Joining a Samba DC to an Existing Active Directory: Difference between revisions

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= Introduction =
= Introduction =


Running one domain controller (DC) is sufficient for a working Active Directory (AD) forest. However, for redundancy and load balancing reasons, you should add further DCs to your AD forest. Joining an additional Samba DC to an existing AD differs from provisioning the first DC in a forest. If you set up a new AD forest, see [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller|Setting up Samba as an Active Directory Domain Controller]].
As well as the ability to join an Active Directory as a [[Setup_a_Samba_AD_Member_Server|Member Server]], it is also possible to join as a Domain Controller.


{{Imbox
The process of joining a Samba server to an existing domain is a bit different to [[Samba_AD_DC_HOWTO|provisioning a new domain]]. This process is the equivalent of the 'dcpromo' command on Windows servers.
| type = warning
| text = Do not provision a Computer as a Samba AD DC, then try to join it to an existing AD domain. This will not work, you only need to run the <code>samba-tool domain join</code> command to join a Computer to the existing AD domain.
}}


{{Imbox
Please note that the following steps are the same - regardless of whether you are joining Samba to an existing Windows based domain or an existing Samba based domain.
| type = warning
| text = If you are joining a Samba as a DC to an existing Windows AD domain that was provisioned as a Windows 2003 (or earlier) DC, you must ensure that it is running a domain integrated DNS server. This dns server must be configured with 2008 behaviour.
}}


{{Imbox
| type = note
| text = An NT4 domain uses only one Primary Domain Controller (PDC) and optionally additional Backup Domain Controllers (BDC). In an AD forest, there is no difference between DCs, except for the [[Flexible_Single-Master_Operations_(FSMO)_Roles|FSMO roles]]. Use only the term "domain controller" or "DC" when you talk about AD to avoid any possibility of confusion.
}}




== Server information ==


This documentation uses the following configuration/settings:


'''Existing DC in the domain:'''
Hostname: DC1
IP: 10.99.0.1
DC is also a DNS server: yes
'''Domain information:'''
DNS Domain Name: samdom.example.com
NT4 Domain Name (NETBIOS): SAMDOM
Kerberos Realm: SAMDOM.EXAMPLE.COM
Domain Administrator: Administrator
Domain Administrator Password: passw0rd
'''DC additionally joined to the domain:'''
Hostname: DC2
IP Address: 10.99.0.2
Installation Directory: /usr/local/samba/



== Versions ==

This documentation is frequently updated to reflect the latest changes. Please see the [[Samba_Release_Planning|Samba Release Planning]] for more specifics.

Please review the release notes for the version you have installed. It may contain important information, not yet reflected in this documentation.





== Prerequisites ==

* The domain must be at least at forest functional level „2003 native“ (not interim!), to join a Samba DC.

* The forests schema must be maximum at version 47 (Server 2008 R2). Later schemas are not supported at the moment and cause Samba to fail during the join. If your forest is Samba driven, the schema version is 47. Only if you have Windows DCs, this has to be checked, by running on a Windows DC:

> dsquery * “CN=Schema,CN=Configuration,DC=Root-Domäne” -Scope Base -attr objectVersion





= Installation =

== Different ways to install ==

'''Always check the [[OS Requirements|OS Requirements]] for dependencies and recommendations.'''


= Preparing the Installation =
You have a few options to install Samba:


For details, see [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller#Preparing_the_Installation|Preparing the Installation]] in the [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller|Setting up Samba as an Active Directory Domain Controller]] documentation.
* [[Build_Samba|Build Samba]] yourself.


* Install [[Binary_Distribution_Packages|binary distribution packages]]. Make sure, that you use a recent Samba installation with Active Directory Domain Controller capabilities!


:* Install from [http://www.enterprisesamba.com/samba/ SerNet Enterprise Samba] package.






= Installing Samba =
== Paths ==


For details, see [[Installing_Samba|Installing Samba]].
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>.


{{Imbox
You can see what version of Samba and client tools, if any, is in your „$PATH“ variable by running:
| type = note
| text = Install a maintained Samba version. For details, see [[Samba_Release_Planning|Samba Release Planning]].
}}


# '''samba -V'''
# '''smbclient -V'''








= Preparing the host for the domain join =
= Preparing the Host for Joining the Domain =


== Local DNS server ==
== Local DNS server ==


By default, the first Domain Controller in a domain automatically acts as a DNS server for AD based zones. For failover reasons, it is recommended to have at least two DC's providing AD DNS services.
By default, the first Domain Controller (DC) in a forest runs a DNS server for Active Directory (AD)-based zones. For redundancy reasons it is recommended to run multiple DCs acting as a DNS server in a network. If you consider providing a DNS service on the new DC:


* For the <code>BIND9_DLZ</code> back end, see [[BIND9_DLZ_DNS_Back_End|BIND9_DLZ DNS Back End]]. Finish this task before you start the Samba DC service.
If you plan to join the additional Domain Controller with BIND as the DNS backend, you have to [[DNS_Backend_BIND|setup BIND as AD backend]] first. If you use the internal or use no local DNS, no further steps are required.
* For the internal DNS no further actions are required.






