Setting up Samba as an Active Directory Domain Controller: Difference between revisions

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= Introduction =
= 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.
Since version 4.0, Samba can also act as a Domain Controller that is compatible with Microsoft Active Directory. This document explains how to set up Samba as an Active Directory Domain Controller. It also is the start for upgrading an existing Samba NT4-style domain to Samba AD.


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|Joining a Samba DC to an Existing Active Directory]].
If you are upgrading an existing Samba Active Directory Domain Controller, please consult your distribution upgrade procedure or refer to the [[Updating_Samba|Updating Samba]] HowTo.


Samba as an AD DC only supports:
'''We <u>do not recommend</u> using the Domain Controller as a file Server'''. The recommendation is to run separate file or [[Setup_a_Samba_AD_Member_Server|Member Servers]].
* the integrated LDAP server as AD back end. For details, see the frequently asked question (FAQ) [[FAQ#Does_Samba_AD_DCs_Support_OpenLDAP_or_Other_LDAP_Servers_as_Back_End.3F|Does Samba AD DCs Support OpenLDAP or Other LDAP Servers as Back End?]]
* the [http://www.h5l.se/ Heimdal] Kerberos Key Distribution Center (KDC).
: Samba provides experimental support for the [https://web.mit.edu/kerberos/ MIT Kerberos] KDC provided by your operating system if you run Samba 4.7 or later and has been built using the <code>--with-system-mitkrb5</code> 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]].


= Preparing the Installation =
Whilst the Domain Controller seems capable of running as a full file server, it is suggested that organisations run a distinct file server to allow upgrades of each without disrupting the other. It is also suggested that medium-sized sites should run more than one DC. It also makes sense to have the DC's distinct from any file servers that may use the Domain Controllers. Also using distinct file Servers avoids the idiosyncrasies in the winbindd configuration on to the Active Directory Domain Controller.


* Select a host name for your AD DC.
= Versions =
: Do not use NT4-only terms as host name, such as <code>PDC</code> or <code>BDC</code>. These modes do not exist in an AD and cause confusion.


* Select a DNS domain for your AD forest. The name will also be used as the AD Kerberos realm.
Samba as an Active Directory Domain Controller requires at least version 4.0.0. But it's always <u>recommended to use the latest stable version</u> of Samba. It will contain fixes for bugs of previous releases and may contain improved Microsoft Active Directory compatibility and additional features. See the [[Samba_Release_Planning|Samba Release Planning]] page for more details about the latest maintained versions and their Release Notes.
: {{Imbox
| type = important
| text = 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 <code>.local</code> for the TLD, this is used by Avahi.
}}
: For additional information, see [[Active_Directory_Naming_FAQ|Active Directory Naming FAQ]].


* Use a static IP address on the DC.
= Server Information =


* Disable tools, such as <code>resolvconf</code>, that automatically update your <code>/etc/resolv.conf</code> DNS resolver configuration file. AD DCs and domain members must use an DNS server that is able to resolve the AD DNS zones.
Below, we will be using the following configuration/settings:


* Verify that no Samba processes are running:
Installation Directory: /usr/local/samba/
# ps ax | egrep "samba|smbd|nmbd|winbindd"
AD DC Hostname: DC1
: If the output lists any <code>samba</code>, <code>smbd</code>, <code>nmbd</code>, or <code>winbindd</code> processes, shut down the processes.
AD DNS Domain Name: samdom.example.com
Kerberos Realm: SAMDOM.EXAMPLE.COM
NT4 Domain Name/NetBIOS Name: SAMDOM
IP Address: 192.168.1.1
Server Role: Domain Controller (DC)
Domain Admin Password: passw0rd
Forwarder DNS Server: 192.168.1.254


* Verify that the <code>/etc/hosts</code> 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:
= Installation =
127.0.0.1 localhost
10.99.0.1 DC1.samdom.example.com DC1
:The host name and FQDN must not resolve to the <code>127.0.0.1</code> IP address or any other IP address than the one used on the LAN interface of the DC.


