[ntp:questions] Re: NTP miss-information

David L. Mills mills at udel.edu
Wed Feb 2 04:25:58 UTC 2005


At the NTP project page www.eecis.udel.edu/~mills/ntp.html you can find 
a number of white papers on generic NTP issues, including the timescale, 
rollover, leapsecond and other arcane issues. In fact, while the NTP 
timestamp does roll over in 2036, the computer clock time will <<not>> 
be affected. You might have some trouble believing that, but see the 
paper and analyze for yourself.


Alain wrote:
> Steve Gibson says in
> http://www.grc.com/port_123.htm
> ----------   
> The network time protocol is a clean, simple, lightweight, and efficient 
> protocol allowing clients to query servers for the current time 
> (including the date). The only glitch is that the 64-bit NTP time value 
> will overflow (suddenly go back to zero) in early February (the 6th or 
> 7th, no one seems to be sure which) in the year 2036. I plan to be 
> relaxing on a beach somewhere on that day.
> The NTP time format is a simple 64-bit number which uses the most 
> significant 32-bits to represent the number of seconds which have 
> elapsed since Midnight of January 1st, 1900. The least significant 
> 32-bits represent the fraction of that second which have elapsed.
> -----------
> For what I have understood, NTP time is formed of 2 64bit numbers, am I 
> right? could someone please point me to the correct intormation so that 
> I can sent to him?
> FYI, he provides a very good firewall tester "Shields-up" at www.grc.com
> Thanks,
> Alain

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