NTP sync issues

[myster1ous]

I was wondering how would I setup the ntp.conf so that when ntpd starts it syncs with the time servers immediately. Any help would be appreciated.

For an example, I set the date/time by using:

# date -u 010101012009
Thu Jan 1 01:01:00 UTC 2009

When I restart ntpd it should resync automatically with the time servers that I have put in the server line in ntp.conf.

Am I doing something wrong?

[Rubberman]

I was wondering how would I setup the ntp.conf so that when ntpd starts it syncs with the time servers immediately. Any help would be appreciated.

For an example, I set the date/time by using:

# date -u 010101012009
Thu Jan 1 01:01:00 UTC 2009

When I restart ntpd it should resync automatically with the time servers that I have put in the server line in ntp.conf.

Am I doing something wrong?

Don't know, but here is a copy of my ntp.conf that works just fine on my CentOS system.

# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer 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
restrict -6 ::1

# Hosts on local network are less restricted.
#restrict 192.168.1.0 mask 255.255.255.0 nomodify notrap

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (pool.ntp.org: Join the NTP Pool!).
server 0.rhel.pool.ntp.org
server 1.rhel.pool.ntp.org
server 2.rhel.pool.ntp.org

#broadcast 192.168.1.255 key 42 # broadcast server
#broadcastclient # broadcast client
#broadcast 224.0.1.1 key 42 # multicast server
#multicastclient 224.0.1.1 # multicast client
#manycastserver 239.255.254.254 # manycast server
#manycastclient 239.255.254.254 key 42 # manycast client

# Undisciplined Local Clock. This is a fake driver intended for backup
# and when no outside source of synchronized time is available.
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

# Key file containing the keys and key identifiers used when operating
# with symmetric key cryptography.
keys /etc/ntp/keys

# Specify the key identifiers which are trusted.
#trustedkey 4 8 42

# Specify the key identifier to use with the ntpdc utility.
#requestkey 8

# Specify the key identifier to use with the ntpq utility.
#controlkey 8
restrict 0.rhel.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 1.rhel.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 2.rhel.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
server pool.ntp.org
restrict pool.ntp.org mask 255.255.255.255 nomodify notrap noquery

[myster1ous]

Thank you, I'll try if it works.

[myster1ous]

Ok I used some of your settings and applied to mine. It works, but is there a way to make it sync instantly when the ntp daemon is restarted?

Here is my ntp.conf

# 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 

# -- 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 nomodify notrap


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

# --- NTP MULTICASTCLIENT ---
#multicastclient			# listen on default 224.0.1.1
# restrict 224.0.1.1 mask 255.255.255.255 nomodify notrap
# restrict 192.168.1.0 mask 255.255.255.0 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 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

#
# Keys file.  If you want to diddle 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

# Specify the key identifier to use with the ntpq utility.
#controlkey 8
restrict 0.rhel.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 1.rhel.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
restrict 2.rhel.pool.ntp.org mask 255.255.255.255 nomodify notrap noquery
server pool.ntp.org
restrict pool.ntp.org mask 255.255.255.255 nomodify notrap noquery

Thanks again

[Rubberman]

I do know that my system syncs with the time server when it boots - I see it in the boot log. I'll see if I can post the ntp startup script in rcN.d - it starts up when moving into runlevel 1. Ok, here it is,K74ntpd. Put it in each rcN.d subdirectory of /etc/rc.d:

#!/bin/bash
#
# ntpd          This shell script takes care of starting and stopping
#               ntpd (NTPv4 daemon).
#
# chkconfig: - 58 74
# description: ntpd is the NTPv4 daemon. \
# The Network Time Protocol (NTP) is used to synchronize the time of \
# a computer client or server to another server or reference time source, \
# such as a radio or satellite receiver or modem.

