rpm -q ntp

rpm -q xntp3 (For RH6.2)

[root@irlp-6290 etc]# rpm -q ntp
ntp-4.1.1-1

# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
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

# --- OUR TIMESERVERS -----
server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org

# --- 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 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 /var/lib/ntp/drift
broadcastdelay 0.008

If your clock is WAY off, ntp will not correct it. To initially sync your clock if there is a large error is to run the command:

ntpdate 0.pool.ntp.org

This command is a "one-off" sync of your clock to an ntp server, regardless of the time difference.

Now that you have the config file in place, you need to start the ntp daemon.

/etc/rc.d/init.d/ntpd start 

/etc/rc.d/init.d/xntpd start  (For RH 6.2)

Wait a few minutes for the time to synchronise, then enter ntpq -c peers (For RH6.2 it is xntpdc -c peers)
You should see an output listing the configured servers, thier status and the time offset:

[root@irlp-6290 etc]# ntpq -c peers -n
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
+128.208.109.7   140.142.2.8      3 u  568 1024  377  201.859   13.496   3.761
*64.142.114.146  64.142.103.194   2 u  549 1024  377  210.226   24.187   1.870
+80.85.129.25    138.195.130.71   3 u  317 1024  377  584.861  -119.63  16.100
 127.127.1.0     LOCAL(0)        10 l   21   64  377    0.000    0.000   0.001

It may take several minutes before your ntp client synchronises, however eventually one server should be listed with an asterisk (*) next to it. This is the server with BEST ACCURACY, and is the server currently being used to synchronise your clock.

Any entries with a plus (+) next to them are accessible, but not currently being used. These are STANDBY servers, in the event that the current active server becomes unavailable.

The last line (127.127.1.0) is an INTERNAL server, that is used as a last resort, if no external servers can be reached. If you see an asterisk (*) next to this line, it means that your machine is in sync with itself, but essentially has a "free-running" clock.

Now all we need to do is to add the ntpd process to your system startup. The easiest way to do this is to enter:

chkconfig --level 345 ntpd on 

chkconfig --level 345 xntpd on  (For RH6.2)