OpenLDAP remains the most widely deployed open-source directory server, and almost every centralized-authentication question in Linux eventually leads back to it. This tutorial takes you from a clean RHEL-family VM all the way to a TLS-secured, replicated, production-ready OpenLDAP deployment — using the same playbook real sysadmins follow.
We start with the absolute fundamentals in LDAP and OpenLDAP basics (what LDAP actually is, why DNs and schemas matter), then install OpenLDAP on Rocky Linux or AlmaLinux, lock it down with TLS, configure replication for high availability, and integrate Linux clients through SSSD so users can log in with LDAP credentials, NFS home directories, and centralized sudo rules. Every chapter is short and idempotent, and every command is tested on a fresh lab VM.
Evaluating 389 Directory Server or Red Hat Directory Server instead? Read OpenLDAP vs 389 Directory Server for an operational comparison, then follow the 389 Directory Server tutorial if that product fits your platform.
If you are new to LDAP, click Start the course and read the LDAP Concepts chapter first — it will save you hours of confusion later. If you already understand the protocol, jump straight to the RHEL-family install chapter.
