Password overview

At SCS, as outlined below, you may have passwords for several different uses. Note that, for security reasons, you should keep your primary SCS Kerberos password unique. If you forget yours, see our page on getting a password reset

On this page:

Your "main" SCS Kerberos ID and password
Kerberos "instances," such as <your_userID>/mail, each with its own password
Your SCS Windows domain ID and password
Local Unix passwords on specific Unix hosts

SCS Kerberos ID & passwords

How to get one: Your main Kerberos password is created as part of the SCS user-account creation process. Download and fill out an SCS account application [.pdf format], have your sponsor sign it, and return it to the Help Desk, GHC 4203.

When to use it: Your main SCS Kerberos ID and password give you access to Facilitized Unix hosts on which you have an account . They also allow you to obtain Kerberos tickets for AFS with kinit and to change local passwords you may have on Facilitized Unix hosts.

How to change it: You can either use the Instance Manager Tool or run the kpasswd command on a Facilitized Unix host to change your main Kerberos password

Kerberos instances & passwords

"Instances" can be considered named "children" of your main Kerberos identity, and each has its own password.

Note: The primary SCS interface for managing Kerberos instances is the interactive, Web-based instance manager. SCS Computing Facilities encourages using this tool or you can run remctl on any Facilitized Unix host.

How to get one: You can use the Instance Manager Tool to create instances yourself, if you wish.

When to use it: Use your mail Kerberos instance password to read e-mail via the SCS POP and IMAP servers. Use your ftp Kerberos instance password to login to our FTP servers. You may have additional instances with specialized uses, as described in the Kerberos documentation.

How to change an instance password: You can either use the Instance Manager or run the command: kpasswd <userID>/<instance> on a Facilitized Unix host (for example: kpasswd bovik/mail) to change Kerberos-instance passwords.

Note that if you forget the password for your mail or ftp instances, you can use the Instance Manager to change these passwords as long as you know your main SCS Kerberos password.

SCS Windows domain ID & password

How to get one: This ID and password are normally created when we process your SCS user account application

When to use it: These credentials allow you to login to any Windows host (with a few exceptions) in the SCS Windows domain.

How to change the password: You can either use the Instance Manager Tool or once logged into a Windows host using the current password, enter: CTRL-ALT-DELETE [simultaneous key-chord] to bring up a dialogue box with the "Change Password..." button.

Local Unix passwords

How to get one: On a Facilitized Unix host to initially set a local password you must be logged in as root. You can then run the command:

     passwd [Username]

to create a local password for the User indicated. Once a local password has been established for a User then that User can change their local password simply by running the passwd command.

To remove a local password the /etc/passwd and /etc/shadow files must be edited by hand. You will need local root access to do this. If you need assisitance with such an operation send email to help@cs.cmu.edu. Once this is done you will then need to use your SCS Kerberos password to login.

When to use it: Some Unix applications, for example, xlock and some graphical display managers, don't understand Kerberos and expect a local password. A local password also allows one to login to hosts that are off the network and thus can't talk to the Kerberos servers.

How to change your local Unix password: See "How to get one" in this section.