Configuring An Ntp Primary Clock - Huawei AR150 Series Configuration Manual

Huawei AR150&200&1200&2200&3200 Series Enterprise
Routers
Configuration Guide - Device Management
Configuration Procedure
Basic NTP configuration contains the configuration of the NTP primary clock and operating
mode.

5.5.1.1 Configuring an NTP primary clock

Context
A device on the network can synchronize its clock in the following manners.
l
l
If both manners are configured, the device selects an optimal clock source by comparing the
clocks determined in the two manners. The clock of a lower stratum is preferred.
An authoritative clock is used as a reference time source for a synchronization subnet, and is
located at the top of a hierarchical structure on the synchronization subnet. The authoritative
clock is stratum0. The current authoritative clock is mostly a Radio Clock or the Global
Positioning System. The time of the authoritative clock is synchronized through the broadcast
UTC time code other than NTP.
In actual circumstances, the NTP server synchronized with the authoritative clock is set as
stratum1, and is used as a master reference clock source. Other devices on the network
synchronize their clocks with the clock of the NTP server, which means the local clock of the
NTP server is configured as the NTP primary clock. The NTP distance from a device on the
network to the master reference clock source, that is, the number of NTP servers on the NTP
synchronization chain, determines the stratum of the clock on the device.
As shown in
synchronization direction is from RouterA to RouterB, and further to RouterC. Only after the
RouterB is synchronized with RouterA, RouterC can synchronize its clock with the clock of
RouterB. After all the devices on the synchronization subnet are synchronized, RouterB and
RouterC are respectively stratum2 and stratum3.
Issue 05 (2014-01-16)
Synchronizing with the local clock: The local clock is used as the reference clock.
Synchronizing with another device on the network: This device is used as an NTP clock
server to provide a reference clock for the local clock.
Figure 5-10, RouterA is the primary clock, and the clock stratum is 1. The clock
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