/etc/ntp.conf

################################################################################
## /etc/ntp.conf
##
## Sample NTP configuration file.
## See package 'ntp-doc' for documentation, Mini-HOWTO and FAQ.
## Copyright (c) 1998 S.u.S.E. GmbH Fuerth, Germany.
##
## Author: Michael Andres,  <ma@suse.de>
##         Michael Skibbe,  <mskibbe@suse.de>
##
################################################################################

##
## Radio and modem clocks by convention have addresses in the
## form 127.127.t.u, where t is the clock type and u is a unit
## number in the range 0-3.
##
## Most of these clocks require support in the form of a
## serial port or special bus peripheral. The particular
## device is normally specified by adding a soft link
## /dev/device-u to the particular hardware device involved,
## where u correspond to the unit number above.
##
## Generic DCF77 clock on serial port (Conrad DCF77)
## Address:     127.127.8.u
## Serial Port: /dev/refclock-u
##
## (create soft link /dev/refclock-0 to the particular ttyS?)
##
# server 127.127.8.0 mode 5 prefer

##
## Undisciplined Local Clock. This is a fake driver intended for backup
## and when no outside source of synchronized time is available.
##
server 127.127.1.0
# local clock (LCL)
fudge 127.127.1.0  stratum 10
# LCL is unsynchronized

##
## Add external Servers using
## # rcntp addserver <yourserver>
##

##
## Miscellaneous stuff
##

driftfile /var/lib/ntp/drift/ntp.drift
# path for drift file

logfile /var/log/ntp
# alternate log file
# logconfig =syncstatus + sysevents
logconfig =all

# statsdir /tmp/                # directory for statistics files
# filegen peerstats  file peerstats  type day enable
# filegen loopstats  file loopstats  type day enable
# filegen clockstats file clockstats type day enable

#
# Authentication stuff
#
keys /etc/ntp.keys
# path for keys file
trustedkey 1
# define trusted keys
requestkey 1
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery
restrict 127.0.0.1 mask 255.255.255.0
restrict -6 ::1

server navobs1.gatech.edu  iburst
server rolex.usg.edu  iburst
server time-a.nist.gov  iburst
server us.pool.ntp.org  iburst
# GPS Serial data reference
# The normally-used server and fudge are commented out
# for the purpose of simplifying debugging.
# server 127.127.28.0  minpoll 4 maxpoll 4
# fudge 127.127.28.0  flag1 0 flag2 0 flag3 0 flag4 0 refid GPS stratum 0 time1 0.450
server 127.127.28.0
fudge 127.127.28.0 refid GPS
# GPS PPS reference
# The normally-used server and fudge are commented out
# for the purpose of debugging.
# server 127.127.28.1  minpoll 4 maxpoll 4 prefer
# fudge 127.127.28.1  flag1 0 flag2 0 flag3 0 flag4 0 refid PPS stratum 0
server 127.127.28.1 prefer
fudge 127.127.28.1 refid PPS
# key (7) for accessing server variables
# controlkey 15                 # key (6) for accessing server variables