Perche il servizio ntpd non parted dopo il riavvio nonostate sia stato abilitato?

Issue

Il servizio ntpd.service non parte dopo essere stato abilitato con "#systemctl enable":

Lo stato del sistema e' come segue:

systemctl status ntpd.service
ntpd.service - Network Time Service
Loaded: loaded (/usr/lib/systemd/system/ntpd.service; enabled)

Active: inactive (dead)

systemctl --failed
UNIT LOAD ACTIVE SUB DESCRIPTION
fprintd.service loaded failed failed Fingerprint Authentication Daemon
rhnsd.service loaded failed failed LSB: Starts the Spacewalk Daemon
rngd.service loaded failed failed Hardware RNG Entropy Gatherer Daemon

LOAD = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB = The low-level unit activation state, values depend on unit type.

3 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.