Remotely Connecting to the Linux Lab Workstations

You must be connected to the skidmore.edu network before you can connect to cslab.skidmore.edu.

If your computer is using the campus wireless (or wired) network

If you are using the campus wireless network (Skidmore Secure) from a campus building or dormitory, you are already on the skidmore.edu network. Skip to Section 2.

If you are not on campus

You must use a virtual private network (VPN) to connect to the campus network. Follow the instructions from the Skidmore Information Technology department to setup a VPN connection to Skidmore. The VPN instructions are at the bottom of this webpage.

You must NOT be on the Skidmore network in order to install and use the VPN.

You will use secure shell (SSH) to remotely access the cslab.skidmore.edu server. SSH is a network protocol that allows you to securely communicate with and run programs, including a Linux shell, on another computer connected to the network. Follow the instructions below for the operating system running on the computer you are using (your personal computer).

By default, SSH is automatically installed on all machines running MacOS.

  1. Open the Terminal application (located in Applications -> Utilities).
  2. Enter the following command: ssh USERNAME@cslab.skidmore.edu, replacing USERNAME with your CS username.
  3. When you press the enter key, SSH will establish a connection with the remote server. The first time you connect, SSH will ask you to accept the host key; enter yes.
  4. When the password prompt appears, enter your CS password and press the enter key. Note that no characters will appear on the screen as you type your password.
  5. When you are successfully connected, you will see a Linux shell prompt from cslab.

Before you can connect to the server for the first time, you will need to install and configure a SSH client.

  1. Download the latest 32-bit Windows installer for PuTTY.
  2. Run the installer.
  3. Open PuTTY.
  4. Select Connection -> Data from the menu on the left. Enter your CS username in the Auto-login username text box.
  5. Select Session from the menu on the left. Enter cslab.skidmore.edu in the Host Name text box, and cslab-skidmore in the Saved Sessions text box. Click the Save button.

Now that PuTTY is configured, you can connect to the server.

  1. Double click cslab-skidmore in the list of saved sessions.
  2. The first time you connect, PuTTY will ask you to accept the server’s host key; click Yes.
  3. When the password prompt appears, enter your CS password and press the enter key; note that no characters will appear on the screen as you type your password.
  4. When you are successfully connected, you will see a Linux shell prompt from cslab.

Most Linux distributions include SSH by default. If not, you’ll need to install it using your package manager. Then, open a terminal window and follow steps 2 through 5 of the Mac OS instructions.

If you receive an error that the host could not be resolved (or does not exist), then you should double-check that you are connected to the campus wired or wireless network or connected to campus using VPN.

If you receive a permission denied error, then you are entering the incorrect username and/or password. Email the department’s system administrator, Lisa Schermerhorn (lscherme@skidmore.edu), to obtain your username and password.

  • You must first be connected to the cslab.skidmore.edu server (see Section 2).
  • These instructions are for using the Linux command line (not for running programs with a graphical user interface). For a command line tutorial, see http://linuxcommand.org/lc3_learning_the_shell.php
  • Once you are connected to cslab.skidmore.edu, you can then ssh to one of the workstations in the CIS 237 lab (named cslabXX, where XX is a number; the machine names are shown on the label on each workstation monitor; for example: cslab01, cslab02, ...., cslab21). Most of the course software is only available on the cslabXX machines.
  • The cslabXX machines have enough power to handle a couple of concurrent users.

Visual Studio Code (VSCode) is a popular text editor that works on all major operating systems. You can download VSCode and install it on your personal computer.

After VSCode is installed, you can install an extension that allows you to remotely edit the files that are saved in your Skidmore cslab account. You must be connected to the Skidmore network (either on campus, or through the VPN) in order to use VSCode to connect to your Skidmore cslab account.

Follow these instructions for installing and configuring the Remote-SSH extension in VSCode:

  • Installation: follow the three steps in this section to make sure you have a SSH client, VSCode, and the Remote-SSH extension.
  • SSH host setup: ignore this section. You will use the cslab server provided by the department.
  • Connect to a remote host: Follow the six steps in this section to connect to the cslab server using user@cslab.skidmore.edu (where you replace “user” with your cslab username).

To run your code you can then use the SSH terminal you installed in Step 1 or you can use the terminal built into VSCode.

You can transfer files from cslab to another computer using sftp (secure file transfer protocol). These instructions discuss how to use sftp from the command line.

Follow the instructions in Section 2 for using ssh to connect to cslab.skidmore.edu. Navigate to the directory immediately above the one that you want to compress.

  1. Section 2 of the Linux Tutorial discusses how to navigate the directory structure from the Linux command line.
  2. For example, if you want to compress all the files in a directory that is named CS376S20, you would navigate to the directory where an ls command shows you this directory name:

    $ ls

    Downloads Music Desktop Documents Pictures

    $ cd Documents/

    $ ls

    CS106F18 CS206S19 CS318F19 CS376S20

  3. Use the zip command to compress the directory. The zip program will produce a file that can be uncompressed by most other operating systems (Windows and Mac): $ zip CS376S20.zip CS376S20
  4. This zip command will create a file called CS376S20.zip.

  1. Open a terminal on your computer
  2. Connect to cslab using sftp: sftp USERNAME@cslab.skidmore.edu
  3. Follow the instructions in Step 4 below for transferring files.

  1. Open the PSFTP program that was installed with PuTTY. Click on the Windows start button and go to "All Programs". Click on PuTTY, then click on PSFTP.
  2. Connect to cslab. In PSFTP, type "open USERNAME@cslab.skidmore.edu" then enter your password when prompted.
  3. Follow the instructions in Step 4 below for transferring files.

  1. Use the cd and ls commands like you do in the Linux terminal. For example, to change to the directory where I saved my CS376S20.zip file:

    stfp> ls

    Downloads Music Desktop Documents Pictures

    sftp> cd Documents/

    sftp> ls

    CS106F18 CS206S19 CS318F19 CS376S20 CS376S20.zip

  2. Use the get command to copy a file from cslab to your local computer: stfp> get CS376S20.zip
  3. Exit sftp: sftp> bye
  4. The file should be in the home directory (or whatever your default directory is) on your personal computer.