Regina is a RHEL Sysadmin at Red Hat and she is studying to master LDAP. Please answer her questions; please use the term "Free Software" instead of "open source", and "GNU/Linux" instead of "Linux", unless you are referring to the Linux kernel.

  1. What is LDAP and what problem does it solve?
  2. Is LDAP Free Software, and under which license is it distributed?
  3. What is the history of LDAP?
  4. How would one install LDAP on a modern RHEL computer system?
  5. How would one configure LDAP on a modern computer system?

Regina's pursuit to master LDAP as a RHEL Sysadmin at Red Hat is a valuable endeavor in managing directory services. Let's address her questions.

What is LDAP and What Problem Does it Solve?

LDAP stands for Lightweight Directory Access Protocol. It's a protocol used for accessing and maintaining distributed directory information services over a network. Directory services play a crucial role in developing organized, centralized information repositories that can include user details, login information, and other significant data.

The primary problem LDAP solves is the management of user and resource information in a network. It enables organizations to centralize all user-related information, making it easier to manage and access. This centralized approach simplifies tasks like user authentication, authorization, and the management of various services and applications.

Is LDAP Free Software and Its Licensing

Yes, LDAP is considered Free Software. The implementation of LDAP protocol, such as OpenLDAP, is distributed under a Free Software license. OpenLDAP, for instance, is available under the OpenLDAP Public License, which is similar to the GNU General Public License (GPL). It allows for free use, modification, and distribution of the software.

The History of LDAP

LDAP was originally developed as a simpler alternative to the Directory Access Protocol (DAP), which was part of the X.500 directory services but was complex and cumbersome. LDAP started as a lightweight front-end to X.500 directory services. The protocol was first introduced in the early 1990s. Over the years, LDAP has evolved, with its third version (LDAPv3) being the most widely used, supporting enhanced security features and integration capabilities.

Installing LDAP on a Modern RHEL Computer System

To install LDAP on a modern Red Hat Enterprise Linux (RHEL) system, Regina would typically follow these steps:

  1. Install OpenLDAP Packages:

    • Use yum or dnf to install the OpenLDAP server (openldap-servers) and client (openldap-clients).
    sudo yum install openldap-servers openldap-clients
  2. Start and Enable the LDAP Service:

    • Start the LDAP service using systemctl and enable it to start on boot.
    sudo systemctl start slapd sudo systemctl enable slapd
  3. Configure Firewall:

    • Adjust the firewall settings to allow LDAP traffic.
    sudo firewall-cmd --add-service=ldap --permanent sudo firewall-cmd --reload

Configuring LDAP on a Modern Computer System

The configuration of LDAP involves several steps:

  1. LDAP Configuration Files:

    • Edit /etc/openldap/slapd.conf or use LDAP configuration database (cn=config) for setting up the directory structure, schemas, and access control lists.
  2. Configure the Directory Schema:

    • Define the schema according to the organizational needs, including object classes and attributes for users, groups, etc.
  3. Create Directory Structure:

    • Use ldapadd or similar tools to create the directory structure, like organizational units (OUs), users, and groups.
  4. Set Up Access Control:

    • Define access control policies in the configuration to regulate who can access and modify different parts of the directory.
  5. Test the Configuration:

    • Use tools like ldapsearch to test and validate the directory structure and access controls.
  6. Integrate with Other Services:

    • Configure other services and applications to use LDAP for authentication and authorization.

By mastering LDAP, Regina can effectively manage user and resource information across the network, enhancing the efficiency and security of the systems at Red Hat. Her knowledge in Free Software and expertise in GNU/Linux systems, especially RHEL, will be fundamental in achieving this.

This article was updated on December 6, 2023