1-12 
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 
Follow these steps to configure NTP authentication on the client: 
To do…  Use the command…  Remarks 
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. 
 
 
NTP authentication requires that the authentication keys configured for the server and the client be the 
same. Besides, the authentication keys must be trusted keys. Otherwise, the clock of the client cannot 
be synchronized with that of the server. 
 
Configuring NTP authentication on the server 
Follow these steps to configure NTP authentication on the server: 
To do…  Use the command…  Remarks 
Enter system view 
system-view 
—