Recipe 10.3 Generating an OID to Use for a New Class or Attribute

10.3.1 Problem

You want to generate an OID to use with a new class or attribute you intend to add to the schema.

10.3.2 Solution

You have two options for generating an OID. First, you can generate a base OID off of the Microsoft OID tree. This can be done with the Oidgen.exe utility from the Resource Kit:

> oidgen
Attribute Base OID: 1.2.840.113556.1.4.7000.233.28688.28684.8.2849.956347.1967079.334190
    Class Base OID: 1.2.840.113556.1.5.7000.111.28688.28684.8.370553.291204.940269.113484

Using Oidgen is really easy, but if you want to implement schema extensions for production use, I strongly suggest you consider using an OID from your company or organization's OID branch. To determine if your company already has an assigned OID, see these sites:

If your organization does not have an assigned OID, go to your country's national registry to request one. The list of registries can be found at the following site:

Once you have a base OID, you can create branches from that OID however you want. For example, if you had a base OID of, you could start new class OIDs under and new attributes under In that case, the first class OID you would create would be and the first attribute OID would be

10.3.3 Discussion

An OID is nothing more than a string of numbers separated by dots (.). OIDs were initially defined by the ITU-T in X.208 and have been used to uniquely identify a variety of things including SNMP MIB objects and LDAP schema classes and attributes. OIDs are hierarchical, and the national registries are responsible for managing and assigning OID branches.

    Chapter 3. Domain Controllers, Global Catalogs, and FSMOs
    Chapter 6. Users
    Appendix A. Tool List