How to open a server for the Internet with a gray IP?

Question

SSH

Hello. A question arose, which I will describe using the example of creating a server for the game.
Available: gray dynamic IP, I'm behind NAT, connection through a router (router) -> ADSL modem -> PC
Desire: open access to the server from the outside for other players without buying VDS and / or white IP (in general, maximum crutches, the main thing is that everyone it worked :) )
What actions did I take: Port forwarding on the router does not solve the situation, I tried it through the NO-IP utility, but the problem remained the same, no one can get access from outside.
I found an option with an ssh tunnel, for example, the ngrok service perfectly performs its task, but a significant minus is not even in a random domain, but in a non-permanent port and address that it issues. Are there alternatives for bringing the computer to the network, or can the topic with the tunnel be developed somehow?
Alas, the networks are not particularly strong, I hope for your help.
Thanks in advance.

Answer 1

Zerotier

Answer 2

so you still have a router first, then an adsl modem, or vice versa? allow everything along the path of the traffic. and on the adsl modem and on the router and on the computer, then determine if there are any applications using certain ports required by that server. and only then bother with no-ip or other ddns service. and the gray dynamics ... Rostelecom, beeline and megaphone of the norms worked as a personal opds server, did not pay for statics.