SSH

You can use "ssh" to access your Linux account from another Linux or Mac OS computer. (It can also be installed on Windows.) Ssh provides a safe and secure connection. It can be used on-campus to connect to the CS lab computers. From off-campus, you can use ssh to access your account by using ssh to connect to the computer named math.hws.edu.

Ssh is built into almost any Linux installation. It is also a standard part of MacOS X on Apple computers. These computers have an "ssh" command that can be used on the command line. For example, to connect to csfac5.hws.edu, you would just use the command

    ssh username@csfac5.hws.edu

where username should be replaced with your user name on your math/cs Linux account. Instead of csfac5, you can use any of the computer names csfac0, csfac1, csfac2, csfac3, csfac4, csfac5, csfac6, or csfac7. To evenly distribute the load, you should randomly pick one of these computers.

This will work only if you are properly connected to the campus "Private" wireless network or to campus ethernet.

(The lab machines cslab0.hws.edu, cslab1.hws.edu, ..., cslab11.hws.edu can also be used for ssh, but those computers are more likely to be turned off or restarted without warning, which isn't nice when you are working on the computer remotely.) From off-campus, you can ssh to math.hws.edu, but not all the applications that you are used to are installed on that computer.

An ssh client logs you into a command line interface. If you want to be able to run GUI applications from the command line, you should add the option "-X" to the ssh command. For example,

     ssh  -X  username@csfac3.hws.edu

For plain text editing over an ssh connection, the old-fashioned text editor nedit is recommended. However, you can even run complex GUI applications like Firefox and Eclipse remotely (though perhaps rather slowly, depending on the speed of your connection. The GUI applications actually run on the remote computer. Your computer is just being used as a display. The "-X" option in the ssh command is what allows you to use GUI applications. (It must be an upper-case X, and there must be spaces before and after -X. If you don't want to use any GUI applications, you can leave out the -X.) Important note: For Mac OS 10.8 and later, X is not pre-installed on your computer. However, it can still be downloaded and installed; see http://xquartz.macosforge.org/landing/. Note that XQuartz is installed on the Macs in the library and Gulick labs.

It is possible to use ssh under Windows. Since ssh is not a standard part of Windows, you must install an ssh program to do so. One such program is "putty," which you can obtain from http://www.chiark.greenend.org.uk/~sgtatham/putty/. Unfortunately, you will not be able to use GUI applications through ssh under Windows, unless you find and install an X11 server on your machine.