Hello,

I am trying to transfer files from one Linux computer to another. Both machines are behind routers. The remote Linux machine is operated by a non-technical person who only knows how to login. The idea is to have him to type the ssh command to create an incoming tunnel.

ssh -R 9000:localhost:22 myuser@something.com

I am also trying to understand tunneling in more detail. I understand it at a higher level but what exactly is going on? What is meant by "forwarding a port"?

Also after I create the incoming tunnel. How do I login into his machine and transfer the files that we need?

Thanks

If the user runs the command on his machine it will initiate a connection to the macihne "something.com". After the login is successful the ssh server will open port 9000 on "something.com" and listen for incomming connections. Any data that is received will be passed back across the encrypted ssh session to port 22 on the user's machine.

Unless you have "GatewayPorts" set to "yes" inside the "something.com" sshd_config file then the port will ony be opened on the loopback address and so you will need to initiate the connection to port 9000 from "something.com" itself and not anothr machine on the network.