NTP: ntpclient: Failed to set NTP Daemon System Flags

This error is normally observed when attempting to start sfptpd in one of the supported PTP and NTP/NTP fallback modes:

warning: ntpclient: mode7: failed to set NTP daemon system flags, Permission denied
error: ntp: failed to disable NTP clock control
critical: failed to create sync module ntp, Permission denied
critical: couldn't create sync engine thread, Permission denied

The error occurs when sfptpd is prevented from communicating with and controlling the local ntpclient on the server. It fails because NTP authentication is either not configured or is not consistent in all required files.

NTP symmetric authentication should be configured in the following files:

• the sfptpd config file
• the /etc/ntp.conf file
• the /etc/ntp/keys file

To resolve this, setup NTP symmetric authentication as described in NTP Authentication.

On some OSs it might be necessary to explicitly enable NTP mode 7 to allow communication with the ntpclient. This is done by adding the following line anywhere in the /etc/ntp.conf file

enable mode7