Event Mib Purpose; Event Mib Structure; Trigger Table - Juniper JUNOSE SOFTWARE FOR E SERIES 11.3.X - SYSTEM BASICS CONFIGURATION GUIDE 2010-10-04 Configuration Manual

Event MIB Purpose

Event MIB Structure

Copyright © 2010, Juniper Networks, Inc.
station. However, by using the SNMP server event manager, you can distribute some of
these functions to E Series routers and automate them.
The rapid growth of networks has made it impractical to directly manage networks from
a single network management station (NMS). This brought about a need for a model
that both automated and distributed event management. The goal was to 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.
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.
Chapter 4: Configuring SNMP
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