== Verify /etc/hosts ==
== Configuring DNS ==


{{Imbox
Verify that the local hostname isn't resolved to 127.0.0.1 in /etc/hosts:
| type = note
| text = The 'nameserver' you set in '/etc/resolv.conf' should be another AD DC, otherwise the join could have difficulty finding a KDC.
}}


{{Imbox
127.0.0.1 localhost.localdomain localhost <strike>DC2.samdom.example.com DC2</strike>
| type = note
10.99.0.2 DC2.samdom.example.com DC2
| text = If you are joining a new DC the 'nameserver' you set in '/etc/resolv.conf' must be another AD DC, otherwise the join will not be work. Once the new join has succeeded, you need to change the 'nameserver' to the new DCs ipaddress, do not use '127.0.0.1' or any other IP.
}}


If the local hostname is resolved to 127.0.0.1, Samba would use this IP for the various DC DNS entries. This would prevent clients from reaching this Domain Controller!


For details, see [[Linux_and_Unix_DNS_Configuration|Linux and Unix DNS Configuration]].




== DNS resolving ==

Configure the host, you want to join as an additional Domain Controller, to use a DNS server that is able to resolve zones from the Active Directory. On Linux and Unixes, this is typically done by adding a „nameserver“ and „search domain“ entry to to /etc/resolv.conf:

nameserver <u>10.99.0.1</u>
search samdom.example.com

Consult your distributions documentation for configuring the usage of a DNS server.

To verify a correct name resolution, try resolving the hostname of one of your existing Domain Controllers:

# '''host -t A <u>DC1</u>.samdom.example.com'''
DC1.samdom.example.com has address 10.99.0.1




Line 121: Line 75:
== Kerberos ==
== Kerberos ==


* Add the following content to /etc/krb5.conf:
Set the following settings in your Kerberos client configuration file <code>/etc/krb5.conf</code>:


[libdefaults]
[libdefaults]
dns_lookup_realm = true
dns_lookup_realm = false
dns_lookup_kdc = true
dns_lookup_kdc = true
default_realm = SAMDOM.EXAMPLE.COM
default_realm = SAMDOM.EXAMPLE.COM


To verify the settings use the <code>kinit</code> command to request a Kerberos ticket for the domain administrator:
* Verify the correct Kerberos setup by obtaining a ticket:


# '''kinit administrator'''
# kinit administrator
Password for administrator@SAMDOM.EXAMPLE.COM:
Password for administrator@SAMDOM.EXAMPLE.COM:

To list Kerberos tickets:
# '''klist'''

# klist
Ticket cache: FILE:/tmp/krb5cc_0
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: administrator@SAMDOM.EXAMPLE.COM
Default principal: administrator@SAMDOM.EXAMPLE.COM
Valid starting Expires Service principal
Valid starting Expires Service principal
09.11.2014 17:34:09 10.11.2014 03:34:09 krbtgt/SAMDOM.EXAMPLE.COM@SAMDOM.EXAMPLE.COM
24.09.2015 19:56:55 25.09.2015 05:56:55 krbtgt/SAMDOM.EXAMPLE.COM@SAMDOM.EXAMPLE.COM
renew until 10.11.2014 17:34:07
renew until 25.09.2015 19:56:53




Line 145: Line 101:




= Configuring Time Synchronisation =
= Join the existing domain as a Domain Controller =


Kerberos requires a synchronised time on all domain members. For further details and how to set up the <code>ntpd</code> service, see [[Time_Synchronisation|Time Synchronisation]].
Before you start the joining, make yourself familiar with the parameters and options of „samba-tool domain join“:


# '''samba-tool domain join --help '''


Expecially the following two options are required, if your future Domain Controllers have multiple NICs. Because „samba-tool“ would auto-choose one of the IPv4/IPv6 addresses, if multiple where found, it might be necessary to bind Samba to the desired interfaces using


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


Join the existing domain (parameter explanation below):


= Joining the Active Directory as a Domain Controller =
# '''samba-tool domain join samdom.example.com DC -Uadministrator --realm=samdom.example.com --dns-backend=BIND9_DLZ'''

To join the domain <code>samdom.example.com</code> as a domain controller (DC) that additionally acts as a DNS server using the Samba internal DNS:

There are three authentication methods you can use, Username & Password or two kerberos methods (the kerberos methods depend on running <code>kinit</code> as an admin user).

Username & Password:
# samba-tool domain join samdom.example.com DC -U"SAMDOM\administrator"

Or:
# samba-tool domain join samdom.example.com DC -k yes

Or:
# samba-tool domain join samdom.example.com DC --use-krb5-ccache=/tmp/krb5cc_0

Using any of the above, should result in output similar to this:

