I don't know if this will be of any help to you but here are the instructions
for RHDS 9.

https://access.redhat.com/documentation/en-us/red_hat_directory_server/9.0/html/administration_guide/secureconnections#requiring-secure-connections


-- 
Patrick Landry Director, University Computing Support Services University of Louisiana at Lafayette P.O. Box 43621 Lafayette, LA 70504 (337) 482-6402 patrick.landry@louisiana.edu ––––––––––––––––––––––––– Université des Acadiens


From: Matthew Aguirre <matt.aguirre@einstein-tech.com>
Sent: Tuesday, March 10, 2020 3:00 PM
To: 389-users@lists.fedoraproject.org <389-users@lists.fedoraproject.org>
Subject: [389-users] Force use of secure connections
 
Is there a way to disable unsecured use of port 389?  I am using FreeIPA, so the client setup uses port 389 with TLS and that is fine, but I'd like to be able to not allow unsecured connections as much as possible.

I was able to do this in OpenLdap, but haven't seen a comparable solution in ds-389.
--
Matt