300 CHAPTER 18: NTP C ONFIGURATIONenabled on the server (assuming that other related configurations areperformed).■ You need to couple the NTP authentication with a trusted key.■ Configurations on the server and the client must be consistent.■ The client with the NTP authentication function enabled is only synchronized tothe server that provides a trusted key.Configuration Procedure Table 338 Configuring the NTP authentication on the clientNTP authentication requires that the authentication keys configured for the serverand the client are the same. Besides, the authentication keys must be trusted keys.Otherwise, the client cannot be synchronized with the server.In NTP server mode and NTP peer mode, you need to associate the specified keywith the corresponding NTP server (active peer) on the client (passive peer). Inthese two modes, multiple servers (active peers) may be configured for aclient/passive peer, and therefore, the authentication key is required to determinewhich server the client is synchronized to.Table 339 Configuring NTP authentication on the serverOperation Command DescriptionEnter system view system-viewEnable the NTPauthentication functiongloballyntp-service authenticationenableRequiredBy default, the NTP authenticationfunction is disabled.Configure the NTPauthentication keyntp-serviceauthentication-keyidkey-idauthentication-model md5valueRequiredBy default, no NTP authenticationkey is configured.Configure the specified keyto be a trusted keyntp-service reliableauthentication-keyidkey-idRequiredBy default, no trusted key isconfigured.Associate the specified keywith the correspondingNTP serverNTP client mode:ntp-service unicast-server {remote-ip | server-name }authentication-keyidkey-idPeer mode:ntp-service unicast-peer {remote-ip | peer-name }authentication-keyidkey-idIn NTP client mode and NTP peermode, you need to associate thespecified key with thecorresponding NTP server on theclient.You can associate the NTP serverwith the authentication key whileconfiguring NTP mode. You canalso use this command toassociate them after configuringNTP mode.Operation Command DescriptionEnter system view system-viewEnable NTP authentication ntp-service authenticationenableRequiredBy default, the NTP authenticationfunction is disabled.
