TERMINAL EMULATORS
MS Windows users need terminal emulation software to connect to skew4 and other Unix hosts. There are three different types of terminal emulators, depending on the protocol used to connect:
- Secure shell
- X-Windows emulators
- Secure File Transfer Protocol (sftp)
- Telnet (disabled on skew4 and WRDS)
Both secure shell and telnet connections provide ASCII connections, unless they are configured to do "X11 tunneling". The necessary software can be downloaded by faculty, staff and students thanks to unlimited and free-of-charge Northwestern site-licenses.
SSH connections
SSH or "secure shell" connections are the recommended method for accessing skew4, as this type of connection encrypts passwords and data, protecting your data and the network. As a matter of fact, off-campus access to skew4 can only be done by SSH.
Northwestern's Academic Technologies has a site-license for SSH Secure Shell (Windows clients and Unix servers) for campus use. Faculty, staff and students may download the setup file from:
Note that secure shell connection on skew4 and all Northwestern hosts are in port 22. SSH is not "Emacs-friendly"; key sequences that require the meta-key (ALT) must use the "Esc" key instead.
If you have a copy of ssh for windows and are setting it up, the process is simple. Simply enter the hostname and your login name followed by your password when it prompts you to. Leave the Password box checked. Hit OK and you have logged in. For more detailed information, be sure to check SSH information page.
Mac users: ssh is part of your operating system. Locate the Terminal application in your Applications > Utilities folder. Open a Terminal session and, at the prompt, type
ssh -X netid@skew4.kellogg.northwestern.edu
The "-X" switch enables X11 forwarding. This allows you to run applications with a GUI (for example, xstata or matlab)
X-Windows emulators
To use Unix applications that require a graphical user interface, users must install a X-Windows emulator.
Northwestern's Academic Technology division has a site-license for StarNet's X-Win32. The following page provides the link to the download page and instructions on how to setup the software for skew4:
License key renewal: If X-Win32 produces a message about an expired license key, you need to update the license key:
- Point your browser to avendesora.at.northwestern.edu/x-win32/, highlight and copy the license key
- Open X-Config, click on the "License" tab
- Paste the new license key; click on the "Apply" button, and on "OK" to close X-Config. X-Win32 will run as before.
Secure File Transfer Protocol (sftp)
Windows users:: An sftp client is part of SSH. When connected to a server with SSH, you can open an SFTP connection by clicking on the SFTP icon (screenshot follows). This will open a screen with two panels. The left panel displays items in your PC (the "client" in the SFTP connection) and the right panel displays items in your home directory in the server.
Mac users:: Installe Cyberduck is a good open source SFTP client.
Telnet connections
Telnet and FTP access to skew4 have been disabled for security reasons. The telnet and ftp protocols pass user IDs and passwords in plan text over the network. Hackers are able to use sniffer programs to capture and interpret them. Northwestern has disabled telnet connections on all email hosts.
To connect to skew4 or any of the university's e-mail servers, we recommend that you use secure shell.