* If you previously ran a Samba installation on this host:
== Different Ways To Install ==
:* Remove the existing <code>smb.conf</code> file. To list the path to the file:


# smbd -b | grep "CONFIGFILE"
'''Always check the [[Operating system requirements|OS Requirements]] for dependencies and recommendations.'''
CONFIGFILE: /usr/local/samba/etc/samba/smb.conf
'''Samba has its own LDAP and Kerberos implementation, using external LDAP and Kerberos server is not recommended.'''


:* Remove all Samba database files, such as <code>*.tdb</code> and <code>*.ldb</code> files. To list the folders containing Samba databases:


# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR"
You have a few options to install Samba:
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.
* [[Build_Samba_from_source|Build Samba]] yourself.


* Remove an existing <code>/etc/krb5.conf</code> file:
* Install [[Distribution_specific_package_installation|binary distribution packages]]. Make sure, that you use a recent Samba installation with Active Directory Domain Controller capabilities! At the moment this means that you cannot setup an AD DC on RHEL systems (Fedora, Centos etc) using system packages, this is due to a conflict between the Heimdal kerberos that Samba uses and the Mit kerberos used by RHEL.


# rm /etc/krb5.conf
:* Install from [http://www.enterprisesamba.com/samba/ SerNet Enterprise Samba] package.


== Paths ==


Take care when running Samba commands if you also have a previous version of Samba installed! To avoid inadvertently running the wrong version of a program, you should consider putting the „/usr/local/samba/bin/“ and „/usr/local/samba/sbin/“ directories at the <u>beginning of your $PATH variable</u>.




You can see what version of Samba and client tools, if any, is in your „$PATH“ variable by running:


= Installing Samba =
# '''samba -V'''
# '''smbclient -V'''


{{:Installing_Samba}}








= Provisioning The Samba Active Directory =


= Provisioning a Samba Active Directory =
'''''Note (Migration):''' If you plan to migrate an existing Samba NT4 domain to Samba AD, you do not manually provision the domain! See the [[Migrating_a_Samba_NT4_domain_to_a_Samba_AD_domain_(classic_upgrade)|Samba Classic Upgrade]] HowTo, instead.''


The Samba AD provisioning process creates the AD databases and adds initial records, such as the domain administrator account and required DNS entries.
'''''Note (Adding additional Domain Controllers):''' If you already have an Active Directory and only want to join a new, additional Samba Domain Controller, you do not provision the domain again! See the [[Join_an_additional_Samba_DC_to_an_existing_Active_Directory|Join a domain as a DC]] HowTo, instead.''


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)|Migrating a Samba NT4 Domain to Samba AD (Classic Upgrade)]].


{{Imbox
'''''<u>Selecting what DNS name to use:</u>''' See [[DNS#Selecting_the_Forest_Root_Domain|Selecting the Forest Root Domain]] for further information and best practice and [[DNS#Avoid_.local_TLD|avoid .local domains]].''
| type = note
| text = The AD provisioning requires root permissions to create files and set permissions.
}}




The <code>samba-tool domain provision</code> command provides several parameters to use with the interactive and non-interactive setup. For details, see:
When Samba sets up the first Domain Controller in a Domain, the provisioning creates an initial Active Directory database. Because of this, the provision command must be executed with root privileges, to be able to write to the installation directory and set the correct permissions on files and folders.


# samba-tool domain provision --help


Before you start the provisioning, make yourself familiar with the parameters and options of 'samba-tool':


{{Imbox
# '''samba-tool domain provision --help '''
| type = note
| text = When provisioning a new AD, it is recommended to enable the NIS extensions by passing the <code>--use-rfc2307</code> parameter to the <code>samba-tool domain provision</code> command. There are no disadvantages to enabling the NIS extensions, but enabling them in an existing domain requires manually extending the AD schema. For further details about Unix attributes in AD, see:
* [[Setting_up_RFC2307_in_AD|Setting up RFC2307 in AD]]
* [[Idmap_config_ad|idmap config = ad]]
}}




