How do I access my UNIX account from home?

Overview

Using SSH, or Secure Shell, it is possible to sign in to a Unix account from a personal computer. Follow the instructions provided below to access a UNIX account from a personal computer.

If you are connecting to this server from off campus, a VPN connection is required. Please see instructions at How do I connect to the Purdue VPN?

Instructions

Windows

When using the Windows operating system, it is first necessary to download and install a SSH client. Popular SSH clients include, but are not limited to:

SecureCRT - Officially supported by ITaP, contact itap@purdue.edu or (765) 494-4000 for additional assistance. This software is free of charge for university use.

PuTTY - Open source SSH client that is free for everyone. PuTTY has a very simple interface that doesn't require an installation which allows for running the application immediately after download. Availablethrough the Engineering Computer Network (ECN).

SSH Client - A very powerful SSH client that also includes a file transfer utility. SSH Client is free for student use, and available through the Engineering Computer Network (ECN).

Additionally, if it is intended for a graphical UNIX program to be executed from the Windows computer, an Xclient will also be necessary. A popular X-client is 'PC-Xware' and is available through the Engineering Computer Network (ECN) by clicking here.

1. If graphical programs are intended to be utilized, start the X-client first.
2. Launch the SSH program and open a new connection window or quick connect window.
3. For the host name, enter the full host name of the UNIX server you wish to use. For example, to connect to 'Expert', the proper address would be 'guru.itap.purdue.edu'.
4. Verify that the port is set to '22' and that the protocol is 'SSH2' if that is an option.
5. Enter the proper Purdue career account username and password. If this option does not appear with the application being utilized, a prompt will appear later.
6. If a graphical program needs to be launched, and an X-server is running, locate the configuration option to enable X-11 tunneling, also known as X-forwarding. See the troubleshooting section below if either option can not be located.
7. Save the connection profile.
8. Click 'Connect' or a similar option (depending on the client being utilized) to initiate the connection.
9. Supply the proper career account credentials.
10. A UNIX command prompt will populate that provides options for executing UNIX commands. If an Xserver is running, a graphical program can be launched by typing the proper name. Follow the command with a space and an '&' symbol if it is necessary to enter additional commands before completing the last command or program.
11. To close the connection, close any open graphical program windows and then enter either 'exit' or 'logout' and press the 'Enter' key. The SSH program and X-server (if one is running) can then be closed if they do not automatically.

Mac OS X and Linux

Mac OS X (with the UNIX tools installed, available on the OS X install DVD) or Linux operating systems have SSH and an X-server already present, with no additional steps for installation necessary.

1. For Mac OS X users who wish to run graphical UNIX programs, launch the X11 terminal. For non-graphical programs under OS X and for any kind of program in Linux, launch the Terminal.
2. Type 'ssh -I username -X -C hostname' and press the 'Enter' key. The '-X' entry enables X-forwarding for graphical programs, so it can be omitted when these programs are not running. The '-C' entry enables compression to help speed up off-campus connections, so it can be omitted when connected to the Purdue AirLink or ResNet networks. The 'username' entry should be the proper career account username, and the 'hostname' entry should be the UNIX systems host name (for example, the expert system entry would be 'guru.itap.purdue.edu').
3. Supply the proper career account password when prompted.
4. A UNIX command prompt will populate where Unix commands can be executed. If the '-X' entry was utilized (and X11 is being used in the OS X operating system), graphical programs can be executed by entering the proper name. Follow the command with a space and an '&' symbol if it is necessary to type additional commands before completing the last command or program.
5. To close the connect, close and open graphical program windows and then type either 'exit' or 'logout' and press the 'Enter' key. The terminal window can be closed if it does not automatically do so.

Troubleshooting

Verify that an account exists on the UNIX server being connected to before attempting to connect.

If an access denied error appears, verify that the username and password that were provided are correct.

If graphical applications cannot be launched, verify that the X-server is running and the X-forwarding is enabled:

In OS X, verify that the '-X' switch is being used in the X11 terminal.

In Linux, verify that the '-X' switch was used.

In Windows, verify that the X-server was started and that the X-forwarding was enabled in the SSH program. For PuTTY, this can be done by navigating to 'Connection', and selecting 'SSH', followed by the 'Tunnels' option. For SecurtCRT, navigate to 'Options', and select 'Session Options' followed by 'Connection', followed by 'Port Forwarding', after which, select 'Remote/X11'. For the SSH Client, select 'Edit', followed by 'Settings', followed by ' Profile Settings', and finally 'Tunneling'.

Still need help?  Click the 'Purdue IT Request' button to start a ticket.