A list of the Simple Network Time Protocol (SNTP) time servers that are available on the Internet (262680)


The information in this article applies to:

  • Microsoft Windows Server 2003, Enterprise Edition
  • Microsoft Windows Server 2003, Standard Edition
  • Microsoft Windows 2000 Server
  • Microsoft Windows 2000 Advanced Server
  • Microsoft Windows 2000 Professional
  • Microsoft Windows Small Business Server 2003, Premium Edition
  • Microsoft Windows Small Business Server 2003, Standard Edition
This article was previously published under Q262680

SUMMARY

This article describes the Simple Network Time Protocol (SNTP) time servers that are available on the Internet.

MORE INFORMATION

There are two levels, or tiers, of Network Time Protocol (NTP) time servers that are available on the Internet. The NTP is defined in Request for Comments (RFC) 1305.

The first-level time servers are primarily intended to act as source time servers for second-level time servers. The first-level time servers may also be capable of providing mission-critical time services. Some first-level time servers may have a restricted access policy.

Second-level time servers are intended for general SNTP time service needs. Second-level time servers usually enable public access. It is recommended that you use second-level time servers for normal SNTP time server configuration because they are usually located on a closer network that can produce faster updates.

It is recommended that you research any time server selection to ensure that it can meet your specific time server requirements.

The National Institute of Standards and Technology (NIST) maintains a network of time servers that provide time and frequency services for the United States. More information about the NIST may be found at the following Web sites:

http://www.boulder.nist.gov/timefreq/service/its.htm

http://www.boulder.nist.gov/timefreq/

The US Naval Observatory also maintains a network of time servers available for public access. To see a list of servers and their descriptions, visit the following US Naval Observatory Web site:

http://tycho.usno.navy.mil/ntp.html

The NTP uses port 123 so this port must be opened on a firewall or router to ensure proper communication with the NTP server.

For more information about the use of time services in Windows Server and Windows NT, click the following article numbers to view the articles in the Microsoft Knowledge Base:

243574 "Could not locate a time server" after setting SNTP time server using NET TIME command

216734 How to configure an authoritative time server in Windows 2000

224799 Basic operation of the Windows Time Service

Time server list

The following list of NTP time servers is provided as a reference only. This list is not intended to be comprehensive. This list describes currently active NTP time servers that may or may not be able to accommodate your time service needs.

Any NTP time server selection should be evaluated to determine if the server in question meets your specific time server requirements.

NIST time servers

  • time-a.nist.gov
    129.6.15.28
    NIST, Gaithersburg, Maryland
  • time-b.nist.gov
    129.6.15.29
    NIST, Gaithersburg, Maryland
  • time-a.timefreq.bldrdoc.gov
    132.163.4.101 (as of December 1, 1999)
    NIST, Boulder, Colorado
  • time-b.timefreq.bldrdoc.gov
    132.163.4.102 (as of December 1, 1999)
    NIST, Boulder, Colorado
  • time-c.timefreq.bldrdoc.gov
    132.163.4.103 (as of December 1, 1999)
    NIST, Boulder, Colorado
  • utcnist.colorado.edu
    128.138.140.44
    University of Colorado, Boulder
  • time.nist.gov
    192.43.244.18
    NCAR, Boulder, Colorado
  • time-nw.nist.gov
    131.107.1.10
    Microsoft, Redmond, Washington
  • nist1.dc.certifiedtime.com
    216.200.93.8
    Abovnet, North Virginia
  • nist1.datum.com
    209.0.72.7
    Datum, San Jose, California
  • nist1.nyc.certifiedtime.com
    208.184.49.129
    Abovnet, New York City
  • nist1.sjc.certifiedtime.com
    207.126.103.202
    Abovnet, San Jose, California

Level-One Time Servers

Arranged by geographic location:

