SNMP Reference Guide

20 Introduction
Managed Object
A managed object is any item in a computer system that can be singled out for discovery, monitoring,
or user intervention and correction.
NOTE: Not all managed objects described in this guide are supported by all systems.
MIB
A MIB acts as a structured road map for managed objects. As an Application Programming Interface
(API), a MIB allows systems management tools to retrieve data maintained by an agent. The server
administrator MIB is divided into several major groups of managed objects.
Variable
A variable is a component of a managed object. A temperature probe, for example, has a variable to
describe its capabilities, its health or status, and certain indexes that you can use to locate specific
temperature probes. One index for the probe would be the probe’s chassis number. Some systems may
have multiple chassis—one chassis for the central processing unit and another chassis for storage.
A chassis within a system can also have more than one temperature probe. Variables for a temperature
probe include its capabilities, status, chassis index, and index.
One-Based Index
When an index is one-based, counting starts at 1. One-based indexing counts the first instance as 1,
the second index as 2, and so on.
Zero-Based Index
When an index is zero-based, counting starts at 0. Zero-based indexing counts the first instance as 0,
the second index as 1, and so on.
Fields
Managed object variables contain fields. In this reference guide, managed object variables have the
following fields defined:
Name is the exact string by which the variable is known in the MIB. MIB variables are named according
to the following conventions:
• Variable names start with a lowercase letter.
• Spaces are not allowed between words in the variable name.
• Acronyms are in uppercase letters, except when an acronym is the first word in the variable name.
• With the exception of the first letter of the variable name and acronyms, all other words in the variable
name start with capital letters.