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Three related leap second issues will be described in this Release-note. 1) CSCvb19326 - NTP leap second failure to insert after leap second occurs 2) CSCvb41889 - NTP leap second inserted every day after leap second occurs 3) CSCvc65670 - NTP leap second inserted every day after leap second occurs The complete fix for these issues will be through CSCvc65670. Leap second is improperly added on the first occurrence, not added at all on the second occurrence, or added every day following a leap second event. The behavior varies based on which of the above fixes you have, and what has occurred since that version was installed.
If the device is running a release after 16.2(1) or 15.5(3)S, but before 16.2(3), 16.3(2) or 15.5(3)S4, it may experience a failure to add a leap second after already having experienced one leap second. This will occur if the device has been in sync with the NTP server continuously between the two leap second events.. NTP will update the time on the device to the correct time on the next NTP update.
There are two different ways this scenario can occur: A)If the device is running a release after 16.2(1) or 15.5(3)S, but before 16.2(3), 16.3(2) or 15.5(3)S4, the device may experience a leap second every day after having experienced one leap second. B) If the device is running a release after 16.2(3), 16.3(2) or 15.5(3)S4, and there is an NTP server incorrectly sending the LS bit set to 1, the device will experience a leap second every day that the NTP server sends this type of update.
These errors will only occur during and after a leap second has occurred as announced by the International Earth Rotation and Reference Systems Service (IERS).
Scenario 1: Force NTP out of sync at least one time between the two leap second events to ensure the 2nd event is not missed. This can be accomplished by removing and reapplying the NTP configuration. Scenario 2: A)Reload is the only workaround for this scenario once it starts occurring. The message that is produced when the erroneous leap second is added every day has no actual impact on the device beyond a minor variation in the clock which will resync with the next NTP update that is received. B) repair or replace the incorrect NTP server.
Images containing the fix for CSCvc65670 will contain a resolution to all of the issues described above.
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