[olug] Time

[Daniel Linder]

patricks at digitalrom.com (PS) wrote:
> |Also,  you mentioned not
> |to use 1st tier ntp servers, why not? Just learning.

To which, Brian Wiese replied:
[snip]
> With network latency over the internet, and going by atomic time, you
> might only be off by a fraction of a second to the atomic clocks.  Not
> really a big deal for me. =)

If I remember the NTP RFC correctly, the NTP protocol will do some
computational magic and achieve a highly accurate "skew" for each server
your system contacts.  Thus, if you server at work uses NTP to
clock.redhat.com and clock2.redhat.com with a network round-trip-time
(rtt) of 1.1ms, it knows that it will have to adjust the time it is told
by these servers by 1.1ms.  Similarialy if your home system is connected
via a PPP connection and the rtt to these servers is 23.4ms it will adjust
your home clock by 23.4ms.

NTP will "just work" (tm) as long as it can get packets to/from the clock
server(s).  For the vast marjoity of us mere mortals doing things on a
crude level of 1/100th of a second resolution, NTP is way more accuracy
than required.  If you are using NTP to keep clocks synchronized in a
fusion reactor, then you might want to "tweak" it a bit... :)

-- 
Daniel Linder