Como ler e entender a MIB SNMP

“How to Read and Understand the SNMP MIB...”

Instantly Understand Any SNMP Device...

Written by Marshall DenHartog

Is your SNMP knowledge good enough? What if

you could instantly understand the capabilities of

any SNMP device?

Reading the SNMP MIB file is the best way to do

that, and this guide teaches you how. This SNMP

MIB white paper is a must-read for anyone who

works with SNMP...

Read this complete guide now:

•Understand the purpose and function of the

MIB...

•Learn how to read the MIB...

•Use the MIB to evaluate any SNMP equipment...

Version 3.1

Released February 5, 2008

root

ccitt (0)

iso (1)

org (3)

dod (6)

directory (1) internet (1) 1.3.6.1

mgmt (2)

experimental (3)

private (4)

enterprises (1)

1.3.6.1.4.1.2682.1 dpsAlarmControl (1) dpsInc (2682)

TMonXM (1)

dpsRTU (2)

dpsRTUsumPClr (102)

joint-iso-ccitt (3)

NetGuardian 832A

T/Mon NOC

www.dpstelecom.com • 1-800-622-3314

“We protect your network like your business depends on it”TM

Demystifying the MIB • DPS Telecom • 4955 East Yale Avenue, Fresno, CA 93727 • [phone] • Fax [phone] • www.dpstelecom.com

2

Contents

What is the MIB? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

What does the MIB do? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Why do I need the MIB?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

How do I get the MIB into my SNMP manager? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Why is the MIB important? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Why do I need to understand the MIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

How do I look at a MIB? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Will I need to edit the MIB? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

How do I read the MIB? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

What does a MIB look like? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Wow! What language is that? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

How ASN.1 builds new terms out of existing terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

What terms are defined in the MIB . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

What is the function of an OID?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

What does an OID look like? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

OK ... but what does it mean?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

When I look at my MIB files, I don’t see long strings of numbers like that . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

So every MIB file needs to describe the entire OID tree? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

How to avoid the most common cause of compile errors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

So I’m reading the MIB What information am I looking for? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

The MIB objects you need to know . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

7 Reasons Why a Basic SNMP Manager is a Lousy Telemetry Master. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

AAbboouutt tthhee AAuutthhoorr

Marshall DenHartog has over ten years’ experience working with SNMP, including

designing private MIB extensions, creating SNMP systems for multiple platforms,

and developing SNMP-based monitoring for several nationwide networks.

DenHartog’s experience with both the theoretical and practical sides of SNMP have

equipped him to write a straightforward guide to the SNMP Management Information

Base.

©