PTP Notification Status Conditions

The PTP status notifications are derived based on the following conditions:

PTP Lock State
Clock Status	Status	Description
Freerun	Clock is out of sync state	If portState is not “SECONDARY” or ClockClass value is NOT “6”, “7”, “135” or timeTraceable flag is FALSE. If holdover time exceeds its provided value. If PMC, ptp4l.conf, or ptp4l are not accessible.
Locked	Clock is in sync state	If portState is “SECONDARY” and ClockClass value is “6”, “7” or “135” and timeTraceable flag is TRUE and PMC, ptp4l.conf, ptp4l or phc2sys are accessible. Locked clockClass values can be changed using the ptp4lClockClassLockedList Helm override. See “Install PTP Notifications” document for instructions.
Holdover	Clock is in holdover state	For NICs using the Intel ice driver: If the state is transitioned from Locked to Holdover AND phc2sys is accessible, and holdover time does not expire For other NIC types: If the state is transitioned from Locked to Freerun AND phc2sys is accessible, and holdover time does not expire.
PTP Clock Class
6	T-GM connected to a PRTC in locked mode (e.g., PRTC traceable to GNSS)	For additional details on clockClass values, refer to ITU-T standard G.8275.1
7	T-GM in holdover, within holdover specification, traceable to Category 1 frequency source
135	T-BC in holdover, within holdover specification traceable to Category 1 frequency source
140	T-GM in holdover, out of holdover specification, traceable to Category 1 frequency source
248	T-GM or T-BC in free-run mode
255	Slave only OC (does not send Announce messages)
OS Clock State
Locked	Clock is out of sync state	phc2sys is running and disciplining the os clock OS clock is within 1000 ns of 37000000000 expected offset from PHC
Holdover	Clock is in holdover state	Holdover timer has not expired phc2sys is not running and not disciplining the os clock OR os clock offset is outside of range
Freerun	Clock is in freerun	Holdover conditions met but holdover timer has expired
GNSS State
SYNCHRONIZED	GNSS data is present	ts2phc is running and disciplining NIC PHC NIC driver DPLL reports GNSS state is locked
FAILURE-NOFIX	GNSS data is not detected	ts2phc is not running, NIC PHC is not being disciplined NIC driver DPLL reports status other than locked
Overall Sync State
Locked	Overall state is locked	The components of the local timing chain necessary for accurately synced time on the local host are in a healthy state This means that a local NIC PHC is locked to an external timing source and the system clock is synchronized to it The ptp-notification container logs indicate which components are part of the local timing chain and affect this notification
Holdover	Overall state is in holdover	One or more components in the local timing chain are in a degraded state (holdover or freerun) Overall sync state holdover time has not expired
Freerun	Overall state is freerun	One or more components in the local timing chain are in a degraded state (holdover or freerun) Overall sync state holdover time has expired

Overall Sync State Description

The overall sync state notification (sync-state) describes the health of the timing chain on the local system. A locked state is reported when the system has reference to an external time source (GNSS or PTP) and the system clock is synchronized to that time source.

This notification helps you to verify that the local system time is being actively synchronized. If a component of the local timing chain enters a degraded state, then a sync-state notification will be produced to indicate that the local timing chain is unhealthy.

The following is an example log output from the ptp-notification container that indicates the components of the local timing chain:

2025-05-01 15:34:48 INFO     Overall sync state chaining info:
os-clock-state = Locked
os-clock's source ptp-device = ptp0
ptp-device's sync-source = PTP
(PTP source) ptp4l-instance-and-state = ('ptp1', 'Locked')
(GNSS source) ts2phc-instance-and-state = NA
Overall sync: previous-state = Freerun, new-state = Locked