[CentOS] Passwords apparently stopped working.

James B. Byrne wrote:
> I encountered a couple of strange events with respect to
> password authentication this morning. Two of our staff
> were unable to login onto several systems using their
> usual passwords.  Both users had last logged in on these
> hosts using their accounts and passwords on Friday past.
<snip>
> Resetting both the passwords to their current values using
> the passwd utility on each system corrected the problem
> insofar as the users were concerned.  However, I am
> somewhat perplexed as to the reason for their passwords to
> stop working in the first place. Is anyone here aware of
> any reason why this might happen?

Is it possible that they'd logged into something else first, and had
multiple credentials, and the systems were trying to get those first?

       mark