Using a supported adapter as a PTP master clock in NTP mode
(ptp_master_ntp.cfg), the local NTP client periodically
synchronizes with a remote NTP server (configurable through the local NTP daemon). NTP
is used to set the system clock and adapter clock and sfptpd keeps the
system clock in sync with the adapter precision oscillator.
Figure 1. Master NTP Mode
The sfptpd daemon synchronizes with the local NTP client every 1 second (default) and this is configurable in the sfptpd configuration file.
If the master is not the active PTP master, it will by default, revert to a PTP slave clock.
Note: When in master clock mode,
sfptpd uses the UTC timescale. Ensure the
ptp_utc_offset option in the sfptpd master
configuration file is set to 0.