Huawei S9300 Configuration Manual page 228

S9300&S9300E Terabit Routing Switch
Configuration Guide - Network Management
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Figure 4-1 NTP basic principle diagram
Step 1:
Step 2:
Step 3:
Step 4:
The process of synchronizing system clocks is as follows:
1.
2.
3.
Issue 01 (2012-03-15)
Before the system clocks of Switch A and Switch B are synchronized, the clock of Switch
A is set to 10:00:00 am and the clock of Switch B is set to 11:00:00 am.
Switch B functions as an NTP time server. That is, Switch A synchronizes its clock with
that of Switch B.
One-way transmission of data packets between Switch A and Switch B takes one second.
Processing of data packets on the Switch A or the Switch B takes one second.
NTP packet 10:00:00am
SwitchA
SwitchA
NTP packet 10:00:00am
SwitchA
NTP packet received at
10:00:03
SwitchA
Switch A sends an NTP packet to Switch B. The packet carries the originating timestamp
when it leaves Switch A, which is 10:00:00 am (T1).
When the NTP packet reaches Switch B, Switch B adds its receiving timestamp to the NTP
packet, which is 11: 00:01 am (T2).
When the NTP packet leaves Switch B, Switch B adds its transmitting timestamp to the
NTP packet, which is 11:00:02 am (T3).
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Network
NTP packet 10:00:00am
Network
11:00:01am
Network
Network
4 NTP Configuration
SwitchB
11:00:01am
SwitchB
11:00:02am
SwitchB
SwitchB
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