How do I know which server is the time server in a domain ?

Snow-Munki · 14 Jun 2008 at 12:32

All the clocks on our network is like 5 mins out

Always thought it was the PDC that set the time and I have changed the reg settings so the time is from the CMOS and not an external time source.

Rebotted loads of times and set the time in the cmos but it keeps resettings back to 5 mins forwards...

How can I find out what is causing this ?

Checked and the server I'm making changes on is the PDC operation master.

m4cc45 · 14 Jun 2008 at 13:35

It's the local DC that sets the time.

You can change a server to be authoritive though.

http://support.microsoft.com/kb/816042

Above link should help you.

M.

Snow-Munki · 14 Jun 2008 at 16:04

thanks, pretty sure I followed the same link earlier.

Oh and we have 5 DC's

m4cc45 · 14 Jun 2008 at 20:11

Well the DC's should take it off the PDC then the clients of the local DC's. By that I mean if you have multiple sites then the users will go to the local DC to get there time and then that DC to the PDC.

I think you need to rever the reg back (presumably on the PDC?) and get that to download of an ntp server (or if you have a device then use this) changing it to CMOS would not be right as that could be out, battery could die, it's not going to update with daylight saving, etc.

M.

Deathwish · 14 Jun 2008 at 22:50

I would hesitate in getting time from an external ntp source. If for some reason it becomes compromised, or just breaks, then you could let your network be at risk of serious time sync issues.

Things like Exchange and SQL really don't like having huge time variations.

Snow-Munki · 16 Jun 2008 at 08:26

Deathwish said:
I would hesitate in getting time from an external ntp source. If for some reason it becomes compromised, or just breaks, then you could let your network be at risk of serious time sync issues.

Things like Exchange and SQL really don't like having huge time variations.

So I shouldn't use an external NTP source, are you saying ?

I tried following the documentation of external time source but it just wouldn't get any data.

And yeah tried the firewall and may no difference.

Deathwish · 16 Jun 2008 at 19:01

Personally, no, I wouldn't. I would have the PDC check the core router for its time (port 123). Periodically, check the time on the router, if its out correct it and the next time the PDC checks it will update and cascade down etc.