nanog mailing list archives

Re: Leap second reminder


From: Deepak Jain <deepak () ai net>
Date: Sat, 31 Dec 2005 17:18:41 -0500


Cisco seems happy as well. (adding leap second, leap second occurs at), etc.

>sh ntp status
Clock is synchronized (adding leap second), stratum 2, reference is xxx.xxx.xxx.xxx
nominal freq is 250.0000 Hz, actual freq is 249.9975 Hz, precision is 2**18
reference time is C7617E39.3A0B3D8C (17:01:29.226 EST Sat Dec 31 2005)
clock offset is 0.5332 msec, root delay is 5.11 msec
root dispersion is 7.72 msec, peer dispersion is 7.14 msec
Leap second occurs at C7619A00.00000000 (19:00:00.000 EST Sat Dec 31 2005)

Happy New Year!

Deepak

Gerry Boudreaux wrote:


On Dec 31, 2005, at 11:58 AM, Kevin Day wrote:



Just a reminder, at midnight UTC there's a leap second added to most time systems.

Some time systems will stop the clock at 23:59:59.999999 for 1 second, some will display 23:59:60 for a second.

Since the last leap second (1998), "leap second aware" time keeping systems(NTP, GPS, etc) have become much more prevalent, so it's much more likely this time that applications and NTP sync'ed devices will see a leap second happen(rather than have them manually corrected later, or not corrected at all). But, I'm not too sure how well everyone has tested applications and devices for how they handle the clock stopping for a second OR an "invalid" time of 23:59:60.

If anyone sees anything die at 00:00:00UTC I'd be interested to know.

-- Kevin


My Juniper seems to be aware:

xxx@juniper> show ntp status
status=4694 leap_add_sec, sync_ntp, 9 events, event_peer/strat_chg,
version="ntpd 4.1.0-a Thu Jul 14 23:46:40 GMT 2005 (1)",
processor="i386", system="JUNOS7.3R1.5", leap=01, stratum=3,
precision=-30, rootdelay=40.669, rootdispersion=49.522, peer=35302,
refid=ntpx.xxx.xxx,
reftime=c7615c1c.65f78359  Sat, Dec 31 2005 13:35:56.398, poll=10,
clock=c7615d8e.d66d698f  Sat, Dec 31 2005 13:42:06.837, state=4,
offset=-2.649, frequency=73.810, jitter=5.194, stability=0.024

note the leap=01 and leap_add_sec






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