28.7. Configuring a System to Authenticate Using OpenLDAP

This section provides a brief overview of how to configure OpenLDAP user authentication. Unless you are an OpenLDAP expert, more documentation than is provided here is necessary. Refer to the references provided in Section 28.9, “Additional Resources” for more information.
Install the Necessary LDAP Packages.
First, make sure that the appropriate packages are installed on both the LDAP server and the LDAP client machines. The LDAP server needs the openldap-servers package.
The openldap, openldap-clients, and nss_ldap packages need to be installed on all LDAP client machines.
Edit the Configuration Files.
  • On the server, edit the /etc/openldap/slapd.conf file on the LDAP server to make sure it matches the specifics of the organization. Refer to Section 28.6.1, “Editing /etc/openldap/slapd.conf for instructions about editing slapd.conf.
  • On the client machines, both /etc/ldap.conf and /etc/openldap/ldap.conf need to contain the proper server and search base information for the organization.
    To do this, run the graphical Authentication Configuration Tool (system-config-authentication) and select Enable LDAP Support under the User Information tab.
    It is also possible to edit these files by hand.
  • On the client machines, the /etc/nsswitch.conf must be edited to use LDAP.
    To do this, run the Authentication Configuration Tool (system-config-authentication) and select Enable LDAP Support under the User Information tab.
    If editing /etc/nsswitch.conf by hand, add ldap to the appropriate lines.
    For example:
    passwd: files ldap
    shadow: files ldap
    group: files ldap

28.7.1. PAM and LDAP

To have standard PAM-enabled applications use LDAP for authentication, run the Authentication Configuration Tool (system-config-authentication) and select Enable LDAP Support under the Authentication tab. For more about configuring PAM, refer to Section 48.4, “Pluggable Authentication Modules (PAM)” and the PAM man pages.