# Source function library.
. /etc/init.d/functions

# Source networking configuration.
. /etc/sysconfig/network

if [ -f /etc/sysconfig/ntpd ];then
        . /etc/sysconfig/ntpd
fi

ntpconf=/etc/ntp.conf
ntpstep=/etc/ntp/step-tickers


RETVAL=0
prog="ntpd"

sync_hwclock() {
        ARC=0
        SRM=0
        UTC=0

        if [ -f /etc/sysconfig/clock ]; then
           . /etc/sysconfig/clock

           # convert old style clock config to new values
           if [ "${CLOCKMODE}" = "GMT" ]; then
              UTC=true
           elif [ "${CLOCKMODE}" = "ARC" ]; then
              ARC=true
           fi
        fi

        CLOCKFLAGS="$CLOCKFLAGS --systohc"

        case "$UTC" in
            yes|true)   CLOCKFLAGS="$CLOCKFLAGS --utc";;
            no|false)   CLOCKFLAGS="$CLOCKFLAGS --localtime";;
        esac
        case "$ARC" in
            yes|true)   CLOCKFLAGS="$CLOCKFLAGS --arc";;
        esac
        case "$SRM" in
            yes|true)   CLOCKFLAGS="$CLOCKFLAGS --srm";;
        esac

        action $"Syncing hardware clock to system time" /sbin/hwclock $CLOCKFLAGS
}

readconf() {
        dostep=''
        dropstr=''
        OPTIND=1
        while getopts ":46aAbc:dD:f:gi:k:l:LnN:p:P:qr:s:t:u:v:V:x" args $OPTIONS;
        do
          case "$args" in
            x) dostep=yes;;
            c) ntpconf="$OPTARG";;
            u) dropstr="-U $(echo $OPTARG | sed 's/:.*//')";;
          esac
        done

        [ -x /usr/sbin/ntpd -a -f $ntpconf ] || exit 0

        tickers=''
        if [ -s "$ntpstep" ]; then
            tickers=$(sed 's/#.*//' $ntpstep)
            echo "$tickers" | grep -qi '[a-z0-9]' && dostep=yes || tickers=''
        fi
        if [ -n "$dostep" -a -z "$tickers" ]; then
            # -x option is used, but step-tickers doesn't exist or contain
            # anything useful, use servers from ntp.conf instead
            tickers=$(awk '$1=="peer"||$1=="server"{print $2}' $ntpconf | \
                fgrep -v 127.127.1.0)
        fi
}

start() {
        # Check that networking is up.
        [ "$NETWORKING" = "no" ] && exit 1

        readconf;

        if [ -n "$dostep" ]; then
            echo -n $"$prog: Synchronizing with time server: "
            /usr/sbin/ntpdate $dropstr -s -b $NTPDATE_OPTIONS $tickers &>/dev/null
            RETVAL=$?
            [ $RETVAL -eq 0 ] && success || failure
            echo
            if [ $RETVAL -eq 0 ]; then
                [ "$SYNC_HWCLOCK" = "yes" ] && sync_hwclock
            else
                OPTIONS="$OPTIONS -g"
            fi
        else
            # -g can replace the grep for time servers
            # as it permits ntpd to violate its 1000s limit once.
            OPTIONS="$OPTIONS -g"
        fi
        # Start daemons.
        echo -n $"Starting $prog: "
        daemon ntpd $OPTIONS
        RETVAL=$?
        echo
        [ $RETVAL -eq 0 ] && touch /var/lock/subsys/ntpd
        return $RETVAL
}

stop() {
        echo -n $"Shutting down $prog: "
        killproc ntpd
        RETVAL=$?
        echo
        [ $RETVAL -eq 0 ] && rm -f /var/lock/subsys/ntpd
        return $RETVAL
}

# See how we were called.
case "$1" in
  start)
        start
        ;;
  stop)
        stop
        ;;
  status)
        status ntpd
        RETVAL=$?
        ;;
  restart|reload)
        stop
        start
        RETVAL=$?
        ;;
  condrestart)
        if [ -f /var/lock/subsys/ntpd ]; then
            stop
            start
            RETVAL=$?
        fi
        ;;
  *)
        echo $"Usage: $0 {start|stop|restart|condrestart|status}"
        RETVAL=3
esac

exit $RETVAL

[Rubberman]

Note that in the ntp script that there is code to sync the clock when starting, but that depends upon the /etc/sysconfig/ntpd configuration file. There is an option there, SYNC_HWCLOCK which if set to yes will sync the hardware clock after successfully calling ntpdate. So, my guess is that you only need to change that script. The contents of mine are (note mine doesn't sync the hw clock):

# Drop root to id 'ntp:ntp' by default.
OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid"

# Set to 'yes' to sync hw clock after successful ntpdate
SYNC_HWCLOCK=no

# Additional options for ntpdate
NTPDATE_OPTIONS=""

I hope this helps.