Install And Configure LDAP Server In CentOS 7

This tutorial describes how to install and configure LDAP server (389-DS) in CentOS 7.

About 389-DS Server

389-DS (389 Directory Server) is an open source enterprise class LDAP server for Linux, and is developed by Red Hat community. It is hardened by real-world use, is full-featured, supports multi-master replication, and already handles many of the largest LDAP deployments in the world. The 389 Directory Server can be downloaded for free, and set up in less than an hour using the graphical console. 389-DS can handle thousands of concurrent users more effectively.


Concerning about 389-DS features, we can list the following:

  • High performance ;
  • Multi-Master Replication, to provide fault tolerance and high write performance ;
  • The codebase has been developed and deployed continuously by the same team for more than a decade ;
  • Active Directory user and group synchronization ;
  • Secure authentication and transport (TLSv1, and SASL) ;
  • Support for LDAPv3 ;
  • On-line, zero downtime, LDAP-based update of schema, configuration, management and in-tree Access Control Information (ACIs) ;
  • Graphical console for all facets of user, group, and server management ;
  • Continuous Integration Testing (lib389) – prevents regressions and helps maintain stability with each release.

For more details, check the Features page.

Install and Configure LDAP server in CentOS 7

In this how-to, I will be using the following system as LDAP server.

  • Operating System: CentOS 7 server
  • Host name: server1.unixmen.local
  • IP Address:


Before installing LDAP server, you must do the following requirements.

1. Set your server fully qualified domain in /etc/hosts file

Edit file /etc/hosts/,

vi /etc/hosts

Add your hostname as shown below.

[...]   server1.unixmen.local    server1

Change the values as per your requirement.

2. Firewall Configuration

Allow the following ldap ports to your iptables.

firewall-cmd --permanent --add-port=389/tcp
firewall-cmd --permanent --add-port=636/tcp
firewall-cmd --permanent --add-port=9830/tcp

Restart firewall.

firewall-cmd --reload

3. Add EPEL and REMI Repository

Follow the below links to install and enable EPEL and REMI repositories.

4. Performance and Security tuning for LDAP server

Before installing LDAP server, we have to adjust some files for performance and security.

Edit file “/etc/sysctl.conf”,

vi /etc/sysctl.conf

Add the following lines at the end.

net.ipv4.tcp_keepalive_time = 300
net.ipv4.ip_local_port_range = 1024 65000
fs.file-max = 64000

Edit file “/etc/security/limits.conf”,

vi /etc/security/limits.conf

Add the following lines at the bottom.

*               soft     nofile          8192   
*               hard     nofile          8192

Edit file “/etc/profile”,

vi /etc/profile

Add the line at the end.

ulimit -n 8192

Edit file “/etc/pam.d/login”,

vi /etc/pam.d/login

Add the line at the end.

session    required     /lib/security/

Now Restart the server.

Install 389 Directory Server

Create a LDAP user account.

useradd ldapadmin
passwd ldapadmin

Install 389-ds-base package using command:

yum install 389-ds-base openldap-clients

Right now, all required packages for 389-DS server are not available in the CentOS repositories. We have to download and install manually the following packages.

Now, install the above packages one by one as shown below.

yum localinstall
yum localinstall
yum localinstall
yum localinstall
yum localinstall
yum localinstall

That’s it.

Configure LDAP server

Now it’s time to configure LDAP server. It’s quite long way process. Run the following command to configure 389 directory server.

You will be asked to answer for a couple of questions. Please read the instructions carefully and answer them accordingly.

If you made any mistake and want to go back to previous screen press CTRL+B and Enter. To cancel the setup press CTRL+C.

This program will set up the 389 Directory and Administration Servers.

It is recommended that you have "root" privilege to set up the software.
Tips for using this program:
 - Press "Enter" to choose the default and go to the next screen
 - Type "Control-B" then "Enter" to go back to the previous screen
 - Type "Control-C" to cancel the setup program

Would you like to continue with set up? [yes]:  ## Press Enter

Your system has been scanned for potential problems, missing patches,
etc. The following output is a report of the items found that need to
be addressed before running this software in a production

389 Directory Server system tuning analysis version 23-FEBRUARY-2012.

NOTICE : System is x86_64-unknown-linux3.10.0-123.9.3.el7.x86_64 (1 processor).

WARNING: 616MB of physical memory is available on the system. 1024MB is recommended for best performance on large production system.

