Connecting and Logging in to CEE/CS Linux Servers

You can connect and log in to the department Linux servers from machines that have a connection to the Internet. From home and campus PCs, you can establish a text-only terminal session using a variety of programs that support SSH such as Putty. With the Linux systems in Science III, you can also establish an X-windows session, which allows graphics and text.

Connecting to a Server

The following sections detail connecting from remote machines to one of the department servers using the SSH protocol. SSH will encrypt your password and session so that no one can sniff the traffic. To log in, you first establish a connection and then authenticate yourself. You will be given an account sheet with your username and password to use to authenticate yourself. Make sure to have the account sheet with you or to memorize your username and password.

The password is case sensitive so enter it exactly as shown on the account sheet, including all upper case letters. Make sure the caps lock key is off as well. If you type your password correctly, you will be logged in and will see the text prompt for the server which looks something like: 

<username>@sleipnir:~$
If you get the "Permission denied" message, double check that your caps lock key is not on and try your password again. Sometimes a 1 (one) looks like an l (lower-case L) and vis versa, so look for that as well.

Connect from Linux/MacOS X

These instructions assume you have the OpenSSH client software installed on your system. Most Linux distributions and MacOS X installations have this software installed by default. If you do not have this software, consult the documentation for your system to learn how to install the software. The Computer Science lab machines have OpenSSH installed.

The command that you will use depends on the server you are trying to connect to. Most students will be using Odin (new server) or Sleipnir (older server) for their classes. You may also be connecting to one of the specialty servers for some classes and your instructor will give you the server name in those cases.

To connect to Odin, open up a terminal window and type the following: 

ssh <username>@odin.cs.csub.edu
To connect to Sleipnir, open up a terminal window and type the following: 
ssh <username>@sleipnir.cs.csub.edu
Enter your password when prompted. The password is case sensitive, so enter all upper and lower case letters as shown on the account sheet. Also make sure the caps lock key is not on.

If you wish to use X-Windows applications on one of the Linux servers, you will need to activate X11 forwarding. Use the following SSH command to activate X11 forwarding: 

ssh -Y <username>@odin.cs.csub.edu
Both these methods will log you into a text interface. If using X11 forwarding, you can then launch X-Windows applications by giving the application's command on the command line.

When you are in one of the CEE/CS labs in Science III, you can leave off the "cs.csub.edu" part of the above commands, as those labs are already part of the cs.csub.edu domain and will look there for the servers.

You can also use the names "odin.cs.csubak.edu" and "sleipnir.cs.csubak.edu" to connect to the servers. The domain name "cs.csubak.edu" is an alias for the domain name "cs.csub.edu", so both work.

Connect from Windows

At home or in campus PC labs, you will need to install Putty or another SSH client on the machine. If you can install software and the machine has no SSH client already installed, download the Putty SSH/telnet client from the CS department download page.

When you launch Putty, it will present a connection dialog. To connect to Odin, enter "odin.cs.csub.edu" for the Host Name and select "SSH" for the Protocol type in the top of the dialog. Optionally, you can save this information by entering a name for the session and clicking save in the bottom of the dialog. Click Open to initiate the connection. You will see a dialog box about saving the key for the server. This is to protect against something called a "man in the middle" attack. Click Yes to connect. Once you connect, log in with your username and password when prompted.

NOTE: Make sure you ONLY enter your username, as printed on the account sheet, when prompted for a login by Putty. Do NOT enter "ssh <username>@odin" as you would to log in from the labs. You have already done the ssh command by double-clicking Putty and you have already told it to connect to the server by entering "odin.cs.csubak.edu" as the Host Name. You only need to tell it the username when you see the login prompt.