[ntp:questions] ntpd -q and driftfile

David Woolley david at ex.djwhome.demon.invalid
Tue Mar 22 08:14:53 UTC 2011

prashant sherin wrote:

>>> The idea is to use it as ntp client.

It would only be an SNTP client, used like this.

> My understanding is that if I run ntpd in daemon mode, it will
> also act like an NTP server listening on UDP port 123. I think running
> ntpd with -q option
> would prevent the server from running and also it would be a good

It will still act as a aerver whilst it is running.  Why are you so 
concerned about people knowing the quality of your system's time?  You 
need to go back a further level in the requirements (although I suspect 
security paranoia).

You can use configuration options to prevent it serving time and to 
ignore packets from IP addresses other than your official servers.

> replacement for ntpdate command
> as stated in the manual page.

Neither ntpdate nor ntpd -q create a frequency solution, so a drift file 
is of no use to them.  ntdp -q may read an existing drift file, but I'm 
not sure if it would save it into the kernel time discipline. You would 
have to populate the file manually.

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