Re: dntpd

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Doesn't dntpd sense that a server is broken and not use it?
:
:Does openntpd do that?
:
:--Peter

    How does one sense that a server is broken?  Maybe with enough
    sources we can detect that one is seriously out of line with the
    others.  In fact, that would be pretty easy to do, I'll look into
    it.

    Try running it with a single server line.  I ran a test on my test
    box with 5 server us.pool.ntp.org lines and this is what I got:

Jun 24 14:28:39 test28 dntpd[858]: dntpd version 1.0 started
Jun 24 14:28:56 test28 dntpd[858]: issuing offset adjustment: -0.005709
Jun 24 14:34:29 test28 dntpd[858]: issuing frequency adjustment: -111.292ppm
Jun 24 14:45:01 test28 dntpd[858]: issuing offset adjustment: -0.017869
Jun 24 15:05:58 test28 dntpd[858]: issuing offset adjustment: 0.028012
Jun 24 15:26:57 test28 dntpd[858]: issuing offset adjustment: -0.005782
Jun 24 15:48:01 test28 dntpd[858]: issuing offset adjustment: 0.011286
Jun 24 17:27:57 test28 dntpd[858]: issuing offset adjustment: -0.010092
Jun 24 19:34:00 test28 dntpd[858]: issuing offset adjustment: 0.013780
Jun 24 19:54:58 test28 dntpd[858]: issuing offset adjustment: -0.025465
Jun 24 20:16:00 test28 dntpd[858]: issuing offset adjustment: 0.021708
Jun 24 22:21:59 test28 dntpd[858]: issuing offset adjustment: -0.006082
Jun 25 00:01:37 test28 dntpd[858]: issuing offset adjustment: -0.021242
Jun 25 00:22:41 test28 dntpd[858]: issuing offset adjustment: 0.016988
Jun 25 01:09:56 test28 dntpd[858]: issuing offset adjustment: 0.008061
Jun 25 03:15:57 test28 dntpd[858]: issuing offset adjustment: 0.001252
Jun 25 04:29:16 test28 dntpd[858]: issuing offset adjustment: -0.024935
Jun 25 04:50:15 test28 dntpd[858]: issuing offset adjustment: -0.002704
Jun 25 06:03:40 test28 dntpd[858]: issuing offset adjustment: 0.024320
Jun 25 08:09:44 test28 dntpd[858]: issuing offset adjustment: -0.027622
Jun 25 08:56:38 test28 dntpd[858]: issuing offset adjustment: 0.012390
Jun 25 09:17:37 test28 dntpd[858]: issuing offset adjustment: 0.008970

    Normally, with a single server line, it issues a frequency correction
    and one or two offset adjustments and that's it for the next day or two.

    With several server lines it will select the one with the best
    stability once or twice an hour, which can ping pong around.  That's
    ok... the above lines are not bad at all, usually corrections are
    only a few milliseconds either way.

					-Matt
					Matthew Dillon 
					<dillon@backplane.com>