Compartir a través de


Event ID 49 — Domain Hierarchy Time Source Acquisition

Applies To: Windows Server 2008 R2

An Active Directory forest has a predetermined time synchronization hierarchy. The Windows Time service (W32time) synchronizes time between computers within the hierarchy, with the most accurate reference clocks at the top. If more than one time source is configured on a computer, the Windows Time service uses Network Time Protocol (NTP) algorithms to select the best time source from the configured sources, based on the computer’s ability to synchronize with that time source. Currently, the Windows Time service is synchronizing time with a time source peer from the domain heirarchy.

Event Details

Product: Windows Operating System
ID: 49
Source: Microsoft-Windows-Time-Service
Version: 6.0
Symbolic Name: MSG_NO_DC_LOCATED_LAST_WARNING
Message: The time provider NtpClient was unable to find a domain controller to use as a time source. NtpClient will continue trying to locate a domain controller every %1 minutes. This message will not be logged again until after a domain controller is found.

Resolve

Investigate domain configuration

The local computer was not able to contact a domain controller. Ensure that the domain controller is functioning correctly and that it can be discovered. Ensure that the local Domain Name System (DNS) server is online and functioning correctly. Review the events in Event Viewer on the domain controller and the DNS server for configuration errors. Resolve any errors that you discover. When the errors are resolved, resynchronize the client computer with the time source peer.

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority. Perform all steps on the computer that is logging the event to be resolved.

To synchronize the client with time source peer:

  1. Open a command prompt as an administrator. To open a command prompt as an administrator, click Start. In Start Search, type Command Prompt. At the top of the Start menu, right-click Command Prompt, and then click Run as administrator. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.
  2. At the command prompt, type w32tm /resync, and then press ENTER. The command output indicates whether the synchronization was successful.

To learn more about the Windows Time service and related tools, see Windows Time Service Tools and Settings (https://go.microsoft.com/fwlink/?LinkID=42984).

Verify

To perform this procedure, you must have membership in Administrators, or you must have been delegated the appropriate authority.

To verify that the Windows Time service is synchronizing correctly:

  1. Open a command prompt as an administrator. To open a command prompt as an administrator, click Start. In Start Search, type Command Prompt. At the top of the Start menu, right-click Command Prompt, and then click Run as administrator. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  2. At the command prompt, type W32TM /resync, and then press ENTER.

  3. At the command prompt, type W32TM /query /status, and then press ENTER.

    This command displays the status of the Windows Time service synchronization. The Last Successful Sync Time line of the output displays the date and time that you ran the W32TM /resync command in the previous step. Also, check the computer name that is shown as the Source. This should be the name of a domain controller (or an administrator-configured time server) in the same Active Directory domain as the local computer.

To verify that the Windows Time service synchronized successfully with its time source, confirm that Event IDs 35 and 37 appear in Event Viewer. If there was a recovery from a previous failure to synchronize with the time source, you also see Event ID 138, which indicates that the Windows Time service is synchronized correctly.

For more information about the Windows Time service, see the Windows Time Service Technical Reference (https://go.microsoft.com/fwlink/?LinkID=25393).

Domain Hierarchy Time Source Acquisition

Active Directory