Leap second tonight

Kevin Oberman oberman at es.net
Wed Dec 31 23:28:16 UTC 2008

> From: Kevin Day <toasty at dragondata.com>
> Date: Wed, 31 Dec 2008 16:41:39 -0600
> Just a reminder that there's a leap second tonight.
> Last time I watched for what happened on 01/01/2006, there was a  
> little bit of chaos: http://markmail.org/message/cpoj3jw5onzhhjkr?q=%22kevin+day%22+leap+second+reminder+nanog&page=1&refer=cnkxb3iv7sls5axu
> I've been told that some of the causes of these problems are fixed on  
> any reasonably recent ntp distribution, but just in case, you might  
> wanna keep an eye out if you're seeing any weirdness. The worst damage  
> I'd heard from anyone after that event was their clock being  
> significantly off for several hours.

While I hope people are not still running NTP versions too old to handle
leap seconds correctly, but that is only a small part of the problem. If
the stratum 1 reference clocks don't handle leap seconds correctly,
there is no way for NTP to deal with it.

We use CDMA clocks and last leap second it took weeks for all of the
cell sites to adjust the last one. As a result, I have set all of our
clocks for manual leap second and set them to adjust tonight at midnight
(UTC).I'll take a look in about 35 minutes and see how it worked.

I've heard reports of various GPS clocks not dealing with the leap
second correctly, as well. Fortunately, not too many need this sort of
accuracy, but those of us who do need to be prepared.
R. Kevin Oberman, Network Engineer
Energy Sciences Network (ESnet)
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)
E-mail: oberman at es.net			Phone: +1 510 486-8634
Key fingerprint:059B 2DDF 031C 9BA3 14A4  EADA 927D EBB3 987B 3751
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