Article ID: 262680 - View products that this article applies to.
This article was previously published under Q262680
This article describes the Simple Network Time Protocol (SNTP) time servers that are available on the Internet.
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.
Time server listNote You may receive an error message that resembles the following:
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https://support.ntp.org/bin/view/Servers/StratumTwoTimeServersNote Please read the "Rules Of Engagement" before using the Stratum Two Time Servers list. To read the "Rules of Engagement," visit the following Web site:
http://support.ntp.org/bin/view/Servers/RulesOfEngagementDomain joined member computers and application servers should be configured to synchronize time by using the domain hierarchy as described in the Domain Hierarchy-Based Synchronization topic at the following Microsoft TechNet Web site:
http://technet.microsoft.com/en-us/library/cc773013(WS.10).aspxTo synchronize non-domain-joined (workgroup) workstations or servers, visit the following Microsoft TechNet Web site:
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:
(http://support.microsoft.com/kb/888794/ )Considerations when hosting Active Directory domain controller in virtual hosting environments
(http://support.microsoft.com/kb/243574/ )"Could Not Locate a Time Server" After Setting SNTP Time Server Using NET TIME Command
(http://support.microsoft.com/kb/216734/ )How to configure an authoritative time server in Windows 2000
(http://support.microsoft.com/kb/224799/ )Basic Operation of the Windows Time Service
(http://support.microsoft.com/kb/951531/ )The W32Time service does not synchronize the CMOS clock time to the Internet time on a Windows XP or Windows Server 2003-based computer after the W32Time service stops
(http://support.microsoft.com/kb/875495/ )How to detect and recover from a USN rollback in Windows Server 2003
(http://support.microsoft.com/kb/939322/ )Support boundary to configure the Windows Time service for high accuracy environments
(http://support.microsoft.com/kb/897615/ )Support policy for Microsoft software running in non-Microsoft hardware virtualization software
(http://support.microsoft.com/kb/289668/ )Advancing time on production computers and the effect on Active Directory and FRS
Article ID: 262680 - Last Review: July 9, 2012 - Revision: 9.0