Designing and Managing Behavior Models - Alarm Actions - Send Trap -
Perl Subroutine Example      Set Attribute

Send Trap

The Send Trap alarm action enables you to send an SNMP v1 trap when a transition occurs and gives you virtually complete control over the contents of the trap.

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   NerveCenter does not send SNMP v3 traps, because under SNMP v3, a node's IP address is no longer sent in the packet's header; therefore, NerveCenter cannot simulate a node's IP address and send the SNMP v3 trap.

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Generally, when one alarm must communicate with another, the first uses the Fire Trigger action to fire a trigger that causes a transition in the second. However, Send Trap can also be used for this type of inter-alarm communication. The first alarm can send a trap to the NerveCenter server, the server can process the trap using a trap mask (which can fire a trigger), and the trigger can cause a transition in the second alarm. This is a more roundabout way of firing the required trigger, but gives you the ability pass the trap's variable bindings, along with the trigger, to the second alarm. In addition, Send Trap enables an alarm being managed by one NerveCenter server to communicate with an alarm being managed by another server, while Fire Trigger does not.

Of course, you aren't limited to sending traps to NerveCenter. You can send a trap to any application that knows how to process SNMP traps.

 
  To add a Send Trap action to a transition:

1. From the Transition Definition window, select the New Action button.

   A pop-up menu listing all alarm actions is displayed.

2. Select Send Trap from the pop-up menu.

   The Send Trap Action dialog is displayed.

   

3. In the Source field, enter information about node whose address you want to appear in the agent-address field of the trap PDU.

   The valid values for this field are:

   • $NodeName (the default value), which represents the node associated with the trigger that caused the transition.
   • $NCHostName, which represents the node on which the active NerveCenter server is running.
   • A node name.
   • An IP address. Using an IP address is generally more efficient than using a node name because it eliminates the name-to-address translation.
4. In the Destination field, enter information about the node to which the trap should be sent.

   The valid values for this field are the same as those for the Source field. $M is the default.

5. Enter in the Port field the number of the port on the destination machine to which the trap should be sent.

   Generally, SNMP traps are received on port 162, so 162 is the default value.

6. Enter a community name in the Community field.

   This is the community name that a manager needs to know in order to access the agent that is sending the trap. The default value is public.

7. Select one of the three options from the Trap Numbers drop-down list: Default, Trap, and Custom.

   If you select Default, your trap's generic trap number will be 6, and its specific trap number will be 1.

   If you select Trap, your trap's generic and specific trap numbers will match those of the trap associated with the trigger that caused the alarm transition.

   If you select Custom, you can specify a generic trap number using the Generic drop-down list. In addition, if you select a generic trap number of 6, you can enter a specific trap number in the Specific field.

8. In the Enterprise field, enter an object identifier, or the corresponding name, for the device that is the source of the trap.

   The valid values for this field are:

   • $P (the default), which indicates that the enterprise field in the trap you're sending should match the enterprise field in the trap associated with the trigger that caused the alarm transition.

     Note that if the trigger that caused the transition with which this action is associated is not caused by a trap, $P will not have a value, and the Send Trap action will not take place.

   • An object identifier, such as 1.3.6.1.4.1.9.
   • A name associated with an object identifier in an ASN.1 file.

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        Be aware that traps from the Open object ID (1.3.6.1.4.1.78) cannot be seen by NerveCenter because they are forwarded to your platform.

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9. Enter information for each variable binding to be included in the trap PDU.

   For each variable binding, perform the following steps.

   1. If you want a variable binding to contain exactly the same information as the corresponding variable binding in the trap associated with the trigger that caused the alarm transition, select $P from the Base Object list and then select the Insert button

      If you perform step a, you can the skip the remaining steps in this procedure. Otherwise, go on to step b.

   2. Select a base object from the Base Object list.
   3. Select an attribute from the Attribute list.
   4. Type an instance in the Instance field.

      Using your base object, attribute, and instance, NerveCenter creates the object identifier portion of the variable binding. For example, if you supply the base object system, the attribute sysUpTime, and the instance 0, NerveCenter builds an OID of 1.3.6.1.2.1.1.3.0.

   5. Enter a value for the attribute instance in the Attribute Value field.
   6. Select the Insert button.
10. Select the OK button in the Send Trap Action dialog.
11. Select the OK button in the Transition Definition window.
12. Select the Save button in the Alarm Definition window.