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This section provides procedures for alarm synchronization on the DSC. For more detailed information about alarm synchronization, refer to the REST API User Guide, Alarm Synchronization.


Alarm synchronization allows all active alarms stored in the Active Trap List on the DSC to be kept in sync with an Element Management System (EMS) or other external client manager, at all times. The synchronization is provided using the REpresentational State Transfer (REST) Application Program Interface (API). For information about the REST API and to view the REST API commands, refer to the REST API User Guide, Alarm Synchronization.


This feature does not impact the existing alarm functionality with the exception of two stateless SNMP traps - Alarm acknowledgement update (6665 alarmAckStateUpdate) and Alarm comment update (6666 alarmCommentUpdate).

Single Trap Stream

By default, the DSC sends out two streams of SNMP traps corresponding to the two management nodes. In order to use the REST API, the Single Trap Stream attribute must be enabled.

Enabling the Single Trap Stream attribute on the Web UI results in only one stream of SNMP traps from the management node, which resolves to the high-availability (HA) IP, to be sent out. The HA IP is used as the shared IP between the EMS and DSC. 


The source IP in the SNMP trap also contains the HA IP.

When registering a DSC node on the EMS for the Alarm synchronization, the DSC node should be registered on the HA IP. The REST API handlers will check that the Active Traps attribute and the Single Trap Stream attribute are set for each incoming HTTP request and will return an error in response to the HTTP request if the DSC is not properly configured for this feature. For more information on Alarm State Synchronization, refer to the REST API Guide, Alarm Synchronization.

To receive an SNMP trap, a host needs to be entered in the Trap Host List. This can be accomplished through the DSC Web UI (refer to SNMP Configuration) or SNMP if EMS Access has been enabled (refer to Configuring Community Directives).  

Configuring Alarm Synchronization on the DSC

The following section provides procedures to enable the alarm synchronization and view active traps.   

To enable Alarm Synchronization

  1. Login to the DSC Web UI.

  2. Under Applications, click SNMP

  3. Enable Single Trap Stream attribute. 

    This ensures only one stream of traps with a source IP in the SNMP trap set to HA IP.

  4. Enable DSC REST API attribute. 

    This allows access to the DSC REST API.

  5. Enable Active Traps attribute. 

    This starts populating the Active Trap List container with outstanding alarms in the form of SNMP traps.


    When the Active Traps attribute is ENABLED or DISABLED, the SNMP application on the Web UI disappears for a few moments and then reappears. This is a normal behavior. 

    The Event Notification Setup for an alarm requires the SNMP Trap and the Dashboard attributes to have the same value (both ENABLED or both DISABLED) when the Active Traps attribute is enabled. Any mismatch will result in the inability to enable REST API. The only exception to this rule is when either one is set to DISABLED_PERMANENTLY.


  6. Click Continue

Once the alarm synchronization is enabled, the DSC stores and lists all active traps on Web UI under Active Trap List. There is no limit to the number of traps that can be stored under the Active Trap List.


If an alarm was manually cleared on the DSC before the Active Traps attribute was enabled, the corresponding clear notification will not be sent to the EMS after the Active Traps attribute is enabled.

If you require a previous cleared alarm to be sent to the EMS, you must manually restore the alarm from the Web UI (refer to Restoring an Alarm), so the DSC can send a new trap notification to the EMS.

To view an Active Trap List

  1. Login to Web UI.

  2. Click SNMP.

  3. Click Active Trap List.

If an alarm is manually cleared through the EMS, it will be removed from the Active Trap List, but will still be visible under the cleared bucket list on the DSC Web UI.

To view an Active Trap

  1. Login to Web UI.

  2. Click SNMP.

  3. Click Active Trap List.

  4. Select an Active Trap.

The Active Trap screen displays the attributes used to construct the SNMP traps sent out to trap hosts. The Active Trap attributes include the Sequence Number, and Date and Time Stamp that can be used by the EMS to monitor any missing traps that may have dropped because of the connectivity related issues.

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