Setting Up The NTP / Time Server.

To set up Windows 10/11 as an NTP server, first ensure the Windows Time service (W32Time) is running automatically, then enable the NTP server functionality by using command-line tools to add a firewall rule for UDP port 123 and configure the registry settings for time providers. 

 

Enable the Windows Time Service 

1. Open the Run dialog by pressing Windows Key + R.
2. Type services.msc and press Enter to open the Services console.
3. Find the Windows Time service in the list.
4. Right-click on it, select Properties, and set the Startup type to Automatic.
5. Click Start to begin the service if it isn't already running. 

 

Configure as an NTP Server 

1. Open Command Prompt as Administrator.
2. Stop the Windows Time service to make changes: net stop W32Time.
3. Add a firewall rule to allow NTP traffic (UDP port 123): netsh advfirewall firewall add rule name=”NTP Server” dir=in protocol=udp localport=123 profile=any enable=yes action=allow.
4. Configure the Registry: The Windows Time service needs to be told to act as a server.
   • Open the Registry Editor (type regedit in the Run dialog).
   • Navigate to HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeTimeProvidersNtpServer.
   • Locate the Enabled value in the right pane and change its value data to 1.
5. Start the Windows Time Service again: net start W32Time.
6. Verify the configuration by running w32tm /query /configuration in the command prompt and checking for output similar to Enabled: 1 (local) and InputProvider: 1 (Local). 

 

Important Considerations

• Firewall: Ensure UDP port 123 is open on your firewall for other devices to connect to your Windows 10 NTP server. 
• Authorization: For domain-joined environments, you may need to configure the server to be an authoritative time source using the registry settings found at HKEY_LOCAL_MACHINESYSTEMCurrentControlSetServicesW32TimeParameters, as described in the Microsoft Learn article. 
• Time Source: The Windows 10 system itself needs a reliable time source to sync with. This can be an external NTP server or the internet.

Configure Clients to use the NTP / Time Server

To change your Windows machine to use the time server, open the Control Panel, select Date and Time, go to the Internet Time tab, click Change Settings, and then select your desired server from the dropdown list, ensuring "Synchronize with an internet time server" is checked. Click Update now to sync the time with the new server, then click OK to save your changes.

Here are the detailed steps:

1. Open the Control Panel: Type Control Panel in the Windows search bar and select the app.
2. Navigate to Date and Time: In the Control Panel, find and click on Date and Time.
3. Go to the Internet Time tab: In the Date and Time window, click on the Internet Time tab.
4. Change settings: Click the Change Settings... button.
5. Select a new server: In the Internet Time Settings window, make sure Synchronize with an internet time server is checked.
6. Enter the DNS name or IP Address of the NTP Server
7. Update now: Click the Update now button to synchronize your computer's clock with the selected server.
8. Confirm changes: Once you see a success message, click OK on the Internet Time Settings window, and then OK again on the Date and Time window.