Q: I tried to change my password using the passwd command or Preferences.app, but it didn't seem to take effect.   Why not?

Q:  How do I remove my password? 

A:  Use the Preferences application to change your password.  If you are on a network composed of NEXTSTEP and non-NEXTSTEP OS's you might also need to update the NIS (formerly known as Yellow Pages) database by running the yppasswd command.  If your account information is stored in NIS, run the following command in a Terminal or Shell:

	machine>yppasswd your-login-name

as in: yppasswd jsmith.

If your account is stored in NetInfoÐwhich is the default in NEXTSTEPÐdo the following to remove your password:

·	Launch NetInfoManager.
·	Open the domain where your account is stored; this is probably the root (/) domain if you
	are on a Network. If you are on a standalone machine, the right (local) domain will come
	up by default.
·	Click the users directory , then double-click your account name. This opens the
	property editor.
·	Click the passwd property, then remove its value and save the changes
	
Removing a password that is stored in NIS is slightly more difficult.  On the yp-master server do the following as root:

·	Edit the /etc/passwd file and remove the passwd field from your account.
·	Then run the following commands in a Shell or Terminal:
	
	ypmaster#cd /etc/yp
	ypmaster#make passwd
	
Warning:

Removing a password from an account is a serious security risk!  Make sure that all the accounts have a password.  Change the passwords once a month.

What makes a good password?  One that's:

·	easy to remember
·	 hard to guess
·	 uses upper and lower case letters, number, and punctuation
·	 is not found in the dictionary
·	 is not a proper name

The UNIX password security mechanism really depends on two things: 

·	the fact that it's hard to decrypt the encrypted passwords
·	users' choosing passwords that are hard to guess (so that brute-force attacks are intractable)

QA82

Valid for 1.0, 2.0, 3.0, 3.1