H3C S5500-SI Series, Руководство по эксплуатации

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1-7
Configuring the Operation Modes of NTP
Devices can implement clock synchronization in one of the following modes:
z
Client/server mode
z
Symmetric mode
z
Broadcast mode
z
Multicast mode
For the client/server mode or symmetric mode, you need to configure only clients or symmetric-active
peers; for the broadcast or multicast mode, you need to configure both servers and clients.
A single device can have a maximum of 128 associations at the same time, including static associations
and dynamic associations. A static association refers to an association that a user has manually
created by using an NTP command, while a dynamic association is a temporary association created by
the system during operation. A dynamic association will be removed if the system fails to receive
messages from it over a specific long time. In the client/server mode, for example, when you carry out a
command to synchronize the time to a server, the system will create a static association, and the server
will just respond passively upon the receipt of a message, rather than creating an association (static or
dynamic). In the symmetric mode, static associations will be created at the symmetric-active peer side,
and dynamic associations will be created at the symmetric-passive peer side; in the broadcast or
multicast mode, static associations will be created at the server side, and dynamic associations will be
created at the client side.
Configuring NTP Client/Server Mode
For devices working in the client/server mode, you only need to make configurations on the clients, but
not on the servers.
Follow these steps to configure an NTP client:
To do… Use the command… Remarks
Enter system view system-view —
Specify an NTP server for the
device
ntp-service unicast-server
{ ip-address | server-name }
[ authentication-keyid keyid |
priority | source-interface
interface-type interface-number
| version number ] *
Required
No NTP server is specified by
default.