Setting up Samba as an Active Directory Domain Controller

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Starting from version 4.0 (released in 2012,) Samba is able to serve as an Active Directory (AD) domain controller (DC). Samba operates at the forest functional level of Windows Server 2008 R2 which is more than sufficient to manage sophisticated enterprises that use Windows 10/11 with strict compliance requirements (including NIST 800-171.)

If you are installing Samba in a production environment, it is recommended to run two or more DCs for failover reasons, more detail on the provisioning of a failover DC can be found elsewhere on the wiki. This documentation describes how to set up Samba as the first DC to build a new AD forest. Additionally, use this documentation if you are migrating a Samba NT4 domain to Samba AD. To join Samba as an additional DC to an existing AD forest, see Joining a Samba DC to an Existing Active Directory.

Samba as an AD DC only supports:

Samba provides experimental support for the MIT Kerberos KDC provided by your operating system if you run Samba 4.7 or later and has been built using the --with-system-mitkrb5 option. In other cases Samba uses the Heimdal KDC included in Samba. For further details about Samba using the MIT KDC, and why it is experimental see Running a Samba AD DC with MIT Kerberos KDC.
  • Hosting and Administering of Group Policy Objects to be used for enterprise fleet management

This tutorial assumes that this is a fresh installation of Samba on a fresh operating system installation. It is important to note that there is a distinction between installing of Samba and Provisioning of Samba. In general, the entire process of setting up a Samba domain controller consists of 5 steps which are relatively straight forward. These steps are as follows:

  1. Installation of Samba and associated packages
  2. Deletion of pre-configured Samba and Kerberos placeholder configuration files
  3. Provisioning of Samba using the automatic provisioning tool
  4. Editing of the smb.conf as needed (enabling of Group Policy and/or other features as needed) see Group Policy for more information
  5. Any environmental configuration based on Unix/Linux Distribution

This page covers a lot of ground for Samba installations on both Unix and Linux systems. The installation process varies slightly based on environment, so expect to follow the linked web pages in multiple tabs throughout this read. For the remainder of this tutorial the following example information is used:

  • Hostname = DC1
  • DC local IP Address =
  • Authentication Domain = SAMDOM.EXAMPLE.COM
  • Top level Domain = EXAMPLE.COM

Preparing the Installation

Fresh Installation

  • Select a DNS domain for your AD forest. It is not recommended to use the top level domain for your organization. This is because the domain used during the installation of Samba will resolve to the domain controller. For Example: If your organization used EXAMPLE.COM as their domain and this was used during the Samba installation process, then the public facing website would no longer be accessible (assuming the publicly accessible website was not running on the DC, which it shouldn't!) It would be wise to define a subdomain for your Domain Controller to reside in. In this tutorial SAMDOM.EXAMPLE.COM is used, however in a lab environment it is not necessary to own a publicly accessible domain and .INTERNAL could hypothetically be used. The name will also be used as the AD Kerberos realm.
For additional information, see Active Directory Naming FAQ.
  • Select a host name for your AD DC which consists of less than 15 characters (netbios limitation.) A fantastic hostname is DC1
Do not use NT4-only terms as host name, such as PDC or BDC. These modes do not exist in an AD and cause confusion.
  • Set a static IP address on the DC and make the associated reservation on your router. Important: The Samba domain controller will become your DNS resolver for all domain-joined workstations. As a result it may be required to assign this IP address outside of your DHCP pool
  • Disable tools, such as resolvconf, that automatically update your /etc/resolv.conf DNS resolver configuration file. AD DCs and domain members must use an DNS server that is able to resolve the AD DNS zones. (More information on this on the Distribution Specific Package Installation page)
  • Verify that the /etc/hosts file on the DC correctly resolves the fully-qualified domain name (FQDN) and short host name to the LAN IP address of the DC. For example:     localhost     DC1
The host name and FQDN must not resolve to the IP address or any other IP address than the one used on the LAN interface of the DC.
  • Remove any existing smb.conf file. To list the path to the file:
# smbd -b | grep "CONFIGFILE"
   CONFIGFILE: /usr/local/samba/etc/samba/smb.conf

Only Applicable if Samba was Previously Installed

  • If you previously ran a Samba installation on this host:
  • Remove all Samba database files, such as *.tdb and *.ldb files. To list the folders containing Samba databases:
  LOCKDIR: /usr/local/samba/var/lock/
  STATEDIR: /usr/local/samba/var/locks/
  CACHEDIR: /usr/local/samba/var/cache/
  PRIVATE_DIR: /usr/local/samba/private/
Starting with a clean environment helps to prevent confusion and ensures that no files from any previous Samba installation will be mixed with your new domain DC installation.

