NTP

ntp.conf

# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help

driftfile /var/lib/ntp/ntp.drift
broadcastdelay 0.008

# Enable this if you want statistics to be logged.
statsdir /var/log/ntpstats/

statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable

# DN42 ntp nodes -- https://wiki.dn42.us/internal/Internal-Services
server ntp.e-utp.dn42 iburst     # Stratum 1, GPS+NMEA
server ntp2.nixnodes.dn42 iburst #
server ntp1.nixnodes.dn42 iburst #
server ntp.martin89.dn42 iburst  # more than one A records/server
server tick.gotroot.dn42 iburst  # Stratum 1, GPS, Vancouver Canada
server tock.gotroot.dn42 iburst  # Stratum 2, Anycast on each node
# pool.ntp.org maps to about 1000 low-stratum NTP servers.  Your server will
# pick a different set every time it starts up.  Please consider joining the
# pool: <http://www.pool.ntp.org/join.html>
server 3.pool.ntp.org iburst
server 2.pool.ntp.org iburst
server 1.pool.ntp.org iburst
server 0.pool.ntp.org iburst
# Other NTP servers
server time.windows.com iburst
server time.nist.gov iburst

# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
# details.  The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
# might also be helpful.
#
# Note that restrict applies to both servers and clients, so a configuration
# that might be intended to block requests from certain clients could also end
# up blocking replies from your own upstream servers.

# By default, exchange time with everybody, but do not allow configuration.
restrict -4 default kod notrap nomodify nopeer noquery limited
restrict -6 default kod notrap nomodify nopeer noquery limited

# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1

# Needed for adding pool entries
restrict source notrap nomodify noquery