1-13 
Configuring Optional NTP Parameters 
Table 1-13 Optional NTP parameters configuration tasks 
Task  Remarks 
Configuring an Interface on the Local Switch to Send NTP messages  Optional 
Configuring the Number of Dynamic Sessions Allowed on the Local Switch  Optional 
Disabling an Interface from Receiving NTP messages  Optional 
 
Configuring an Interface on the Local Switch to Send NTP messages 
Table 1-14 Configure an interface on the local switch to send NTP messages 
Operation  Command  Description 
Enter system view 
system-view 
— 
Configure an interface on the 
local switch to send NTP 
messages 
ntp-service source-interface 
Vlan-interface vlan-id 
Required 
 
 
If you have specified an interface in the ntp-service unicast-server or ntp-service unicast-peer 
command, this interface will be used for sending NTP messages. 
 
Configuring the Number of Dynamic Sessions Allowed on the Local Switch 
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 server/client 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. 
Table 1-15 Configure the number of dynamic sessions allowed on the local switch 
Operation  Command  Description 
Enter system view 
system-view 
—