The value of the object tmnxLudbHostPppPassword specifies
the password of this host.
This object can only be set if tmnxLudbHostPppUserName is not an
empty string.
If the value of this object is not an empty string, then the value
of tmnxLudbHostPppPasswordType must be either 'pap(2)' or 'chap(3)'.
This object will always return an empty string on a read.