2056 CHAPTER 111: NTP CONFIGURATIONupon the receipt of a message, rather than creating an association (static ordynamic). In the symmetric mode, static associations will be created at thesymmetric-active peer side, and dynamic associations will be created at thesymmetric-passive peer side; In the broadcast or multicast mode, staticassociations will be created at the server side, and dynamic associations will becreated at the client side.Configuring NTPServer/Client ModeFor devices working in the server/client mode, you only need to makeconfigurations on the clients, and not on the servers.Follow these steps to configure an NTP client:n ■ In the ntp-service unicast-server command, ip-address must be a hostaddress, rather than a broadcast address, a multicast address or the IP addressof the local clock.■ When the interface sending the NTP packet is specified by thesource-interface argument, the source IP address of the NTP packet will beconfigured as the primary IP address of the specified interface.■ A device can act as a server to synchronize the clock of other devices only afterits clock has been synchronized. If the clock of a server has a stratum levelhigher than or equal to that of a client’s clock, the client will not synchronize itsclock to the server’s.■ You can configure multiple servers by repeating the ntp-serviceunicast-server command. The clients will choose the optimal referencesource.Configuring the NTPSymmetric ModeFor devices working in the symmetric mode, you need to specify asymmetric-passive on a symmetric-active peer.Following these steps to configure a symmetric-active device:n ■ In the symmetric mode, you should use the ntp-service refclock-mastercommand or any NTP configuration command in “Configuring the OperationTo do... Use the command... RemarksEnter systemviewsystem-view -Specify an NTPserver for thedevicentp-service unicast-server [ vpn-instancevpn-instance-name ] { ip-address | server-name }[ authentication-keyid keyid | priority |source-interface interface-type interface-number |version number ] *RequiredNo NTP server isspecified bydefault.To do... Use the command... RemarksEnter systemviewsystem-view -Specify asymmetric-passive peer for thedevicentp-service unicast-peer [ vpn-instancevpn-instance-name ] { ip-address | peer-name }[ authentication-keyid keyid | priority |source-interface interface-type interface-number |version number ] *RequiredNo NTP server isspecified bydefault.
