How to connect to ssh/VPN from a non-standard port to an external server?

Question

linux

There is a server behind a firewall with all ports forbidden, except for some. The firewall setting is not available.
http requests go through (ports 80/443 are open), but ssh fails to connect.

Let's say there is port 8888 guaranteed to be open on the firewall. How can I connect via ssh to an external server using it?

The same question about connecting to a VPN on an arbitrary port.

Answer 1

It looks like you did not understand how the firewall is configured.
If only port 8888 was open outside, you could not connect anywhere at all, because any connection outside uses a random free port to establish a session.
For example, you use a browser to go to a remote http-80 server, your browser opens some port 26482 locally.
Therefore, I assume that port 8888 is open on the contrary for listening, and you need to configure sshd so that it listens on port 8888.

Answer 2

To connect on port 8888, ssh must listen on this port - in order for ssh to listen on this port, in the ssh settings (/etc/ssh/sshd_config) you must specify to listen on this port
The same about spn

Answer 3

Read about ssh tunneling