[154450] in North American Network Operators' Group
Re: F-ckin Leap Seconds, how do they work?
daemon@ATHENA.MIT.EDU (Robert E. Seastrom)
Wed Jul 4 09:50:20 2012
To: Tyler Haske <tyler.haske@gmail.com>
From: "Robert E. Seastrom" <rs@seastrom.com>
Date: Wed, 04 Jul 2012 09:48:30 -0400
In-Reply-To: <CAJEFqDeGr+zH39-BT3EbTGR=j8CTzL3+2gvsg6j_QDKysrqndQ@mail.gmail.com> (Tyler
Haske's message of "Wed, 4 Jul 2012 00:02:57 -0400")
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
Tyler Haske <tyler.haske@gmail.com> writes:
> Someone running an NTP Server connected to a cesium clock could run
> the leap-second time code. Since its *their job* to have the correct
> time, they can do all the fancy rarely used things that make parts of
> the Internet die every couple of years.
Ah, Tyler, I see the problem here.
An NTP server is not like an XML-spitting web server which one
consults each and every time one wants to know a piece of data (for
instance a stock quote, the weather, or in this case, what time it
is).
NTP assumes a local clock, and the results of periodic queries to
higher-than-or-equal-to-local-stratum servers are used to _discipline_
the local clock, steering it to have minimal error.
Local clocks have to be consulted much too frequently (logging,
timestamping, etc) for "just put it in the cloud" to work.
You might want to read up on NTP (wikipedia provides a reasonable
introduction).
cheers,
-r
