25.3.1 Incident forwarding
- Organization of this subsection
(1) Management events
When the Northbound destination includes management events, NNMi forwards each management event incident to the Northbound application when that incident changes to the Registered lifecycle state.
The OID of the forwarded management event is the SNMP object ID on the Management Event Configuration form in the NNMi console. NNMi forwards all custom management events with the OID 1.3.6.1.4.1.11.2.17.19.2.0.9999.
(2) Third-party SNMP traps
When the Northbound destination includes third-party SNMP traps, NNMi forwards each incoming SNMPv1, v2c, or v3 format trap to the Northbound application when the associated incident changes to the Registered lifecycle state. NNMi preserves the original trap varbinds in order (as defined in the MIB) and appends the NNMi-specific varbinds to the message payload. If the original trap does not contain all the defined varbinds, NNMi pads NULL values for the missing varbinds. If the MIB is not loaded in NNMi, NNMi cannot correctly reconstruct the trap and append the NNMi incident data; NNMi does not forward such a trap.
Note the following about third-party SNMP traps:
-
Because NNMi reconstructs a trap from its SNMP trap incident, the forwarded trap is in SNMPv2c format regardless of the format of the original trap when NNMi received it.
-
The forwarded SNMP trap shows the NNMi management server as the source object. To determine the original source object, examine the values of the (n + 21)th varbind, nnmiIncidentSourceNodeHostname (1.3.6.1.4.1.11.2.17.19.2.2.21), and the (n + 24)th varbind, nnmiIncidentSourceNodeMgmtAddr (1.3.6.1.4.1.11.2.17.19.2.2.24), where n is the number of varbinds defined for the trap in the MIB.
If any of the devices that NNMi manages also send traps to the Northbound application, the Northbound application must manage the duplicate device traps.
For a comparison of trap forwarding mechanisms, see 6.1.2 Trap and incident forwarding.