[ntp:questions] NTP on LAN

Steve Kostecke kostecke at ntp.org
Thu Sep 18 17:24:33 UTC 2008

On 2008-09-18, 05IT042 <raghuramos1987 at gmail.com> wrote:

> I have 2 computers connected on the same lan. I want one of them to be
> set up as a NTP server and the other to be setup as a NTP client. This
> is my initial goal. I tried giving the ip address of the server in the
> client's /etc/ntp.conf file

The ntp.conf on the "client" should, at a minimum, consist of:

	driftfile /path/to/ntp.drift
	server <address/hostname of your ntp server>

Replace "/path/to/ntp.drift" with a full path + filename to a
location which is writable ny the ntp user. A typical location is

> and i gave localhost( in the servers /etc/ntp.conf file.

This will not do what you think it will do.

If you have no real time sources (i.e. remote time servers or locally
attached ref-clocks) available you may use the Undisciplined Local
Clock (or LocalCLK or LOCAL) or Orphan Mode.

The LocalCLK and Orphan Mode merely allow ntpd to claim to synchronized
to _something_ and serve time to others. They do not make the time
correct. Nor do they control any drift or make your clock tick at the
correct rate.

If at all possible you should provide a sufficient number of real time
sources to ntpd.

If your application is not critical you may wish to use the NTP Pool
(see http://support.ntp.org/pool and http://www.pool.ntp.org/). The
mininal configuration for a server using the pool is:

	driftfile /path/to/ntp.drift
I	server 0.pool.ntp.org iburst
	server 1.pool.ntp.org iburst
	server 2.pool.ntp.org iburst
	server pool.ntp.org

To use the just Undisciplined Local Clock the minimal configuration is:

	driftfile /path/to/ntp.drift
	fudge stratum 10

To use just Orphan Mode the minimal configuration is:

	driftfile /path/to/ntp.drift
	tos orphan 10

You may add the 127.127.1.x lines or the orphan line to an ntp.conf
in addition to remote time servers. Orphan Mode is preferred if your
version of NTP supports it.

> After this how do i go about checking if
> they're even getting synchronized or anything at all?

> Also some links for learning more would also be appreciated.

The NTP home-page is http://www.ntp.org/

The NTP Public Services Project home-page is http://support.ntp.org/

Documentation indices are available at
http://www.ntp.org/documentation.html and http://support.ntp.org/doc

Documentation for the NTP Development release series is located at

Documentation for NTP Stable releases is included in the ./html/
directory in the Distribution and is archived at http://doc.ntp.org/

> OS: Ubuntu Hardy Heron on both server and client.

What version of NTP are you using?

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

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