Azure Front Door is a global, scalable entry-point that uses the Microsoft global edge network to create fast, secure, and widely scalable web applications. The solution requires both protection against common web vulnerabilities and optimized routing for global traffic. Azure Front Door Premium tier meets these requirements by providing global load balancing to route traffic to the lowest latency backend. It also includes a fully managed Web Application Firewall (WAF) that protects applications from common exploits and vulnerabilities, such as SQL injection and cross-site scripting. This combination of features in a single service directly addresses all the stated needs.

A. Azure Application Gateway: This is a regional load balancer. While it includes a WAF, it cannot optimize traffic routing for users across multiple global regions as effectively as a global service.

B. Azure Content Delivery Network (CDN): A CDN is primarily designed to cache and serve static content from edge locations. It does not provide the required comprehensive WAF protection or dynamic traffic routing capabilities.

C. Azure Firewall: This is a stateful network firewall designed to protect Azure Virtual Network resources. It operates at Layers 3 and 4 and is not a Web Application Firewall (WAF) for protecting against web-based attacks.

1. Microsoft Documentation

"What is Azure Front Door?": "Azure Front Door is a global

scalable entry-point that uses the Microsoft global edge network... Azure Front Door works at Layer 7 (HTTP/S layer) ... Key features include: ... Global load balancing ... Web Application Firewall (WAF)".

2. Microsoft Documentation

"Azure Front Door tier comparison": This document explicitly lists the features of the Standard and Premium tiers. The table shows that the Premium tier includes "Full-featured Web Application Firewall (WAF)" with "Bot protection

" "Managed rule sets

" and "Custom rules."

3. Microsoft Documentation

"What is Azure Web Application Firewall on Azure Front Door?": "Azure Web Application Firewall (WAF) on Azure Front Door provides centralized protection for your web applications. WAF defends your web services against common exploits and vulnerabilities."

4. Microsoft Documentation

"What is Azure Application Gateway?": "Azure Application Gateway is a web traffic load balancer that enables you to manage traffic to your web applications. It's a regional service and all resources including the gateway are placed in a single virtual network." This confirms its regional scope

making it unsuitable for global traffic optimization.