Using SSH for Remote Access

SSH (Secure Shell Protocol) gives remote access to remote computer. In its basic form it allows the execution of command lines in a terminal, if the remote machine is running an SSH server. It can also be used for remote graphical user interfaces.

Connecting to an SSH Server

For connecting to a remote machine, it needs to run an SSH server. On the client side, an SSH connection can be established without additional installations from the terminal on Linux and MAC machines and - since version 10 - from Windows. SSH receives the following command, with the remote user's credentials (username and ip-address). This user needs to be installed on the remote machine. The remote SSH server will ask for the user's password, if no SSH key has been installed.

$ ssh username@address

X11 Forwarding

X11, or the X Window System is a framework for a graphical user interface (GUI) environment, used on Unix systems. With X11 Forwarding, SSH can also be used to run applications with a GUI, remotely. When connecting to an SSH server from a Linux machine, simply add the -X argument to do so:

$ ssh -X username@address

X11 On Mac

On Mac you need to install xqwartz <https://www.xquartz.org/> to enable X11 Forwarding. Afterwards, the -X argument will enable X11 Forwarding:

$ ssh -X username@address

X11 on Windows

Although SSH will be possible from Windows' builtin Power Shell or Windows Terminal, X11 Forwarding requires Putty and additional tools:

  • install putty

  • install vcxsrv

  • enable X11 in Putty

Remote Commands

SSH can also be used to send single commands, without starting a remote session. This example launches the jack_simple_client, which plays a continuing sine tone on the remote machine.

$ ssh -t username@address 'jack_simple_server'