North America

  • Palo Alto, CA: Systems Research Center, Compaq Computer Corp.
    204.123.2.72: usno.pa-x.dec.com; CNAME: navobs1.pa-x.dec.com
    Service area: U.S. pacific and mountain time zones
  • Marina del Rey, CA: USC Information Sciences Institute
    128.9.176.30: timekeeper.isi.edu
    Service Area: CalRen2 and Los Nettos region
  • Washington, DC: U.S. Naval Observatory
    192.5.41.41: tock.usno.navy.mil
    192.5.41.40: tick.usno.navy.mil
    Service Area: NSFNET
  • Ottawa, Ontario, Canada: National Research Council of Canada
    time.chu.nrc.ca
    Service Area: Canada
  • Raleigh, NC: North Carolina State University
    152.1.58.124: terrapin.csc.ncsu.edu
    Service Area: Southeastern U.S.
  • Cambridge, MA: MIT Information Systems
    18.72.0.3: bitsy.mit.edu
    Service Area: NSFNET and NEARnet area
  • Cambridge, MA: MIT
    18.26.4.105: bonehed.lcs.mit.edu
    Service Area: Eastern U.S.
  • Palo Alto, CA: Internet Software Consortium
    192.5.5.250: clock.isc.org
    Service Area: BARRnet, Alternet-west, and CIX-west
  • Cambridge, MA: Open Software Foundation
    130.105.4.59: clock.osf.org
    Service Area: NSFNET and NEARnet region
  • Palo Alto, CA: ViaNet Communications
    209.81.9.7: clock.via.net
  • Cleveland, OH: Lewis Research Center (NASA)
    128.156.1.43: lerc-dns.lerc.nasa.gov
    Service Area: NSFNET and OARNET
  • Colorado Springs, CO: Schriever AFB
    204.34.198.40: navobs1.usnogps.navy.mil; CNAME: tick.usnogps.navy.mil
    204.34.198.41: navobs2.usnogps.navy.mil; CNAME: tock.usnogps.navy.mil
    Service area: U.S. pacific and mountain time zones
  • St. Louis, MO: Washington University
    128.252.19.1: navobs1.wustl.edu; CNAME: tick.wustl.edu
    Service area: U.S. central time zone
  • Research Triangle Park, NC: MCNC
    192.101.21.1: ncnoc.ncren.net
    Service area: NC-REN region
  • Cupertino, CA: HP
    192.6.38.127: ntp-cup.external.hp.com
    Service Area: West coast U.S.
  • Newark, DE: Conectiv Communications
    138.39.7.20: ntp1.delmarva.com
    Service area: Cable & Wireless Network (formerly MCInet)
  • University Park, PA: Penn State University
    128.118.46.3: otc1.psu.edu
    Service Area: NSFNET, PREPNET, and JvNCnet

Europe

  • Borowiec, Poland: Astrogeodynamical Observatory, Space Research Centre
    150.254.183.15: vega.cbk.poznan.pl
    Service Area: Poland and Europe
  • Stockholm, Sweden: Stupi AB
    192.36.143.151: Time2.Stupi.SE
    Service Area: Europe
  • Torino, Italy: IEN Galileo Ferraris
    193.204.114.1: time.ien.it
    Service Area: Italy and Europe
  • Zurich, Switzerland: Integrated Systems Lab, Swiss Fed. Inst. of Technology
    129.132.2.21: swisstime.ethz.ch
    Service Area: Switzerland and Europe
  • Torino, Italy: CSTV of National Research Council
    150.145.33.1: tempo.cstv.to.cnr.it
    Service Area: Italy and Europe
  • Erlangen, Germany: University Erlangen-Nuernberg
    ntp0.fau.de; ntp1.fau.de; ntp2.fau.de;
    ntps1-0.uni-erlangen.de; ntps1-1.uni-erlangen.de; ntps1-2.uni-erlangen.de
    Service Area: Germany and Europe
  • Berlin, Germany: Technische Universitaet Berlin
    130.149.17.21: ntps1-0.cs.tu-berlin.de
    130.149.17.8: ntps1-1.cs.tu-berlin.de
    Service Area: Germany and Europe
  • Germany
    131.173.17.7: ntps1-1.rz.Uni-Osnabrueck.DE
    Service Area: Germany and Europe
  • Sweden
    192.36.143.150: Time1.Stupi.SE
    Service Area: SUnet and NORDUnet Sweden

East Asia and Pacific Rim

  • Hong Kong: The Chinese University of Hong Kong.
    137.189.6.18: clock.cuhk.edu.hk
    Service Area: Hong Kong, China, and South East Asia
  • Fukuoka, Japan: Fukuoka University
    133.100.9.2: clock.nc.fukuoka-u.ac.jp
    133.100.11.8: clock.tl.fukuoka-u.ac.jp
    Service Area: Japan and Pacific area