If your future Domain Controller has multiple NICs, the following two options are required. This is because 'samba-tool' would auto-choose one of the IPv4/IPv6 addresses if multiple interfaces were found, therefore it is necessary to bind Samba to the desired interfaces using


== Parameter Explanation ==
--option="interfaces=lo eth0" --option="bind interfaces only=yes"


Set the following parameters during the provisioning:


{| class="wikitable"
Interactively provision a new domain (parameter explanation below):
!Interactive Mode Setting
!Non-interactive Mode Parameter
!Explanation
|-
|<code>--use-rfc2307</code>
|<code>--use-rfc2307</code>
|Enables the NIS extensions required for the ADUC Unix Attributes tab.
|-
|<code>Realm</code>
|<code>--realm</code>
|Kerberos realm. The uppercase version of the AD DNS domain. For example: <code>SAMDOM.EXAMPLE.COM</code>.
|-
|<code>Domain</code>
|<code>--domain</code>
|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: <code>samdom</code>. Do not use the computers short hostname.
|-
|<code>Server Role</code>
|<code>--server-role</code>
|Installs the domain controller <code>DC</code> role.
|-
|<code>DNS backend</code>
|<code>--dns-backend</code>
|Sets the DNS back end. The first DC in an AD must be installed using a DNS back end. Note that the <code>BIND9_FLATFILE</code> is not supported and will be removed in a future Samba version.
|-
|<code>DNS forwarder IP address</code>
|not available
|This setting is only available when using the <code>SAMBA_INTERNAL</code> DNS back end. For details, see [[Samba_Internal_DNS_Back_End#Setting_up_a_DNS_Forwarder|Setting up a DNS Forwarder]].
|-
|<code>Administrator password</code>
|<code>--adminpass</code>
|Sets the domain administrator password. If the password does not match the complexity requirements, the provisioning fails. For details, see [https://technet.microsoft.com/en-us/library/cc786468%28v=ws.10%29.aspx Microsoft TechNet: Passwords must meet complexity requirements].
|}


# '''samba-tool domain provision --use-rfc2307 --interactive'''
Other parameters frequently used with the <code>samba-tool domain provision</code> command:
* <code>--option="interfaces=lo eth0" --option="bind interfaces only=yes"</code>: If your server has multiple network interfaces, use these options to bind Samba to the specified interfaces. This enables the <code>samba-tool</code> command to register the correct LAN IP address in the directory during the join.
Realm [SAMDOM.EXAMPLE.COM]: ''SAMDOM.EXAMPLE.COM''

Domain [SAMDOM]: ''SAMDOM''

Server Role (dc, member, standalone) [dc]: ''dc''
{{Imbox
DNS backend (SAMBA_INTERNAL, BIND9_FLATFILE, BIND9_DLZ, NONE) [SAMBA_INTERNAL]: ''SAMBA_INTERNAL''
| type = note
DNS forwarder IP address (write 'none' to disable forwarding) [192.168.1.1]: ''192.168.1.254''
| text = do NOT use <code>NONE</code> as the DNS backend, it is not supported and will be removed in a future Samba version.
Administrator password: ''passw0rd''
}}
Retype password: ''passw0rd''

{{Imbox
| type = note
| text = If using Bind as the DNS backend, do NOT use <code>BIND9_FLATFILE</code>, it is not supported and will be removed in a future Samba version.
}}

{{Imbox
| type = important
| text = Once you have provisioned the first DC in an AD domain, do not provision any further DCs in the same domain, [[Joining_a_Samba_DC_to_an_Existing_Active_Directory|Join]] any further DCs.
}}



== Provisioning Samba AD in Interactive Mode ==

To provision a Samba 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 IPv4 addresses
Looking up IPv6 addresses
Looking up IPv6 addresses
Line 131: Line 205:
DOMAIN SID: S-1-5-21-2614513918-2685075268-614796884
DOMAIN SID: S-1-5-21-2614513918-2685075268-614796884


