H3C Technologies H3C WX6000 Series Access Controllers - Manual (Page 491)

54-6
Broadcast mode
Figure 54-5 Broadcast mode
In the broadcast mode, a server periodically sends clock synchronization messages to the broadcast
address 255.255.255.255, with the Mode field in the messages set to 5 (broadcast mode). Clients listen
to the broadcast messages from servers. After a client receives the first broadcast message, the client
and the server start to exchange messages, with the Mode field set to 3 (client mode) and 4 (server
mode) to calculate the network delay between client and the server. Then, the client enters the
broadcast client mode and continues listening to broadcast messages, and synchronizes its local clock
based on the received broadcast messages.
Multicast mode
Figure 54-6 Multicast mode
In the multicast mode, a server periodically sends clock synchronization messages to the
user-configured multicast address, or, if no multicast address is configured, to the default NTP multicast
address 224.0.1.1, with the Mode field in the messages set to 5 (multicast mode). Clients listen to the
multicast messages from servers. After a client receives the first multicast message, the client and the
server start to exchange messages, with the Mode field set to 3 (client mode) and 4 (server mode) to
calculate the network delay between client and the server. Then, the client enters the multicast client
mode and continues listening to multicast messages, and synchronizes its local clock based on the
received multicast messages.