[ntp:questions] Re: ntp time synchronization

Piotr Trojanek ptrojane at mion.elka.pw.edu.pl
Thu Aug 21 15:26:18 UTC 2003

In article <bi2nmb$4l829$1 at ID-42950.news.uni-berlin.de>, Thomas Jachmann wrote:
>So let's see if I get this right:
>The package ntp-simple contains the demon that queries ntp servers and sets
>the local date accordingly

true. it is called "-simple" because was compiled without external reference
clocks drivers, ie. for GPS or DCF receivers. the only source from it can
"take" the time are then other NTP servers.

>while the package ntp contains the demon that
>acts as an ntp server itself?

false. "ntp" package contains utilities useful for monitoring of
running 'ntpd' process -- ie. ntpq and ntpdc utilities.
they acts for NTP and ntpd similar role like host, nslookup and dig
play for DNS and named.

so you usually don't have to install them on every workstation.
just try command "ntpq -p your_server_hostname" and
"ntpq -p another_host_with_ntpd_running_hostname".

>I only have one process ntpd on my time server
>as well as on my client... shouldn't there be two processes on the server

no. NTP is handled by only one process, both for acting as a client
(quering some public NTP server about time) and as a server which
provides time for your LAN.

but don't panic, when for just several seconds after start there will
be two 'ntpd' processes runing -- the second one does dirty job with
ntp.conf config file and DNS queries (this can be wrong information,
but you should get idea about the role of second process). once
all setup is finished, there should be only one 'ntpd'.

>BTW, the client doesn't change its time... does this take some time (hours)?

yes, it can take some time. you can monitor it with 'ntpq' command.
common reasons of failures is firewalling port 123, UDP.

>Can I check in some log files (which?) what's going wrong?

try running it from command line, with few "-d" options.

or you can put this line to your /etc/ntp.conf file:
logconfig +allclock +allinfo +allevents +allstatistics +allsync +allpeer

now ntpd will chat to syslog or add line:
logfile /var/log/ntp.log

but then you should check to update your logrotate scripts.

Piotr Trojanek

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