A list of the Simple Network Time Protocol (SNTP) time servers
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.
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
Resources:
http://support.microsoft.com/kb/262680
http://tycho.usno.navy.mil/ntp.html
http://tf.nist.gov/
http://tf.nist.gov/service/its.htm
