如何在NTP服务器中添加a秒文件表

Question

NTP server is not sending the packets with leap indicator bit set. Is it beacuse of the absence of leap second table file? How can i install that file ?

Answer 1

No... Leaps are usually advertised from an upstream (Higher stratum) server closer to the insertion time. I Can't remember exactly how long in advance this is done but I remember back in 2012 all of my time hierarchy was showing the correct bits set before it happened.

If you want to use your own leap file then have a look at this link it should help you out.

leapfile "/path/to your/leap-file" is the basic config directive for ntp4.2.6 and newer.

Answer 2

It is possible that your NTP server was not notified about the leap second as it should have been, due to a lack of knowledge of the impending leap second by some of the stratum 1 time servers. Quoting from the ntpd support documentation :

Past experience has shown many stratum 1 servers do not advertise pending leap seconds during the day prior to the event. Installing a leapfile on your NTP server ensures it will notify its clients of the pending leap as well as handle the event gracefully.

Time servers which are aware of an impending leap second start advertising it during the day prior to the leap second.

For ntpd versions 4.2.6 and newer, one needs to download the leap seconds file from https://www.ietf.org/timezones/data/leap-seconds.list , or an alternative location. The file is then added to the ntpd configuration file (usually /etc/ntp.conf on Linux) with the following directive:

# Assuming the file is named leap-seconds.list,
# and is located in /var/lib/ntp/
leapfile /var/lib/ntp/leap-seconds.list

For more in-depth information, see the section Using the NIST Leap Second File in the NTP support documentation.