
Table 4-4 Configure NTP broadcast client mode 
Operation Command 
Configure NTP broadcast client mode
 ntp-service
broadcast
-
client 
Disable NTP broadcast client mode
 undo
ntp-service
broadcast
-
client 
This command must be configured on the interface to be used for receiving NTP 
broadcast messages. 
V. Configure NTP multicast server mode 
This task specifies an interface on the local router to send NTP multicast messages. 
In this case, the local router is running as a multicast server and periodically sends 
multicast messages to the multicast clients. 
Perform the following configuration in interface view. 
Table 4-5 Configure NTP multicast server mode 
Operation Command 
Configure NTP multicast server mode
ntp-service
multicast-server
 [ 
X.X.X.X
 ] [ 
authentication-keyid
keyed 
| 
ttl
ttl-number | version
number 
] * 
Disable NTP multicast server mode
 undo ntp-service
multicast-server 
NTP version is in the range of 1 to 3 and defaults to 3, authentication key ID is in the 
range of 1 to 4294967295, the Time-To-Live (TTL) value of multicast packets is in the 
range of 1 to 255, and the multicast IP address defaults to 224.0.1.1. 
This command must be configured on the interface to be used for sending NTP 
multicast messages. 
VI. Configure NTP multicast client mode 
This task specifies an interface on the local router to receive NTP multicast messages. 
In this case, the local router is running as a multicast client. The local router first 
detects the multicast message packets from the server. Upon the receipt of the first 
message packet, the local router enters a temporary Client/Server mode to exchange 
the message with the remote server for the purpose of estimating the network delay, 
and then it switches to the multicast client mode to assume the work of detecting the 
multicast message packets with which it can synchronize the local clock.  
Perform the following configuration in interface view. 
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