[ntp:questions] ntpdate.c unsafe buffer write
smith at cag.zko.hp.com
Sat Feb 9 12:41:54 UTC 2008
Richard B. Gilbert wrote:
> David Woolley wrote:
>> David L. Mills wrote:
>>> You make some good points. However, if folks want SNTP from here I
>>> think they would prefer it in its own distribution rather than bundle
>>> it with the huge NTP distribution. You can make a strong argument to
>>> host here
>> I don't think you are ever going to get rid of ntpdate from the
>> distribution (as supplied by packagers and vendors) until ntpd offers
>> a mode which sets the time within about one second of being started.
>> I'm not convinced that SNTP will displace ntpdate for this purpose.
>> People don't want to delay boot sequences, but they also don't want to
>> start applications until the time has been set.
> How long does "ntpd -g" take to set the time? As I understand it, it's
> supposed to query the configured servers, make a "best guess" as to what
> time it is, set that, and then go to normal operation.
> That should put you within a second or so. If you need better, either
> wait for it, or keep your server alive 24x7x365. I think most data
> centers do run 24x7x365. If you're talking about a "data center" that
> lives under the boss's desk, consider buying a UPS and hope that the
> power doesn't fail for longer than the run time.
David is right.
He means be done with it, including hard-setting the clock, within a second.
The accuracy expected, based on "ntpdate -b" as the benchmark you are trying to
replace, is within a small number of milliseconds of the specified servers.
Sorry, "ntpd -q" doesn't meet the requirements.
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