3 ntp configuration, Ntp overview, Applications of ntp – H3C Technologies H3C S7500E Series Switches User Manual
Page 65: Ntp configuration
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NTP Configuration
When configuring NTP, go to these sections for information you are interested in:
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Configuring the Operation Modes of NTP
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Configuring the Local Clock as a Reference Source
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Configuring Optional Parameters of NTP
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Configuring Access-Control Rights
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Configuring NTP Authentication
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Displaying and Maintaining NTP
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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.
Applications of NTP
An administrator can by no means keep time synchronized 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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In analysis of the log information and debugging information collected from different
devices in network management, time must be used as reference basis.
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All devices must use the same reference clock in a charging system.
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To implement certain functions, such as scheduled restart of all devices within the network,
all devices must be consistent in timekeeping.
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When multiple systems process a complex event in cooperation, these systems must use
that same reference clock to ensure the correct execution sequence.