ntp.conf

# replace the following time servers to the ones close to you
# see http://support.ntp.org/bin/view/Servers/NTPPoolServers
server 0.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 2.pool.ntp.org iburst
server 3.pool.ntp.org iburst

interface ignore wildcard
interface listen br0

logfile /opt/var/spool/ntp/ntp.log
driftfile /opt/var/spool/ntp/ntp.drift
#leapfile /opt/var/spool/ntp/leap-seconds.list # https://hpiers.obspm.fr/iers/bul/bulc/ntp/leap-seconds.list

restrict default limited kod nomodify notrap nopeer noquery # restrictive default IPv4
restrict -6 default limited kod nomodify notrap nopeer noquery # restrictive default IPv6
restrict source nomodify notrap noquery # required for pool directive if using restrictive default permissions
restrict 127.0.0.1 # permissive localhost IPv4
restrict -6 ::1 # permissive localhost IPv6

disable auth stats