Implementation Principle Of Ntp - H3C S5600 Series Operation Manual

Operation Manual – NTP
H3C S5600 Series Ethernet Switches
To perform incremental backup operations between a backup server and a host,
you must make sure they adopt the same time.
NTP has the following advantages:
Defining the accuracy of clocks by stratum to synchronize the clocks of all devices
in a network quickly
Supporting access control (see section
Configuring Access Control
Configuring NTP
Sending protocol packets in unicast, multicast, or broadcast mode
Note:
The clock stratum determines the accuracy, which ranges from 1 to 16. The stratum
of a reference clock ranges from 1 to 15. The clock accuracy decreases as the
stratum number increases. A stratum 16 clock is in the unsynchronized state and
cannot serve as a reference clock.
The local clock of an S5600 Ethernet switch cannot be set as a reference clock. It
can serve as a reference clock source to synchronize the clock of other devices only
after it is synchronized.

1.1.2 Implementation Principle of NTP

Figure 1-1
Ethernet switch A (Device A) is connected to Ethernet switch B (Device B) through
Ethernet ports. Both having their own system clocks, they need to synchronize the
clocks of each other through NTP. To help you to understand the implementation
principle, we suppose that:
Before the system clocks of Device A and Device B are synchronized, the clock of
Device A is set to 10:00:00 am, and the clock of Device B is set to 11:00:00 am.
Device B serves as the NTP server, that is, the clock of Device A will be
synchronized to that of Device B.
It takes one second to transfer an NTP message from Device A to Device B or
from Device B to Device A.
Authentication)
shows the implementation principle of NTP.
Right) and MD5 encrypted authentication (see section
1-2
Chapter 1 NTP Configuration