SYN packet handling in the wild

This article delves into the complexities of SYN packet handling in Linux and how Cloudflare tackles this issue. It explains that each listening TCP socket has two separate queues: the SYN Queue, which stores incoming SYN packets and handles retries; and the Accept Queue, which contains fully established connections ready to be picked up by an application. The article also discusses queue size limits, perfect backlog values, slow applications, SYN floods, and how Cloudflare mitigates these issues at scale. It concludes with a look at the evolving landscape of Linux SYN packet handling and its future prospects.