Raspberry Pi NTP config with fudge factors

[Frank Nicholas]

This is the “/etc/ntp.conf” I used when I ran my NTP server on a Raspberry Pi with the Adafruit breakout board (same as current hat).  I list it because of the “fudge” line.  This was commonly accepted as the proper fudge settings, especially for time2 - 0.350:
# /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

# http://www.eecis.udel.edu/~mills/ntp/html/drivers/driver20.html explains 
# these settings
# Slightly modified, but credit to:
# Paul Kennedy @ (http://www.raspberrypi.org/phpBB3/viewtopic.php?f=41&t=1970&start=80)
server 127.127.20.0 mode 17 minpoll 3 iburst true prefer
fudge 127.127.20.0 flag1 1 time2 0.350
server tock.usshc.com iburst
server clock.isc.org iburst
server tick.apple.com iburst

# 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 0.debian.pool.ntp.org iburst
server 1.debian.pool.ntp.org iburst
server 2.debian.pool.ntp.org iburst
server 3.debian.pool.ntp.org iburst
enable auth monitor             # enable the good stuff

# By default, exchange time with everybody, but don't allow configuration.
restrict -4 default kod notrap nomodify nopeer noquery
restrict -6 default kod notrap nomodify nopeer noquery

# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1
restrict 192.168.169.0 mask 255.255.255.0 nomodify nopeer notrap

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.ntpsec.org/pipermail/devel/attachments/20160505/4eaf1fa0/attachment.html>