Tracking down the time.

[ddrueding]

I have a client where, about once every other day, all the computer clocks go wrong at the same time (about 22 minutes fast every time). They only have one DC, and it is also the DHCP server, but how is it's clock going wrong? Is it linked to a bad online time server? How do I tell?

 

[blakerwry]

DC's, like domain members, just use the w32time service for synchronization.

By default, I believe the DC will use the hardware clock (may have changed in more recent versions of windows), but can be configured to use NTP as a source as well. You can find a wealth of information online about how to configure the w32 time service.

I've never had a problem with a public NTP server, which makes me wonder if they are perhaps using a local router as a time source, or have some 3rd party time software setup.

A basic list of w32time commands can be found here

 

[sechs]

All NT-based OSes keep the time in software after startup.

Have you looked at the date and time control panel to see what server it's using? Alternately, you can use net time through a console, but I'm pretty rusty on some of the appropriate commands.