SNTP服务器是什么意思

复制来的

SNTP：简单网络时间协议（Simple Network Time Protocol）

SNTPV4 由 NTP 改编而来，主要用来同步因特网中的计算机时钟。 SNTP 适用于无需完全使用 NTP 功能的情况。比较以前的 NTP 和 SNTP 版本， SNTPV4 的引入没有改变 NTP 规范和原有实现过程，它是对 NTP 的进一步改进，支持以一种简单、无状态远程过程调用模式执行精确而可靠的操作，这类似于 UDP / TIME 协议。

强烈建议 SNTP 仅用于同步子网的末端情况。 SNTP 客户机操作于子网末端，一个 SNTP 客户机不应靠另一个 SNTP 客户机来同步。 SNTP 服务器位于子网根部（即第 1 层），且不应有其它时间同步源，除了有用的可靠无线电波（RADIO）及调制解调器时间服务器外。一般通过冗余时间同步源、不同子网路径及完整的 NTP 运行算法等共同作用，可实现基本服务器的完全可靠度。如果所有的时间同步源失效或大部分时间不准确，主同步时间源就会切换到使用无线电波或调制解调器，所以，在主服务器上使用 SNTP 而不是 NTP 时要多加注意。

与 NTP 及 SNTP 相比， SNTPV4 中唯一改进了协议头使其适用于 IPV6 和 OSI 寻址。此外 SNTPV4 包括了对基本 V3 模式的可选项扩展，包括任意播模式（anycast）和认证方式（用于组播和任意播模式）。

