Active Directory

Active Directory (AD) is Microsoft's directory service, and it's the most common LDAP implementation you'll encounter in enterprise environments. If your organization runs Windows domains, AD is almost certainly the directory behind logins, email addresses, and group-based permissions.

Active Directory speaks standard LDAP — everything you learned in Getting Started (DNs, entries, binds, searches, filters) applies directly. AD also layers on Windows-specific protocols (Kerberos for authentication, DNS for service discovery, replication between domain controllers), but none of that is required to use AD as an LDAP directory from application code.

A few things consistently trip people up when moving from generic LDAP knowledge to Active Directory specifically:

• The base DN is derived from the DNS domain name, not chosen freely — see LDAP in Active Directory.
• Attribute names differ from other directories in places — sAMAccountName instead of uid, userAccountControl instead of a simple disabled flag.
• Bind failures carry rich, AD-specific detail in an extended error string, not just a bare LDAP result code — see Authentication in Active Directory.

1. LDAP in Active Directory — domain-to-DN mapping and connection basics.
2. Users — how AD models user accounts.
3. Groups — AD-specific group types and nesting.
4. Common attributes — a reference table of frequently used AD attributes.
5. Authentication — decoding AD's extended bind error codes.

Start with LDAP in Active Directory.