Systems Management Protocols

MIBs

There are two standard types of Management Information Bases (MIBs):

Internet MIBs


Defined and standardized by the Internet community Define attributes common across resources of the same class

Vendor MIBs


Extend Internet MIBs with attributes that belong to a particular manufacturer's device Represent the majority of MIBs in use

The combination of Internet and Vendor MIBs delivers the adaptability necessary for describing heterogeneous devices. However, because each vendor MIB describes unique attributes, management applications must load and compile all MIBs associated with managed devices.

The MIB is organized according to a defined standard, the Open System Interconnection's Structure of Management Information (SMI). An Object Identifier (OID) that belongs to a parent in the SMI references the attributes in the MIB; each of the MIB attributes has a value. The information in the MIB for a specific device allows the SNMP agent to monitor or manage that device.

SNMP architecture defines a set of commands that an SNMP management software application can use to retrieve or change the attributes of a managed device (or managed object). An SNMP agent (management agent) provides attributes describing the characteristics and current state of the managed device.

SNMP does not specify how to interpret and act on specific attribute values; decisions at this level are left to specific management applications.

Component instrumentation, such as the Dell OpenManage Server Agent, causes the management agent to initiate communication only upon the occurrence of an exceptional event. When the component instrumentation detects a problem, it sends an unsolicited message to the management agent, which passes an alert to the management console. The systems administrator responds to the alert (or trap) by issuing appropriate commands from the console.