Problem:
How do I Use a Domain Controller as NTP Server but the time is Synced with PDC Emulator and not an external time source?
Solution:
Open the registry at:
hkey_local_machine\system\currentcontrolset\services\w32time\config
The key is to set your AnnounceFlags to 5 as below. These settings will allow you to use your Domain Controller as an NTP server but for it to sync with the PDC emulator not an external time source.
Other Settings:
Some commands you can run to verify status:
w32tm /query /status w32tm /resync w32tm /query /source