SNMP Reference Guide

• The Server Administrator CIM Reference Guide documents the Common Information Model (CIM)

provider, an extension of the standard management object format (MOF) file. The Server-

Administrator CIM provider documents supported classes of management objects.

• The Glossary provides information on the terms used in this document.

Introduction to the Server Administrator SNMP Subagent

This guide provides formatted information drawn primarily from the MIB files written for the Server

Administrator services that support the SNMP protocol.

For each of the variables defined in the MIBs, the following fields are specified:

• Variable name

• OID or unique identifying number

• Description

• Data type of the variable (for example: integer, string, octet string)

• Whether the variable is accessible, not accessible, or read-only

• Index or indexes, if applicable

For each MIB group that has unique variable definitions, tables are included in the last section of the

section to explain the meaning of the terms.

Standards for writing MIBs are defined by the Internet Engineering Task Force (IETF). Structure of

Management Information (SMI) is a standard that specifies the rules for defining the structure and type of

managed objects and events in a MIB. SMIv1 is specified in Request For Comments (RFC) 1155. The Server

Administrator MIB conforms to the SMIv1 standard.

SNMP is a systems management standard originally designed for network management. SNMP manages

much more than networks. Information Technology (IT) professionals use SNMP for monitoring and

managing computer systems and the various components and peripherals supported by their systems.

SNMP standards are defined by the Internet Engineering Task Force (IETF). SNMP version 1 was published

in August 1988 and is the most commonly supported version of SNMP. SNMP version 2 was first

published in May 1993, but has not gained widespread market acceptance. SNMP version 3 was recently

completed and has addressed security issues that exist in version 1.

All SNMP systems consist of one or more managed systems that provide data through an SNMP agent to

a management system. The management system provides a user interface to view data from the

managed systems. The management system and managed systems communicate over a network

(typically through User Datagram Protocol/Internet Protocol [UDP/IP]).

The management system and a managed system communicate by means of a common data schema.

SNMP MIB files define the structure, type, and values of the SNMP data. While MIBs can be standardized

or enterprise specific, most operating systems supply SNMP agents for the standard MIB-I and MIB-II

schemas. MIB-I defines a base set of standard management information for systems implementing the

Internet Protocol (IP) suite. MIB-II defines characteristics of the system, characteristics of network

interfaces, and characteristics of components of the IP on the system. In addition to the standard MIBs,

many hardware vendors have defined MIBs that provide management data specific to their systems and

peripheral devices.

Monitored data can be retrieved through SNMP using the Get command. Typically, this command

requires the host name or IP address of the target machine as well as the OID of the data to retrieve.

Exact details are dependent on the operating system and the development tools being used to create the

management application. The Get command has a variant known as GetNext.