[ntp:questions] Date Jumped

Maynard maynard7fold at gmail.com
Wed Jan 13 13:34:21 UTC 2010


On Jan 13, 4:23 am, Rob <nom... at example.com> wrote:
> Maynard <maynard7f... at gmail.com> wrote:
> > On 1/7/10, the date on our domain controller jumped to 12/7/10, and
> > was there for about 11 minutes before it reverted back to the current
> > date.  At the time this happened, our NTP server was pointed to
> > pool.ntp.org.  We also have a few Novell servers that were pointed to
> > the same IP addresses as our Server 2003 Domain Controller, and the
> > NTP server for our Novell network also jumped ahead.  Are we the only
> > ones that had this issue on this day?  Or are there others out there
> > that experienced the same problem on the 7th.  Thanks
>
> This can happen any time.  pool.ntp.org is a large collection of
> servers that joined a voluntary pool of servers.  Any single server
> in this pool can send the wrong date and time if it likes to, or if
> there is an error.
>
> The central system that populates the pool.ntp.org DNS name does check
> if the time is right on each server, and removes the address from the
> pool if it isn't.
>
> But once your system has started ntpd and resolved the name pool.ntp.org
> to an address, the address will not change even if the time server goes
> bad.
>
> When you know the address of the server that was in actual use, it may
> be possible to track down the cause (error or sabotage).  With only the
> name there is little you can do.
>
> It is better to use at least 3 different servers from the pool.  I.e.
> use servernames 1.pool.ntp.org 2.pool.ntp.org 3.pool.ntp.org for 3
> different servers.
>
> That way, of one fails or plays nasty games, your time will not be
> affected.

Thanks for all the help.  Looks like I have some digging to do.




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