I don't know in detail about 2.2.28, but OpenLDAP 2.2 should support that control when back-bdb is used. However I think nobody really bothers about checking such an outdated version (the current is
2.4.13).
It's not really by choice that I'm dealing with 2.2.28 unfortunately. What is back-bdb? I haven't been able to find any documentation on it.
Thanks for the help.
NJM