SNMP Object ID Format for SNMPv2c\SNMPv3 Traps
NNMi requires that all SNMP traps have an object identifier (SNMP Object ID).
To specify an SNMP trap object ID (OID), open the MIB definition file for the device of interest to look up the correct ID. The MIB file includes object identifiers for all of the traps that the configured SNMP agent (SNMPv1, SNMPv2c, or SNMPv3) generates for a particular device.
In the SNMP Object ID attribute of the SNMP Trap Incident Configuration form, enter the SNMP Object ID attribute value for the SNMP trap that you want to see in the console incident views.
Note You can use a wildcard character (*) in the SNMP Object ID attribute to create an SNMP Trap Incident configuration for multiple OIDs. This feature enables you to use the same SNMP Trap Incident Configuration for similar traps. For example, you might have a device class for which you might want to capture a particular kind of trap as an SNMP Trap Incident and ignore the rest.
When using the wildcard (*) character in the SNMP Object ID (OID) attribute, note the following:
- The OID must be unique.
- Only one wildcard character is permitted within the SNMP OID attribute.
- The wildcard must appear at the end of an OID. For example .1.3.6.1.4.1.* is valid; however, .1.3.6.1.4.*.2 is NOT valid.
- NNMi permits wildcards only in OIDs beginning with .1.3.6.1.4 (private MIBs).
- The wildcard character is not valid for an SNMPv1 generic trap because these traps do not begin with .1.3.6.1.4.
- When checking whether an SNMP Trap Incident Configuration exists, NNMi’s TrapFilter uses only implicit matching when checking generic SNMPv1 traps OIDs. See About the Trap Service Stages for more information about TrapFilter.
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NNMi matches the OID value using the longest match. Specific OID matches take precedence over an OID that is matched using the wildcard character.
Click here for an example:
The following table provides an example of precedence between a specific OID and one that includes a wildcard. This example also illustrates how NNMi uses the longest match.
Example of Matching Incoming SNMP Traps Using Specific and Longest Match Criteria SNMP OID Attribute Configuration Incoming SNMP Trap Match Criteria .1.3.6.1.4.1.2.3 .1.3.6.1.4.1.2.3 Specific OID takes precedence over the wildcard OID configuration. .1.3.6.1.4.1.* .1.3.6.1.4.1.2
The wildcard OID takes precedence because it is the longest match. .1.3.6.1.4.* Using the specific OID and longest match criteria, this configuration is not the best match for these incoming traps. See above. - NNMi handles each OID as if it contains an implicit wildcard. For example, when NNMi receives a trap whose OID is .1.3.6.1.6.3.1.1.5.4.100, NNMi logs the trap as SnmpLinkUp (.1.3.6.1.6.3.1.1.5.4) and generates an SNMPLinkUp incident.
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If a trap's OID matches both an implicit and explicit wildcard, the longer one is used. If the length is the same, NNMi uses the implicit OID. Click here for an example:
The following table provides an example of precedence between implicit and explicit wildcards.
Example of Matching Incoming SNMP Traps Using Implicit and Explicit Wildcard Criteria SNMP OID Attribute Configuration Incoming SNMP Trap Match Criteria .1.3.6.1.4.1.2.3.* .1.3.6.1.4.1.2.3.4 The longest OID takes precedence. .1.3.6.1.4.1.2 .1.3.6.1.4.1.2.3
The implicit OID takes precedence. .1.3.6.1.4.1.* Using the length and implicit criteria, this configuration is not the best match for these incoming traps. See above.