Administration Guide › Action Alerts › Working with SNMP Traps › About MIB Files › Custom MIBs

Custom MIBs

You can create custom MIB files from the provided boilerplate text by adding selected varbinds from the CA-ELM.MIB file content. A custom MIB file for a single alert contains a subset of the contents of the CA-ELM.MIB file. A custom MIB for an alert differs from CA-ELM.MIB in these ways:

• The custom MIB defines only the fields sent by that alert.
• The custom MIB defines a trap that lists these fields in the sequence in which they are sent.
• The custom MIB trap is defined with the OID, 1.3.6.1.4.1.791.9845.3.x, where x is a value between 1 and 999.

  Note: An alert that uses a custom MIB specifies this OID as the value for Custom Trap ID.

• A custom MIB includes the dynamicData varbind only if the query includes calculated fields.

  Calculations can be applied to any field. The event_count field is an example field to which calculations are commonly, but not always, applied. Event_count in the query, System Event Count by Event Action, is a calculated field; it is calculated with Sum. To determine whether a field is calculated, examine the query where the field is defined. An example of a definition of event_count where it is a calculated field follows:

  System_Event_Count_By_Event_Action.xml:    <Column columnname="event_count" datatype="I" displayname="Count" functionname="sum" resultname="event_count" sortdesc="true" sortorder="1" visible="true"/>