clock slow down on GSR,about 10 seconds a day

[lichuan liu]

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

[lgijssel]

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

[lichuan liu]

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

[Joseph W. Doherty]

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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.

[paolo bevilacqua]

    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.