1-11 
Configuration Prerequisites 
NTP authentication configuration involves:  
z  Configuring NTP authentication on the client 
z  Configuring NTP authentication on the server 
Observe the following principles when configuring NTP authentication: 
z  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). 
z  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. 
z  The local clock of the client is only synchronized to the server that provides a trusted key. 
z  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. 
z  Configurations on the server and the client must be consistent. 
Configuration Procedure 
Configuring NTP authentication on the client 
Table 1-11 Configure NTP authentication on the client 
Operation  Command  Description 
Enter system view 
system-view 
— 
Enable the NTP authentication 
function 
ntp-service authentication 
enable 
Required 
Disabled by default. 
Configure the NTP 
authentication key 
ntp-service 
authentication-keyid key-id 
authentication-model md5 
value 
Required 
By default, no NTP 
authentication key is 
configured. 
Configure the specified key as a 
trusted key 
ntp-service reliable 
authentication-keyid key-id 
Required 
By default, no trusted key is 
configured. 
Configure on the 
client in the 
server/client mode  
ntp-service unicast-server 
{ remote-ip | server-name } 
authentication-keyid key-id 
Associat
e the 
specified 
key with 
the 
correspo
nding 
NTP 
server 
Configure on the 
symmetric-active 
peer in the 
symmetric peer 
mode 
ntp-service unicast-peer 
{ remote-ip | peer-name } 
authentication-keyid key-id 
Required 
For the client in the NTP 
broadcast/multicast mode, 
you just need to associate 
the specified key with the 
client on the corresponding 
server.