Finding a writeable DC for domain 'samdom.example.com'
Finding a writeable DC for domain 'samdom.example.com'
Found DC dc1.samdom.example.com
Found DC dc1.samdom.example.com
Password for [WORKGROUP\administrator]: passw0rd
Password for [SAMDOM\administrator]:
workgroup is SAMDOM
workgroup is SAMDOM
realm is samdom.example.com
realm is samdom.example.com
checking sAMAccountName
Adding CN=DC2,OU=Domain Controllers,DC=samdom,DC=example,DC=com
Adding CN=DC2,OU=Domain Controllers,DC=samdom,DC=example,DC=com
Adding CN=DC2,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
Adding CN=DC2,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
Line 170: Line 137:
Setting account password for DC2$
Setting account password for DC2$
Enabling account
Enabling account
Adding DNS account CN=dns-DC2,CN=Users,DC=samdom,DC=example,DC=com with dns/ SPN
Setting account password for dns-DC2
Calling bare provision
Calling bare provision
Looking up IPv4 addresses
Looking up IPv6 addresses
No IPv6 address will be assigned
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
A Kerberos configuration suitable for Samba 4 has been generated at /usr/local/samba/private/krb5.conf
Provision OK for domain DN DC=samdom,DC=example,DC=com
Provision OK for domain DN DC=samdom,DC=example,DC=com
Starting replication
Starting replication
Line 185: Line 162:
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1206/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1206/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1608/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1608/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1618/1618] linked_values[28/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1618/1618] linked_values[42/0]
Replicating critical objects from the base DN of the domain
Replicating critical objects from the base DN of the domain
Partition[DC=samdom,DC=example,DC=com] objects[98/98] linked_values[23/0]
Partition[DC=samdom,DC=example,DC=com] objects[100/100] linked_values[23/0]
Partition[DC=samdom,DC=example,DC=com] objects[395/297] linked_values[23/0]
Partition[DC=samdom,DC=example,DC=com] objects[386/286] linked_values[23/0]
Done with always replicated NC (base, config, schema)
Done with always replicated NC (base, config, schema)
Replicating DC=DomainDnsZones,DC=samdom,DC=example,DC=com
Replicating DC=DomainDnsZones,DC=samdom,DC=example,DC=com
Partition[DC=DomainDnsZones,DC=samdom,DC=example,DC=com] objects[41/41] linked_values[0/0]
Partition[DC=DomainDnsZones,DC=samdom,DC=example,DC=com] objects[44/44] linked_values[0/0]
Replicating DC=ForestDnsZones,DC=samdom,DC=example,DC=com
Replicating DC=ForestDnsZones,DC=samdom,DC=example,DC=com
Partition[DC=ForestDnsZones,DC=samdom,DC=example,DC=com] objects[19/19] linked_values[0/0]
Partition[DC=ForestDnsZones,DC=samdom,DC=example,DC=com] objects[19/19] linked_values[0/0]
Partition[DC=ForestDnsZones,DC=samdom,DC=example,DC=com] objects[38/19] linked_values[0/0]
Committing SAM database
Committing SAM database
Sending DsReplicateUpdateRefs for all the replicated partitions
Sending DsReplicaUpdateRefs for all the replicated partitions
Setting isSynchronized and dsServiceName
Setting isSynchronized and dsServiceName
Setting up secrets database
Setting up secrets database
Joined domain SAMDOM (SID S-1-5-21-469703510-2364959079-1506205053) as a DC
Joined domain SAMDOM (SID S-1-5-21-469703510-2364959079-1506205053) as a DC


See the <code>samba-tool domain join --help</code> command's output for further information.
<u>Parameter explanations:</u>


Other parameters frequently used with the <code>samba-tool domain join</code> command:
* Domain: AD Domain Name


* <code>--dns-backend=NAMESERVER-BACKEND</code>: Use the supplied DNS server backend. Valid options are <code>SAMBA_INTERNAL</code> or <code>BIND9_DLZ</code>, unless you want to use Bind9, there is no need to supply this option.
* Server Role: „DC“ for Domain Controller
:: If you use the internal DNS server, you will not be asked for a forwarder and the one in /etc/resolv.conf will not be obtained automatically. You must supply one with <code>--option="dns forwarder=forwarder_ipaddress"</code>.
* <code>--site=SITE</code>: Directly join the host as DC to a specific [[Active_Directory_Sites|Active Directory Site]].


* <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.
* Username: Account that is allowed to join new Domain Controllers. Typically it is the Domain Administrator.


{{Imbox
* Realm: Kerberos Realm
| type = note
| text = If the other DCs are Samba DCs and were provisioned with <code>--use-rfc2307</code>, you Should add <code>--option='idmap_ldb:use rfc2307 = yes'</code> to the join command
}}


* DNS backend: You have to choose whether to use the Internal DNS server (SAMBA_INTERNAL), BIND9 (BIND9_DLZ) or no DNS backend (NONE). The Internal DNS is the default and the best choice for simple DNS requirements. It doesn't need any further action. For complex DNS requirements, BIND9_DLZ is recommended. Don't use BIND9_FLATFILE! It's not documented or supported! See [[DNS_Backend_BIND|DNS Backend BIND]] 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]].


* Site: If you have setup Active Directory Sites, it's possible, to directly join a new DC into a specified AD site.






