Changes your network password in Network Information Services (NIS).
yppasswd [ -f [ Name ] | -s [ Name [ ShellProg ]] ]
The yppasswd command changes (or installs) a network password and associates it with the name you specify in the UserName parameter. To create or change a password, you must be the owner of the password you want to change. The Network Information Services (NIS) password can be different from the one on your own machine. Root users on an NIS server can change the password of another user without knowing the user's original password. Root users on an NIS client, however, do not have this privilege.
When you enter the yppasswd command on the command line, the system prompts you to enter the old password. When you do this, the system prompts you to enter the new password. The password you enter can be as small as four characters long if you use a mixture of uppercase and lowercase characters. Otherwise, the password has to be six characters long or longer. These rules are relaxed if you are insistent enough.
If you enter the old password incorrectly, you have to enter the new password before the system will give you an error message. The system requires both passwords because the update protocol sends them to the server at the same time. The server catches the error and notifies you that you entered the old password incorrectly.
To verify the new password, the system prompts you to enter it again. For this new password to take effect, the yppasswdd daemon must be running on your NIS server.
yppasswd Joe
This example demonstrates how to change the NIS password for the user named Joe. The system prompts you to enter Joe's old password and then his new password.
The yppasswdd daemon.
Network Information Services (NIS) Overview for System Management in AIX 5L Version 5.2 Network Information Services (NIS and NIS+) Guide.