SNMP Manager Programmer's Guide

Introduction to Manager Services
SNMP Manager Programmer’s Guide–134249
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MIB Object Attributes
The numbers in MIB definitions describe an object hierarchy for all vendors’ SNMP
objects. For objects in the previous example, the hierarchy looks like this for the
collection of objects describing the subagent process:
iso (1)
org (3)
dod (6)
internet (1)
private (4)
enterprises (1)
tandem (169)
nonstopsystems (3)
zhrm (180)
zhrmSaProcess (4)
zhrmSaProcCurrTime (1)
zhrmSaProcVersion (2)
zhrmSaProcName (3)
.
.
.
zhrmSwitchToBackupNow (18)
The numbers associated with and above each object in the hierarchy together constitute
an object identifier (OID) for each object in the hierarchy. In the example above, the
OID of the subagent process object, zhrmSaProcName, is 1.3.6.1.4.1.169.3.180.4.3.
When a manager sends a request packet, the packet contains resource specifications,
called variable bindings, that use numeric identifiers based on OIDs to identify MIB
objects. Response packets also use numeric identifiers to identify MIB objects.
MIB Object Attributes
In addition to OIDs, MIB objects have other attributes associated with them that are
important for managers:
Name, access, and syntax attributes
The value of the object
Whether the object is scalar or tabular
The MIB definition of an object assigns a name to the object, describes how the object
can be accessed by a manager, and indicates the syntax that any of the object’s values
must assume. The following MIB definition, taken from the MIB for the Host
Resources Subagent, is for an object named zhrmDynamRefreshNow:
zhrmDynamRefreshNow OBJECT-TYPE
SYNTAX INTEGER { autoDynamicRefresh(0),
forceDynamicRefresh(1) }
ACCESS read-write
STATUS mandatory
DESCRIPTION
“When set to 1 (forceDynamicRefresh) MIB objects whose
values are controlled by the -d startup parameter are
refreshed...”
::= { zhrmRefresh 8 }