How to make the server accessible via external ip?

Question

Computer networks

I have a remote server (VDS) with a node js server application. How can I access this server via ip and port?

Answer 1

the application must listen on some port and wait for the request.
the server must be connected to the internet.
the corresponding port must NOT be closed by a firewall.
send a request to the server address, specifying the desired port, the application sends a Chootam in response.
bingo!