How to forward port without using vpn?

Question

Computer networks

There is 1 server outside the local network with a white ip, there are two clients behind nat, one client as an rdp server, the other as a client of this server.
So here is how it can be implemented without using vpn.
I’ll give you an example, this is a teamviewer, I don’t think it’s necessary to explain how it works =)
And yes, in my case you can’t use it

Answer 1

if anyone stumbles upon this topic, this article helped https://habr.com/en/post/441806/

Answer 2

Just the VPN you need. There are many different types of VPN, you can choose according to your taste. Explain what is the problem for you to organize a VPN?
If you don’t like VPN, then you can call it a tunnel, the essence does not change from changing the name.

Answer 3

You need a server that will accept a connection
when using udp, you could directly organize a channel, but I don’t know such tools for organizing vpn or a communication channel, technically there is a possibility.
If you don’t want to set up vpn, take an ssh server, it has support for port forwarding in any direction out of the box, in your case both connect to the same ssh server, with the settings for one -L port: address: port, for the other -R port: address: port, but this mechanism is not reliable, if the connection order is incorrect (or there is a reconnection during operation), the connection will not work. One way redirection can be arranged using a firewall on this iptables server, this is more reliable.
By the way, ssh also has a built-in vpn(though a little 'inferior', there is not tap but tun)

Answer 4

You need to set up a reverse proxy server on a white IP. Then, you will specify this very white address in the client settings, and it will already interact with the server behind NAT.
The only question is whether there is such a server for rdp. There are rumors that there is some kind of Remote Desktop Gateway , but I haven't checked it.

Answer 5

In the case when both clients are behind NAT, the
Teamweaver uses its own servers for the primary connection between clients, so it also goes by "vpn" (I'm exaggerating of course)