25-8z In the ntp-service unicast-server command, ip-address must be a unicast address, rather than abroadcast address, a multicast address or the IP address of the local clock.z When the source interface for NTP messages is specified by the source-interface argument, thesource IP address of the NTP messages will be configured as the primary IP address of thespecified interface.z A device can act as a server to synchronize the clock of other devices only after its clock has beensynchronized. If the clock of a server has a stratum level higher than or equal to that of a client’sclock, the client will not synchronize its clock to the server’s.z You can configure multiple servers by repeating the ntp-service unicast-server command. Theclients will choose the optimal reference source.Configuring the NTP Symmetric Peers ModeFor devices working in the symmetric mode, you need to specify a symmetric-passive peer on asymmetric-active peer.Following these steps to configure a symmetric-active device:To do… Use the command… RemarksEnter system view system-view —Specify a symmetric-passivepeer for the devicentp-service unicast-peer [ vpn-instancevpn-instance-name ] { ip-address |peer-name } [ authentication-keyid keyid |priority | source-interface interface-typeinterface-number | version number ] *RequiredNosymmetric-passivepeer is specified bydefault.z In the symmetric mode, you should use any NTP configuration command in Configuring theOperation Modes of NTP to enable NTP; otherwise, a symmetric-passive peer will not processNTP messages from a symmetric-active peer.z In the ntp-service unicast-peer command, ip-address must be a unicast address, rather than abroadcast address, a multicast address or the IP address of the local clock.z When the source interface for NTP messages is specified by the source-interface argument, thesource IP address of the NTP messages will be configured as the primary IP address of thespecified interface.z Typically, at least one of the symmetric-active and symmetric-passive peers has beensynchronized; otherwise the clock synchronization will not proceed.z You can configure multiple symmetric-passive peers by repeating the ntp-service unicast-peercommand.