Installing Samba

Provisioning a Samba Active Directory

The Samba AD provisioning process creates the AD databases and adds initial records, such as the domain administrator account and required DNS entries. Samba comes with a built in command lined tool called samba-tool which can be used to automatically configure your smb.conf when ran in interactive mode.

If you are migrating a Samba NT4 domain to AD, skip this step and run the Samba classic upgrade. For details, see Migrating a Samba NT4 Domain to Samba AD (Classic Upgrade).

The samba-tool domain provision command provides several parameters to use with the interactive and non-interactive setup. For details, see:

# samba-tool domain provision --help

Parameter Reference

Set the following parameters during the provisioning:

Interactive Mode Setting Non-interactive Mode Parameter Explanation
--use-rfc2307 --use-rfc2307 Enables the NIS extensions required for the ADUC Unix Attributes tab.
Realm --realm Kerberos realm. The uppercase version of the AD DNS domain. For example: SAMDOM.EXAMPLE.COM.
Domain --domain NetBIOS domain name (Workgroup). This can be anything, but it must be one word, not longer than 15 characters and not containing a dot. It is recommended to use the first part of the AD DNS domain. For example: samdom. Do not use the computers short hostname.
Server Role --server-role Installs the domain controller DC role.
DNS backend --dns-backend Sets the DNS back end. The first DC in an AD must be installed using a DNS back end. Note that the BIND9_FLATFILE is not supported and will be removed in a future Samba version.
DNS forwarder IP address not available This setting is only available when using the SAMBA_INTERNAL DNS back end. For details, see Setting up a DNS Forwarder.
Administrator password --adminpass Sets the domain administrator password. If the password does not match the complexity requirements, the provisioning fails. For details, see Microsoft TechNet: Passwords must meet complexity requirements.

Other parameters frequently used with the samba-tool domain provision command:

  • --option="interfaces=lo eth0" --option="bind interfaces only=yes": If your server has multiple network interfaces, use these options to bind Samba to the specified interfaces. This enables the samba-tool command to register the correct LAN IP address in the directory during the join.

Provisioning Samba AD in Interactive Mode

As mentioned above, when run as root, samba-tool will automatically configure your smb.conf to build a domain controller. Interactive Mode will not automatically enable Group Policy support. However this can be added in afterwards by manually editing smb.conf.

With the existing smb.conf file removed, provision a Samba AD interactively by running:

# samba-tool domain provision --use-rfc2307 --interactive
 Server Role (dc, member, standalone) [dc]: dc
 DNS forwarder IP address (write 'none' to disable forwarding) []:
Administrator password: Passw0rd
Retype password: Passw0rd
Looking up IPv4 addresses
Looking up IPv6 addresses
No IPv6 address will be assigned
Setting up share.ldb
Setting up secrets.ldb
Setting up the registry
Setting up the privileges database
Setting up idmap db
Setting up SAM db
Setting up sam.ldb partitions and settings
Setting up sam.ldb rootDSE
Pre-loading the Samba 4 and AD schema
Adding DomainDN: DC=samdom,DC=example,DC=com
Adding configuration container
Setting up sam.ldb schema
Setting up sam.ldb configuration data
Setting up display specifiers
Modifying display specifiers
Adding users container                                                                                                                                                                                        
Modifying users container                                                                                                                                                                                     
Adding computers container                                                                                                                                                                                    
Modifying computers container                                                                                                                                                                                 
Setting up sam.ldb data                                                                                                                                                                                       
Setting up well known security principals                                                                                                                                                                     
Setting up sam.ldb users and groups                                                                                                                                                                           
Setting up self join                                                                                                                                                                                          
Adding DNS accounts                                                                                                                                                                                           
Creating CN=MicrosoftDNS,CN=System,DC=samdom,DC=example,DC=com                                                                                                                                                
Creating DomainDnsZones and ForestDnsZones partitions                                                                                                                                                         
Populating DomainDnsZones and ForestDnsZones partitions                                                                                                                                                       
Setting up sam.ldb rootDSE marking as synchronized                                                                                                                                                            
Fixing provision GUIDs                                                                                                                                                                                        
A Kerberos configuration suitable for Samba 4 has been generated at /usr/local/samba/private/krb5.conf                                                                                                        
Setting up fake yp server settings                                                                                                                                                                            
Once the above files are installed, your Samba4 server will be ready to use                                                                                                                                   
Server Role:           active directory domain controller                                                                                                                                                     
Hostname:              DC1                                                                                                                                                                                    
NetBIOS Domain:        SAMDOM                                                                                                                                                                                 
DNS Domain:                                                                                                                                                                       
DOMAIN SID:            S-1-5-21-2614513918-2685075268-614796884

