Setting up Samba as an Active Directory Domain Controller
Starting from version 4.0 (released in 2012,) Samba is able to serve as an Active Directory (AD) domain controller (DC). Samba can operates at a forest functional level of Windows Server 2008 R2 which is more that 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:
- The integrated LDAP server as AD back end. For details, see the frequently asked question (FAQ) Does Samba AD DCs Support OpenLDAP or Other LDAP Servers as Back End?
- The Heimdal Kerberos Key Distribution Center (KDC).
- 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-mitkrb5option. 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
Installation of Samba and associated provisioning of a domain controller does not automatically translate into Group Policy functionality. Please keep this in mind, and expect to update this flag in the
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:
- Installation of Samba and associated packages
- Deletion of per-configured Samba and Kerberos placeholder configuration files
- Provisioning of Samba using the automatic provisioning tool
- Editing of the
smb.confas needed (enabling of Group Policy and/or other features as needed) see Group Policy for more information
- 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 =
- DC local IP Address =
- Domain =
Preparing the Installation
- Select a host name for your AD DC which consists of less than 15 characters (netbios limitation.) A fantastic hostname is
- Do not use NT4-only terms as host name, such as
BDC. These modes do not exist in an AD and cause confusion.
- Select a DNS domain for your AD forest. If accessing the domain controller outside of your enterprise, it would be wise to utilize the top level domain of your organization. In this tutorial
SAMDOM.EXAMPLE.COMis used, however in a lab environment it is not necessary to own a publicly accessible domain and
.INTERNALcould hypothetically be used. The name will also be used as the AD Kerberos realm.
Make sure that you provision the AD using a DNS domain that will not need to be changed. Samba does not support renaming the AD DNS zone and Kerberos realm. Do not use
.localfor the TLD, this is used by Avahi.
- For additional information, see Active Directory Naming FAQ.
- Important: Use a static IP address on the DC and make the associated reservation on your router. 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.confDNS resolver configuration file. AD DCs and domain members must use an DNS server that is able to resolve the AD DNS zones.
- Verify that the
/etc/hostsfile 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:
127.0.0.1 localhost 10.99.0.1 DC1.samdom.example.com DC1
- The host name and FQDN must not resolve to the
127.0.0.1IP address or any other IP address than the one used on the LAN interface of the DC.
Only Applicable if Samba was Previously Installed
- If you previously ran a Samba installation on this host:
- Remove the existing
smb.conffile. To list the path to the file:
- Remove the existing
# smbd -b | grep "CONFIGFILE" CONFIGFILE: /usr/local/samba/etc/samba/smb.conf
- Remove all Samba database files, such as
*.ldbfiles. To list the folders containing Samba databases:
- Remove all Samba database files, such as
# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR" 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.
- Remove an existing
# rm /etc/krb5.conf
|Install a maintained Samba version. For details, see Samba Release Planning.|
Provisioning a Samba Active Directory
|The AD provisioning requires root permissions to create files and set permissions.|
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).
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
|When provisioning a new AD, it is recommended to enable the NIS extensions by passing the |
Set the following parameters during the provisioning:
|Interactive Mode Setting||Non-interactive Mode Parameter||Explanation|
||Enables the NIS extensions required for the ADUC Unix Attributes tab.|
||Kerberos realm. The uppercase version of the AD DNS domain. For example: |
||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: |
||Installs the domain controller |
||Sets the DNS back end. The first DC in an AD must be installed using a DNS back end. Note that the |
||not available||This setting is only available when using the |
||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-toolcommand to register the correct LAN IP address in the directory during the join.
|do NOT use |
|If using Bind as the DNS backend, do NOT use |
|Once you have provisioned the first DC in an AD domain, do not provision any further DCs in the same domain, Join any further DCs.|
Provisioning Samba AD in Interactive Mode
As mentioned above,
samba-tool when ran as route 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 the
smb.conf to add it in later. Open the Group Policy page in a new tab for later reading
|The installation of Samba will create a |
With the existing
smb.conf file removed, provision a Samba AD interactively by running run:
# samba-tool domain provision --use-rfc2307 --interactive Realm [SAMDOM.EXAMPLE.COM]: SAMDOM.EXAMPLE.COM Domain [SAMDOM]: SAMDOM Server Role (dc, member, standalone) [dc]: dc DNS backend (SAMBA_INTERNAL, BIND9_FLATFILE, BIND9_DLZ, NONE) [SAMBA_INTERNAL]: SAMBA_INTERNAL DNS forwarder IP address (write 'none' to disable forwarding) [10.99.0.1]: 188.8.131.52 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: samdom.example.com DOMAIN SID: S-1-5-21-2614513918-2685075268-614796884
|The interactive provisioning mode supports passing further parameters to the |
Provisioning Samba AD in Non-interactive Mode
For example, to provision a Samba AD non-interactively with the following settings:
- Server role:
- NIS extensions enabled
- Internal DNS back end
- Kerberos realm and AD DNS zone:
- NetBIOS domain name:
- Domain administrator password:
# 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.
- Set up the BIND DNS server and the
BIND9_DLZmodule. For details, see Setting up a BIND DNS Server.
- 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:
search samdom.example.com nameserver 10.99.0.1
Create a reverse zone
You can optionally add a reverse lookup zone.
# samba-tool dns zonecreate <Your-AD-DNS-Server-IP-or-hostname> 0.99.10.in-addr.arpa -U Administrator Password for [administrator@SAMDOM.EXAMPLE.COM]: Zone 0.99.10.in-addr.arpa 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.
|You must start the Samba AD DC before you can add a reverse zone.|
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 example:
# cp /usr/local/samba/private/krb5.conf /etc/krb5.conf
|Do not create a symbolic link to the the generated |
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 does not provide System V init scripts,
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.
Verifying the File Server
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.
To verify that your AD DNS configuration works correctly, query some DNS records:
- The tcp-based
_ldapSRV record in the domain:
$ host -t SRV _ldap._tcp.samdom.example.com. _ldap._tcp.samdom.example.com has SRV record 0 100 389 dc1.samdom.example.com.
- The udp-based
_kerberosSRV resource record in the domain:
$ host -t SRV _kerberos._udp.samdom.example.com. _kerberos._udp.samdom.example.com has SRV record 0 100 88 dc1.samdom.example.com.
- The A record of the domain controller:
$ host -t A dc1.samdom.example.com. dc1.samdom.example.com has address 10.99.0.1
If one or more tests fail, see Troubleshooting.
- Request a Kerberos ticket for the domain administrator account:
$ kinit administrator Password for administrator@SAMDOM.EXAMPLE.COM:
If you do not pass the principal in the
user@REALMformat to the
kinitcommand, the Kerberos realm is automatically appended.
Always enter the Kerberos realm in uppercase.
- 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
Kerberos requires synchronized time on all domain members. For further details and how to set up the
chrony service, see Time Synchronization. However if Samba is being used as a domain controller to administer Group Policy, tt is possible to define a Group Policy Object that synchronizes workstations with
time.windows.com post installation which simplifies this
Using the Domain Controller as a File Server
Whilst the Samba AD DC is able to provide file shares, just 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
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.
|If you do use an AD DC as a fileserver, you must be aware that it can be problematic and can cause strange errors.|
|If you do use an AD DC as a fileserver, do not add any of the 'idmap config' lines used on a Unix domain member. They will not work and will cause problems.|
|If you do use an AD DC as a fileserver, You must set the permissions from Windows, do not attempt to use any of the old methods (force user etc) . They will not work correctly and will cause problems.|
For further details, see Samba AD DC Troubleshooting.
See User Documentation.