Each SNMP object has a name and numeric
identifier. For example, in the system
group, the network object named SysDescr
with object identifier 1.3.6.1.2.1.1.1 contains a description of the
device.
An object can have one or more instances,
depending on the configuration of the monitored device. For
example, a device can have two network adapters, in which case
there will be two instances of the ifPhysAddress object, which has object identifier
1.3.6.1.2.1.2.2.1.6. In this case,
you need to specify an instance number at the end of the object
identifier (such as 1.3.6.1.2.1.2.2.1.6.1). If you do not specify an
instance, it defaults to zero.