H3C Technologies H3C SecPath F1000-E - Manual (Page 112)

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• Stratum—An 8-bit integer indicating the stratum level of the local clock, with the value ranging from
1 to 16. The clock precision decreases from stratum 1 through stratum 16. A stratum 1 clock has the
highest precision, and a stratum 16 clock is not synchronized and cannot be used as a reference
clock.
• Poll—An 8-bit signed integer indicating the poll interval, namely the maximum interval between
successive messages.
• Precision—An 8-bit signed integer indicating the precision of the local clock.
• Root Delay—Roundtrip delay to the primary reference source.
• Root Dispersion—Maximum error of the local clock relative to the primary reference source.
• Reference Identifier—Identifier of the particular reference source.
• Reference Timestamp—Local time at which the local clock was last set or corrected.
• Originate Timestamp—Local time at which the request departed the client for the service host.
• Receive Timestamp—Local time at which the request arrived at the service host.
• Transmit Timestamp—Local time at which the reply departed the service host for the client.
• Authenticator—Authentication information.
NTP operation modes
Devices that run NTP can implement clock synchronization in one of the following modes:
• Client/server mode
• Symmetric peers mode
• Broadcast mode
• Multicast mode
You can select operation modes of NTP as needed. If the IP address of the NTP server or peer is unknown
and many devices in the network need to be synchronized, you can adopt the broadcast or multicast
mode; while in the client/server and symmetric peers modes, a device is synchronized from the specified
server or peer, and thus clock reliability is enhanced.
Client/server mode
Figure 45 Client/server mode
When operating in client/server mode, a client sends a clock synchronization message to servers, with
the Mode field in the message set to 3 (client mode). Upon receiving the message, the servers
automatically operate in server mode and send a reply, with the Mode field in the messages set to 4
Network
Server Client
Clock
synchronization
message
(Mode3)
Automatically works in
client/server mode and
sends a reply
Reply ( Mode 4)
Performs clock filtering and
selection, and synchronizes its
local clock to that of the
optimal reference source