[ntp:questions] Leap second info in ntp-4.2.4p4

Harlan Stenn stenn at ntp.org
Tue Jun 2 18:05:43 UTC 2015

Mohan Kannekanti writes:
> Hi,
> We are currently using ntpd version 4.2.4p4.

Please see http://support.ntp.org/bin/view/Dev/ReleaseTimeline and
understand your choice.

You are running software that was released in December of 2006, and was
EOL'd in December of 2009 with 4.2.6, which fixed between 630-1000

4.2.6 was EOL'd in December of 2014 by the release of 4.2.8, which fixed
over 1,100 issues.

> As Leap second insertion is very close, we are trying to be safe from it.
> here are few questions,
> - Is 4.2.4p4 capable of receiving "Leap Second" information from NTP
> servers??


>   Below is our configuration.
>   "server time.nist.gov  maxpoll  10  minpoll  6
>    disable monitor
>    restrict default noquery
>    restrict -6 default noquery"
> - Is there any way that I can test whether the current version is providing
> of "Leap Second"??
> - Are there any configuration changes required??

Required, no.

Useful, almost certainly.  For example, you could keep an updated
leapseconds file on your server and refer to that in your config file.

Have you tested your kernels to make sure they can handle a leap second?

What about how your client machines will behave during the leap second?

> - If our version is not good for handling leap second,
>       1. What will be closest version to upgrade from 4.2.4p4.?? or

Why would you *not* want to run the latest release of NTP?

>       2. Any patches that we can apply to make 4.2.4p4 safe.??

Perhaps, but you'd have to:

- look at somewhere between 1,700 and 2,100 patches
- decide which ones you wanted
- apply and test the patches

I'd also recommend your company (and EVERYBODY else who cares about
network time) join the NTP Consortium at Network Time Foundation now:


The bind-9 tarball is about 8MB.  The ntp tarball is about 6.5MB.

We don't have even 5% of the resources to develop and maintain NTP that
ISC has to develop and maintain BIND.
Harlan Stenn <stenn at ntp.org>
http://networktimefoundation.org - be a member!

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