An Object Identifier (OID) is a unique identifier assigned to a specific object. The identifier consists of a sequence of numbers that identify the source of the object, as well as the object itself. This sequence of numbers is variable in length, so in addition to the sequence of numbers, there is a length field. OIDs are organized in a tree structure; the sequence of numbers identifies the various branches of the subtree that a given object comes from.
The root of the tree is the ISO (International Standards Organization) trunk. Its value is one (1). Each branch below the root further identifies the source of the given object. All SNMP objects are members of the subtree identified by iso.org.dod.internet or
Each additional component further defines the exact location of an object. The numbers for each subtree are assigned by the IETF to ensure that all branches are unique. While it is good to know that OID identification structure exists, in general, OID management is done by SNMP Management Console and no specific OID knowledge is required to use SNMP Management Console.