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NTP Issues Today



In a message written on Mon, Nov 19, 2012 at 04:21:55PM -0700, Van Wolfe wrote:
> Did anyone else experience issues with NTP today?  We had our server
> times update to the year 2000 at around 3:30 MT, then revert back to 2012.

I'm surprised the various time geeks aren't all posting their logs, so
I'll kick off:

/tmp/parse-peerstats.pl peerstats.20121119
56250 76367.354 192.5.41.41 91b4 -378691200.312258363 0.088274002 0.014835425 0.263515353
56250 77391.354 192.5.41.41 91b4 -378691200.312258363 0.088274002 0.018668790 0.263749719
56250 78204.354 192.5.41.40 90b4 -378691200.785377324 0.088179350 0.014812585 0.263668835
56250 78416.355 192.5.41.41 91b4 -378691200.785974681 0.088312507 0.014832943 0.209966600
56250 79229.355 192.5.41.40 90b4 -378691200.785377324 0.088179350 0.018668723 378691200.785523713
56250 79442.355 192.5.41.41 91b4 -378691200.785974681 0.088312507 0.018689918 378691200.786114931

Or in more human readable form:
/tmp/parse-peerstats.pl peerstats.20121119
192.5.41.41 off by -378691200.312258363
192.5.41.41 off by -378691200.312258363
192.5.41.40 off by -378691200.785377324
192.5.41.41 off by -378691200.785974681
192.5.41.40 off by -378691200.785377324
192.5.41.41 off by -378691200.785974681

The script, if you want to run against your own stats:

#!/usr/bin/perl

while (<>) {
  chomp;
  ($day, $second, $addr, $status, $offset, $delay, $disp, $skew) = split;
  if (($offset > 10) || ($offset < -10)) {
#    print "$addr off by $offset\n"; # More human friendly
    print "$_\n";                   # Full details
  }
}

It just looks for servers off by more than 10 econds and then prints
the line.  378691200 seconds is ~12 years, which lines up with the
year 2000 dates some are reporting.

The IP's are tick.usno.navy.mil and tock.usno.navy.mil.

I can confirm from my vantage point that tick and tock both went about
12 years wrong on Nov 19th for a bit, I can also report that my NTP
server with sufficient sources correctly determined they were haywire
and ignored them.

If your machines switched dates yesterday it probably means you're
NTP infrastructure is insufficiently peered and diversified.

-- 
       Leo Bicknell - bicknell at ufp.org - CCIE 3440
        PGP keys at http://www.ufp.org/~bicknell/
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