Operation Manual – NTPH3C S3100 Series Ethernet Switches Chapter 1 NTP Configuration1-161.6.1 Configuring an Interface on the Local Switch to Send NTP messagesTable 1-14 Configure an interface on the local switch to send NTP messagesOperation Command DescriptionEnter system view system-view —Configure an interface onthe local switch to sendNTP messagesntp-servicesource-interfaceVlan-interface vlan-idRequiredCaution:If you have specified an interface in the ntp-service unicast-server or ntp-serviceunicast-peer command, this interface will be used for sending NTP messages.1.6.2 Configuring the Number of Dynamic Sessions Allowed on the LocalSwitchA single device can have a maximum of 128 associations at the same time, includingstatic associations and dynamic associations. A static association refers to anassociation that a user has manually created by using an NTP command, while adynamic association is a temporary association created by the system during operation.A dynamic association will be removed if the system fails to receive messages from itover a specific long time. In the server/client mode, for example, when you carry out acommand to synchronize the time to a server, the system will create a static association,and the server will just respond passively upon the receipt of a message, rather thancreating an association (static or dynamic). In the symmetric mode, static associationswill be created at the symmetric-active peer side, and dynamic associations will becreated at the symmetric-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.Table 1-15 Configure the number of dynamic sessions allowed on the local switchOperation Command DescriptionEnter system view system-view —Configure the maximumnumber of dynamic sessionsthat can be established onthe local switchntp-servicemax-dynamic-sessions numberRequiredBy default, up to 100dynamic sessions can beestablished locally.