142. Clients listen to the broadcast messages from servers. When a client receives the first broadcastmessage, the client and the server start to exchange messages with the Mode field set to 3 (clientmode) and 4 (server mode), to calculate the network delay between client and the server.3. Then the client enters broadcast client mode. The client continues listening to broadcast messages,and synchronizes its local clock based on the received broadcast messages.Multicast modeFigure 10 Multicast modeIn multicast mode:1. A server periodically sends clock synchronization messages to the user-configured multicastaddress, 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).2. Clients listen to the multicast messages from servers. When a client receives the first multicastmessage, the client and the server start to exchange messages with the Mode field set to 3 (clientmode) and 4 (server mode), to calculate the network delay between client and server.3. Then, the client enters multicast client mode. It continues listening to multicast messages, andsynchronizes its local clock based on the received multicast messages.NOTE:In symmetric peers mode, broadcast mode and multicast mode, the client (or the symmetric active peer)and the server (the symmetric passive peer) can work in the specified NTP working mode only after theyexchange NTP messages with the Mode field being 3 (client mode) and the Mode field being 4 (servermode). During this message exchange process, NTP clock synchronization can be implemented.NTP configuration task listComplete the following tasks to configure NTP:Task RemarksConfiguring the operation modes of NTP RequiredConfiguring optional parameters of NTP OptionalConfiguring access-control rights OptionalConfiguring NTP authentication Optional
