Configuring AD Domain Controller to sync off a NTP source

1) Check which is the PDC emulator (Users & Computers → Operations Masters) 2) on The PDC configure with NTP peer list to sych (space seperated)

w32tm /config /manualpeerlist:"0.ie.pool.ntp.org,0x1 1.ie.pool.ntp.org,0x1
w32tm /config /reliable:yes

This details are stored here:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\

Change type from “NT5DS” to “NTP” (using registry).

Restart w32time service

w32tm /resync
w32tm /query /status

And use wireshark and event viewer to confirm all OK.

for more info see:
http://www.articlesbase.com/networks-articles/how-to-configure-windows-server-as-a-ntp-server-108481.html

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config\AnnounceFlags 
Set the ‘Announce Flags’ registry entry to 5, to indicate a reliable time source.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NTPClient\SpecialPollInterval
The ‘Special Poll Interval’ registry entry defines the period in seconds that the Windows 2003 machine should poll the NTP server. A recommended value is 900 seconds, which equates to every 15 minutes.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\NtpServer
The ‘NTP Server’ parameter is used to provide a list of IP addresses or DNS names, separated by a space, of NTP servers that the Windows 2003 machine can synchronise to. 

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\TimeProviders\NTPServer\Enabled
Changing the ‘Enabled’ flag to the value 1 enables the NTP Server.

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Parameters\Type
Change the server type to NTP by specifying ‘NTP’ in the ‘Type’ registry entry.