4. Naming Hierarchy

The root of the subtree administered by the Internet Assigned Numbers Authority (IANA) for the Internet is:

     internet       OBJECT IDENTIFIER ::= { iso 3 6 1 }

That is, the Internet subtree of OBJECT IDENTIFIERs starts with the prefix:

     1.3.6.1.

Several branches underneath this subtree are used for network management:

     mgmt           OBJECT IDENTIFIER ::= { internet 2 }
     experimental   OBJECT IDENTIFIER ::= { internet 3 }
     private        OBJECT IDENTIFIER ::= { internet 4 }
     enterprises    OBJECT IDENTIFIER ::= { private 1 }

However, the SMI does not prohibit the definition of objects in other portions of the object tree.

The mgmt(2) subtree is used to identify "standard" objects.

The experimental(3) subtree is used to identify objects being designed by working groups of the IETF. If an information module produced by a working group becomes a "standard" information module, then at the very beginning of its entry onto the Internet standards track, the objects are moved under the mgmt(2) subtree.

The private(4) subtree is used to identify objects defined unilaterally. The enterprises(1) subtree beneath private is used, among other things, to permit providers of networking subsystems to register models of their products.