[ntp:questions] Re: sync immediately

Tom Smith smith at cag.zko.hp.com
Mon Oct 3 21:05:22 UTC 2005

ibrahim Akyildiz wrote:
>   Hi;
> How can i configure my ntp clients for immediately synchronize with ntp server?

There have been several answers here so far, but perhaps not to
the question you intended to ask.

To allow ntpd to synchronize as quickly as possible with the servers
you have configured in your ntp.conf, add the "ibust" option at the
end of the "server" line. Being synchronized with a server does not
necessarily mean that the time has been set to the same time as the

To set the time as quickly as possible BEFORE you start ntpd to a time
within a small number of milliseconds of the server(s), the standard
method used by every operating system I am aware of is
"ntpdate -b [server] [server] ....". It is as reliable as your
servers and your network.

Two alternatives for the latter have been introduced recently, but
neither is exactly equivalent. One is "ntpd -q -g" used together with
what would often/usually be a separate ntp.conf configured specifically
for that purpose. The second is the use of the sntp application which
is not built and installed by default when building the NTP package.
To get this, you must add the "--with-sntp" option to "configure".


More information about the questions mailing list