{{Imbox
| type = note
| text = The interactive provisioning mode supports passing further parameters to the <code>samba-tool domain provision</code> command. This enables you to modify parameters that are not part of the interactive setup.
}}


<u>Parameter explanations:</u>




== Provisioning Samba AD in Non-interactive Mode ==
<u>--use-rfc2307:</u> Enables the NIS extensions, they allow you to easily [[Administer_Unix_Attributes_in_Active_Directory_via_RFC2307|manage users/groups with the Windows tool Active Directory Users and Computers (ADUC)]], without manual counting UIDs/GIDs. It is recommended to enable this feature during the provisioning, there are no problems in not using it, but you may later find that it becomes a requirement and enabling it, means that you do not have to manually add the Schema extension later. For further information about RFC2307, see the [[General_information_on_RFC2307|General information on RFC2307]] and [[Setting_up_RFC2307_in_AD|Setting up RFC2307 in AD]] pages.


For example, to provision a Samba AD non-interactively with the following settings:
* Server role: <code>dc</code>
* NIS extensions enabled
* Internal DNS back end
* Kerberos realm and AD DNS zone: <code>samdom.example.com</code>
* NetBIOS domain name: <code>SAMDOM</code>
* Domain administrator password: <code>Passw0rd</code>


# samba-tool domain provision --server-role=dc --use-rfc2307 --dns-backend=SAMBA_INTERNAL --realm=SAMDOM.EXAMPLE.COM --domain=SAMDOM --adminpass=Passw0rd
<u>--interactive:</u> Use interactive provisioning. The defaults are the values in the squared brackets, they will be used if no input is made.




<u>Realm:</u> Kerberos Realm. It will automatically be used as the Active Directory DNS domain name, so it must be the same as the dns name of the machine you are provisioning on, it must always be entered in uppercase.




<u>Domain:</u> NT4/NetBIOS Domain Name. Usually the first part of the AD DNS domain name in uppercase, whatever you use, make sure it is just one word with no more than 15 characters, do not use '''any''' punctuation marks i.e. ! @ # $ % ^ & ( ) - _ ' { } . ~


= Setting up the AD DNS back end =


Skip this step if you provisioned the DC using the <code>SAMBA_INTERNAL</code> DNS back end.
<u>Server Role:</u> 'dc' for Domain Controller, do not use anything else, none of the other options are working at present.


* Set up the BIND DNS server and the <code>BIND9_DLZ</code> module. For details, see [[Setting_up_a_BIND_DNS_Server|Setting up a BIND DNS Server]].


* Start the BIND DNS server. For example:
<u>DNS backend:</u> You have decide here, whether to use the Internal DNS server or BIND9 as the DNS backend. The default is the Internal DNS and the best choice for simple DNS requirements and doesn't require any further action. For complex DNS requirements, BIND9_DLZ is recommended. Do not use BIND9_FLATFILE! It's not documented or supported! See [[Configure_BIND_as_backend_for_Samba_AD|Configure BIND as backend for Samba AD]] for further information about using BIND. The DNS backend choice made during the provisioning isn't permanent. [[Changing_the_DNS_backend|It can be changed afterwards]].
# systemctl start named
: For details how to start services, see you distribution's documentation.


<u>DNS forwarder IP address:</u> You are only prompted for this if you chose the Internal DNS as the backend. It defines the IP address of one DNS server to which DNS queries should be forwarded to when your DNS server isn't authoritative. Commonly it is your providers DNS server IP address.


'''''Note:''' You should always use a subdomain of your domain name (e. g. samdom.example.com). Never use your domain name (example.com) for your Active Directory DNS domain, this is to stop problems when accessing servers using that name (e. g. web server), but resolving to different IPs other than your Domain Controllers!''




= Configuring the DNS Resolver =
<u>Administrator password:</u> The Domain Administrators password. It must meet the complex password requirements:
* At least 8 characters
* Containing three of the following four character groups
** Uppercase letters
** Lowercase letters
** Numerals
** Symbols (all keyboard characters not defined as letters or numerals)
If the password doesn't fulfil the complexity requirements, the provisioning will fail and you will have to start over (remove the 'smb.conf'in that case).