NOTICE : The net.ipv4.tcp_keepalive_time is set to 7200000 milliseconds
(120 minutes). This may cause temporary server congestion from lost
client connections.

WARNING: There are only 1024 file descriptors (soft limit) available, which
limit the number of simultaneous connections.

WARNING : The warning messages above should be reviewed before proceeding.

Would you like to continue? [no]: yes ## Type 'Yes' and press Enter

Choose a setup type:

1. Express
 Allows you to quickly set up the servers using the most
 common options and pre-defined defaults. Useful for quick
 evaluation of the products.

2. Typical
 Allows you to specify common defaults and options.

3. Custom
 Allows you to specify more advanced options. This is 
 recommended for experienced server administrators only.

To accept the default shown in brackets, press the Enter key.

Choose a setup type [2]:  ## Press Enter

Enter the fully qualified domain name of the computer
on which you're setting up server software. Using the form

To accept the default shown in brackets, press the Enter key.

Warning: This step may take a few minutes if your DNS servers
can not be reached or if DNS is not configured correctly. If
you would rather not wait, hit Ctrl-C and run this program again
with the following command line option to specify the hostname:

Computer name [server1.unixmen.local]:  ## Press Enter

The servers must run as a specific user in a specific group.
It is strongly recommended that this user should have no privileges
on the computer (i.e. a non-root user). The setup procedure
will give this user/group some permissions in specific paths/files
to perform server-specific operations.

If you have not yet created a user and group for the servers,
create this user and group using your native operating
system utilities.

System User [nobody]: ldapadmin ## Type LDAP user name which we created earlier
System Group [nobody]: ldapadmin ## Type ldap group

Server information is stored in the configuration directory server.
This information is used by the console and administration server to
configure and manage your servers. If you have already set up a
configuration directory server, you should register any servers you
set up or create with the configuration server. To do so, the
following information about the configuration server is required: the
fully qualified host name of the form
<hostname>.<domainname>(e.g., the port number
(default 389), the suffix, the DN and password of a user having
permission to write the configuration information, usually the
configuration directory administrator, and if you are using security
(TLS/SSL). If you are using TLS/SSL, specify the TLS/SSL (LDAPS) port
number (default 636) instead of the regular LDAP port number, and
provide the CA certificate (in PEM/ASCII format).

If you do not yet have a configuration directory server, enter 'No' to
be prompted to set up one.

Do you want to register this software with an existing
configuration directory server? [no]:  ## Press Enter

Please enter the administrator ID for the configuration directory
server. This is the ID typically used to log in to the console. You
will also be prompted for the password.

Configuration directory server
administrator ID [admin]:  ## Press Enter
Password:   ## Type Password
Password (confirm):  ## Re-type password

The information stored in the configuration directory server can be
separated into different Administration Domains. If you are managing
multiple software releases at the same time, or managing information
about multiple domains, you may use the Administration Domain to keep
them separate.

If you are not using administrative domains, press Enter to select the
default. Otherwise, enter some descriptive, unique name for the
administration domain, such as the name of the organization
responsible for managing the domain.

Administration Domain [unixmen.local]:  ## Press Enter

The standard directory server network port number is 389. However, if
you are not logged as the superuser, or port 389 is in use, the
default value will be a random unused port number greater than 1024.
If you want to use port 389, make sure that you are logged in as the
superuser, that port 389 is not in use.

Directory server network port [389]:  ## Press Enter

Each instance of a directory server requires a unique identifier.
This identifier is used to name the various
instance specific files and directories in the file system,
as well as for other uses as a server instance identifier.

Directory server identifier [server1]:  ## Press Enter

The suffix is the root of your directory tree. The suffix must be a valid DN.
It is recommended that you use the dc=domaincomponent suffix convention.
For example, if your domain is,
you should use dc=example,dc=com for your suffix.
Setup will create this initial suffix for you,
but you may have more than one suffix.
Use the directory server utilities to create additional suffixes.

Suffix [dc=unixmen, dc=local]:  ##Press Enter

Certain directory server operations require an administrative user.
This user is referred to as the Directory Manager and typically has a
bind Distinguished Name (DN) of cn=Directory Manager.
You will also be prompted for the password for this user. The password must
be at least 8 characters long, and contain no spaces.
Press Control-B or type the word "back", then Enter to back up and start over.

