Synchronizing Server 2008 R2 (PDC) / Network Time with External Time Source (NTP Server)

Ever struggle to keep time correct in your network environment? How about across multiple sites? It’s best to to use an external NTP server.

Network Time Protocol (NTP) is a networking protocol for clock synchronization between computer systems over packet-switched, variable-latency data networks.

There are plenty of reliable free NTP servers to choose from however, we recommend

Here is a helpful tip to synchronize your Windows Server 2008 R2 time to an external time source.

NOTE: Before you begin, don’t forget to open the default UDP 123 port (inbound and outbound) on your gateway firewall.

  1. First, locate your PDC Server. Open the command prompt and type: C:\>netdom /query fsmo
  2. Log in to your PDC Server and open the command prompt.
  3. Stop the W32Time service: C:\>net stop w32time
  4. Configure the external time sources, type: C:\> w32tm /config /syncfromflags:manual /manualpeerlist:”,,”
  5. Make your PDC a reliable time source for the clients. Type: C:\>w32tm /config /reliable:yes
  6. Start the w32time service: C:\>net start w32time
  7. The windows time service should begin synchronizing the time. You can check the external NTP servers in the time configuration by typing: C:\>w32tm /query /configuration
  8. You can also check the status of each individual NTP peer by running: C:\>w32tm /query /peers
  9. To update other workstation or server clocks immediately you can run C:\>w32tm /resync from the workstation or server.
  10. As you always should, review the Event Viewer for any errors.

Here are several other free NTP servers available for use: and

For more information about w32tm commands please review:


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