ntpd Helpful Hints

Links to General Information

general
servers
win32

unix/linux helpful commands

command	description
ntpdate hostname	force sync; needs ntpd down first
ntpstat	show time synch status
ntpdc	special (read useful) query program
ntptrace	trace heirarchy back to time root note: patience after changes/restart (~300s?)
ntptime	read kernel time variables
ntpq	standard query program
ntpd	daemon

sample /etc/ntp.conf

    # 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 [TODO:subnet] mask [TODO:netmask] nomodify notrap

    # --- OUR TIMESERVERS -----
    server [TODO:hostname]
    server [TODO:backup]
    server ntp-1.cso.uiuc.edu    #130.126.24.24 IPs valid 01/11/2005
    server ntp3.cs.wisc.edu      #128.105.37.11
    server clock.nyc.he.net      #209.51.161.238
    server clock.sjc.he.net      #216.218.254.202

    # --- 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 127.127.1.1
    fudge 127.127.1.1 stratum 3 refid NIST

    # 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/ntp.drift

    # Gather some runtime info
    statsdir /var/lib/ntp/stats/
    logfile /var/log/ntpd.log

    # 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

    # Other options
    statistics sysstats peerstats
    disable auth
    enable stats