[ntp:questions] Re: abuse or bug ?
davids at webmaster.com
Fri Jan 28 03:25:18 UTC 2005
"Henk P. Penning" <henkp at cs.uu.nl> wrote in message
news:Pine.GSO.4.44.0501270856030.14692-100000 at castor.cs.uu.nl...
> it has been noted that some clients poll time servers at
> a rate of 1 packet per second, for an unlimited period.
> Is this a bug in the standard ntpd software
Nobody has yet found the standard ntpd software to do this, as far as I
know, you are the first to report it.
> abuse by bad software or badly configured clients ?
So it seems.
> The example below make me think it is a bug.
> client : 220.127.116.11 (in cs.northwestern.edu)
> hardware : Sun, SunBlade 150
> operating system :
> Linux gandalf 2.4.26-sparc-r2 #14 Wed Sep 22 15:27:12 CDT 2004 sparc64
> sun4u TI UltraSparc IIe (Hummingbird) GNU/Linux
> ntp : ntp 4.2.0-r2
> config :
> server pool.ntp.org
> driftfile /var/lib/ntp/ntp.drift
> restrict default notrust nomodify
> restrict 127.0.0.1
These 'restrict' lines will likely stop the server from being reachable.
> It has sent 438851 packets in the last 129.3 hours to 'ntp.cs.uu.nl'.
> The client says the server is unreachable.
How confident are you in this number? It definitely seems strange. NTP
should not poll a non-responding server more than once every 64 seconds.
> There may well be a problem with the client's ntpd config
> or the clients network setup ; the interesting thing is that
> standard ntpd software with a 'normal config', running on
> of-the-shelf hardware, can show the undesired behaviour.
That is very strange.
More information about the questions