Sysadmin > NtP > RaspberryGpsNtpServer > RaspberrypiNtpConf
 # /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help

driftfile /var/lib/ntp/ntp.drift

# 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

#enable calibrate

server mode 17 minpoll 3
fudge flag1 1 flag2 0 flag3 0 time1 0.00 time2 0.5 refid PPS
#fudge flag1 1 flag2 0 flag3 1 time1 0.00 time2 0.279013 refid PPS
#fudge flag1 1 time2 0.496

server noselect
server noselect

leapfile "/etc/leap-seconds"

# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
# details.  The web page <>
# 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 don't allow configuration.
restrict default notrap nomodify nopeer noquery
restrict -6 default notrap nomodify nopeer noquery

# Local users may interrogate the ntp server more closely.
restrict -6 ::1

# Clients from this (example!) subnet have unlimited access, but only if
# cryptographically authenticated.
#restrict mask notrust

# If you want to provide time to your local subnet, change the next line.
# (Again, the address is an example only.)

# If you want to listen to time broadcasts on your local subnet, de-comment the
# next lines.  Please do this only if you trust everybody on the network!
#disable auth