Problem
The problems I was experiencing was that any attempt to change a user
password was met with:
[root@vlamp temp]# passwd tempuser
Changing password for user tempuser.
New password:
BAD PASSWORD: it is based on a dictionary word
Retype new password:
RPC: Can't encode arguments
The password has not been changed on vlamp.
or
[root@vlamp temp]# yppasswd tempuser
Changing NIS account information for tempuser on vlamp.
Please enter root password:
Changing NIS password for tempuser on vlamp.
Please enter new password:
Please retype new password:
Error while changing the NIS password.
The NIS password has not been changed on vlamp.
Solution
Eventually I got around this problem by ensuring that users are always
added with a default password:
# useradd -p password username
After this is done, yppasswd works successfully.