NTP.CONF

NTP.CONF is the configuration file for the Network Time Protocol Daemon. This file has many elements however, only a few defaults need to change as underlined in the following sample file.

# Prohibit general access to this service.
 
# Enable NTP on this server
 
restrict default nomodify notrap noquery
 
# Permit all access over the loopback interface.  This could
 
# be tightened as well, but to do so would effect some of
 
# the administrative functions.
 
restrict 127.0.0.1
 
# -- CLIENT NETWORK -------
 
# Permit systems on this network to synchronize with this
 
# time service.  Do not permit those systems to modify the
 
# configuration of this service.  Also, do not use those
 
# systems as peers for synchronization.
 
# restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap
 
# --- OUR TIMESERVERS -----
 
# or remove the default restrict line
 
# Permit time synchronization with our time source, but do not
 
# permit the source to query or modify the service on this system.
 
# restrict mytrustedtimeserverip mask 255.255.255.255 nomodify 
notrap noquery
 
# server mytrustedtimeserverip
 
server ntp.cis.strath.ac.uk     ## The Time server should local # 
--- NTP MULTICASTCLIENT ---
 
#multicastclient			# listen on default 224.0.1.1
 
# restrict 224.0.1.1 mask 255.255.255.255 notrust nomodify notrap
 
# restrict 192.168.1.0 mask 255.255.255.0 notrust nomodify notrap
 
# --- GENERAL CONFIGURATION ---
 
#
 
# Undisciplined Local Clock. This is a fake driver intended for 
backup
 
# and when no outside source of synchronized time is available. The
 
# default stratum is usually 3, but in this case we elect to use 
stratum
 
# 0. Since the server line does not have the prefer keyword, this 
driver
 
# is never used for synchronization, unless no other
 
# synchronization source is available. In case the local host is
 
# controlled by some external source, such as an external oscillator 
or
 
# another protocol, the prefer keyword would cause the local host to
 
# disregard all other synchronization sources, unless the kernel
 
# modifications are in use and declare an unsynchronized condition.
 
#
 
#server	127.127.1.0	# local clock
 
#fudge	127.127.1.0 stratum 10
 
#
 
# Drift file.  Put this in a directory which the daemon can write 
to.
 
# No symbolic links allowed, either, since the daemon updates the 
file
 
# by creating a temporary in the same directory and then 
rename()'ing
 
# it to the file.
 
#
 
driftfile /etc/ntp/drift
 
broadcastdelay	0.008
 
#
 
# Authentication delay.  If you use, or plan to use someday, the
 
# authentication facility you should make the programs in the 
auth_stuff
 
# directory and figure out what this number should be on your 
machine.
 
#
 
authenticate yes
 
#
 
# Keys file.  If you want to check your server at run time, make a
 
# keys file (mode 600 for sure) and define the key number to be
 
# used for making requests.
 
#
 
# PLEASE DO NOT USE THE DEFAULT VALUES HERE. Pick your own, or 
remote
 
# systems might be able to reset your clock at will. Note also that
 
# ntpd is started with a -A flag, disabling authentication, that
 
# will have to be removed as well.
 
#
 
keys		/etc/ntp/keys
 

Use this command to validate the NTPD operation:

Ntpq –c peers