IBM recommends people use Tivoli Directory Server for LDAP authentication with AIX. Which is free for AIX use and contains all the proprietary schemas necessary. But, if you already have OpenLDAP, IBM uses a proprietary schema that makes full integration difficult. Or if you want to use the LDAP server for more than just AIX authentication, you have to buy the full product.
You can authenticate in RFC 2307 mode, but you miss most of the AIX specific user attributes. This schema works with RFC 2307AIX mode in AIX. Some modifications had to be made, mainly boolean attributes don’t work well between OpenLDAP and AIX. I don’t know if AIX or OpenLdap is more RFC compliant, but it’s broken. So, those are converted to text attributes, and seem to work well.
This schema is provided as-is, if it breaks free and destroys your world, it’s not my fault. If you fix anything broken, please send me the changes.