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JUNOSe 11.1.x System Basics Configuration Guide
allow devices to monitor themselves and other devices, and to take action under
certain conditions.
The Event MIB (RFC 2981) defines a method for creating trigger conditions, testing
those conditions, and determining which action to take when a trigger meets those
conditions.
The Event MIB allows you to define test conditions for object integers that are
accessible in the agent, making it possible to monitor any aspect of a device without
defining specific notifications and complicating the agent definition. In this model,
because devices have the ability to monitor themselves or other devices, the
processing is distributed throughout the network. Also, sending the information only
to the NMS that uses an event model reduces both network overhead and processing
drain on the NMS.
Event MIB Structure
The Event MIB has three major parts: the trigger table, the objects table, and the
event table. These tables also contain subordinate MIB tables that contain more
detailed information about the trigger tests.
Trigger Table
The trigger table (mteTriggerTable) lists any currently-defined trigger conditions.
Triggers fall into three categories existence, Boolean, and threshold.
An existence trigger tests for the existence of a MIB object instance; you can specify
that the trigger occur by either the appearance, disappearance, or change in value
of a MIB instance.
A Boolean trigger tests whether the value of a MIB object (base syntax integer) is
equal, unequal, greater than, less than, less than or equal to, or greater than or equal
to some defined value.
A threshold trigger verifies a MIB object (base syntax integer) in relation to either a
rising threshold value, falling threshold value, or both.
You can configure both Boolean and threshold tests to trigger on an absolute value
or a delta value over a determined polling interval.
Subordinate MIB tables exist within the trigger section of each type of trigger test.
In other words, each type of trigger (existence, threshold, and Boolean) contains a
table that stores added information about that type of trigger test.
For example, a trigger entry of a specific type of test in the mteTriggerTable creates
a linked entry in the appropriate subtable. In turn, this subtable contains more specific
information about the specific test.
A delta table also exists within the trigger tables. This table stores information about
any delta values based on any Boolean and threshold triggers. The delta table stores
a MIB object that indicates whether any discontinuities occurred for any delta trigger
(for example, a router reset).
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Configuring the SNMP Server Event Manager
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Troubleshooting
