Computing Facilities    links to the SCS and CMU home pages Carnegie Mellon School of Computer Science Carnegie Mellon University
 
Advanced search tips 
 Documentation
 » Introduction to Facilities 
 » Accounts & passwords 
 » AFS 
 » Application software 
 » AV help 
 » Backups & restores 
 » E-mail & netnews 
 » Networking 
 » Printing 
 » Purchasing 
 » Security 
 » Software licensing 
 » Support charges 
 » Web publishing 
 » Your health 
 » Macintosh support 
 » Unix/Linux support 
 » Windows PC support 

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, WeH 3613.

When to use it: Your main SCS Kerberos ID and password give you access to Facilitized Unix hosts on which you have an account and to the Jeeves server. 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: To change your main Kerberos password, run the kpasswd command on a Facilitized Unix host.

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, as we are phasing out Jeeves support for these functions. If you prefer a command-line interface, Jeeves will remain available for a while, or you can run remctl on any Facilitized Unix host.

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

Note that if you forget the password for your mail or ftp instances, you can use still use Jeeves 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: After you've logged into a Windows host using this 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, the command: passwd
will create or change a local password. You can give your main SCS Kerberos password when it asks you for "Old password".

The command: passwd -r
will remove your local password. 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.

Related documentation

Kerberos in SCS
About Kerberos in SCS.
How to choose good passwords
How to choose good passwords that can be remembered.
Encryption & password security
How to protect your passwords from being eavesdropped from the network.
Windows passwords
Additional information on Windows passwords