Synchronize time with external NTP

Time synchronization is an important aspect for all computers on the network. By default, the clients 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. I usually 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 outbound) on your (corporate) 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:”0.pool.ntp.org, 1.pool.ntp.org, 2.pool.ntp.org”

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. Check the Event Viewer for any errors.
9. If you need manual synchronize to NTP server :

   C:>w32tm /config /update

Tested on Windows Server 2008 R2 (Build 7600).