Linux Active-Directory Equivalent

(Last Updated On: June 24, 2021)



Microsoft’s Active Directory (AD) is a directory service for Windows domain networks. It comes as a set of processes and services with most Windows Server operating systems. At first, Active Directory was exclusively responsible for domain management. However, after then, Active Directory became a catch-all term for a variety of directory-based identity-related services. A domain controller is a server that runs the Active Directory Domain Service (AD DS) role. In a Windows domain network, it authenticates and authorizes all users and computers. They are creating and enforcing security policies across all machines, as well as installing and updating software. For example, when a user login into a Windows domain machine, Active Directory validates the password and decides if the person is a system administrator or a regular user. It also enables for information management and storage, authentication and authorization procedures, and the deployment of other associated services such as Certificate Services, Active Directory Federation Services, Lightweight Directory Services, and Rights Management Services.

You can either create your Active Directory-type solution using Kerberos and OpenLDAP (Active Directory is just Kerberos and LDAP anyhow) or use a program like Puppet (or OpenLDAP itself) for policies, or you can use FreeIPA as an integrated solution. For example, when a user login into a Windows domain machine, Active Directory validates the password and decides if the person is a system administrator or a regular user. I am a big fan of the FreeIPA project and believe it has a lot of promise. Standard RHEL6 subscriptions, I believe, include a commercially sponsored version of FreeIPA.

However, what you’re after is more of a fileserver solution than an authentication solution (which is what AD is). You must set up an NFS server and export an NFS share from your fileserver to your network if you want your files to be accessible from any machine you connect to. NFSv4 would conduct proper authentication with Kerberos and mix nicely with the authentication choices I stated above. NFSv3 has IP-range based ACLs; NFSv4 would be able to do proper authentication with Kerberos and mix nicely with the authentication options I stated above. If your network includes Windows computers, you’ll want to set up a Samba server to share your files with Linux and Windows computers. Samba3 can act as a domain controller in the NT4 style, but Samba4 can act as a domain controller in the Windows 2003 style.

How To Link A Linux Server To A Domain In Active Directory?

How To Link A Linux Server To A Domain In Active Directory?

Do you need to administer Linux computers and user accounts in an Active Directory domain from a central location? It is how you do it. For many businesses, Microsoft’s Active Directory (AD) is the preferred directory service. However, if you and your team are in charge of a mixed Windows and Linux environment, you’ll most likely want to centralize authentication across both platforms. So I’ll show you how to join an Active Directory domain with Linux PCs.

The requirement for centralized access management and Active Directory, For many years, Microsoft’s Active Directory, sometimes known as AD, has controlled the lion’s share of the enterprise access control industry. Institutions and individuals use it worldwide to regulate access to the organization’s resources centrally. It allows you to manage users, passwords, and resources like computers and control who can access what. Some of you reading this article, particularly those who work in large institutions, have dealt with AD previously. Typically, the interaction involves logging in to any workstation in the business with a single set of login credentials. That’s only the tip of the iceberg. Consider a company with 40 computer systems and 70 employees. Some employees work shifts, while others have a set schedule. Some people have access to printers, whereas others do not. Creating local user accounts on each computer a user wants access to be the usual way of working. Consider how much effort the end-user support team has to do. To keep things in sync, when a user changes his password for any reason, he must also update the password on all computers to which he previously had access. There will be chaos in no time. Consider what would happen if two members of the staff resigned. I don’t need to tell you about the tedious labor that must be redone whenever the staffing or workstations are changed. It is a nightmare for IT departments. A time that could spend on more creative endeavors is now being spent reinventing the wheel. I haven’t even mentioned controlling printer access.

Directory service like Active Directory thrives in this environment. It might save your life. Each user is generated as an object in a central database with a single set of credentials in Active Directory. Every computer system is also made into an object. Every user can automatically log in to any workstation using the same set of credentials. Any account changes that need to be made are made once at the central database. Members of staff can access the printers using the same set of credentials. The printers’ authentication mechanism can be coupled with AD to achieve that. Happy users, happy IT team. Access to diverse resources can be managed and managed using groups and organizational units. It only gets better, and we can use this Directory to hold staff phone numbers and email addresses, and other information. What happens if someone leaves? It’s no problem. Deactivate the user’s account. On the spot, the person’s access to all resources is revoked. The greater the size of the company, the more centralized management is required. It saves both time and emotions. A directory service is just an orderly manner of itemizing all of an organization’s resources and providing simple access to those items. AD is essentially a distributed database that can be accessed remotely using the Lightweight Directory Access Protocol (LDAP) (LDAP). LDAP is an open protocol for accessing directory services from a distance using connection-oriented media like TCP/IP. AD isn’t the only directory service that adheres to the x.500 standard and can be accessed via LDAP. OpenLDAP and FreeIPA are two other directory services.