Provisioning Samba AD in Non-interactive Mode

For example, to provision a Samba AD non-interactively with the following settings:

  • Server role: dc
  • NIS extensions enabled
  • Internal DNS back end
  • Kerberos realm and AD DNS zone:
  • NetBIOS domain name: SAMDOM
  • Domain administrator password: Passw0rd
# samba-tool domain provision --server-role=dc --use-rfc2307 --dns-backend=SAMBA_INTERNAL --realm=SAMDOM.EXAMPLE.COM --domain=SAMDOM --adminpass=Passw0rd

Setting up the AD DNS back end

Skip this step if you provisioned the DC using the SAMBA_INTERNAL DNS back end.

  • Start the BIND DNS server. For example:
# systemctl start named
For details how to start services, see you distribution's documentation.

Configuring the DNS Resolver

Domain members in an AD use DNS to locate services, such as LDAP and Kerberos. For that, they need to use a DNS server that is able to resolve the AD DNS zone.

On your DC, set the AD DNS domain in the search and the IP of your DC in the nameserver parameter of the /etc/resolv.conf file. For example:


Do not add any other lines, your DC should use itself as its nameserver and find all other dns data from its dns server.

Configuring Kerberos

In an AD, Kerberos is used to authenticate users, machines, and services.

During the provisioning, Samba created a Kerberos configuration file for your DC. Copy this file to your operating system's Kerberos configuration. For instance, if you built Samba yourself:

# cp /usr/local/samba/private/krb5.conf /etc/krb5.conf

Your krb5.conf path probably will be different, always use the path in the provision output. However, wherever Samba creates the krb5.conf, you need to copy it to /etc/krb5.conf.

The pre-created Kerberos configuration uses DNS service (SRV) resource records to locate the KDC.

Testing your Samba AD DC

To start the samba service manually, enter:

# samba

Samba does not provide System V init scripts, systemd, upstart, or other services configuration files.

  • If you installed Samba using packages, use the script or service configuration file included in the package to start Samba.
  • If you built Samba, see Managing the Samba AD DC Service.

Create a reverse zone

You can optionally add a reverse lookup zone.

# samba-tool dns zonecreate <Your-AD-DNS-Server-IP-or-hostname> -U Administrator
Password for [administrator@SAMDOM.EXAMPLE.COM]:
Zone created successfully

If you need more than one reverse zone (multiple subnets), just run the above command again but with the data for the other subnet.

The reverse zone is directly live without restarting Samba or BIND.

Now that you have created a reversezone, it would be a good time to create the PTR (reverse) dns record for the new DC.

For a DC with the FQDN of and the ipaddress of, to add a record to the, you would run a command like this:

# samba-tool dns add <Your-AD-DNS-Server-IP-or-hostname> 1 PTR -U Administrator
Password for [administrator@SAMDOM.EXAMPLE.COM]:
Record added successfully

Verifying the File Server (Optional)

To list all shares provided by the DC:

Before Samba 4.11.0:

$ smbclient -L localhost -N
Anonymous login successful
Domain=[SAMDOM] OS=[Unix] Server=[Samba x.y.z]

        Sharename       Type      Comment
        ---------       ----      -------
        netlogon        Disk      
        sysvol          Disk      
        IPC$            IPC       IPC Service (Samba x.y.z)
Domain=[SAMDOM] OS=[Unix] Server=[Samba x.y.z]

