Working Principle Of Ntp - Huawei Quidway S5600 Series Operation Manual

Operation Manual – NTP
Quidway S5600 Series Ethernet Switches-Release 1510
Note:
The accuracy of a clock is determined by its stratum, which ranges from 1 to 16.
The stratum of the reference clock ranges from 1 to 15. The accuracy descends
with the increasing of stratum number. The clocks with the stratum of 16 are in
unsynchronized state and cannot serve as reference clocks.
The local clock of an S5600 series switch cannot operate as a reference clock.
And an S5600 series switch can serve as a time server only when it is
synchronized.

1.1.2 Working Principle of NTP

The working principle of NTP is shown in Figure 1-1.
In Figure 1-1, The Ethernet switch A (LS_A) is connected to the Ethernet switch B
(LS_B) through their Ethernet ports. Both of them have system clocks of their own,
and they need to synchronize the clocks of each other through NTP. For ease of
understanding, suppose that:
Before the system clocks of LS_A and LS_B are synchronized, the clock of LS_A
is set to 10:00:00am, and the clock of LS_B is set to 11:00:00am.
LS_B serves as the NTP time server, that is, the clock of LS_A will be
synchronized to that of LS_B.
It takes one second for a packet sent by one switch to reach the other.
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Chapter 1 NTP Configuration