Configuration Guide Configuring NTP
13 Configuring NTP
13.1 Overview
The Network Time Protocol (NTP) is an application-layer protocol that enables network devices to synchronize time. NTP
enables network devices to synchronize time with their servers or clock sources and provides high-precision time correction
(the difference from the standard time is smaller than one millisecond in a LAN and smaller than decades of milliseconds in a
WAN). In addition, NTP can prevent attacks by using encrypted acknowledgment.
Currently, Ruijie devices can be used both as NTP clients and NTP servers. In other words, a Ruijie device can synchronize
time with a time server, and be used as a time server to provide time synchronization for other devices. When a Ruijie device
is used as a server, it supports only the unicast server mode.
The NTP function is not supported on AP110-W or AP120-W.
Protocols and Standards
RFC 1305 : Network Time Protocol (Version 3)
13.2 Applications
Synchronizing Time Based on an
External Reference Clock Source
A device is used as a client that synchronizes time with an external clock source. After
successful synchronization, it is used as a server to provide time synchronization for
other devices.
Synchronizing Time Based on a
Local Reference Clock Source
A device uses a local clock as a reliable NTP reference clock source and is also used as
a server to provide time synchronization for other devices.
13.2.1 Synchronizing Time Based on an External Reference Clock Source
Scenario
As shown in Figure 13-1:
DEVICE-A is used as a reliable reference clock source to provide time synchronization for external devices.
DEVICE-B specifies DEVICE-A as the NTP server and synchronizes time with DEVICE-A.
After successful synchronization, DEVICE-B provides time synchronization for DEVICE-C.
Figure 13-1