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.
= Testing Your Samba Domain Controller =


On your DC, set the AD DNS domain in the <code>search</code> and the IP of your DC in the <code>nameserver</code> parameter of the <code>/etc/resolv.conf</code> file. For example:
'''Note: If you are running any „smbd“, „nmbd“ or „winbindd“ processes from previous installations, they need to be stopped before starting „samba“ from your new installation!'''


search samdom.example.com
To start the Samba Active Directory Domain Controller in „standard“ mode, which is suitable for production use, run
nameserver 10.99.0.1


# '''samba'''




Samba doesn't yet have init scripts included. You can find examples on the [[Samba4/InitScript|Samba Init-Script]] page.




= Create a reverse zone =
Run „smbclient“, to check if Samba provides the AD DC default shares „netlogon“ and „sysvol“ created in your „smb.conf“ during provisioning/upgrading:


You can optionally add a reverse lookup zone.
$ '''smbclient -L localhost -U%'''
Domain=[SAMDOM] OS=[Unix] Server=[Samba 4.x.y]
Sharename Type Comment
--------- ---- -------
netlogon Disk
sysvol Disk
IPC$ IPC IPC Service (Samba 4.x.y)
Domain=[SAMDOM] OS=[Unix] Server=[Samba 4.x.y]
Server Comment
--------- -------
Workgroup Master
--------- -------


# samba-tool dns zonecreate <Your-AD-DNS-Server-IP-or-hostname> 0.99.10.in-addr.arpa
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.
To test that authentication is working, you should try to connect to the „netlogon“ share, using the Domain Administrator account, created during provisioning:


The reverse zone is directly live without restarting Samba or BIND.
$ '''smbclient //localhost/netlogon -UAdministrator -c 'ls''''
Enter Administrator's password: ''passw0rd''
Domain=[SAMDOM] OS=[Unix] Server=[Samba 4.x.y]
. D 0 Sat Jul 5 08:40:00 2014
.. D 0 Sat Jul 5 08:40:00 2014
49386 blocks of size 524288. 42093 blocks available




If the tests fail, check out the [[Samba_AD_DC_Troubleshooting|Samba AD DC Troubleshooting]] page.






= 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 example:
= Configure DNS =


# cp /usr/local/samba/private/krb5.conf /etc/krb5.conf
A working DNS is essential to the correct operation of Active Directory. E. g. without the right DNS entries, Kerberos won't work, which in turn means that many of the basic features won't work! It is worth spending some extra time ensuring your DNS setup is correct, as debugging problems caused by incorrect DNS configuration, can take a lot of time later.


{{Imbox
| type = important
| text = Do not create a symbolic link to the the generated <code>krb5.conf</code> file. In Samba 4.7 and later, the <code>/usr/local/samba/private/</code> directory is no longer accessible by other users than the <code>root</code> user. If the file is a symbolic link, other users are not able to read the file and, for example, dynamic DNS updates fail if you use the <code>BIND_DLZ</code> DNS back end.
}}


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


== DNS Backends ==


For additional information on the supported DNS backends and as a decision aid to help choose which fits best to your needs, see the [[DNS#Which_DNS_backend_should_I_choose.3F|DNS]] page.






= Testing your Samba AD DC =
=== Samba Internal DNS Server ===


To start the <code>samba</code> service manually, enter:
By default Samba uses its Internal DNS and no further configuration is required. The forwarder was already set during the provisioning and can be changed in your „smb.conf“ (reload of „samba“ is required after changes).


# samba


Samba does not provide System V init scripts, <code>systemd</code>, <code>upstart</code>, 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|Managing the Samba AD DC Service]].


=== BIND9 DNS Backend ===


If you chose „BIND9_DLZ“ during your provisioning, see the [[Configure_BIND_as_backend_for_Samba_AD|Configure BIND as backend for Samba AD]] documentation for additional setup instructions.