Australia

  • Melbourne Australia: The University of Melbourne
    128.250.36.2: ntp.cs.mu.OZ.AU
    Service area: Australia and New Zealand

Level-Two Time Servers

Arranged by geographic location:

North America

NTP time servers:
  • Quebec, Canada: Canadian Meteorological Center
    ntp1.cmc.ec.gc.ca; ntp2.cmc.ec.gc.ca
    Service Area: Eastern Canada
  • Ontario, Canada: National Research Council of Canada
    time.chu.nrc.ca; time.nrc.ca
    Service Area: Canada
  • Saskatchewan, Canada: University of Regina
    142.3.100.15: timelord.uregina.ca
    Service Area: Canada
  • Ontario, Canada: University of Toronto
    tick.utoronto.ca; tock.utoronto.ca
    Service Area: Eastern Canada
  • Mexico: Audiotel office
    ntp2a.audiotel.com.mx; ntp2c.audiotel.com.mx; ntp2b.audiotel.com.mx
    Service Area: Avantel, MCINet, and Mexico
  • Santa Cruz, CA: Scruz-net, inc.
    165.227.1.1: ns.scruz.net
    Service area: Western U.S.
  • San Diego, CA: UCSD Academic Computing Services/Network Operations
    132.239.254.49: ntp.ucsd.edu
    Service Area: CERFNET; NSFNET, SDSC region, and nearby
  • Quincy, California
    ntp1.mainecoon.com; ntp2.mainecoon.com
    Service Area: North America
  • Newark, DE: University of Delaware
    128.175.1.3: louie.udel.edu
    Service Area: CAIRN, Abilene, and vBNS
  • Atlanta, GA: CNSG
    ntp.shorty.com
    Service Area: Southeast U.S.
  • Kennesaw, GA: PeachNet
    rolex.peachnet.edu; timex.peachnet.edu
    Service Area: PeachNet (Georgia) and Southeast U.S.
  • Urbana-Champaign, IL: University of Illinois
    ntp-0.cso.uiuc.edu; ntp-1.cso.uiuc.edu; ntp-2.cso.uiuc.edu
    Service Area: CICNET, Midwest, and NCSA region
  • Chicago, IL: Argonne National Laboratory
    ntp-1.mcs.anl.gov; ntp-2.mcs.anl.gov
    Service Area: NSF/ANSNet, CICNet, NetIllinois, and ESNet
  • West Lafayette, IN: Purdue University
    gilbreth.ecn.purdue.edu; harbor.ecn.purdue.edu; molecule.ecn.purdue.edu
    Service area: NSFNET and CICNET area
  • Manhattan, KS: KansasNet OnLine Services
    199.240.130.1: ntp1.kansas.net
    199.240.130.12: ntp2.kansas.net
    Service area: Central U.S. and Great Plains
  • Boston, MA: UMass-Boston CS dept.
    158.121.104.4: timeserver.cs.umb.edu
    Service Area: New England
  • Minneapolis/St Paul, MN: University of Minnesota
    ns.nts.umn.edu; nss.nts.umn.edu
    Service Area: CICNET region
  • Columbia, MO: University of Missouri-Columbia
    128.206.206.12: everest.cclabs.missouri.edu
    Service Area: MOREnet
  • Omaha, NE: Radiks Internet Access
    205.138.126.83: allison.radiks.net
    Service Area: Midwest U.S.
