w32tm Windows Server NTP Network Time

Correct time synchronization in an AD domain environment is a prerequisite for stable operation. This article describes how NTP (w32tm) is configured on a Windows Server (FSMO). As a rule, the PDC operations master is the NTP service server in a forest. A PDC emulator in a domain is synchronized with an external time source. In order for a domain controller to be regarded as a reliable time source, this must be specified explicitly.

w32tm time server

In order to make the PDC emulator a reliable time source that regularly synchronizes with time servers on the Internet, the following commands from PowerShell are executed as administrator:

net stop w32time

w32tm /config /syncfromflags:manual /manualpeerlist:"0.ch.pool.ntp.org 1.ch.pool.ntp.org"

w32tm /config /reliable:yes

net start w32time

Show which time server is currently in use.

w32tm /query /source

Execute the time synchronization immediately.

w32tm.exe /resync /rediscover /nowait

Any clients and servers in domain forest as well as shared storages can now synchronize the time with the PDC emulator.

The firewall permit UDP port 123 inbound, e.g. allow outgoing.

The NTP configuration can also be done via GPO by calling gpmc.msc.

Following Test Displays a graph of the offset between synchronizing computers.

w32tm /stripchart /computer:pdc.domain.local /samples:1 /dataonly

The configuration can also be checked in the registry.

What is w32tm

In computing, w32tm is a command-line tool of Microsoft Windows operating systems used to diagnose problems occurring with time setting or to troubleshoot any problems that might occur during or after the configuration of the Windows Time service. It was introduced as a standard feature of Windows XP.

The command can be used to convert an NTTE or NTP formatted date into a readable format.