Here is some information before diving into configuration files:
stratum: indicates that it's not very reliable data
127.127.1.0: time given by the machine (BIOS)
peer: defines a server of the same stratum as the server (same level/same geographic location), which allows for more reliability. Using 1 server + peers provides a more refined configuration than having only geographically distant servers.
Debian
Here's the configuration file for a time server (/etc/inet/ntp.conf):
# /etc/ntp.conf, configuration for ntpd# ntpd will use syslog() if logfile is not definedlogfile/var/log/ntpd
driftfile/var/lib/ntp/ntp.drift
statsdir/var/log/ntpstats/
statisticsloopstatspeerstatsclockstats
filegenloopstatsfileloopstatstypedayenablefilegenpeerstatsfilepeerstatstypedayenablefilegenclockstatsfileclockstatstypedayenable# Servers to use to updateserver0.fr.pool.ntp.orgprefer
server1.fr.pool.ntp.org
server2.fr.pool.ntp.org
# ... and use the local system clock as a reference if all else failsserver127.127.1.0
# fudge 127.127.1.0 stratum 13# Local users may interrogate the ntp server more closely.restrict127.0.0.1
# Allow local network to synchronize to this serverrestrict192.168.0.0mask255.255.255.0nomodifynotrap
broadcastdelay0.008
After configuring and restarting the service, you must wait a few minutes for the server to synchronize.
Solaris
Here's the configuration file for Solaris (/etc/inet/ntp.conf):
## Copyright 1996-2003 Sun Microsystems, Inc. All rights reserved.# Use is subject to license terms.## /etc/inet/ntp.server## An example file that could be copied over to /etc/inet/ntp.conf and# edited; it provides a configuration template for a server that# listens to an external hardware clock, synchronizes the local clock,# and announces itself on the NTP multicast net.## This is the external clock device. The following devices are# recognized by xntpd 3-5.93e:## XType Device RefID Description# -------------------------------------------------------# 1 local LCL Undisciplined Local Clock# 2 trak GPS TRAK 8820 GPS Receiver# 3 pst WWV PSTI/Traconex WWV/WWVH Receiver# 4 wwvb WWVB Spectracom WWVB Receiver# 5 true TRUE TrueTime GPS/GOES Receivers# 6 irig IRIG IRIG Audio Decoder# 7 chu CHU Scratchbuilt CHU Receiver# 8 parse ---- Generic Reference Clock Driver# 9 mx4200 GPS Magnavox MX4200 GPS Receiver# 10 as2201 GPS Austron 2201A GPS Receiver# 11 arbiter GPS Arbiter 1088A/B GPS Receiver# 12 tpro IRIG KSI/Odetics TPRO/S IRIG Interface# 13 leitch ATOM Leitch CSD 5300 Master Clock Controller# 15 * * TrueTime GPS/TM-TMD Receiver# 17 datum DATM Datum Precision Time System# 18 acts ACTS NIST Automated Computer Time Service# 19 heath WWV Heath WWV/WWVH Receiver# 20 nmea GPS Generic NMEA GPS Receiver# 22 atom PPS PPS Clock Discipline# 23 ptb TPTB PTB Automated Computer Time Service# 24 usno USNO USNO Modem Time Service# 25 * * TrueTime generic receivers# 26 hpgps GPS Hewlett Packard 58503A GPS Receiver# 27 arc MSFa Arcron MSF Receiver## * All TrueTime receivers are now supported by one driver, type 5.# Types 15 and 25 will be retained only for a limited time and may# be reassigned in future.## Some of the devices benefit from "fudge" factors. See the xntpd# documentation.# Either a peer or server. Replace "XType" with a value from the# table above.# Servers to use to updateserver0.fr.pool.ntp.orgprefer
server1.fr.pool.ntp.org
server2.fr.pool.ntp.org
# fudge 127.127.XType.0 stratum 0broadcast224.0.1.1ttl4enableauthmonitor
driftfile/var/ntp/ntp.drift
statsdir/var/ntp/ntpstats/
filegenpeerstatsfilepeerstatstypedayenablefilegenloopstatsfileloopstatstypedayenablefilegenclockstatsfileclockstatstypedayenablekeys/etc/inet/ntp.keys
trustedkey0requestkey0controlkey0
Create a drift file as indicated in the configuration:
May 24 16:48:05 chronos ntpd[14262]: ntp engine ready
May 24 16:48:24 chronos ntpd[14262]: peer 91.121.45.45 now valid
May 24 16:48:24 chronos ntpd[14262]: peer 81.93.183.116 now valid
May 24 16:48:27 chronos ntpd[14262]: peer 94.23.220.143 now valid
May 24 17:27:13 chronos ntpd[14262]: clock is now synced