= Starting the Samba Service =


To start the <code>samba</code> Samba Active Directory (AD) domain controller (DC) service manually, enter:


# samba
= Check DNS entries =


Samba does not provide System V init scripts, <code>systemd</code>, <code>upstart</code>, or other services configuration files.
For a successful setup and failover purposes, it is required, that all important DNS records are added to the DNS zones. [[Check_and_fix_DNS_entries_on_DC_joins|Check, if the important DNS records are existing]] and if not (see [https://bugzilla.samba.org/show_bug.cgi?id=10928 Bug #10928]), [[Check_and_fix_DNS_entries_on_DC_joins|add them manually]]. '''Don't skip this step!'''
* 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]].




Line 227: Line 211:




= Adaptations for the BIND DNS backend =
= Verifying the DNS Entries =


{{Imbox
This step can be skipped if the DC was joined with SAMBA_INTERNAL or without DNS backend.
| type = note
| text = Once the join has succeeded You should change the first nameserver in /etc/resolv.conf to the new DC's ipaddress. This will aid in the creation of the required dns records not created by the join.
}}


If you join a Samba DC that runs Samba 4.7.0 and later, <code>samba-tool</code> will create the required initial DNS entries automatically. To manually create these records on an earlier version, see [[Verifying_and_Creating_a_DC_DNS_Record|Verifying and Creating a DC DNS Record]]. Once Samba starts, the <code>samba_dnsupdate</code> script should create all the other required DNS entries.




== Workaround: Fix keytab permissions ==


This workaround is required, until [https://bugzilla.samba.org/show_bug.cgi?id=10881 Bug #10881] is solved for the version of Samba you're running!


Fix permissions on the 'dns.keytab' file, to allow BIND to read this file:


= Configuring the BIND9_DLZ DNS Back End =
# '''chmod 640 /usr/local/samba/private/dns.keytab'''
# '''chgrp named /usr/local/samba/private/dns.keytab'''


If you selected the <code>BIND9_DLZ</code> DNS back end during the domain join, set up the BIND configuration. For details, see [[BIND9_DLZ_DNS_Back_End|BIND9_DLZ DNS Back End]].
''Note: If you use Samba packages (Distro or from other sources), make sure that the account BIND uses, is able to reach the dns.keytab file. Some package installations set too restrictive permissions on the folders.''


Otherwise, BIND will not able to update your zone(s)! One of the results is, that 'samba_dnsupdate' can't add e. g. the important DNS entries, that clients use, to locate the new DC. In case of an failure of your other DC, domain logons using your new DC wouldn't be possible!






== Enable the BIND9_DLZ module, suitable to the BIND version==


= Built-in User & Group ID Mappings =
Make sure, that the correct BIND9_DLZ module for your BIND version is enabled in /usr/local/samba/private/named.conf. Uncomment the module for your BIND version and comment the other:
{{:SysVol replication (DFS-R)}}


dlz "AD DNS Zone" {
# For BIND 9.8.0
database "dlopen /usr/local/samba/lib/bind9/dlz_bind9.so";
# For BIND 9.9.0
# database "dlopen /usr/local/samba/lib/bind9/dlz_bind9_9.so";
};


To use a Sysvol Replication workaround, all domain controllers (DC) must use the same ID mappings for built-in users and groups.
The example above enables the module for BIND 9.8.x (default).


By default, a Samba DC stores the user & group IDs in 'xidNumber' attributes in 'idmap.ldb'. Because of the way 'idmap.ldb' works, you cannot guarantee that each DC will use the same ID for a given user or group. To ensure that you do use the same IDs, you must:


* Create a hot-backup of the <code>/usr/local/samba/private/idmap.ldb</code> file on the existing DC:


# tdbbackup -s .bak /usr/local/samba/private/idmap.ldb


: This creates a backup file <code>/usr/local/samba/private/idmap.ldb.bak</code>.


* Move the backup file to the <code>/usr/local/samba/private/</code> folder on the new joined DC and remove the <code>.bak</code> suffix to replace the existing file.
= GID mappings of built-in groups =


* Run <code>net cache flush</code> on the new DC.
There are current issues with GID mappings of built-in groups. The GIDs of groups owning files and directories on in the sysvol folder may differ between Domain Controllers. Currently Samba doesn't provide a replication of these GIDs.


* You will now need to sync Sysvol to the new DC.
Use the following workaround, if you encounter any problems:


* Reset the Sysvol folder's file system access control lists (ACL) on the new DC:
* Shutdown Samba on the new joined Domain Controller.


# samba-tool ntacl sysvolreset
* Create a hot-backup of idmap.ldb on the first Domain Controller:


# '''tdbbackup -s .bak /usr/local/samba/private/idmap.ldb'''


* Move the backup file „/usr/local/samba/private/idmap.ldb.bak“ to "/usr/local/samba/private" on the newly joined Domain Controller and remove the .bak suffix, this will replace the original file.


* Start Samba on the new joined Domain Controller again.


* Reset the ACLs on the local sysvol folder of the new joined Domain Controller:


= Verifying Directory Replication =
# '''samba-tool ntacl sysvolreset'''


After the domain controller (DC) has been started, the knowledge consistency checker (KCC) on the Samba DC creates replication agreements to other DCs in the Active Directory (AD) forest. It can take up to 15 minutes until the KCC creates the auto-generated replication connections.


For details about how to verify that the directory replication works correctly, see [[Verifying the Directory Replication Statuses]].


