[ntp:questions] [Q] Why do many time servers time out on queries from ntpq -p?
Dennis Hilberg, Jr.
timekeeper at dennishilberg.com.invalid
Sat Apr 12 05:44:35 UTC 2008
Maurice Volaski wrote:
> I've been trying the peers command in ntpq on a number of time
> servers and finding that for as many that do respond, there are about
> an equal number that do not. An example of a failing response is:
> ntpq> host sundial.columbia.edu
> current host set to hickory.cc.columbia.edu
> ntpq> peers
> hickory.cc.columbia.edu: timed out, nothing received
> ***Request timed out
> I can reproduce identical successes and failures from 3 computers
> running different OSs on independent networks.
> These I've tried work just fine:
> But these time out:
> All of the above were tested and gave the same results on
> kennedy1.aecom.yu.edu (Linux with ntpq 4.2.4p4 at 1.1520-o)
> fluxsoft.com (FreeBSD with ntpq 4.2.0-a)
> ool-45766590.dyn.optonline.net (Mac OS X with ntpq 4.1.1 at .786)
If the server operator has 'noquery' specified in the default restriction it
will prevent the server from responding to ntpq and ntpdc.
Interestingly, I actually wrote a script that uses 'ntpq -pn' to randomly
query client entries in my ntp_clients_stats log file. I've found that only
about one percent respond on average.
Dennis Hilberg, Jr. \ timekeeper(at)dennishilberg(dot)com
NTP Server Information: \ http://saturn.dennishilberg.com/ntp.php
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