What type of firewall protects application servers from HTTP traffic?

A Web Application Firewall (WAF) is specifically designed to protect web applications by filtering and monitoring HTTP traffic between a web application and the internet. It operates at the application layer of the OSI model, which allows it to inspect the content of HTTP requests and responses. This enables a WAF to identify and block threats such as SQL injection, cross-site scripting (XSS), and other vulnerabilities that target the application layer. By focusing on the nuances of application data, a WAF can provide tailored rules and protections suited for web applications, making it the ideal choice for safeguarding application servers from HTTP traffic.

In contrast, other choices serve different functions. A network firewall operates primarily at the network layer and focuses on filtering traffic based on IP addresses and ports rather than the specific behaviors of web application traffic. An application gateway, while it can provide some level of application-level protection, is more commonly used to manage traffic between internal networks and external services rather than providing the specific protections associated with a WAF. A proxy server can act as an intermediary between a client and a server and might offer some security benefits, but it does not specifically address the application-layer threats that a WAF is designed to combat.