Does the operating system have a limit on the number of open passive TCP sockets?

Question

Nginx

Help, Habr! After all, you know this for sure!
Of course, * nix-systems are of interest.

Passive = server socket, i.e. the one that listen.

And it is desirable to understand how much RAM is spent on one socket. As I understand it, this is a matter of buffer size for storing send / recv data, right?

Answer 1

There is a non-illusory and obvious limitation on listen.

Answer 2

65535 like, no?

Answer 3

/proc/sys/fs/file-max