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.

Starting NTP Development Discussion

This is where we discuss and debate what goes in StartingNTP.

Setting the clock before starting.

It has been suggested that ntpd -gq ; ntpd is not the best way to start ntpd. Since the -g option allows a single step operation and requires that ntp halt rather than do another step if another is needed, it seems to me that quitting after setting the clock and restarting without restrictions is a good, if not the best, way to do it.

-- RichardBGilbert - 16 Sep 2004

ntp will not halt if another step is needed, unless the step is greater than SANITY (1000, by default) seconds.

The only reason to separate into the two steps you describe is if you want to use a different configuration file for startup and runtime.

Otherwise, there is no functional difference between ntpd -gq ; ntpd and ntpd -g.

(And remember about iburst and -N, at least. But those are described in the main topic.)

-- HarlanStenn - 16 Sep 2004