== Verifying the File Server ==


To list all shares provided by the DC:


Before Samba 4.11.0:
== Configure /etc/resolv.conf ==


$ smbclient -L localhost -N
Your Domain Controller requires a name server that knows your AD zone to resolve Active Directory DNS queries correctly. To accomplish this, you can add just your AD DCs IP and domain name to your „/etc/resolv.conf“:
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:
domain samdom.example.com
nameserver 192.168.1.1


smbclient -L localhost -N
'''''Note:''' If your server is set up to receive its IP configuration via DHCP, the „/etc/resolv.conf“ file might be automatically updated. Refer to your distributions documentation on how to stop/change this behavior, although DHCP is not recommended on a DC!''
Anonymous login successful
Sharename Type Comment
--------- ---- -------
sysvol Disk
netlogon Disk
IPC$ IPC IPC Service (Samba 4.12.6-Debian)
SMB1 disabled -- no workgroup available




{{Imbox
| type = note
| text = The <code>netlogon</code> and <code>sysvol</code> shares were auto-created during the provisioning and must exist on a DC.
}}


To verify authentication, connect to the <code>netlogon</code> 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|Troubleshooting]].
== Testing DNS ==


To test that DNS is working properly, run the following commands and compare the output to what is shown:



$ '''host -t SRV _ldap._tcp.samdom.example.com.'''
== Verifying DNS ==

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

* The tcp-based <code>_ldap</code> SRV 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.
_ldap._tcp.samdom.example.com has SRV record 0 100 389 dc1.samdom.example.com.


* The udp-based <code>_kerberos</code> SRV resource record in the domain:
$ '''host -t SRV _kerberos._udp.samdom.example.com.'''

$ host -t SRV _kerberos._udp.samdom.example.com.
_kerberos._udp.samdom.example.com has SRV record 0 100 88 dc1.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 192.168.1.1


$ 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|Troubleshooting]].
If you receive any errors, check your system logs to locate the problem.






== Verifying Kerberos ==


* Request a Kerberos ticket for the domain administrator account:


$ kinit administrator
= Configure Kerberos =
Password for administrator@SAMDOM.EXAMPLE.COM:


: {{Imbox
Kerberos is an important part of Active Directory. Typically the configuration is done in /etc/krb5.conf. During provisioning, a working sample configuration will be created. You can replace your krb5.conf file with the sample by copying or creating a symlink:
| type = note
| text = If you do not pass the principal in the <code>user@REALM</code> format to the <code>kinit</code> command, the Kerberos realm is automatically appended.<br />Always enter the Kerberos realm in uppercase.
}}


* List the cached Kerberos tickets:
# '''ln -sf /usr/local/samba/private/krb5.conf /etc/krb5.conf'''


$ 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|Troubleshooting]].


== Testing Kerberos ==


Use „kinit“ to obtain a Kerberos ticket:


# '''kinit administrator@SAMDOM.EXAMPLE.COM'''
Password for administrator@SAMDOM.EXAMPLE.COM:
Warning: Your password will expire in 41 days on Sat Aug 16 21:41:28 2014


'''''Note:''' You must specify your realm in uppercase letters!''


= Configuring Time Synchronisation =
'''''Note:''' Depending on your distribution, „kinit“ may just return you to a prompt when successful.''


Kerberos requires synchronised time on all domain members. For further details and how to set up the <code>ntpd</code> or <code>chrony</code> service, see [[Time_Synchronisation|Time Synchronisation]].


To verify that Kerberos is working and that you had received a ticket, run:


# '''klist'''
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: administrator@SAMDOM.EXAMPLE.COM
Valid starting Expires Service principal
07/05/14 23:20:17 07/06/14 09:20:17 krbtgt/SAMDOM.EXAMPLE.COM@SAMDOM.EXAMPLE.COM
renew until 07/06/14 23:20:15






= 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 organisations, having more than one DC is a really good backup measure, and makes upgrades safer
= Configure NTP =
* 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 organisation 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.


