Windows NTP server

This document explains how to enable and disable the Windows NTP server.

Note: Commands here must be run in an administrative command prompt

Installing and enabling the NTP server

Enabling the Windows NTP server and adding a firewall rule

w32tm /register
netsh advfirewall firewall add rule name="Windows Time Service" dir=in action=allow profile=private,domain service=w32time

Alternative configuration

The firewall command can be altered to get more precise control of who can sync the time. Options here replace identical options in the command above

• profile=any Allow people to sync time on untrusted networks too.
• enable=no Create the rule but do not enable it yet.
• remoteip=localsubnet Allow only clients on your local subnet to sync
• localip=W.Y.X.Z For computers with multiple interfaces, only apply the rule for the given local IP address

Enabling and disabling the rule

netsh advfirewall firewall set rule name="Windows Time Service" new enable=X

Set X to no or yes

Uninstalling the NTP server

w32tm /unregister
netsh advfirewall firewall delete rule name="Windows Time Service" dir=in