieved at all times.

3. Automatic Scalability

Like most Azure services, Front Door allows configuration to automatically adjust the capacity of our infrastructure based on workload. This ensures adequate scalability to handle fluctuations in demand and optimize available resources.

4. Optimization of content delivery

Front Door uses caching and compression techniques to deliver static content more efficiently. So, apart from reducing load times, we will also reduce computational costs as it will not be necessary for requests to reach the AppService, as the content will be cached by Front Door.

5. Advanced Security

This is a crucial aspect that greatly influenced our decision to implement Azure Front Door. This service provides us with an additional layer of protection by acting as a single point of entry to our web applications. By configuring Front Door, we can take advantage of several security measures, including:

WAF Rules (Web Application Firewall) Front Door allows us to set web application firewall rules to protect our applications against common threats. Such as SQL injection attacks, cross-site scripting (XSS), and other types of application-level attacks. These rules help detect and block malicious activity, ensuring the integrity and confidentiality of our data.
DDoS Protection (Denial of Service) Azure Front Door protects against distributed denial of service (DDoS) attacks. By functioning as a gateway layer, Front Door can mitigate and filter unwanted traffic. Protecting our web applications and ensuring their availability even during DDoS attacks.
Use of SSL and TLSFront Door supports the configuration of SSL/TLS certificates to enable secure connections between users and our applications. This ensures that transmitted information is encrypted and protected against unauthorized interception or tampering.
Protection against code injection attacksFront Door protects against code injection attacks, preventing the execution of malicious code in our applications. Security measures such as input validation and prevention of unauthorized code execution prevent attacks and ensure the integrity of applications and data.
Here is a clear example of using a single point of entry, improving security:

If we look closely at these two architectures in which Azure Front Door is present, we can clearly understand that its main function is to act as the single point of entry. This means that all user requests are first directed to Front Door. This is responsible for managing and redirecting the traffic to the different services or endpoints concerned.

Generic Architecture for Web Applications
Optimized storage with logical data classification

Advantages and disadvantages of Azure Front Door

In the case we discussed at the beginning of this article, Front Door was the most appropriate choice, but it could have been another Azure service. Let’s look at the advantages and disadvantages of Azure Front Door:

Advantages of Azure Front Door

  • Improved performance: Azure Front Door uses intelligent routing and global load balancing to optimise application performance and ensure a faster experience for users.
  • Improved availability: By load balancing and redirecting requests to available endpoints, Front Door improves application availability and reduces the risk of downtime.
  • Advanced security: Front Door acts as a single point of entry and provides security features such as web application firewall (WAF) and protection against denial of service (DDoS) attacks, helping to protect the application from threats.
  • Optimized content delivery: Front Door uses caching and compression techniques to deliver static content more efficiently, reducing load times and optimising resource utilisation.

Disadvantages of Azure Front Door

  • Additional costs: Azure Front Door offers different pricing tiers (tiers) based on the network traffic and routing rules implemented. Depending on configuration and usage, it may generate additional costs compared to other solutions. It will also be affected by the region and the amount of data served in Azure. It is advisable to take these factors into account when evaluating the total cost of using Azure Front Door.
  • Complex initial setup: Properly configuring and tuning Front Door can require technical expertise and experience in managing cloud services. Initial setup can be complex for those unfamiliar with the Azure platform.
Improved performanceAdditional cost
Improved availabilityComplex Initial Configuration
Enhanced Security

What about Azure Application Gateway?

We mentioned that our choice was Front Door, but we also considered using Azure Application Gateway. Both services are designed to optimize the delivery of content in the cloud. Although a detailed comparison of both services would require a separate article, we can provide an overview of their differences.


As we have seen so far Azure Front Door focuses on improving performance, availability, and security through features such as intelligent routing, global load balancing, automatic scalability, and advanced security. It is designed to act as a single point of entry for our web applications, prioritizing the optimisation of content delivery.


Azure Application Gateway, on the other hand, focuses on web application routing and application-level load balancing. It provides a solution to manage traffic and improve the security, performance, and availability of web applications.

In our project, we chose Azure Front Door because of its comprehensive approach to optimizing content delivery, which was a priority for us. The choice between the two services will depend on the specific requirements and needs of each project and the web applications to be implemented.

We can say that the strength of Front Door is content, a Content Delivery Network (CDN). In addition to load balancing (NLB) being the strength of Azure Application Gateway.

In conclusion…

After presenting the Azure Gateway and Azure Front Door services, we discussed that Azure Front Door is an ideal solution to meet the needs of a corporate website. In addition to its advanced cloud performance, availability, and security features.

It offers intelligent routing, global load balancing, automatic scalability, and advanced security. In addition, it optimizes content delivery through caching and compression. Considering the cost and complexity of the deployment, as is typical for Azure services.

Azure Front Door was chosen over Azure Application Gateway because of its capability as a Content Delivery Network (CDN). On the other hand, Azure Application Gateway excels at load balancing (NLB) and web application routing.

In short, Azure Front Door was the right choice. This is due to its features that improved content delivery, performance, and security.

Oriol Fernandez – Product Owner at Itequia