HTTP 洪水攻击是一种大规模分布式拒绝服务 (DDoS) 攻击，旨在利用 HTTP 请求使目标服务器不堪重负。
An HTTP flood attack is a type of volumetric distributed denial-of-service (DDoS) attack designed to overwhelm a targeted server with HTTP requests. Once the target has been saturated with requests and is unable to respond to normal traffic, denial-of-service will occur for additional requests from actual users.
HTTP flood attacks are a type of “layer 7” DDoS attack. Layer 7 is the application layer of the OSI model, and refers to internet protocols such as as HTTP. HTTP is the basis of browser-based internet requests, and is commonly used to load webpages or to send form contents over the Internet. Mitigating application layer attacks is particularly complex, as the malicious traffic is difficult to distinguish from normal traffic.
In order to achieve maximum efficiency, malicious actors will commonly employ or create botnets in order to maximize the impact of their attack. By utilizing many devices infected with malware, an attacker is able to leverage their efforts by launching a larger volume of attack traffic.
Other avenues for stopping HTTP floods include the use of a web application firewall (WAF), managing an IP reputation database in order to track and selectively block malicious traffic, and on-the-fly analysis by engineers. Having an advantage of scale with over 20 million Internet properties allows Cloudflare the ability to analyze traffic from a variety of sources and mitigate potential attacks with quickly updated WAF rules and other mitigation strategies to eliminate application layer DDoS traffic.Cloudflare DDoS Protection