  • Las Vegas, NV: University of Nevada System Computing Services
    131.216.1.101: cuckoo.nevada.edu
    Service Area: NevadaNet, NSFNET, and SDSC region
  • Las Vegas, NV: UNLV College of Engineering
    tick.cs.unlv.edu; tock.cs.unlv.edu
    Service Area: Sprintnet
  • New York City, NY: Columbia University
    ntp.ctr.columbia.edu
    Service Area: Sprintlink and NYSERnet
  • Ithaca, NY: Cornell University
    192.35.82.50: ntp0.cornell.edu
    Service Area: NSFNET and NYSER region
  • New York, NY: Morningside Campus, Columbia University
    sundial.columbia.edu
    Service Area: NYSERnet
  • New York City, NY: Columbia University Computer Science Department
    timex.cs.columbia.edu
    Service Area: PSINET; NSFNET, and NYSER region
  • Norman, Oklahoma: University of Oklahoma
    129.15.22.8: constellation.ecn.uoknor.edu
    Service Area: Midnet
  • Coos Bay, OR: Koala Computers
    207.48.109.6: tick.koalas.com
    Service Area: Northwestern U.S.
  • University Park, PA: Penn State University
    128.118.25.3: clock.psu.edu
    Service Area: Internet2, vBNS, CERFnet(AT&T IP Services), PSC/NCNE, and CASC
  • Pittsburgh, PA: Pittsburgh Supercomputing Center
    128.182.58.100: fuzz.psc.edu
    Service area: NSFNET and PSC region
  • Pittsburgh, PA: Carnegie Mellon Electrical and Computer Engineering
    ntp-1.ece.cmu.edu; ntp-2.ece.cmu.edu
    Service Area: PREPNET and PSC region
  • Dallas, TX: Cox School of Business, Southern Methodist University
    129.119.80.126: ntp.cox.smu.edu
    Service Area: NSFNET and SESQUI region
  • Hughes Springs, TX: First National Bank
    209.144.20.76: ntp.fnbhs.com
    Service area: Northeast Texas
  • Houston, Tx: Baylor College of Medicine
    128.249.1.10: ntp.tmc.edu
    Service Area: NSFNET and SESQUI region
  • College Station, TX: Texas A&M University
    165.91.52.110: ntp5.tamu.edu
    Service area: NSFNET, SESQUI region, THEnet, and TAMUSDSN
  • Plano, TX: Greyware Automation Products
    tick.greyware.com; tock.greyware.com
    Service Area: South-Central U.S.
  • Blacksburg, VA: Virginia Tech Computing Center
    ntp-1.vt.edu; ntp-2.vt.edu
    Service Area: Southeast U.S.
  • Arlington, VA: Center for Seismic Studies
    140.162.1.3: ntp.cmr.gov
    Service Area: NSFNET and SURA region
  • Richland, WA: Washington State University
    192.31.216.30: clock.tricity.wsu.edu
    Service Area: NSFNET and NorthWestNet
  • Washington, U.S.: Mill Creek
    time.ultimeth.net
    Service Area: Northwest U.S.
  • Wisconsin, U.S.: Computer Science Department, University of Wisconsin-Madison
    ntp1.cs.wisc.edu; ntp2.cs.wisc.edu; ntp3.cs.wisc.edu
    Service Area: U.S. and any

