NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p15 was released on 23 June 2020. It addresses 1 medium-severity security issue in ntpd, and provides 13 non-security bugfixes over 4.2.8p13.

Please see the NTP Security Notice for vulnerability and mitigation details.

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Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.

SNTP Issues

Related Topics: deprecating ntpdate, Open SNTP Bug list

New SNTP

At some point we will probably want to split some of this into a separate topic or few.

The sntp code must have an appropriate license (NTP/ISC/MIT/BSD-without-advertising).

The sntp code must be a complete and accurate implementation of the current/proposed SNTP specification.

The SNTP code should also be able to be separated from the rest of the NTP codebase.

It is OK to have the SNTP code have a support library that is shared with the NTP code.

There are tricky things like making sure we do the correct logging to wtmp and/or utmp (or their *x versions) whenever the time is stepped.

Then the slope gets a bit more slippery.

What about logging? (and it could be better still)

What about exit status?

Also, I want to keep using autogen for the options processing and man page generation.

-- HarlanStenn - 27 Oct 2007

Old SNTP

We must get rid of the "daemon" code in the current SNTP program, and make the beast conform (as best and fully as we can) to the proposed/draft SNTP spec (RFC 4330).

-- HarlanStenn - 10 Jul 2005

sntp currently will not display any results if the remote server is unsynchronized. This makes sense. However, it may be useful to display the value returned by the remote server in this case, with an indication that the remote server is unsynchronized.

Here are some choices:

• 2006 Sep 12 20:16:04.123 UNSYNCHRONIZED
• 2006 Sep 12 20:16:04.123 +/- infinity

-- HarlanStenn - 12 Sep 2006

The current output from sntp looks like:

 % sntp -u localhost
 2006 Nov 24 23:37:23.361 + 0.000 +/- 0.001 secs
 %

Should the number of decimal places displayed be a function of the precision of the remote host?

Should we display the precision of the remote host?

-- HarlanStenn - 24 Nov 2006