Liangxu Linux

Apr 22, 2026 · Operations

How Servers Handle Millions of Concurrent Connections Despite the 65,535 TCP Port Limit

The article explains that the 65,535 TCP port limit applies only to client-side temporary ports, while server concurrency is constrained by memory, file descriptors, and CPU, and outlines practical optimization techniques such as load balancing, epoll, kernel tuning, and connection reuse to achieve million‑scale traffic.