{{Imbox
| type = note
| text = To optimize replication latency and cost, the KCC in Samba 4.5 and later no longer creates a fully-meshed replication topology between all DCs. For further details, see [[The Samba KCC]].
}}




= Start Samba =


To start the Samba Active Directory Domain Controller in „standard“ mode, which is suitable for production use, run


# '''samba'''


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


Before you start the BIND daemon, verify that the DNS directory partitions have been successfully replicated:


# samba-tool drs showrepl
...
==== INBOUND NEIGHBORS ====
...
DC=DomainDnsZones,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Thu Sep 24 20:08:45 2015 CEST was successful
0 consecutive failure(s).
Last success @ Thu Sep 24 20:08:45 2015 CEST
...
DC=ForestDnsZones,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Thu Sep 24 20:08:45 2015 CEST was successful
0 consecutive failure(s).
Last success @ Thu Sep 24 20:08:45 2015 CEST


If the replication works correctly, start the BIND service. See your distribution's documentation for information how to start a service.






= Directory replication =


A few minutes after you have started Samba, connections with other DC will be established automatically.


= Testing your Samba AD DC =
# '''samba-tool drs showrepl'''
Default-First-Site-Name\DC2
DSA Options: 0x00000001
DSA object GUID: df4bdd8c-abc7-4779-b01e-4dd4553ca3e9
DSA invocationId: 8e30d69f-c20f-4744-9833-5b050e611375
==== INBOUND NEIGHBORS ====
CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Sun Nov 9 19:56:07 2014 CET was successful
0 consecutive failure(s).
Last success @ Sun Nov 9 19:56:07 2014 CET
DC=DomainDnsZones,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Sun Nov 9 19:56:06 2014 CET was successful
0 consecutive failure(s).
Last success @ Sun Nov 9 19:56:06 2014 CET
CN=Configuration,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Sun Nov 9 19:56:07 2014 CET was successful
0 consecutive failure(s).
Last success @ Sun Nov 9 19:56:07 2014 CET
DC=ForestDnsZones,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Sun Nov 9 19:56:07 2014 CET was successful
0 consecutive failure(s).
Last success @ Sun Nov 9 19:56:07 2014 CET
DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ Sun Nov 9 19:56:13 2014 CET was successful
0 consecutive failure(s).
Last success @ Sun Nov 9 19:56:13 2014 CET
==== OUTBOUND NEIGHBORS ====
CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ NTTIME(0) was successful
0 consecutive failure(s).
Last success @ NTTIME(0)
DC=DomainDnsZones,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ NTTIME(0) was successful
0 consecutive failure(s).
Last success @ NTTIME(0)
CN=Configuration,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ NTTIME(0) was successful
0 consecutive failure(s).
Last success @ NTTIME(0)
DC=ForestDnsZones,DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ NTTIME(0) was successful
0 consecutive failure(s).
Last success @ NTTIME(0)
DC=samdom,DC=example,DC=com
Default-First-Site-Name\DC1 via RPC
DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
Last attempt @ NTTIME(0) was successful
0 consecutive failure(s).
Last success @ NTTIME(0)
==== KCC CONNECTION OBJECTS ====
Connection --
Connection name: 5745d481-1d26-48f4-ab65-273263e28a45
Enabled : TRUE
Server DNS name : DC1.samdom.example.com
Server DN name : CN=NTDS Settings,CN=DC1,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
TransportType: RPC
options: 0x00000001
Warning: No NC replicated for Connection!


== Verifying the File Server ==
'''Depending on your replication settings - if defined - it may take a few minutes until all connections are established. So please be patient!''' On the long shot that the outbound connections aren't established automatically - even not after several minutes - you can force the replication (generally not necessary!). See [[Samba-tool_drs_replicate|samba-tool drs replicate]].


For details, see [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller#Verifying_the_File_Server|Verifying the File Server]] in the [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller|Setting up Samba as an Active Directory Domain Controller]] documentation.
''Note about the„Warning: No NC replicated for Connection!“ line: It can be safely ignored. See [[FAQ#Message:_Warning:_No_NC_replicated_for_Connection.21|FAQ: Message: Warning: No NC replicated for Connection!]]''






== Testing the Local DNS Server ==


Skip this step if you selected <code>--dns-backend=NONE</code> during the join.


Query the local DNS server to resolve the domain name <code>samdom.example.com</code>:


# host -t A samdom.example.com localhost
Using domain server:
Name: localhost
Address: 127.0.0.1#53
Aliases:
samdom.example.com has address 10.99.0.1
samdom.example.com has address 10.99.0.2


The local DNS resolves the domain name to the IP addresses of all domain controllers (DC).
= Start BIND =


In case you receive no or a different result, review this documentation and check:
Please check (samba-tool drs showrepl), that the DC=ForestDnsZones,DC=samdom,DC=example,DC=com and DC=DomainDnsZones,DC=samdom,DC=example,DC=com partitions are already replicated!
* the system log files,
* the Samba log files,
* the BIND log files, if the <code>BIND9_DLZ</code> is used.


If so, it's time to start BIND now, if you have a BIND9_DLZ backend.




