The phc_ctl utility is part of Linux PTP. If linuxptp is installed on the server, phc_ctl can be used to set the adapter clock and compare the time offset against the system clock.
Get System Clock Time
# phc_ctl CLOCK_REALTIME get
Get NIC Clock Time
# phc_ctl <interface> get
Compare System and NIC Clocks
# phc_ctl /dev/ptpN cmp
Set NIC Clock from System Clock
# phc_ctl /dev/ptpN set
The NIC clock can be specified by the
sfptpd interface or by device number.