[ntp:questions] ntpd won't sync

Steve Kostecke kostecke at ntp.isc.org
Tue May 8 11:45:24 UTC 2007

On 2007-05-08, David Durrleman <0nrh2b802 at sneakemail.com> wrote:

> I am trying to set up ntp to sync my computer's clock to the internet.
> I don't want to act as a server or any other complicated stuff.

ntpd defaults to serving time to others, so it's _more_ work to
configure ntpd to _not_ be a server.

> I am behind a NAT, but I don't have a firewall.

You may not have a local firewall, but your ISP may have one between you
and the world.

> My ntp.conf looks like this:
> server 0.fr.pool.ntp.org
> server 1.fr.pool.ntp.org
> server 2.fr.pool.ntp.org
> driftfile /var/lib/ntp/ntp.drift
> logfile /var/log/ntp.log

Please check your ntp.conf very carefully for restrict statements. A
common cause of the problem that you are reporting is a 'restrict
default ignore' line that is included in the default ntp.conf file
shipped with some OSes.

There are a few things that you can do to make your configuration
better, although none of them will have any effect on the problem that
you are reporting.

1. Append 'iburst' to your server lines. This will speed up initial sync
from ~5 minutes to ~20 seconds.

2. Add another server line for more redundancy.

> The output of ntpq -p -rv is:
> state=1, frequency=-1.348

Did you take this statistics snapshot shortly after starting ntpd?

>      remote      refid  st t when poll reach delay offset jitter
>  roxane.home-dn. .INIT. 16 u    -   64    0  0.000  0.000  0.000
>  rtr-002.dsi13.n .INIT. 16 u    -   64    0  0.000  0.000  0.000
>  chihiro.bleu-pa .INIT. 16 u    -   64    0  0.000  0.000  0.000

Your peer status billboard is showing that ntpd has not received any
replies from those remote time servers. If captured this billboard
immediately after ntpd was started (i.e. within the first 64 seconds)
this may be normal. But if captured this billboard after ntpd has been
running for a few minutes then something is blocking port 123/UDP.

> What could be wrong with this setup ?

Are you using PPPoE ?

Steve Kostecke <kostecke at ntp.isc.org>
NTP Public Services Project - http://ntp.isc.org/

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