Directory Manager DN [cn=Directory Manager]: ## Press Enter
Password: ## Type Password 
Password (confirm): ## Re-enter password

The Administration Server is separate from any of your web or application
servers since it listens to a different port and access to it is

Pick a port number between 1024 and 65535 to run your Administration
Server on. You should NOT use a port number which you plan to
run a web or application server on, rather, select a number which you
will remember and which will not be used for anything else.

Administration port [9830]:  ## Press Enter

The interactive phase is complete. The script will now set up your
servers. Enter No or go Back if you want to change something.

Are you ready to set up your servers? [yes]:  ## Press Enter
Creating directory server . . .
Your new DS instance 'server1' was successfully created.
Creating the configuration directory server . . .
Beginning Admin Server creation . . .
Creating Admin Server files and directories . . .
Updating adm.conf . . .
Updating admpw . . .
Registering admin server with the configuration directory server . . .
Updating adm.conf with information from configuration directory server . . .
Updating the configuration for the httpd engine . . .
Starting admin server . . .
The admin server was successfully started.
Admin server was successfully created, configured, and started.
Exiting . . .
Log file is '/tmp/setupOLhgGH.log'

Congratulations! We have successfully configured 389 Directory Server.

Starting/Stopping 389-ds services

Make the LDAP server services to start automatically on every reboot.

systemctl enable
systemctl enable dirsrv-admin

To start directory server, run:

systemctl start



To stop it, run:

systemctl stop



Likewise, to start directory admin, run:

systemctl start dirsrv-admin



To stop it:

systemctl stop dirsrv-admin



Likewise, you can check the status of the both services using commands:

systemctl status
systemctl status dirsrv-admin

To restart the above services. run:

systemctl restart
systemctl restart dirsrv-admin

All configuration files will be found under /etc/dirsrv/ directory and all log files will found under /var/log/dirsrv/ directory.

Test LDAP Server

Now let us test our LDAP Server now for any errors using following command.

ldapsearch -x -b "dc=unixmen,dc=local"

Sample output:

# extended LDIF
# LDAPv3
# base <dc=unixmen,dc=local> with scope subtree
# filter: (objectclass=*)
# requesting: ALL

# unixmen.local
dn: dc=unixmen,dc=local
objectClass: top
objectClass: domain
dc: unixmen

# Directory Administrators, unixmen.local
dn: cn=Directory Administrators,dc=unixmen,dc=local
objectClass: top
objectClass: groupofuniquenames
cn: Directory Administrators
uniqueMember: cn=Directory Manager

# Groups, unixmen.local
dn: ou=Groups,dc=unixmen,dc=local
objectClass: top
objectClass: organizationalunit
ou: Groups

# People, unixmen.local
dn: ou=People,dc=unixmen,dc=local
objectClass: top
objectClass: organizationalunit
ou: People

# Special Users, unixmen.local
dn: ou=Special Users,dc=unixmen,dc=local
objectClass: top
objectClass: organizationalUnit
ou: Special Users
description: Special Administrative Accounts

# Accounting Managers, Groups, unixmen.local
dn: cn=Accounting Managers,ou=Groups,dc=unixmen,dc=local
objectClass: top
objectClass: groupOfUniqueNames
cn: Accounting Managers
ou: groups
description: People who can manage accounting entries
uniqueMember: cn=Directory Manager

# HR Managers, Groups, unixmen.local
dn: cn=HR Managers,ou=Groups,dc=unixmen,dc=local
objectClass: top
objectClass: groupOfUniqueNames
cn: HR Managers
ou: groups
description: People who can manage HR entries
uniqueMember: cn=Directory Manager

# QA Managers, Groups, unixmen.local
dn: cn=QA Managers,ou=Groups,dc=unixmen,dc=local
objectClass: top
objectClass: groupOfUniqueNames
cn: QA Managers
ou: groups
description: People who can manage QA entries
uniqueMember: cn=Directory Manager

# PD Managers, Groups, unixmen.local
dn: cn=PD Managers,ou=Groups,dc=unixmen,dc=local
objectClass: top
objectClass: groupOfUniqueNames
cn: PD Managers
ou: groups
description: People who can manage engineer entries
uniqueMember: cn=Directory Manager

# search result
search: 2
result: 0 Success

# numResponses: 10
# numEntries: 9

The output will look something like above. If you have got result as 2 shown in the  above output, you’re done.

Now, our LDAP server is ready to use.

Check our next article to manage LDAP server graphically using 389 management console.

You might want to setup LDAP server CentOS 6.x systems. If yes, refer the following link.


Reference Links: