Windows 10 is ignoring time changes on Samba 4 DC

Question

I have got and VM with a Samba 4 installed as AD DC. It is also NTP server and the time on the server is correct. Tested with ntpdate -q ntp-server, which gives the correct time and date:

ntpdate -q dc01
-> server 10.0.0.25, stratum 2, offset -0.000003, delay 0.02570
->  5 Apr 00:29:02 ntpdate[19581]: adjust time server 10.0.0.25 offset -0.000003 sec

Today I started my Windows 10 client first time after the winter to summer time change and it's still in winter time. I tried following, to no avail:

w32tm /config /syncfromflags:domhier /update
-> The command completed successfully.

net stop w32time
-> The Windows Time service is stopping.
   The Windows Time service was stopped successfully.

net start w32time
-> The Windows Time service is starting.
-> The Windows Time service was started successfully.

w32tm /resync
-> Sending resync command to local computer
-> The computer did not resync because no time data was available.

I assume 'Sending resync command to local computer' means tell the NTP client to connect to the NTP server (the AD DC VM) to get the time correction.

Obviously nothing happens.

As additional hint and maybe of value: The "Internet Time" tab in the "Date and Time" configuration dialog is not showing, what seems to be normal in case of domain clients.

Thanks for any input!

Answer 1

Finally some random w32time related posts let me to the solution. First, logging helps:

w32tm /debug /enable /file:c:\temp\ntpDebug.log /size:102400 /entries:0-300
w32tm /resync
-> Sending resync command to local computer
-> The computer did not resync because no time data was available.

In the logfile, there had been the AD DC listed as time server, but it still claimed to have no time server to ask.

The error message "Tx timestamp not returned and may be unsupported on the current network interface" let me to following microsoft support article.

w32tm /config /manualpeerlist:"dc01,0x8 dc02,0x8" /syncfromflags:MANUAL
net stop w32time
net start w32time
w32tm /resync
-> Sending resync command to local computer
   The command completed successfully.

Obviously Samba 4 doesn't like Windows 10 symmetric active mode requests. Hence, use 0x8 to switch the time client to client mode.

Don't forget to switch off logging:

w32tm /debug /disable

Here we go :)