3com 4210 PWR 9-Port 3CR17341-91-ME ユーザーズマニュアル

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 35: NTP C

ONFIGURATION

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In networks with higher security requirements, the NTP authentication function 
must be enabled to run NTP. Through password authentication on the client and 
the server, the clock of the client is synchronized only to that of the server that 
passes the authentication. This improves network security. Table 290 shows the 
roles of devices in the NTP authentication function.

NTP authentication configuration involves:

■

Configuring NTP authentication on the client

■

Configuring NTP authentication on the server

Observe the following principles when configuring NTP authentication:

■

If the NTP authentication function is not enabled on the client, the clock of the 
client can be synchronized to a server no matter whether the NTP 
authentication function is enabled on the server (assuming that other related 
configurations are properly performed).

■

For the NTP authentication function to take effect, a trusted key needs to be 
configured on both the client and server after the NTP authentication is 
enabled on them.

■

The local clock of the client is only synchronized to the server that provides a 
trusted key.

■

In addition, for the server/client mode and the symmetric peer mode, you need 
to associate a specific key on the client (the symmetric-active peer in the 
symmetric peer mode) with the corresponding NTP server (the 
symmetric-passive peer in the symmetric peer mode); for the NTP 
broadcast/multicast mode, you need to associate a specific key on the 
broadcast/multicast server with the corresponding NTP broadcast/multicast 
client. Otherwise, NTP authentication cannot be enabled normally.

■

Configurations on the server and the client must be consistent.

Table 290   Description of the device roles in NTP authentication function

Client 

Client in the server/client mode 

Client in the broadcast mode 

Client in the multicast mode 

Symmetric-active peer in the symmetric peer 
mode 

Server 

Server in the server/client mode 

Server in the broadcast mode 

Server in the multicast mode 

Symmetric-passive peer in the symmetric peer 
mode