'''''Note:''' NTP is optional, but highly recommended!''


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.
Active Directory requires an accurate time synchronization between all participant machines for Kerberos to work properly. It's highly recommended to use NTP or another form of time synchronization on your Domain Controller!


If you must use the Samba DC as a fileserver, you should be aware that the auto-enabled <code>acl_xattr</code> 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.
The [[Time_syncronisation|Time Synchronisation]] documentation will provide all neccessary information for configuring NTP on Domain Controllers, Member Servers and clients.


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


To provide network shares with the full capabilities of Samba, set up a Samba domain member with file shares. For details, see:
* [[Setting_up_Samba_as_a_Domain_Member|Setting up Samba as a Domain Member]]
* [[Samba_File_Serving|Samba File Serving]]




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|Configuring Winbindd on a Samba AD DC]].


= Troubleshooting =


{{Imbox
If you encounter any problems when using the documentation, see the [[Samba_AD_DC_Troubleshooting|Samba AD DC Troubleshooting]] page.
| type = important
| text = If you do use an AD DC as a fileserver, you must be aware that it can be problematic and can cause strange errors.
}}


{{Imbox
| type = important
| text = 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.
}}


{{Imbox
| type = important
| text = 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.
}}








= Further Documentation =


= Troubleshooting =
The Samba Wiki provides a lot of useful [[User_Documentation|documentation]] on administering your DC, ([[Backup and restore an Samba AD DC|backup and recovery]], [[Shares_with_Windows_ACLs|setup and configure file shares]], etc.), daily work ([[Joining_a_Windows_client_to_a_domain|join a Windows client to a Domain]], [[Installing RSAT|installing RSAT on Windows for AD Management]], etc.) or [[Authenticating_other_services_against_AD|authenticating other services against AD]].

For further details, see [[Samba_AD_DC_Troubleshooting|Samba AD DC Troubleshooting]].






See the [[User_Documentation|Samba Wiki user documentation]] for many other HowTos, tutorials and information.


= Further Samba-related Documentation =


See [[User_Documentation|User Documentation]].






= Report Your Success/Failure! =


We would encourage you to report your successes and failures to the [mailto:samba@lists.samba.org samba] mailing list on https://lists.samba.org.


----
Suggestions on improving the documentation has the same importance as reporting [https://bugzilla.samba.org/ Bugs] and complications.
[[Category:Domain Control]]
[[Category:Active Directory]]

Revision as of 12:50, 9 September 2020

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:

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.

Preparing the Installation

  • Select a host name for your AD DC.
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.
  • Select a DNS domain for your AD forest. The name will also be used as the AD Kerberos realm.
For additional information, see Active Directory Naming FAQ.
  • Use a static IP address on the DC.
  • 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.
  • Verify that no Samba processes are running:
# ps ax | egrep "samba|smbd|nmbd|winbindd"
If the output lists any samba, smbd, nmbd, or winbindd processes, shut down the processes.
  • 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:
127.0.0.1     localhost
10.99.0.1     DC1.samdom.example.com     DC1
The host name and FQDN must not resolve to the 127.0.0.1 IP address or any other IP address than the one used on the LAN interface of the DC.
  • If you previously ran a Samba installation on this host:
  • Remove the existing smb.conf file. 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 *.tdb and *.ldb files. To list the folders containing Samba databases:
# 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 /etc/krb5.conf file:
# rm /etc/krb5.conf



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.

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 Explanation

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

To provision a Samba 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


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: 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 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:

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
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.



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 example:

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


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.


Verifying DNS

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 _ldap._tcp.samdom.example.com.
_ldap._tcp.samdom.example.com has SRV record 0 100 389 dc1.samdom.example.com.
  • The udp-based _kerberos SRV 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:
  • 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 synchronised time on all domain members. For further details and how to set up the ntpd or chrony service, see Time Synchronisation.



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 organisations, 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 organisation 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.




Troubleshooting

For further details, see Samba AD DC Troubleshooting.



Further Samba-related Documentation

See User Documentation.