Configuring the Time Service: NtpServer and SpecialPollInterval

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Frank — Wed, 19 Mar 2008 05:07:37 GMT

Hi, just wanted to say this is an excellent article. This finally have cleared up one of my confusions about setting up NTP, namely: Why does MS tell me I have to add ,0x1 to the end of a DNS name? http://support.microsoft.com/kb/816042

Reading that KB article again, it's really perfectly clear the way they state it. For some reason though I always mis-interpreted the meaning until now. I thought the ,0x1 was somehow telling Windows that it's a DNS name, rather than an IP address. (Obviously that would be dumb.)

Finally makes sense now though. Thanks!

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Ryan Sizemore — Wed, 19 Mar 2008 05:15:07 GMT

Glad to hear you like it. If you can think of any other topics that have you puzzled regarding w32time, let me know and I'll try to add some clarification.

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Frank — Fri, 21 Mar 2008 04:11:48 GMT

Actually, now that you mention it, why does the article recommend using 0x1? Is there something wrong with letting NTP decide the interval on its own?

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Ryan Sizemore — Fri, 21 Mar 2008 08:39:36 GMT

Nope, nothing wrong with that at all. Most domain admins prefer to have the PDC (or root time source) sync at a regular interval, so this post mirrors those requests.

re: Configuring the Time Service: NtpServer and SpecialPollInterval

brorymes — Thu, 05 Jun 2008 21:14:15 GMT

Just checking (possible typo?):

In both examples, time.windows.com is followed by 0x01, although you indicate that both the 0x01 and 0x08 flags apply (i.e. SpecialInterval + Client).

Shouldn't time.windows.com be followed by 0x09 in both examples, since (0x01 OR 0x08) = 0x09?

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Gary — Wed, 08 Oct 2008 16:43:25 GMT

Ryan,

Just had a time problem that caused me to do some research on W32Time. We have two time sources defined but the active one had a problem which caused a change of time by 365 days. The question was can W32Time be configured to sample two times sources and compare them, if I'm reading correctly then this is not possible.

Regards,

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Ryan Sizemore — Wed, 08 Oct 2008 19:14:31 GMT

Gary:

It would be best to ask these questions on the forums, but nonetheless...

If a feature like that existed, how would we know which one was the correct one? The correct way to solve this is to impose a set of limits on the phase correction. See the article above about Max*PhaseCorrection. This will limit the size of the time jump that w32time can make, thus preventing your 365 day jumps.

In Windows Server 2008, we imposed a new set of default limits of 48 hours to prevent this type of problem. You should consider setting those same limits in your environment.

Ryan

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Gus — Sun, 14 Dec 2008 01:34:12 GMT

Do I need special software for my MS web server 2003 to synchronize my routers time. I am trying to use the ntp services on my cisco devices to get the time from my web server using only W32time services. What a drag!!!

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Ryan Sizemore — Sun, 14 Dec 2008 03:32:38 GMT

No, you don't need special software. You need to enable the NtpServer, which will allow your cisco device to sync with the web server. Take a look at the article titled "Configuring a Standalone NtpServer". It should cover everything you need.

Ryan

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Donno Cole — Mon, 19 Oct 2009 13:52:51 GMT

I find that when using an IP address for the time server, the 0x01 switch is not being applied properly. The IP address fails to resolve and no time packets are received from the server.

Is there a trick to get it to work with an IP address?

Thank you!

re: Configuring the Time Service: NtpServer and SpecialPollInterval

Ryan Sizemore — Mon, 19 Oct 2009 15:34:35 GMT

Hi Donno,

Using an IP address should be no different than using a DNS name. For example, "123.234.12.23,0x01" should be all that you need.