Single process listening on multiple ports and multiple processes listening on the same port

A single process listens on multiple ports

A single process creates multiple socket bindings for different ports, TCP, and UDP are all rows

multiple processes listening on the same port (multiple processes listen on same port)

The way you create a subprocess by fork can be done in other cases.

When the connection arrives, the child process, parent process can accept, this is the famous "surprise group" problem (Thundering herd problem).

NGINX's master/work processing method:

Flow of an NGINX worker process

The CLOSE-ON-EXEC flag of the FFD can be set to avoid child processes inheriting FD.