Using SSH

  • When using ssh on Unix, you can specify an account to login with on the remote server with the -l command line argument:
    ssh -l account_name server_name_or_ip_address

    When using a Windows or MacOS client, you usually need to specify the account with which to login with on some configuration or connection dialog window, as well as the server to connect to of course.

    By default, most ssh clients use the login name with which you logged in on your local machine to establish the connection.

  • The SSH client will try to use your public and private key pair to connect, but usually it will fall back to regular password authentification if such a key pair is not available. Also the encryption method to be used in the communication can be selected, but usually the default is OK.

  • If the connection succeeds, you get a terminal window with a (terminal) session on the remote host. All communication of this session is encrypted and safe from eavesdropping.

  • You can use an ssh key agent to avoid having to give the passphrase to your key pair each time you use ssh (see also the Setting up SSH section).

  • You can also use ssh to forward (protocols of) other applications through a safe, encrypted passage over the internet. To find out more about this forwarding (also called V(irtual) P(rivate) N(etwork) and/or tunneling) feature of ssh, consult this page.
    Usually the X11 protocol is tunneled by default, so you can use ssh as a safe channel for X11 applications.
    Other examples of using the tunneling capabilities are reading your mail, consulting a calendar of directory server,  ...

  • Consider using the -C command line switch for ssh on Unix or a similar option for the ssh client on Windows/MacOS: this compresses everything before it is sent over the network; if the network between the remote site and your local client is slow, this will improve the quality of your connection considerably, especially when using ssh as a safe tunnel for X11.

  • Use the scp and/or sftp commands to transfer files in a secure way. They are very similar to respectively rcp and ftp. Consult your documentation (man pages or help file) for more information.
    The SSH Secure Shell implementation on Windows provides a very good graphical sftp client, with which you can transfer files in a secure way from and to your Windows machine.