== Verifying Kerberos ==


For details, see [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller#Verifying_Kerberos|Verifying Kerberos]] in the [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller|Setting up Samba as an Active Directory Domain Controller]] documentation.




= /etc/resolv.conf on the new Domain Controller =


If the DNS on your new Domain Controller is working, you should think about adding it to /etc/resolv.conf.


As a best practice, you should never have just one nameserver entry in Domain Controllers /etc/resolv.conf! Because if it will fail, this DC isn't able to resolve AD zones any more. This would cause several other services, that rely on DNS like directory replication, to fail.


= DNS Configuration on Domain Controllers =
So always rely on at least two DNS server, that are able to resolve AD DNS zones:

The DNS configuration on domain controllers (DC) is important, because if it is unable to locate other DCs the replication will fail.

Set the local IP of the DC as the primary name server. For example:

On the new joined DC, use the local <code>10.99.0.2</code> IP as primary <code>nameserver</code> entry:


nameserver 10.99.0.2
nameserver 10.99.0.2
nameserver 10.99.0.1
search samdom.example.com
search samdom.example.com


Line 434: Line 358:




= Configuring Winbindd on a Samba AD DC =
= SysVol replication =

''Optional''. For details, see [[Configuring_Winbindd_on_a_Samba_AD_DC|Configuring Winbindd on a Samba AD DC]].




Currently replication of the SysVol share isn't implemented. If you make any changes
on that share, you have to keep them in sync on all your Domain Controllers. An example, how to achieve this automatically, is provided in the [[SysVol_Replication|SysVol Replication]] documentation.




= Using the Domain Controller as a File Server =


For details, see [[Setting_up_Samba_as_an_Active_Directory_Domain_Controller#Using_the_Domain_Controller_as_a_File_Server|Using the Domain Controller as a File Server]].




= Testing directory replication =


To check that replication is working correctly between your two domain controllers, try adding/modifying e. g. a user on one DC using either the Samba command line tools or the Windows GUI admin tools. Then check that the changes shows up within a few seconds on the other Domain Controller.




= Sysvol Replication =


Samba currently does not automatically replicate Sysvol, you must use some other form of replication. For community supported workarounds, see [[SysVol_replication_(DFS-R)|Sysvol Replication]].
== ldapcmp ==


{{Imbox
You may wish to use [[Samba-tool_ldapcmp|samba-tool ldapcmp]] to verify that the same data
| type = note
is being served from all Domain Controllers.
| text = If there are more than the default GPOs in Sysvol on the other DC(s), you must sync Sysvol to the new DC, <code>samba-tool ntacl sysvolreset</code> will throw an error if you do not.
}}




Line 458: Line 387:




= Testing the Directory Replication =
= Replication DNS between Win AD DC fail =


To test that the directory replication works correctly, add for example a user on an existing DC and verify that it shows up automatically on the newly joined DC.
Steps provided by xdexter.
Some users report that their windows AD DC DNS record don't replicate back to Samba DC.


Optionally use the <code>ldapcmp</code> utility to compare two directories. For details, see [[Samba-tool_ldapcmp|samba-tool ldapcmp]].
# '''samba-tool drs showrepl'''


Will not show DC=ForestDnsZones and DC=DomainDnsZones ON "OUTBOUND NEIGHBORS"


Below are some steps on windows 2003, 2008 might be different.


1. Logon to a Windows domain controller with an Enterprise admin account (Prefer to logon to the replication partner of the problematic DC)


2. Run ntdsutil in a Domain Controller


= Troubleshooting =
3. Run "domain management" command in ntdsutil


For further details, see [[Samba_AD_DC_Troubleshooting|Samba AD DC Troubleshooting]].
4. Run "Connections" command and then connect to local server by "Connect to server localdcname" command. (Replace localdcname with local DC's hostname)


5. Hit Q and enter.


6. Run the following command and you will see that your problematic server is not listed in the output, although it should since it has DNS server installed.
If you are replicating a DNS zone to the forest then run "List NC Replicas DC=ForestDnsZones,DC=domain,DC=com"
If you are replicating a DNS zone to the domain then run "List NC Replicas DC=DomainDnsZones,DC=domain,DC=com"
Before continuing to the next step make sure that there is no object under "LostAndFoundConfig" (serves as a container for lost forestwide objects) container.
You can check this with ADSIEDIT.msc under Configuration Partition. If there is an object first check its "lastKnownParent" attribute and if you decide if this is not an orphaned object then move it to its location.
If you decide this is an orphaned object then delete it.


7. Now add your problematic Domain Controller with DNS server install to the NC's you are replicating. By running following commands.


8. For Forest wide DNS partition:
"Add NC Replica DC=ForestDnsZones,DC=domain,DC=com problemdcname.domain.com" (problematic DC name must be in full DNS name format).
For Domain wide DNS partition:
"Add NC Replica DC=DomainDnsZones,DC=domain,DC=com problemdcname.domain.com" (problematic DC name must be in full DNS name format).


