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Do Junos OS platforms respond to the "leap-second calculations"?

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This article describes how Junos OS platforms support "leap-second calculations."


All Juniper platforms that run Junos OS support the "leap-second" adjustment.

If the NTP server is aware of the leap-second calculations, then the Junos device will also add the 1-second delay by default. Nothing specific needs to be done on the Junos devices to enable this.

NTP automatic time synchronization works only if the times on the two systems are very close. Very close means between 128 milliseconds and 128 seconds apart.

Beyond this, the time is not changed at all. If the time is more than 1000 seconds off, NTP records the following system log message:

Mar 16 16:41:41 5htp-fxp0 xntpd[28243]: time error 4217 over 1000 seconds; set clock manually

If the time is this far off, you need to reset the clock manually:

admin@router1# set date ntp

This command uses the NTP servers that you have configured. You do not have to reboot the router for the new time to take effect.

Juniper's PTP (Precision Time Protocol) implementation in Junos OS can detect and forward leap-second changes from the head node of synchronization (grandmaster) to the end nodes (base stations/servers).

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