ptp time synchronization on centos6/rhel

Question

I need to setup time synchronization using PTP (precision time protocol). I'll get server address. I found ptpd server (version 2.1). I created startup files in /etc/init.d. But wondering what options other than showing on which interface I should listen for broadcasts I should use. Does anyone had experience setting this up?

Solution

Here are steps I've did and got ptp working as a slave. I've used ptpd2 on Centos 6.0, but should work anywhere. Startup scripts I found somewhere online - can't find that link again today.

Download ptpd2 source package from sourceforge.

After downloaded, compile it:

tar xzfv ptpd-2.1.0.tar.gz
cd ptpd-2.1.0/src
make
sudo cp ptpd2 /usr/bin/ptpd2

create startup script for ptpd2 in /etc/rc.d/init.d/ptpd2

#!/bin/sh
#
# ptpd Precision Time Protocol daemon
#
# chkconfig:   - 30 70
# description: ptpd implements a sub ms time coordination of LAN connected computers \
#              implementing IEEE 1588

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

exec="/usr/bin/ptpd2"
prog="ptpd2"

[ -e /etc/sysconfig/$prog ] && . /etc/sysconfig/$prog

lockfile=/var/lock/subsys/$prog

start() {
    [ -x $exec ] || exit 5
    echo -n $"Starting $prog: "
    # if not running, start it up here, usually something like "daemon $exec"
    daemon --user root $exec $PTPDARGS
    retval=$?
    echo
    [ $retval -eq 0 ] && touch $lockfile
    return $retval
}

stop() {
    echo -n $"Stopping $prog: "
    # stop it here, often "killproc $prog"
    killproc $prog
    retval=$?
    echo
    [ $retval -eq 0 ] && rm -f $lockfile
    return $retval
}

restart() {
    stop
    start
}

reload() {
    restart
}

force_reload() {
    restart
}

rh_status() {
    # run checks to determine if the service is running or use generic status
    status $prog
}

rh_status_q() {
    rh_status >/dev/null 2>&1
}


case "$1" in
    start)
        rh_status_q && exit 0
        $1
        ;;
    stop)
        rh_status_q || exit 0
        $1
        ;;
    restart)
        $1
        ;;
    reload)
        rh_status_q || exit 7
        $1
        ;;
    force-reload)
        force_reload
        ;;
    status)
        rh_status
        ;;
    condrestart|try-restart)
        rh_status_q || exit 0
        restart
        ;;
    *)
        echo $"Usage: $0 {start|stop|status|restart|condrestart|try-restart|reload|force-reload}"
        exit 2
esac
exit $?

Create configuration file in /etc/sysconfig/ptpd2:

#
# PTPD Configuration
#

PTPDARGS="-D -b eth2 -f /var/log/ptpd.log"

Add ptpd to be started on system boot:

/sbin/chkconfig --level 35 ptpd2 on

and start ptpd daemon: service start ptpd2

Enjoy.

Let me know if you have better solution.

Comments

[mdpc]

Is this a different protocol than the ntp daemon, included in the distribution, already provide?

[sashk]

@DavidSchwartz: I specifically was told to use PTP. NTP is not accurate enough for that task.

[Admin]

Did you setup a server to be the master clock?

[sashk]

@luc no, this setup was for slave. difference is in arguments you pass via PTPDARGS in /etc/sysconfig/ptpd2