[ntp:questions] Standalone time server
mayer at ntp.org
Thu May 21 13:27:47 UTC 2009
Sullivan, George E. wrote:
> First I want to apologize for asking this question. I've looked online
> for an answer to it and there seems to be a lot of questions like it.
> But I haven't yet found a definitive answer. Maybe I'm not phrasing the
> search query correctly.
> First is this even possible? I have a server I want to be a time
> server. It can NOT connect to the Internet. It can NOT receive a signal
> from some attached device. It can NOT receive a signal from a wireless
> source. All this is due to security constraints. So the source of time
> updates will be human initiated. I'll have to act as the "time source"
> and manually via the "date" command, enter the time. I'll have to get
> the time from an online source such as one of those atomic clock sites
> or one of the real Internet Time Servers and set this server's clock
> manually. Super/extreme accuracy is not critical, but keeping the
> systems within a few seconds of each other would be nice. I've noticed
> some of my systems stray as much as a few minutes over a week or two.
> So if this server can act as a human updated time server, then my
> clients can potentially use the ntpd to update themselves or even use
> ntpdate in a cronjob to update themselves. Either is ok for my needs.
> So, if this is possible what would my server's ntp.conf file look like?
> Are there other files, instead, I need to configure?
What you are looking for is called Orphan mode where there is no
external source of time and the important thing is to keep the clocks of
other systems synchronized with each other. You should read up on this
here: https://support.ntp.org/bin/view/Support/OrphanMode which will
give you a start. You will need to used the latest 4.2.5 development
release as it was first implemented there and there have been a number
of recent fixes in this area. It should become the stable release fairly
soon if you are worried about using development releases and it's for
the US Government. You cannot use the version you are currently using
Once you have read that and related documents you can ask followup
questions here. Steve has experience with how to set this up.
> Lastly, thanks to all you ntp gurus for considering this and for perhaps
> helping. Obviously you can tell I'm not proficient at working with ntp.
> TECH: Red Hat Enterprise Linux Advanced Server Version 5.3.
> NTP Version 4.2.2, actual RPM name is ntp-4.2.2p1-7.el5
> 32 Bit, x86 Dell 2950
> Clients - a mix of Red Hat 3 update 4,5,6,7,8 and some Red Hat
> George Sullivan
> SAIC IISBU
> Columbia, Md.
> questions mailing list
> questions at lists.ntp.org
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