[ntp:questions] Date Jumped

Rob nomail at example.com
Wed Jan 13 10:23:26 UTC 2010

Maynard <maynard7fold 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

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

More information about the questions mailing list