SecureShell: Difference between revisions
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By default, SSH only gives the user shell access to a host. Enabling X11 Forwarding allows users to run applications with Graphical User Interfaces. | By default, SSH only gives the user shell access to a host. Enabling X11 Forwarding allows users to run applications with Graphical User Interfaces. | ||
Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS | Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS [[OpenLAB]] using X11 Forwarding. | ||
wing:~ Ben$ ssh '''-X''' bkirz@openlab.umiacs.umd.edu | wing:~ Ben$ ssh '''-X''' bkirz@openlab.umiacs.umd.edu | ||
Revision as of 20:38, 6 February 2009
Secure Shell (or SSH) is a network protocol allowing two computers to exchange data securely over an insecure network. By default use of SSH brings the user to a terminal, but the protocol can be used for other types of data transfer such as SFTP and SCP.
Connecting to an SSH Server
Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS OpenLAB.
wing:~ Ben$ ssh bkirz@openlab.umiacs.umd.edu
This will give you access to a terminal on any one of the OpenLAB servers. Note that by default you will not have access to applications that require X11 to run.
On Windows XP or Vista hosts there are no SFTP clients installed by default. Users can install PuTTY, which will enable SSH and SFTP access.
Alternatively, all users can use the UMIACS Intranet SFTP Web Applet located here without installing any additional software.
X11 Forwarding
By default, SSH only gives the user shell access to a host. Enabling X11 Forwarding allows users to run applications with Graphical User Interfaces.
Under RedHat Linux 3, 4, and 5, and Mac OS X, the following command from a terminal will connect a client computer to the UMIACS OpenLAB using X11 Forwarding.
wing:~ Ben$ ssh -X bkirz@openlab.umiacs.umd.edu
Note: Mac users must have X11 installed in their systems for X11 forwarding to work. This can be checked by looking for X11.app in /Applications/Utilities. You can find the installer here.
Windows users can enable X11 forwarding in PuTTY by opening the PuTTY Configuration Pane, and checking the box marked "Enable X11 Forwarding" under Categories->Connection->SSH->Tunnels.
Note that the UMIACS Intranet SFTP Web Applet does not allow X11 Forwarding.
SSH Tunneling
You can tunnel one or more ports through an SSH connection such that your packets will look like they are coming from the host you are tunneling to. This is helpful for services that you would be normally blocked by a firewall.
Please see the SecureShellTunneling page for more information.