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 shows the system time configuration items. 

System time configuration items 

Manual 

Select to manually configure the system time, including the 

setting of Year, Month, Day, Hour, Minute, and Second. 

Source Interface 

Set the source interface for an NTP message. 
If you do not want the IP address of a certain interface on the 

local device to become the destination address of response 

messages, you can specify the source interface for NTP 

messages, so that the source IP address in the NTP 

messages is the primary IP address of this interface. 

Key 1 

Key 2 

Set NTP authentication key. 
The NTP authentication feature should be enabled for a 

system running NTP in a network where there is a high 

security demand. This feature enhances the network security 

by means of client-server key authentication, which prohibits a 

client from synchronizing with a device that has failed 

authentication. 
You can set two authentication keys, each of which is 

composed of a key ID and key string. 

z

 

ID is the ID of a key. 

z

 

Key string is a character string for MD5 authentication key.

NTP Server 

1/Reference 

Key ID 

NTP 

External 

Reference 

Source 

NTP Server 

2/Reference 

Key ID 

Specify the IP address of an NTP server, and configure the 

authentication key ID used for the association with the NTP 

server. Only if the key provided by the server is the same with 

the specified key will the device synchronize its time to the 

NTP server. 
You can configure two NTP servers. The clients will choose 

the optimal reference source. 

 

z

 

As shown in 

, the local clock of Device A is set as the reference clock. 

z

 

Switch B works in the client mode, and uses Device A as the NTP server. 

z

 

Configure NTP authentication on Device A and Switch B. 

Network diagram for configuring system time 

Device A

Switch B

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