07-08-2011 12:58 AM - edited 03-03-2019 06:19 AM
i config ntp on one GSR as NTP source. I found clock time slow down 10 seconds one day, i try another cisco GSR, about slow down 2-3 seconds one day.
i check my watch , it is acuurate with public time.
does anyone meet same problem
thank you
tom
07-08-2011 02:59 AM
You need an external reference clock for accurate timekeeping.
From your description it looks like the clock is unsynchronized.
The attached information provides guidelines for proper setup of ntp
http://www.cisco.com/en/US/tech/tk869/tk769/technologies_white_paper09186a0080117070.shtml
regards,
Leo
07-13-2011 12:26 AM
HI Leo,
This is not about NTP. It's about clock on GSR itself. i found clock of GSR is not accurate , every day it slow down 10 seconds.
for example
i config time according to my watch, but nextday i find clock it slow down for 10 seconds.
i check another GSR, it slow down for 3 second one day.
thank you !
tom
07-13-2011 10:09 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
It's certainly possible the internal clock for your GSR keeps time poorly; I've seen similar with servers. In theory, the on-board clock, I believe, could be designed to use a public utility's AC to keep it from gaining or losing time, but they generally don't appear to do so.
The solution is using NTP from an accurate time source.
PS:
An alternative solution, if any particular device's internal clock consistently loses or gains the same amount of time per day, is to have a KRON task adjust for the slippage on a reoccurring basis.
07-17-2011 04:55 AM
This is not about NTP. It's about clock on GSR itself. i found clock of GSR is not accurate , every day it slow down 10 seconds.for example
i config time according to my watch, but nextday i find clock it slow down for 10 seconds.
i check another GSR, it slow down for 3 second one day.
The answers you have been given are 100% correct, now please try to understand in different words:
For accurate timing, do NOT use router clock (any model). ONLY use NTP clock.
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide