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the last day of a chosen month, so that second 23:59:58 of that date would be followed immediately by
second 00:00:00 of the following date.
Because the Earth's rotation speed varies in response to climatic and geological events, UTC leap
seconds are irregularly spaced and unpredictable. Insertion of each UTC leap second is usually
decided about six months in advance by the International Earth Rotation and Reference Systems
Service (IERS), when needed to ensure that the difference between the UTC and UT1 readings will
never exceed 0.9 second.
NTP and SNTP
FastIron 07.3.00c and earlier releases implements SNTP for time synchronization. In FastIron
07.3.00d, NTP can be used for time synchronization in FCX devices with router images. From FastIron
8.0 release onwards, NTP can be used for time synchronization in all FastIron devices with both router
and switch images.
NTP and SNTP implementations cannot operate at the same time and one of them has to be disabled.
On downgrading from FastIron 07.3.00d to FastIron 07.3.00c or lower version, the entire NTP
configuration is lost.
NTP server
A NTP server will provide the correct network time on your device using the Network time protocol
(NTP). Network Time Protocol can be used to synchronize the time on devices across a network. A
NTP time server is used to obtain the correct time from a time source and adjust the local time in each
connecting device.
The NTP server functionality is enabled when you use the ntp command, provided SNTP configuration
is already removed.
When the NTP server is enabled, it will start listening on the NTP port for client requests and responds
with the reference time. Its stratum number will be the upstream time server's s 1. The stratum
1 NTP server is the time server which is directly attached to the authoritative time source.
The device cannot be configured as primary time server with stratum 1. It can be configured as
secondary time server with stratum 2 to 15 to serve the time using the local clock.
The NTP server is stateless and will not maintain any NTP client information.
System as an Authoritative NTP Server
The NTP server can operate in master mode to serve time using the local clock, when it has lost
synchronization. Serving local clock can be enabled using the master command. In this mode, the
NTP server stratum number is set to the configured stratum number. When the master command is
configured and the device was never synchronized with an upstream time server and the clock setting
is invalid, the server will respond to client's request with the stratum number set to 16. While the
device is operating in the master mode and serving the local clock as the reference time, if
synchronization with the upstream server takes place it will calibrate the local clock using the NTP
time. The stratum number will switch to that of the synchronized 1. And when synchronization
is lost, the device switches back to local clock time with stratum number as specified manually (or the
default).
NOTE
Local time and time zone has to be configured before configuring the master command.
NTP and SNTP
38 FastIron Ethernet Switch Administration Guide
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