----
9. Force replication on problematic DC from its partner (where follow the steps from 1 to 8).
[[Category:Active Directory]]
[[Category:Domain Control]]

Latest revision as of 10:26, 26 September 2023

Introduction

Running one domain controller (DC) is sufficient for a working Active Directory (AD) forest. However, for redundancy and load balancing reasons, you should add further DCs to your AD forest. Joining an additional Samba DC to an existing AD differs from provisioning the first DC in a forest. If you set up a new AD forest, see Setting up Samba as an Active Directory Domain Controller.



Preparing the Installation

For details, see Preparing the Installation in the Setting up Samba as an Active Directory Domain Controller documentation.



Installing Samba

For details, see Installing Samba.



Preparing the Host for Joining the Domain

Local DNS server

By default, the first Domain Controller (DC) in a forest runs a DNS server for Active Directory (AD)-based zones. For redundancy reasons it is recommended to run multiple DCs acting as a DNS server in a network. If you consider providing a DNS service on the new DC:

  • For the BIND9_DLZ back end, see BIND9_DLZ DNS Back End. Finish this task before you start the Samba DC service.
  • For the internal DNS no further actions are required.


Configuring DNS


For details, see Linux and Unix DNS Configuration.



Kerberos

Set the following settings in your Kerberos client configuration file /etc/krb5.conf: 

[libdefaults]
    dns_lookup_realm = false
    dns_lookup_kdc = true
    default_realm = SAMDOM.EXAMPLE.COM

To verify the settings use the kinit command to request a Kerberos ticket for the domain administrator: 

# kinit administrator
Password for administrator@SAMDOM.EXAMPLE.COM:

To list Kerberos tickets: 

# klist
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: administrator@SAMDOM.EXAMPLE.COM

Valid starting       Expires              Service principal
24.09.2015 19:56:55  25.09.2015 05:56:55  krbtgt/SAMDOM.EXAMPLE.COM@SAMDOM.EXAMPLE.COM
	renew until 25.09.2015 19:56:53



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.



Joining the Active Directory as a Domain Controller

To join the domain samdom.example.com as a domain controller (DC) that additionally acts as a DNS server using the Samba internal DNS:

There are three authentication methods you can use, Username & Password or two kerberos methods (the kerberos methods depend on running kinit as an admin user).

Username & Password: 

# samba-tool domain join samdom.example.com DC -U"SAMDOM\administrator"

Or: 

# samba-tool domain join samdom.example.com DC -k yes

Or: 

# samba-tool domain join samdom.example.com DC --use-krb5-ccache=/tmp/krb5cc_0

Using any of the above, should result in output similar to this: 

Finding a writeable DC for domain 'samdom.example.com'
Found DC dc1.samdom.example.com
Password for [SAMDOM\administrator]:
workgroup is SAMDOM
realm is samdom.example.com
Adding CN=DC2,OU=Domain Controllers,DC=samdom,DC=example,DC=com
Adding CN=DC2,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
Adding CN=NTDS Settings,CN=DC2,CN=Servers,CN=Default-First-Site-Name,CN=Sites,CN=Configuration,DC=samdom,DC=example,DC=com
Adding SPNs to CN=DC2,OU=Domain Controllers,DC=samdom,DC=example,DC=com
Setting account password for DC2$
Enabling account
Calling bare provision
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
A Kerberos configuration suitable for Samba 4 has been generated at /usr/local/samba/private/krb5.conf
Provision OK for domain DN DC=samdom,DC=example,DC=com
Starting replication
Schema-DN[CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com] objects[402/1550] linked_values[0/0]
Schema-DN[CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com] objects[804/1550] linked_values[0/0]
Schema-DN[CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com] objects[1206/1550] linked_values[0/0]
Schema-DN[CN=Schema,CN=Configuration,DC=samdom,DC=example,DC=com] objects[1550/1550] linked_values[0/0]
Analyze and apply schema objects
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[402/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[804/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1206/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1608/1618] linked_values[0/0]
Partition[CN=Configuration,DC=samdom,DC=example,DC=com] objects[1618/1618] linked_values[42/0]
Replicating critical objects from the base DN of the domain
Partition[DC=samdom,DC=example,DC=com] objects[100/100] linked_values[23/0]
Partition[DC=samdom,DC=example,DC=com] objects[386/286] linked_values[23/0]
Done with always replicated NC (base, config, schema)
Replicating DC=DomainDnsZones,DC=samdom,DC=example,DC=com
Partition[DC=DomainDnsZones,DC=samdom,DC=example,DC=com] objects[44/44] linked_values[0/0]
Replicating DC=ForestDnsZones,DC=samdom,DC=example,DC=com
Partition[DC=ForestDnsZones,DC=samdom,DC=example,DC=com] objects[19/19] linked_values[0/0]
Committing SAM database
Sending DsReplicaUpdateRefs for all the replicated partitions
Setting isSynchronized and dsServiceName
Setting up secrets database
Joined domain SAMDOM (SID S-1-5-21-469703510-2364959079-1506205053) as a DC

See the samba-tool domain join --help command's output for further information.