协议结构

SNTP 信息具有与 NTP 相同的格式：

2 5 8 16 24 32bit

LI VN Mode Stratum Poll Precision

Root Delay

Root Dispersion

Reference Identifier

Reference timestamp （64）

Originate Timestamp （64）

Receive Timestamp （64）

Transmit Timestamp （64）

Key Identifier (optional) （32）

Message digest (optional) （128）

这些应该都是的，大家自已找找看有没有能用的（等于号前面的部份）。

fartein.ifi.uio.no=Norway, University of Oslo

ntp.lth.se=Sweden, Lund Institute of Technology

time.service.uit.no=Norway, University of Tromsoe

ntp0.pipex.net=UK, Cambridge

ntp0.nl.net=Netherlands, Amsterdam, NLnet

ntp2.pipex.net=UK, Cambridge

ntp0.ja.net=UK, University of Cambridge Computer Laboratory

ntp.cs.strath.ac.uk=Scotland, Strathclyde University, Glasgow

ntp1.strath.ac.uk=Scotland, Glasgow, Strathclyde University

ntp2a.mcc.ac.uk=England, University of Manchester, Manchester

ntp4.strath.ac.uk=Scotland, Glasgow, Strathclyde University

ntp0.strath.ac.uk=Scotland, Glasgow, Strathclyde University

ntps1-1.cs.tu-berlin.de=Germany, Berlin, Technische Universitaet Berlin

ntp1.pipex.net=UK, Cambridge

ntp2.strath.ac.uk=Scotland, Glasgow, Strathclyde University

ntp.univ-lyon1.fr=France, Lyon, CISM

ntps1-0.cs.tu-berlin.de=Germany, Berlin, Technische Universitaet Berlin

ntp3.strath.ac.uk=Scotland, Glasgow, Strathclyde University

ntps1-0.uni-erlangen.de=Germany, Erlangen, University Erlangen-Nuernberg

ntps1-2.uni-erlangen.de=Germany, Erlangen, University Erlangen-Nuernberg

ntps1-1.uni-erlangen.de=Germany, Erlangen, University Erlangen-Nuernberg

time.ijs.si=Slovenia, J. Stefan Institute, Ljubljana

biofiz.mf.uni-lj.si=Slovenia, University of Ljubljana

info.cyf-kr.edu.pl=Poland, Academic Computer Centre, Krakow

bitsy.mit.edu=USA, MA, Cambridge, MIT Information Systems

nic.near.net=USA, MA, Cambridge

time-b.nist.gov=

ntp-1.ece.cmu.edu=USA, PA, Pittsburgh, Carnegie Mellon

swisstime.ethz.ch=Switzerland, Zurich, Integrated Systems Laboratory

time-a.nist.gov=time-a.nist.gov

ntp-2.ece.cmu.edu=USA, PA, Pittsburgh, Carnegie Mellon

otc1.psu.edu=USA, PA, Penn State University

timex.peachnet.edu=USA, GA, Kennesaw, PeachNet NOC

fuzz.psc.edu=USA, PA, Pittsburgh, PSC Supercomputer Center

timex.cs.columbia.edu=USA, NY, New York, Columbia University

vtserf.cc.vt.edu=USA, VA, Virginia Tech Computing Center

clock-1.cs.cmu.edu=USA, PA, Pittsburgh, Carnegie Mellon University

gilbreth.ecn.purdue.edu=USA, IN, West Lafayette, Purdue University

harbor.ecn.purdue.edu=USA, IN, West Lafayette, Purdue University

molecule.ecn.purdue.edu=USA, IN, West Lafayette, Purdue University

nss.unet.umn.edu=USA, MN, St. Paul

ns.unet.umn.edu=USA, MN, Minneapolis

clock.psu.edu=PA, Penn State University, University Park

noc.near.net=USA, MA, Cambridge

salmon.maths.tcd.ie=Ireland, Dublin, Trinity College

ntp.ctr.columbia.edu=USA, NY, New York, Columbia University

finch.cc.ukans.edu=USA, Kansas University Computer Center

ntp-0.cso.uiuc.edu=USA, IL, Champaign, University of Illinois

ntp.maths.tcd.ie=Ireland, Trinity College, Dublin

nss.nts.umn.edu=USA, MN, St Paul

tock.usno.navy.mil=USA, Washington DC, U.S. Naval Observatory

eagle.tamu.edu=USA, Texas A&M University

ntp5.tamu.edu=TX, Texas A&M University, College Station

www2.cmc.ec.gc.ca=Canada, Canadian Meteorological Centre, Dorval

kuhub.cc.ukans.edu=USA, KN, Lawrence, Kansas University

ntp-2.cso.uiuc.edu=USA, IL, Champaign, University of Illinois

zeus.tamu.edu=USA, TX, College Station, Texax A&M

www1.cmc.ec.gc.ca=Canada, Canadian Meteorological Centre, Dorval

ntp-1.mcs.anl.gov=USA, IL, Chicago, Argonne National Laboratory

ntp1.cs.wisc.edu=University of Wisconsin-Madison, Computer Science Department

tmc.edu=USA, TX, Houston, Baylor College of Medicine

ntp.css.gov=USA, VA, Arlington, Center for Seismic Studies

time.nist.gov=USA, CO, Boulder, National Center for Atmospheric Research

ntp-2.mcs.anl.gov=USA, IL, Argonne National Laboratory

time-A.timefreq.bldrdoc.gov=USA, CO, National Institue of Standards and Technology

ntp3.cs.wisc.edu=University of Wisconsin-Madison, Computer Science Department

clock1.unc.edu=USA, NC, Chapel Hill, University of North Carolina

tock.cs.unlv.edu=USA, NV, Las Vegas, UNLV Computer Science Department

louie.udel.edu=USA, DE, University of Delaware

tick.cs.unlv.edu=USA, NV, Las Vegas, UNLV Computer Science Department

cuckoo.nevada.edu=USA, NV, Las Vegas, University of Nevada

time.nrc.ca=Canada, National Research Council of Canada, Ottawa

rolex.peachnet.edu=USA, GA, Kennesaw, PeachNet NOC

mizbeaver.udel.edu=USA, DE, Newark, University of Delaware

clepsydra.dec.com=USA, CA, Palo Alto, DEC Research Laboratory

tick.utoronto.ca=Canada, University of Toronto

ntp.nasa.gov=USA, CA, NASA Ames Research Center

timelord.cs.uregina.ca=Canada, Saskatchewan, University of Regina

everest.cclabs.missouri.edu=USA, MO, University of Missouri-Columbia

ntp.ucsd.edu=USA, CA, San Diego, UCSD Computer Science &Engineering

wwvb.isi.edu=USA, CA, Marina del Rey, USC Information Sciences Institute

tick.usno.navy.mil=USA, Washington DC, U.S. Naval Observatory

clock.isc.org=USA, CA, Palo Alto, Internet Software Consortium

chime.utoronto.ca=Canada, University of Toronto

sundial.columbia.edu=USA, NY, New York, Mornigside Campus Columbia University

ntp0.cornell.edu=USA, NY, Cornell University, Ithaca

ntp.saard.net=Australia, The University of Adelaide

augean.eleceng.adelaide.edu.au=Austrialia, University of Adelaide

clock.nc.fukuoka-u.ac.jp=Japan, Fukuoka, Fukuoka University

ntp.adelaide.edu.au=Australia, University of Adelaide

clock.tl.fukuoka-u.ac.jp=Japan, Fukuoka, Fukuoka University

timeserver.cs.umb.edu=USA, MA, Boston, University of Massachusetts

gazette.bcm.tmc.edu=USA, TX, Houston, Baylor College of Medicine

1 通过开始菜单，输入regedit命令后打开注册表设定画面。

2 修改以下选项的键值

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NtpServer内的「Enabled」设定为1，打开NTP服务器功能

SNTP服务器设置操作步骤图

3 修改以下键值HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags设定为5

该设定强制主机将它自身宣布为可靠的时间源，从而使用内置的互补金属氧化物半导体 (CMOS) 时钟。

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