Setting up Samba as an Active Directory Domain Controller
Introduction
Starting from version 4.0, Samba is able to run as an Active Directory (AD) domain controller (DC). If you are installing Samba in a production environment, it is recommended to run two or more DCs for failover reasons.
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). The AD-compatible Heimdal KDC is included in Samba and automatically installed.
Preparing the Installation
- Select a DNS domain for your Active Directory (AD) forest. 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. - For additional information, see Active Directory Naming FAQ.
- Use a static IP address on the domain controller (DC).
- Disable tools, such as
resolvconf, that automatically update your/etc/resolv.confDNS resolver configuration file. Active Directory (AD) DCs and domain members must use an DNS server that is able to resolve the AD DNS zones.
- Verify that no Samba processes are running:
# ps ax | egrep "samba|smbd|nmbd|winbindd"
- If the output lists any
samba,smbd,nmbd, orwinbinddprocesses, shut down the processes.
- 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.localdomain 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.
- If there is an existing
smb.conffile on this host, it must be removed:
- To list the path to the file:
# smbd -b | grep "CONFIGFILE" CONFIGFILE: /usr/local/samba/etc/samba/smb.conf
- Remove all Samba database files, such as
*.tdband*.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.
Installing Samba
For details, see Installing Samba.
 | Only install a maintained Samba version. For details, see Samba Release Planning. |
Provisioning a Samba Active Directory
The Samba Active Directory (AD) provisioning process creates the AD databases and adds initial records, such as the domain administrator account and required DNS entries.
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 AD provisioning requires root permissions to create files and set permissions. |
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
| When provisioning a new AD, it is recommended to enable the NIS extensions by passing the --use-rfc2307 parameter to the samba-tool domain provision command. This enables you to store Unix attributes in AD, such as user IDs (UID), home directories paths, group IDs (GID). Enabling the NIS extensions has no disadvantages. However, enabling them in an existing domain requires manually extending the AD schema. For further details about Unix attributes in AD, see:
|
Parameter Explanation
You have to set the following parameters during the provisioning process:
| Interactive Mode Setting | Non-interactive Mode Parameter | Explanation |
|---|---|---|
--use-rfc2307
|
--use-rfc2307
|
Enables the NIS extensions. |
Realm
|
--realm
|
Kerberos realm. This is also used as the AD DNS domain. For example: samdom.example.com.
|
Domain
|
--domain
|
NetBIOS domain name. It is recommended to use the first part of the AD DNS domain. For example: samdom.
|
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 thesamba-toolcommand to register the correct LAN IP address in the directory during the join.
Provisioning Samba AD in Interactive Mode
To provision a Samba Active Directory (AD) interactively, 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]: 8.8.8.8 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 samba-tool domain provision command. This enables you to modify parameters that are not part of the interactive setup. |
Provisioning Samba AD in Non-interactive Mode
For example, to provision a Samba Active Directory (AD) non-interactively with the following settings:
- Server role:
dc - NIS extensions enabled
- Internal DNS back end
- Kerberos realm and AD DNS zone:
samdom.example.com - 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 domain controller (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 Active Directory (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 domain controller (DC), set the AD DNS domain in the domain and the IP of your DC in the nameserver parameter of the /etc/resolv.conf file. For example:
domain samdom.example.com nameserver 10.99.0.1
Configuring Kerberos
In an Active Directory (AD), Kerberos is used to authenticate users, machines, and services.
During the provisioning, Samba created a Kerberos configuration file for your domain controller (DC). To use, remove any existing /etc/krb5.conf file and create a symbolic link to the pre-configured Kerberos configuration:
# rm /etc/krb5.conf # ln -sf /usr/local/samba/private/krb5.conf /etc/krb5.conf
The pre-created Kerberos configuration uses DNS service (SRV) resource records to locate the Kerberos distribution center (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 your distribution's documentation for how to create a script or configuration to start services. For user-created example System V init scripts, see Samba AD Init Script Examples.
Verifying the File Server
To list all shares provided by the domain controller (DC):
$ smbclient -L localhost -U%
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
--------- -------
| The netlogon and sysvol shares were auto-created during the provisioning and must exist on a DC. |
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
To verify that your Active Directory (AD) DNS configuration works correctly, query some DNS records:
- The tcp-based
_ldapservice (SRV) resource 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.
Verifying Kerberos
- Request a Kerberos ticket for the domain administrator account:
$ kinit administrator Password for administrator@SAMDOM.EXAMPLE.COM:
The Kerberos realm is automatically appended, if you do not pass the principal in the user@REALMformat to thekinitcommand.
Set Kerberos realms always 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 Synchronisation
Kerberos requires a synchronised time on all domain members. For further details and how to set up the ntpd service, see Time Synchronisation.
Configuring Winbindd on a Samba AD DC
Optional. For details, see Configuring Winbindd on a Samba AD DC.
Using the Domain Controller as a File Server
The Samba Active Directory (AD) domain controller (DC) is able to provide file shares, just like all other installation modes. However, the Samba team does not recommend using a DC as a file server because the DC smbd process has some limitations compared with the service in non-DC setups. For example, the auto-enabled acl_xattr virtual file system (VFS) object enables you to only configure shares with Windows access control lists (ACL). Running shares with POSIX ACLs on a Samba DC is not supported. To provide network shares with the full capabilities of Samba, set up a Samba domain member with file shares. For details, see:
If you 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.
Troubleshooting
For further details, see Samba AD DC Troubleshooting.
See User Documentation.