South America

  • Buenos Aires, Argentina: Network Access Point
    200.49.40.1: CNAME: tick.nap.com.ar
    200.49.32.1: CNAME: tock.nap.com.ar
    Service Area: Argentina
  • Buenos Aires, Argentina: Sinectis S.A.
    time.sinectis.com.ar
    Service Area: Argentina
  • Brazil: Brazilian Research Network
    200.144.121.33: ntp.cais.rnp.br
    Service Area: Brazil
  • Venezuela: VELUG, Grupo de Usuarios Linux de Venezuela
    150.185.192.250: ntp.linux.org.ve
    Service Area: Arica

Europe

  • Zurich, Switzerland: Swiss Fed. Inst. of Technology
    129.132.98.11: bernina.ethz.ch
    Service Area: Switzerland and Europe
  • Location: Copenhagen, Denmark, Europe
    clock.netcetera.dk; clock2.netcetera.dk
    Service area: Denmark, Scandinavia, and Northern Europe
  • Spain: Altea
    slug.ctv.es
    Service Area: Spain
  • Pieksamaki, Finland: Keski-Savon Oppimiskeskus
    tick.keso.fi; tock.keso.fi
    Service area: Finland
  • Meudon, France: Observatoire de Paris-Meudon
    ntp.obspm.fr
    Service Area: France and Europe
  • Lyon, France: CISM
    ntp.univ-lyon1.fr
    Service Area: France, Switzerland, Italy, and Europe
  • Paris, France: VIA, Ecole Centrale
    138.195.130.70: ntp.via.ecp.fr
    Service Area: France and Europe
  • Budapest, Hungary: KFKI Research Institute for Particle and Nuclear Physics
    148.6.0.1: time.kfki.hu
    Service Area: HUNGARNET
  • Italy: Net4u Srl, Vercelli, Italy
    195.32.52.129: ntps.net4u.it
    Service area: Italy
  • Oslo, Norway: University of Oslo
    129.240.64.3: fartein.ifi.uio.no
    Service Area: NORDUnet
  • Oslo, Norway: Alcanet International
    time.alcanet.no
    Service Area: Europe
  • Krakow, Poland: Academic Computer Centre
    149.156.4.11: info.cyf-kr.edu.pl
    Service Area: Poland and Europe
  • Lund, Sweden: Lund Institute of Technology
    130.235.20.3: ntp.lth.se
    Service Area: Sweden and NORDUnet
  • Ljubljana, Slovenia: Institute of Biophysics, University of Ljubljana
    biofiz.mf.uni-lj.si 193.2.69.11
    Service Area: Slovenia and Europe
  • Ljubljana, Slovenia: Hydrometeorological Institute of Slovenia
    hmljhp.rzs-hm.si
    Service Area: Slovenia and Europe
  • Ljubljana, Slovenia: Academic and Research Network of Slovenia
    ntp1.arnes.si; ntp2.arnes.si
    Service Area: Slovenia and Europe
  • Ljubljana, Slovenia: J. Stefan Institute
    time.ijs.si
    Service Area: Slovenia and Europe

British Isles

  • Dublin, Ireland: School of Mathematics, Trinity College
    ntp.cs.tcd.ie; ntp.maths.tcd.ie; ntp.tcd.ie
    Service Area: Ireland and U.K.
  • Glasgow, Scotland: Strathclyde University
    ntp.cs.strath.ac.uk
    Service Area: U.K., Europe, and any
  • Cambridge, U.K.
    ntp0.uk.uu.net; ntp1.uk.uu.net;
    ntp2.uk.uu.net
    Service Area: UUNET (formerly known in the U.K. as PIPEX) and U.K.
  • Manchester, England: University of Manchester
    ntp2a.mcc.ac.uk; ntp2b.mcc.ac.uk;
    ntp2c.mcc.ac.uk; ntp2d.mcc.ac.uk
    Service Area: U.K.
  • Buckinghamshire U.K.: Wibble U.K., Aylesbury
    tick.tanac.net
    Service area: U.K.

Asia

  • Moscow, Russia: Landau Institute for Theoretical Physics
    193.233.9.7: ntp.landau.ac.ru
    Service area: Russia
  • Russia: Pushchino (near Moscow)
    194.149.67.130: ntp.psn.ru
    Service area: Russia
  • Chernogolovka, Russia: Chernogolovka Scientific Center (near Moscow)
    193.233.46.10: sign.chg.ru
    Service Area: Russia

East Asia and Pacific Rim

  • Tokyo, Japan: Cyber Fleet, Inc.
    203.139.30.195: ntp.cyber-fleet.net
    Service Area: Japan and East Asia
  • Seoul, Korea: Inet, Inc.
    time.nuri.net
    Service Area: Korea, Japan, Hong Kong, and East Asia
  • Hamilton, New Zealand: The University of Waikato
    truechimer.waikato.ac.nz; truechimer1.waikato.ac.nz;
    truechimer2.waikato.ac.nz; truechimer3.waikato.ac.nz
    Service Area: New Zealand
  • Singapore and the Philippines:
    ntp.shim.org
    Service Area: Singapore

Africa

  • Lagos, Nigeria: Supernet300
    ntp.supernet300.com
    Service Area: Western Africa (primarily Nigerian NITEL backbone)
  • Pietermaritzburg, South Africa: Natal University
    143.128.82.200: ntp.cs.unp.ac.za
    Service area: South Africa

Australia

  • Adelaide, South Australia: The University of Adelaide
    129.127.28.4: augean.eleceng.adelaide.edu.au
    129.127.40.3: ntp.adelaide.edu.au
    203.21.37.18: ntp.saard.net
    Service area: AARNet
  • Carlton, Victoria, Australia: eSec Limited
    203.21.84.4: time.esec.com.au
Modification Type:MinorLast Reviewed:1/20/2006
Keywords:kbinfo kbnetwork KB262680
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