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

  • --dns-backend=NAMESERVER-BACKEND: Use the supplied DNS server backend. Valid options are SAMBA_INTERNAL or BIND9_DLZ, unless you want to use Bind9, there is no need to supply this option.
If you use the internal DNS server, you will not be asked for a forwarder and the one in /etc/resolv.conf will not be obtained automatically. You must supply one with --option="dns forwarder=forwarder_ipaddress".
  • --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.



Starting the Samba Service

To start the samba Samba Active Directory (AD) domain controller (DC) 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 DNS Entries

If you join a Samba DC that runs Samba 4.7.0 and later, samba-tool will create the required initial DNS entries automatically. To manually create these records on an earlier version, see Verifying and Creating a DC DNS Record. Once Samba starts, the samba_dnsupdate script should create all the other required DNS entries.



Configuring the BIND9_DLZ DNS Back End

If you selected the BIND9_DLZ DNS back end during the domain join, set up the BIND configuration. For details, see BIND9_DLZ DNS Back End.



Built-in User & Group ID Mappings

Samba in its current state doesn't support SysVol replication via DFS-R (Distributed File System Replication) or the older FRS (File Replication Service) used in Windows Server 2000/2003 for Sysvol replication.

We Currently advise administrators to use one of the following workarounds:



To use a Sysvol Replication workaround, all domain controllers (DC) must use the same ID mappings for built-in users and groups.

By default, a Samba DC stores the user & group IDs in 'xidNumber' attributes in 'idmap.ldb'. Because of the way 'idmap.ldb' works, you cannot guarantee that each DC will use the same ID for a given user or group. To ensure that you do use the same IDs, you must:

  • Create a hot-backup of the /usr/local/samba/private/idmap.ldb file on the existing DC:
# tdbbackup -s .bak /usr/local/samba/private/idmap.ldb
This creates a backup file /usr/local/samba/private/idmap.ldb.bak.
  • Move the backup file to the /usr/local/samba/private/ folder on the new joined DC and remove the .bak suffix to replace the existing file.
  • Run net cache flush on the new DC.
  • You will now need to sync Sysvol to the new DC.
  • Reset the Sysvol folder's file system access control lists (ACL) on the new DC:
# samba-tool ntacl sysvolreset



Verifying Directory Replication

After the domain controller (DC) has been started, the knowledge consistency checker (KCC) on the Samba DC creates replication agreements to other DCs in the Active Directory (AD) forest. It can take up to 15 minutes until the KCC creates the auto-generated replication connections.

For details about how to verify that the directory replication works correctly, see Verifying the Directory Replication Statuses.



Starting BIND

Before you start the BIND daemon, verify that the DNS directory partitions have been successfully replicated: 

# samba-tool drs showrepl
...
==== INBOUND NEIGHBORS ====
...
DC=DomainDnsZones,DC=samdom,DC=example,DC=com
	Default-First-Site-Name\DC1 via RPC
		DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
		Last attempt @ Thu Sep 24 20:08:45 2015 CEST was successful
		0 consecutive failure(s).
		Last success @ Thu Sep 24 20:08:45 2015 CEST
...
DC=ForestDnsZones,DC=samdom,DC=example,DC=com
	Default-First-Site-Name\DC1 via RPC
		DSA object GUID: 4a6bd92a-6612-4b15-aa8c-9ec371e8994f
		Last attempt @ Thu Sep 24 20:08:45 2015 CEST was successful
		0 consecutive failure(s).
		Last success @ Thu Sep 24 20:08:45 2015 CEST

If the replication works correctly, start the BIND service. See your distribution's documentation for information how to start a service.



Testing your Samba AD DC

Verifying the File Server

For details, see Verifying the File Server in the Setting up Samba as an Active Directory Domain Controller documentation.


Testing the Local DNS Server

Skip this step if you selected --dns-backend=NONE during the join.

Query the local DNS server to resolve the domain name samdom.example.com: 

# host -t A samdom.example.com localhost
Using domain server:
Name: localhost
Address: 127.0.0.1#53
Aliases:

samdom.example.com has address 10.99.0.1
samdom.example.com has address 10.99.0.2

The local DNS resolves the domain name to the IP addresses of all domain controllers (DC).

In case you receive no or a different result, review this documentation and check:

  • the system log files,
  • the Samba log files,
  • the BIND log files, if the BIND9_DLZ is used.


Verifying Kerberos

For details, see Verifying Kerberos in the Setting up Samba as an Active Directory Domain Controller documentation.



DNS Configuration on Domain Controllers

The DNS configuration on domain controllers (DC) is important, because if it is unable to locate other DCs the replication will fail.

Set the local IP of the DC as the primary name server. For example:

On the new joined DC, use the local 10.99.0.2 IP as primary nameserver entry: 

nameserver 10.99.0.2
search samdom.example.com



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

For details, see Using the Domain Controller as a File Server.



Sysvol Replication

Samba currently does not automatically replicate Sysvol, you must use some other form of replication. For community supported workarounds, see Sysvol Replication.



Testing the Directory Replication

To test that the directory replication works correctly, add for example a user on an existing DC and verify that it shows up automatically on the newly joined DC.

Optionally use the ldapcmp utility to compare two directories. For details, see samba-tool ldapcmp.



Troubleshooting

For further details, see Samba AD DC Troubleshooting.



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