How to find out if the server is running on a given ip address and on a given port?

Question

PHP

Interested in all types of proxy servers.
As a server with a password and without.

Answer 1

with or without a password - you won’t know
for the rest there are two scripts: ProxyJudge V2.35 and AZ Environment variables 1.04 , I specifically indicated the versions - these are the latest ones, the scripts themselves are old, no later than 2013, but nothing better has yet been invented