        Server               Comment
        ---------            -------

        Workgroup            Master
        ---------            -------

From Samba 4.11.0:

smbclient -L localhost -N
Anonymous login successful

    Sharename       Type      Comment
    ---------       ----      -------
    sysvol          Disk      
    netlogon        Disk      
    IPC$            IPC       IPC Service (Samba 4.12.6-Debian)
SMB1 disabled -- no workgroup available

To verify authentication, connect to the netlogon share using the domain administrator account:

$ smbclient //localhost/netlogon -UAdministrator -c 'ls'
Enter Administrator's password: 
Domain=[SAMDOM] OS=[Unix] Server=[Samba x.y.z]
 .                                   D        0  Tue Nov  1 08:40:00 2016
 ..                                  D        0  Tue Nov  1 08:40:00 2016

               49386 blocks of size 524288. 42093 blocks available

If one or more tests fail, see Troubleshooting.

Verifying DNS (Optional)

To verify that your AD DNS configuration works correctly, query some DNS records:

  • The tcp-based _ldap SRV record in the domain:
$ host -t SRV has SRV record 0 100 389
  • The udp-based _kerberos SRV resource record in the domain:
$ host -t SRV has SRV record 0 100 88
  • The A record of the domain controller:
$ host -t A has address
  • If you have created a reverse zone, the PTR record of the domain controller:
$ host -t PTR domain name pointer

If one or more tests fail, see Troubleshooting.

Verifying Kerberos (Optional)

This is not explicitly required, but it is a good idea to verify that your Domain Controller's authentication mechanisms are operating as intended. To test this, login by requesting a Kerberos ticket for the Domain Administrator account:

$ kinit administrator
Password for administrator@SAMDOM.EXAMPLE.COM:
  • List the cached Kerberos tickets:
$ klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: administrator@SAMDOM.EXAMPLE.COM

Valid starting       Expires              Service principal
01.11.2016 08:45:00  12.11.2016 18:45:00  krbtgt/SAMDOM.EXAMPLE.COM@SAMDOM.EXAMPLE.COM
	renew until 02.11.2016 08:44:59

If one or more tests fail, see Troubleshooting.

Configuring Time Synchronization (Optional Depending on Use-Case)

Kerberos requires synchronized time on all domain members. For further details and how to set up the ntpd or chrony service, see Time Synchronization. However if Samba is being used as a domain controller to administer Group Policy, it is possible to define a Group Policy Object that synchronizes workstations with post installation which simplifies this

Using the Domain Controller as a File Server (Optional)

While the Samba AD DC is able to provide file shares like all other installation modes, the Samba team does not recommend using a DC as a file server for the following reasons:

  • For anything but the smallest organizations, having more than one DC is a really good backup measure, and makes upgrades safer
  • It encourages upgrades of the DC to also be upgrades of the host OS every year or two, because there isn't complex data to transition or other services involved.
  • This means upgrades can be done by installing fresh, and replicating in the changes, which is better tested in Samba, gains new features and avoids a number of lingering data corruption risks.
  • The DC and file-server have different points at which an organization would wish to upgrade. The needs for new features on the DC and file server come at different times. Currently the AD DC is evolving rapidly to gain features, whereas the fileserver, after over 20 years, is quite rightly more conservative.
  • mandatory smb signing is enforced on the DC.

If you do decide to use the Samba DC as a fileserver, please consider running a VM, on the DC, containing a separate Samba Unix domain member and use this instead.

If you must use the Samba DC as a fileserver, you should be aware that the auto-enabled acl_xattr virtual file system (VFS) object enables you to only configure shares with Windows access control lists (ACL). Using POSIX ACLs with shares on a Samba DC does not work.

You should be aware that if wish to use a vfs object on a DC share e.g. recycle, you must not just set vfs objects = recycle in the share. Doing this will turn off the default vfs objects dfs_samba4 and acl_xattr. You must set vfs objects = dfs_samba4 acl_xattr recycle.

To provide network shares with the full capabilities of Samba, set up a Samba domain member with file shares. For details, see:

If you only have a small domain (small office, home network) and do not want to follow the Samba team's recommendation and use the DC additionally as a file server, configure Winbindd before you start setting up shares. For details, see Configuring Winbindd on a Samba AD DC.


For further details, see Samba AD DC Troubleshooting.

Further Samba-related Documentation

See User Documentation.