Hi, We have been getting errors on our DCs, and time synchronisation issues for some time. We have 3 Win 2008 DCs and 1 Win 2003 DC PDC is our DC01 (2008), which also holds RID role. Other roles (Schema master, Domain naming master, and Infrastructure master) are currently owned by the Win2003 DC. Several client machines have had problems as a result with time synchronisation. On Win2008 DC01 (last seen 25/06/11) Log Name: System Source: W32Time Date: 25/06/2011 9:09:02 PM Event ID: 36 Task Category: None Level: Warning Keywords: Classic User: N/A Description: The time service has not synchronized the system time for 86400 seconds because none of the time service providers provided a usable time stamp. The time service will not update the local system time until it is able to synchronize with a time source. If the local system is configured to act as a time server for clients, it will stop advertising as a time source to clients. The time service will continue to retry and sync time with its time sources. Check system event log for other W32time events for more details. Run 'w32tm /resync' to force an instant time synchronization. Also related Event IDs: 47, 12 On Win 2003 DC, errors are: Event Type: Error Event Source: W32Time Event Category: None Event ID: 29 Date: <var>Date</var> Time: <var>Time</var> User: N/A Computer: <var>ComputerName</var> Description: The time provider NtpClient is configured to acquire time from one or more time sources, however none of the sources are currently accessible. No attempt to contact a source will be made for 15 minutes. NtpClient has no source of accurate time. For more information, see Help and Support Center at http://support.microsoft.com. net time /querysntp results in: Win2008DC01: The current SNTP value is: ntp.per.connect.com.au,0x1 Win2008DC02: The current SNTP value is: time.windows.com,0x9 Win2008DC03: The current SNTP value is: time.windows.com,0x9 Win2003DC01: The current SNTP value is: time.uwa.edu.au Should we have ONLY one NTP server speciifed across all DCs, or is this configuration correct?... I have read in other forums that the PDC Emulator should be configured to sync with an external time source and reconfigure the other machines to use only domain time. Is this correct, and if so, can you confirm how this is done? Many thanks..

Hi. has the Server more than one IP adress ? We had the Problem that we only allowed the "main" IP adress to conntact the Timeservers, but windows uses the mathematical best matched IP to conntact the Syncserver. Can you ping the target Servers ?

Time synchronization is an important aspect for all computers on the network . By default, the client's computers get their time from a Domain Controller and the Domain Controller gets his time from the domain’s PDC Operation Master. Therefore the PDC must synchronize his time from an external source . Use the servers listed at the NTP Pool Project website. Before you begin, don’t forget to open the default UDP 123 port (in and out) on your firewall . First, locate your PDC Server: Open the command prompt on a DC and type: C:\>netdom /query fsmo Log in to your PDC Server and open the command prompt. Stop the W32Time service: C:\>net stop w32time Configure the external time sources, type: C:\> w32tm /config /syncfromflags:manual /manualpeerlist:”0.pool.ntp.org, 1.pool.ntp.org, 2.pool.ntp.org” Make your PDC a reliable time source for the clients: Type:C:\>w32tm /config /reliable:yes Start the w32time service: C:\>net start w32time The windows time service should begin synchronizing the time.

Hello, the PDCEmulator DC should be configured to an external time source or stratum device. more details in: http://msmvps.com/blogs/mweber/archive/2010/06/27/time-configuration-in-a-windows-domain.aspx Normal;y all DCs sync with the PDCEmulator. Make sure no firewall is blocking port 123 UDP.Best regards Meinolf Weber Disclaimer: This posting is provided "AS IS" with no warranties or guarantees , and confers no rights.

Hi and thanks you for your answer. I plan to configure PDC to point to pool.ntp.org (as per niryair suggestion) Given that we currently have 3 different time servers, which is clearly wrong. You say that other DCs 'normally' synch with the PDC, however how do I 'ensure' that the other DCs synchronise with the PDC. Many thanks.

Thanks very much for your reply. I will be using pool.ntp.org as a time source for PDC.