Chapter 1 Ntp Configuration; Ntp Overview; Applications Of Ntp - H3C S5500-EI series Operation Manual

Operation Manual – NTP
H3C S5500-EI Series Ethernet Switches

Chapter 1 NTP Configuration

Note:
The local clock of an S5500-EI 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.
When configuring NTP, go to these sections for information you are interested in:

NTP Overview

NTP Configuration Task list
Configuring the Operation Modes of NTP
Configuring Optional Parameters of NTP
Configuring Access-Control Rights
Configuring NTP Authentication
Displaying and Maintaining NTP
NTP Configuration Examples
1.1 NTP Overview
Defined in RFC 1305, the Network Time Protocol (NTP) synchronizes timekeeping
among distributed time servers and clients. NTP runs over the User Datagram Protocol
(UDP), using UDP port 123.
The purpose of using NTP is to keep consistent timekeeping among all
clock-dependent devices within the network so that the devices can provide diverse
applications based on the consistent time.
For a local system running NTP, its time can be synchronized by other reference
sources and can be used as a reference source to synchronize other clocks.

1.1.1 Applications of NTP

An administrator can by no means keep synchronized time among all the devices within
a network by changing the system clock on each station, because this is a huge amount
of workload and cannot guarantee the clock precision. NTP, however, allows quick
clock synchronization within the entire network while it ensures a high clock precision.
NTP is used when all devices within the network must be consistent in timekeeping, for
example:
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Chapter 1 NTP Configuration