On the other hand, AD is a well-established Windows-based service that comes pre-installed on Windows Server systems. In other words, if your company has a lot of Windows systems, it’ll be the clear winner. One of the reasons for its widespread use is this. FreeIPA and other Linux-based directory services provide outstanding service for a Linux stable. When the rubber meets the road, the decision comes down to which of the two you can put up quickly, given your current surroundings and the skill level of your crew. A directory service is just an orderly manner of itemizing all of an organization’s resources and providing simple access to those items. AD is essentially a distributed database that can be accessed remotely using the Lightweight Directory Access Protocol (LDAP) (LDAP). If that’s what you’re looking for, keep reading to learn how to achieve it. Of course, we can add a Windows system to a FreeIPA domain, but that is beyond the scope of this paper.


This article assumes you have at least some basic knowledge of Active Directory, particularly user and computer account administration. Aside from that, it must fulfill the following needs:

  • An AD account with the permissions required to join a system to the domain.
  • A Linux server (for this demonstration, utilized a CentOS 7 server).
  • Make sure your Linux server knows how to locate the domain controller using DNS.

To make this article easier for everyone, here’s a summary of important details. Make any necessary changes to the setup of the lab you can use for this study.

  • net is the AD domain name.
  • Linux server hostname: centy2
  • The user account for joining the domain: Korea (Full name – Fiifi Korea)

Packages To Install

Realmd is the most important package to install for this configuration. Aside from Realmd, we must install a slew of other packages for this to work. Realmd makes discovering and interacting with Active Directory domains much easier. It uses sssd to perform the actual lookups required for remote authentication and other heavy domain operations. I won’t go into detail about the other packages on the list for the sake of brevity. On the other hand, a fast Google search should be of tremendous assistance to anyone interested in the details.

Realmd (Interacting With The Domain)

Realmd (Interacting With The Domain)

After installing all of the packages, the first step is to link the CentOS system to the Active Directory domain. For this, we use the realm application. The realm client and Realmd are both installed at the same time. May use it to add, remove, limit access, and perform a variety of other functions.

Harness The Power Of Active Directory Across Linux

Within Windows, Active Directory serves as a centralized management point. On the other hand, user IDs on Linux and UNIX may be stored on separate servers or in distinct identity silos, complicating operations and jeopardizing security. Managing identification on local systems or separate identity stores is a problem for organizations with hundreds or thousands of UNIX and Linux servers. Consolidating identity into a single directory can be difficult and time-consuming because there are many distinct and often overlapping identity silos. Most alternative options necessitate a complete rationalization and homogenization of all user IDs before consolidation can take place. Within your existing Active Directory infrastructure, Centrify Authentication Service unifies your IT infrastructure by centralizing identity and access management for non-Windows systems, devices, and apps.

Centrify allows you to connect to Active Directory in the following ways:

  • Integrate Linux systems with Active Directory without installing software on the domain controller or changing the schema.
  • Evaluate systems for identity-related vulnerabilities automatically.
  • Using Centrify Zones, quickly move user identities into Active Directory, avoiding the need to rationalize Linux namespaces.
  • From NIS or /etc./passed, easily migrate to centralized identity and access control.
  • Implement standard security standards and handle compliance reporting from a central location.
  • Support Active Directory’s centrally managed password policies and configurable user naming conventions.
  • Can use · Individuals’ Active Directory accounts to assign access rights and privileges to them. Ascertain accountability and provide detailed compliance reporting on who has access to which systems.
  • Grant users the right to access only those systems required for business purposes based on their job role(s).
  • Use Centrify Zone-based access controls to their full potential. Define administrative boundaries for groups of systems, each of which has its own set of allowed users, administrators, and security rules.
  • Automatically discover the nearest domain controller, the global catalog, one/two-way trusts, multi-site environments, domain controller fail-over, and disjoint Active Directory-DNS namespaces are all supported in real-world DNS and Active Directory systems.
  • Automate the Kerberos stack configuration on Linux, including automatic keytab file updates and keytab versioning, time synchronization with Active Directory domain controllers, and local caching for detached mode.
  • Through Active Directory, provide single sign-on (SSO) access to Linux and UNIX computers.
  • Add Linux users and computers to Active Directory Group Policy Management.
  • Use Centrify-enabled OpenSSH and PuTTY tools to connect to servers with ease.
  • Integrate popular apps with Active Directory, such as Hadoop and NoSQL.


radius linux

Another active directory alternative for Linux is the RADIUS (Remote Authentication Dial-In User Service) protocol. Radius is a protocol for establishing user authentication on a local network. Users can log into a network using a unique username and password by using the Radius server. Radius can also segment users’ traffic or segregate their traffic into sub-networks. Radius allows businesses to store user profiles in a central database (Radius Server) shared by remote systems.


Knowing what Active Directory is and what it does and what a domain controller does isn’t a difficult subject once you understand the procedure. Domain controllers validate your authority, whereas Active Directory is in charge of your identity and security access.

Leave a Reply

Your email address will not be published. Required fields are marked *