86Configuring the maximum number of dynamic associationsNTP has the following types of associations:• Static association—A manually created association.• Dynamic association—Temporary association created by the system during NTP operation. Adynamic association is removed if no messages are exchanged within about 12 minutes.The following describes how an association is established in different association modes:• Client/server mode—After you specify an NTP server, the system creates a static association on theclient. The server simply responds passively upon the receipt of a message, rather than creating anassociation (static or dynamic).• Symmetric active/passive mode—After you specify a symmetric-passive peer on a symmetric activepeer, static associations are created on the symmetric-active peer, and dynamic associations arecreated on the symmetric-passive peer.• Broadcast or multicast mode—Static associations are created on the server, and dynamicassociations are created on the client.A single device can have a maximum of 128 concurrent associations, including static associations anddynamic associations.Perform this task to restrict the number of dynamic associations to prevent dynamic associations fromoccupying too many system resources.To configure the maximum number of dynamic associations:Step Command Remarks1. Enter system view. system-view N/A2. Configure the maximumnumber of dynamic sessionsallowed to be established.ntp-service max-dynamic-sessionsnumberBy default, the command canestablish up to 100 dynamicsessions.Configuring a DSCP value for NTP packetsThe DSCP value determines the sending precedence of a packet.To configure a DSCP value for NTP packets:Step Command Remarks1. Enter system view. system-view N/A2. Set a DSCP value for NTPpackets.• IPv4 packets:ntp-service dscp dscp-value• IPv6 packets:ntp-service ipv6 dscpdscp-valueThe defaults for a DSCP value:• 48 for IPv4 NTP packets.• 56 for IPv6 NTP packets.Configuring the local clock as a reference sourceFollow these guidelines when you configure the local clock as a reference source:
