Setting up Samba as a Domain Member: Difference between revisions
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= Introduction = |
= Introduction = |
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A Samba domain member is a Linux machine joined to a domain that is running Samba and does not provide domain services, such as an NT4 primary domain controller (PDC) or Active Directory (AD) domain controller (DC). |
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In the context of Samba, you usually only hear about servers ([[Active_Directory_Domain_Controller|AD DCs]], [[NT4_Domains|NT4 PDCs]], [[File_sharing|file servers]], etc.). You usually do not hear much about a Samba workstation as a Domain Member, similar to hosts running a version of Windows e. g. Windows 10 Pro or some other workstation edition. What if you want to join a Linux workstation to the domain, to authenticate user logins against your Domain Controller(s)? |
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On a Samba domain member, you can: |
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Generally speaking, a Samba server is just a Samba workstation that provides file shares or print services. This is how we will structure our documentation here - being a Domain Member is the prerequisite for configuring a Samba [[File_sharing|file]] and/or [[Setup_a_Samba_print_server|print]] server. |
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* Use domain users and groups in local ACLs on files and directories. |
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* Set up shares to act as a file server. |
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* Set up printing services to act as a print server. |
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* Configure PAM to enable domain users to log on locally or to authenticate to local installed services. |
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For details about setting up a Samba NT4 domain or Samba AD, see [[Domain_Control|Domain Control]]. |
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= Installation = |
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= Preparing the Installation = |
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You have the following options to install Samba: |
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== General Preparation == |
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* [[Build_Samba_from_Source|Build Samba]] yourself |
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* Verify that no Samba processes are running: |
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* Install [[Distribution-specific_Package_Installation|distribution specific packages]] |
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# ps ax | egrep "samba|smbd|nmbd|winbindd" |
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: If the output lists any <code>samba</code>, <code>smbd</code>, <code>nmbd</code>, or <code>winbindd</code> processes, shut down the processes. |
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* If you previously run a Samba installation on this host: |
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* Install SerNet [http://www.samba.plus Samba+]/[http://www.samba.plus/older-packages/ Enterprise] packages |
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:* Remove the existing <code>smb.conf</code> file. To list the path to the file, enter: |
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# smbd -b | grep "CONFIGFILE" |
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CONFIGFILE: /usr/local/samba/etc/samba/smb.conf |
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:* Remove all Samba database files, such as <code>*.tdb</code> and <code>*.ldb</code> files. To list the folders containing Samba databases: |
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# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR" |
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LOCKDIR: /usr/local/samba/var/lock/ |
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STATEDIR: /usr/local/samba/var/locks/ |
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CACHEDIR: /usr/local/samba/var/cache/ |
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PRIVATE_DIR: /usr/local/samba/private/ |
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: Starting with a clean environment helps you to prevent confusion, and no files from your previous Samba installation are mixed with your new domain member installation. |
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= Preparing the host for the domain join = |
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== AD DNS zone resolution == |
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== Preparing a Domain Member to Join an Active Directory Domain == |
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Many things in an Active Directory, such as Kerberos, rely on DNS. Therefore it is required that the host is able to resolve AD DNS zones. If you have multiple DCs acting as a DNS server, it's recommended to setup multiple nameserver entries for fail over reasons. |
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=== Configuring DNS === |
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On Linux and Unixes, you usually configure DNS settings in /etc/resolv.conf: |
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For details, see [[Linux_and_Unix_DNS_Configuration|Linux and Unix DNS Configuration]]. |
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nameserver 10.99.0.1 |
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nameserver 10.99.0.2 |
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search samdom.example.com |
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Some tools, such as NetworkManager, may overwrite manual changes in that file. Please consult your distributions documentation for configuring name resolution. |
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To verify a correct name resolution, try resolving the hostname of one of your Domain Controllers: |
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=== Configuring Kerberos === |
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# host -t A DC1.samdom.example.com |
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DC1.samdom.example.com has address 10.99.0.1 |
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Samba supports Heimdal and MIT Kerberos back ends. To configure Kerberos on the domain member, set the following in your <code>/etc/krb5.conf</code> file: |
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[libdefaults] |
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default_realm = SAMDOM.EXAMPLE.COM |
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dns_lookup_realm = false |
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dns_lookup_kdc = true |
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The previous example configures Kerberos for the <code>SAMDOM.EXAMPLE.COM</code> realm. |
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== NTP == |
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The Samba teams recommends not setting further parameters in the <code>/etc/krb5.conf</code> file. |
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In an Active Directory, accurate time synchronization is necessary for Kerberos, to prevent replay attacks and for resolving directory replication conflicts. For those reasons, if the time differs to your AD, your host won't be able to access AD servers and any shares it provides won't be accessible by others. See [[Time_Synchronisation|Time Syncronisation]] for further information and [[Time_Synchronisation#Configuring_time_synchronisation_on_a_Samba_Domain_Members|configuration examples]]. |
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== Local hostname resolution == |
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During the Domain join, Samba tries to register/update the hosts name and IP in your AD DNS. This requires that "net" can resolve both, either using DNS or /etc/hosts. To verify, run |
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=== Configuring Time Synchronisation === |
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Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see [[Time_Synchronisation#Configuring_Time_Synchronisation_on_a_Unix_Domain_Member|Configuring Time Synchronisation on a Unix Domain Member]]. |
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=== Local Host Name Resolution === |
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When you join the host to the domain, Samba tries to register the host name in the AD DNS zone. For this, the <code>net</code> utility must be able to resolve the host name using DNS or using a correct entry in the <code>/etc/hosts</code> file. |
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To verify that your host name resolves correctly, use the <code>getent hosts</code> command. For example: |
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# getent hosts M1 |
# getent hosts M1 |
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10.99.0.5 M1.samdom.example.com M1 |
10.99.0.5 M1.samdom.example.com M1 |
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The host name and FQDN must not resolve to the <code>127.0.0.1</code> IP address or any other IP address other than the one used on the LAN interface of the domain member. |
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The commands output must show the correct LAN interface IP (not 127.*.*.*!) and the hostname including the AD DNS zone. Additional alias names are optional. If you get a different output, fix it in your DNS or by adding/changing the /etc/hosts entry: |
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If no output is displayed or the host is resolved to the wrong IP address and you are not using dhcp, set the correct entry in the <code>/etc/hosts</code> file. For example: |
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127.0.0.1 localhost |
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10.99.0.5 M1.samdom.example.com M1 |
10.99.0.5 M1.samdom.example.com M1 |
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If you are using dhcp, check that <code>/etc/hosts</code> only contains the '127.0.0.1' line shown above. If you continue to have problems, contact the sysadmin who controls your DHCP server. |
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* On debian related systems you will also see the line <code>127.0.1.1 hostname</code> in /etc/hosts, remove it before you install samba. |
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* Please keep the line : <code>127.0.0.1 localhost</code> |
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if you need to add aliases to the machine hostname, add them to the end of the line that starts with the machines ipaddress, not the 127.0.0.1 line. |
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== Preparing a Domain Member to Join an NT4 Domain == |
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For joining a host to an NT4 domain, no preparation is required. |
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= Installing Samba = |
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For details, see [[Installing_Samba|Installing Samba]]. |
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{{Imbox |
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| type = note |
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| text = Install a maintained Samba version. For details, see [[Samba_Release_Planning|Samba Release Planning]]. |
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}} |
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= Configuring Samba = |
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== Setting up a Basic <code>smb.conf</code> File == |
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When Setting up smb.conf on a Unix domain member, you will need to make a few decisions. |
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* Do you require users and groups to have the same IDs everywhere, including Samba AD DCs ? |
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* Do you only want your users and groups to have the same IDs on Unix domain members ? |
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After making your decision, you will have another decision to make, this decision could affect what you think you have already decided. |
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* Do you want or need individual users to have different login shells and/or Unix home directory paths ? |
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If you need your users to have different login shells and/or Unix home directory paths, or you want them to have the same ID everywhere, you will need to use the winbind 'ad' backend and add RFC2307 attributes to AD. |
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{{Imbox |
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| type = note |
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| text = The RFC2307 attributes are not added automatically when users or groups are created. |
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}} |
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{{Imbox |
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| type = important |
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| text = The ID numbers found on a DC (numbers in the 3000000 range) are NOT rfc2307 attributes They cannot and will not be used on Unix Domain Members, if you want to have the same ID numbers everywhere, you must add uidNumber & gidNumber attributes to AD and use the winbind 'ad' backend on Unix Domain Members. If you do decide to add uidNumber & gidNumber attributes to AD, you do not need to use numbers in the 3000000 range and in fact it would definitely be a good idea to use a different range. |
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}} |
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If your users will only use the Samba AD DC for authentication and will not store data on it or log into it, you can use the the winbind 'rid' backend, this calculates the user and group IDs from the Windows RID, if you use the same [global] section of the smb.conf on every Unix domain member, you will get the same IDs. |
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If you use the 'rid' backend you do not need to add anything to AD and in fact, any RFC2307 attributes will be ignored. |
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When using the 'rid' backend you must set the 'template shell' and 'template homedir' parameters in smb.conf, these are global settings and everyone gets the same login shell and Unix home directory path, unlike the RFC2307 attributes where you can set individual Unix home directory paths and shells. |
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There is another way of setting up Samba, this is where you require your users and groups to have the same ID everywhere, but only need your users to have the same login shell and use the same Unix home directory path. You can do this by using the winbind 'ad' backend and using the template lines in smb.conf. This way you only have to add uidNumber & gidNumbers attributes to AD. |
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Having decided which winbind backend to use, you now have a further decision to make, the ranges to use with 'idmap config' in smb.conf. |
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By default on a Unix domain member, there are multiple blocks of users & groups: |
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* The local system users & groups: These will be from 0-999 |
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* The local Unix users and groups: These start at 1000 |
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* The 'well Known SIDs': ???? |
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* The DOMAIN users and groups: ADUC, by default, starts these at 10000 |
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* Trusted domains: ???? |
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* Anything that isn't a 'well Known SID' or a member of DOMAIN or a trusted domain: ???? |
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As you can see from the above, you shouldn't set either the '*' or 'DOMAIN' ranges to start at 999 or less, as they would interfere with the local system users & groups. You also should leave a space for any local Unix users & groups, so starting the 'idmap config' ranges at 3000 seems to be a good compromise. |
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You need to decide how large your 'DOMAIN' is likely to grow to and you also need to know if you have any trusted domains or if you may need to have any in future. |
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Bearing the above information in mind, you could set the 'idmap config' ranges to the following: |
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:{| class="wikitable" |
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!Domain |
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!Range |
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|- |
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|<code>*</code> |
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|'''3000-7999''' |
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|- |
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|<code>DOMAIN</code> |
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|'''10000-999999''' |
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|} |
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You could also have any trusted domains starting at: |
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:{| class="wikitable" |
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!Domain |
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!Range |
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|- |
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|<code>TRUSTED</code> |
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|'''1000000-9999999''' |
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|} |
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If you set the '*' range above the 'DOMAIN' range, the ranges will conflict if the 'Domain' grows to the point that the next ID would be the same as the '*' range start ID. |
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With the above suggested ranges, no range will overlap or interfere with another. |
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You may also have seen examples of the '*' range being used for everything, this is not recommended and should not be used. |
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= Setup a Domain Member smb.conf file = |
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Before joining |
Before joining the domain, configure the domain member's <code>smb.conf</code> file: |
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* To locate the file, enter: |
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'''Note:''' You should use the same "smb.conf" file on all domain members you set up in the domain. |
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# smbd -b | grep CONFIGFILE |
# smbd -b | grep CONFIGFILE |
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CONFIGFILE: /usr/local/samba/etc/smb.conf |
CONFIGFILE: /usr/local/samba/etc/smb.conf |
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* After reading this wikipage, edit the <code>smb.conf</code> file and use this example configuration as a basis to set yours, do not just 'cut & paste' it: |
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In the following you see an smb.conf example sufficient to join a domain, if you add an "idmap config" part, fitting to your environment: |
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[global] |
[global] |
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Line 85: | Line 214: | ||
log level = 1 |
log level = 1 |
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# |
# Default ID mapping configuration for local BUILTIN accounts |
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# |
# and groups on a domain member. The default (*) domain: |
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# - must not overlap with any domain ID mapping configuration! |
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# on the available winbind idmap backends, |
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# - must use a read-write-enabled back end, such as <code>tdb</code>. |
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# Choose the one that fits your requirements |
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# |
# - '''Adding just this is not enough''' |
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# - '''You must set a DOMAIN backend configuration, see below''' |
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idmap config * : backend = tdb |
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# Just adding one of the following three lines is not enough!! |
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idmap config * : range = 3000-7999 |
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# |
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# - [[idmap_config_ad|use the winbind 'ad' backend.]] |
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# Or |
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# - [[idmap_config_rid|use the winbind 'rid' backend.]] |
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# Or |
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# - [https://www.samba.org/samba/docs/man/manpages-3/idmap_autorid.8.html use the winbind 'autorid' backend.] |
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:For information on the parameters, see the <code>smb.conf(5)</code> man page. |
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See the manpage of "smb.conf" for detailed information about the parameters and options used. |
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* '''You must add an ID mapping configuration, for each domain that you want Samba to be aware of, to the <code>[global]</code> section of your <code>smb.conf</code> file.''' |
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= The domain join = |
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* '''You must click on one of the following hyperlinks to find information about the Samba domain back ends:''' |
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:{| class="wikitable" |
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'''<u>A note on provisioning</u>:''' A Domain Member <u>must not</u> be provisioned by using "samba-tool"! This would setup an AD DC on your Domain Member with some parts turned off and writes to sam.ldb instead of passdb.tdb. Don't use this way to join, to avoid unwanted side effects! The Domain Member provisioning option will be removed in the future. |
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!Back End |
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!Documentation |
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!Man Page |
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|- |
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|<code>ad</code> |
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|'''[[Idmap_config_ad|idmap config ad]]''' |
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|<code>idmap_ad(8)</code> |
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|- |
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|<code>rid</code> |
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|'''[[Idmap_config_rid|idmap config rid]]''' |
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|<code>idmap_rid(8)</code> |
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|- |
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|<code>autorid</code> |
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|'''[[Idmap_config_autorid|idmap config autorid]]''' |
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|<code>idmap_autorid(8)</code> |
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|- |
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|<code>hash</code> |
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|[[Idmap_config_hash|idmap config hash]] |
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|<code>idmap_hash(8)</code> |
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|- |
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|<code>ldap</code> |
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|[[Idmap_config_ldap|idmap config ldap]] |
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|<code>idmap_ldap(8)</code> |
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|- |
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|<code>nss</code> |
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|[[Idmap_config_nss|idmap config nss]] |
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|<code>idmap_nss(8)</code> |
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|} |
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:{{Imbox |
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The following command will join the host to the domain and automatically register/update its DNS record: |
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| type = important |
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| text = Add an additional ID mapping configuration for every domain. The ID ranges of the default (<code>*</code>) domain and other domains configured in the <code>smb.conf</code> file must not overlap. |
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}} |
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== Mapping the Domain Administrator Account to the Local <code>root</code> User == |
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Samba enables you to map domain accounts to a local account. Use this feature to execute file operations on the domain member's file system as a different user than the account that requested the operation on the client. |
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{{Imbox |
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| type = note |
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| text = Mapping the domain administrator to the local <code>root</code> account is optional. Only configure the mapping if the domain administrator must be able to execute file operations on the domain member using <code>root</code> permissions. You should be aware that mapping Administrator to the <code>root</code> account will not allow you to log onto Unix domain members as <code>Administrator</code>. |
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}} |
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To map the domain administrator to the local <code>root</code> account: |
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* Add the following parameter to the <code>[global]</code> section of your <code>smb.conf</code> file: |
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username map = /usr/local/samba/etc/user.map |
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* Create the <code>/usr/local/samba/etc/user.map</code> file with the following content: |
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!root = SAMDOM\Administrator |
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:{{Imbox |
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| type = important |
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| text = When using the <code>ad</code> ID mapping back end, do not set the <code>uidNumber</code> attribute for the domain administrator account. If the account has the attribute set, the value overrides the local UID <code>0</code> of the <code>root</code> user and thus the mapping fails. |
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}} |
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For further details, see <code>username map</code> parameter in the <code>smb.conf(5)</code> man page. |
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= Joining the Domain = |
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* To join the host to an Active Directory (AD), enter: |
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# net ads join -U administrator |
# net ads join -U administrator |
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Line 113: | Line 304: | ||
Joined 'M1' to dns domain 'samdom.example.com' |
Joined 'M1' to dns domain 'samdom.example.com' |
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* To join the host to an NT4 domain, enter: |
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If you encounter any error message(s), see [[Troubleshooting_Samba_Domain_Members|Troubleshooting Samba Domain Members]]. |
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# net rpc join -U administrator |
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If you use the parameter : bind interfaces only = yes in smb.conf, join with : |
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Enter administrator's password: Passw0rd |
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Joined domain SAMDOM. |
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{{Imbox |
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= libnss_winbind = |
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| type = important |
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| text = Do not provision or join a domain member using the <code>samba-tool</code> utility. These options are unsupported and can cause problems with your AD replication. The options will be removed from <code>samba-tool</code> in a future release. |
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}} |
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If you have problems joining the domain, check your configuration. For further help, see [[Troubleshooting_Samba_Domain_Members|Troubleshooting Samba Domain Members]]. |
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Domain users and groups are made available to your local system through libnss_winbind. The [[#Setup_a_Domain_Member_smb.conf_file|smb.conf configuration]] was already done in a previous step. Next is to tell your system to retrieve that information from winbindd by adding "winbind" to the following two lines of your /etc/nsswitch.conf: |
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passwd: files winbind |
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group: files winbind |
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Keep the existing database "files" (sometimes you may find "compat" instead of "files"). It defines that accounts and groups are first looked up in local files (/etc/passwd and /etc/group), then using Winbindd. |
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'''Note:''' Do not add 'winbind' to the 'shadow' line, this has been reported to cause problems with 'wbinfo', it is also totally unneeded. |
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'''Note:''' you cannot have users & groups with the same name in the local files and the domain i.e. a user 'foo' that appears in /etc/passwd would be the same user as 'DOMAIN\foo', in this instance you would need to remove or rename one of the users. |
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= Configuring the Name Service Switch = |
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'''Important:''' If you have compiled Samba, you may need to add two symbolic links. See [[Libnss_winbind_Links|libnss_winbind Links]] for OS specific information on where to place them. Samba package installations usually place the file directly in the OS library path or have the links included. |
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To enable the name service switch (NSS) library to make domain users and groups available to the local system: |
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* Append the <code>winbind</code> entry to the following databases in the <code>/etc/nsswitch.conf</code> file: |
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passwd: files <u>winbind</u> |
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group: files <u>winbind</u> |
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:* Keep the <code>files</code> entry as first source for both databases. This enables NSS to look up domain users and groups from the <code>/etc/passwd</code> and <code>/etc/group</code> files before querying the Winbind service. |
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:* Do not add the <code>winbind</code> entry to the NSS <code>shadow</code> database. This can cause the <code>wbinfo</code> utility fail. |
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= Start daemons = |
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:{{Imbox |
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Depending on how you use your Domain Member, you have to start different daemons: |
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| type = note |
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| text = Do not use the same user names in the local <code>/etc/passwd</code> file as in the domain. |
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}} |
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* If you compiled Samba, add symbolic links from the <code>libnss_winbind</code> library to the operating system's library path. For details, see [[Libnss_winbind_Links|libnss_winbind Links]]. If you used packages to install Samba, the link is usually created automatically. |
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For a pure Domain Member (domain logons only): |
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# winbindd |
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For Domain Members [[File_sharing|sharing directories (file server)]] and/or [[Setup_a_Samba_print_server|printers (print server)]]: |
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# smbd |
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# nmbd |
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# winbindd |
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'''Note:''' You do not start the 'samba' daemon on a domain member. |
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= Starting the Services = |
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If you installed Samba using packages, you usually have init scripts or systemd/upstart support included. If you have compiled Samba, you will need to write your own scripts. For automatic startup of the service(s) at boot time, please consult you distributions documentation. |
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To start the services on a domain member: |
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* Start the <code>winbindd</code> service to enable the name service switch (NSS) library to look up domain users and groups: |
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# winbindd |
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* If you set up file shares or printer services on the domain member, additionally start the <code>smbd</code> and <code>nmbd</code> service: |
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# smbd |
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= Testing Winbindd domain controller connectivity = |
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# nmbd |
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:{{Imbox |
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== wbinfo == |
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| type = note |
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| text = You must not start the <code>samba</code> service on a domain member. This service is required only on Active Directory (AD) domain controllers (DC). |
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}} |
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Samba does not provide System V init scripts, <code>systemd</code>, <code>upstart</code>, or service files for other init services. |
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You first need to check if winbind is able to connect to a domain controller with wbinfo --ping-dc: |
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* If you installed Samba using packages, use the script or service configuration file provided by the package to start Samba. |
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* If you built Samba, see your distribution's documentation for how to create a script or configuration to start services. |
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# wbinfo --ping-dc |
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checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded |
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== Using domain accounts/groups in OS commands == |
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If you have included [[#libnss_winbind|libnss_winbind]] in your system and setup smb.conf correctly, the following commands should print the relevant information for the supplied user or group: |
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= Testing the Winbindd Connectivity = |
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# getent passwd demo01 |
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demo01:*:10000:10000:demo01:/home/demo01:/bin/bash |
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... |
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== Sending a Winbindd Ping == |
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# getent group Domain\ Users |
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domain users:x:10000: |
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... |
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To verify if the Winbindd service is able to connect to Active Directory (AD) Domain Controllers (DC) or a primary domain controller (PDC), enter: |
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# wbinfo --ping-dc |
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'''Note:''' If you do not get any output, verify that |
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checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded |
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* [[#libnss_winbind|libnss_winbind]] configuration is correct - especially that "ldconfig" is able to find "libnss_winbind.so.2" and "libnss_winbind.so" |
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* smb.conf is setup correctly |
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* if using [[idmap_config_ad|idmap config ad]], accounts/groups have [[Maintaining_Unix_Attributes_in_AD_using_ADUC|RFC2307 attributes]] set |
|||
If the previous command fails, verify: |
|||
* That the <code>winbindd</code> service is running. |
|||
* Your <code>smb.conf</code> file is set up correctly. |
|||
'''Note:''' if you want to display all users & groups with 'getent', add these lines to your smb.conf (This is only recommended for testing): |
|||
winbind enum users = yes |
|||
winbind enum groups = yes |
|||
== Using Domain Accounts and Groups in Operating System Commands == |
|||
Any domain accounts/groups shown by getent or id can be used in the OS, i.e. |
|||
=== Looking up Domain Users and Groups === |
|||
# id demo01 |
|||
uid=10000(demo01) gid=10000(domain users) groups=10000(domain users),2001(BUILTIN\users) |
|||
The <code>libnss_winbind</code> library enables you to look up domain users and groups. For example: |
|||
# chown demo01:"domain users" file.txt |
|||
# ls -s file.txt |
|||
-rw-------. 1 demo01 domain users 992 18. Oct 2015 file.txt |
|||
* To look up the domain user <code>SAMDOM\demo01</code>: |
|||
# getent passwd SAMDOM\\demo01 |
|||
'''Note:''' For various reasons, Administrator needs to be mapped to the Unix user 'root', this is done automatically on a Samba AD DC. On a domain member you will need to add a line to 'smb.conf': |
|||
SAMDOM\demo01:*:10000:10000:demo01:/home/demo01:/bin/bash |
|||
* To look up the domain group <code>Domain Users</code>: |
|||
username map = /usr/local/samba/etc/user.map |
|||
# getent group "SAMDOM\\Domain Users" |
|||
You will then need to create /usr/local/samba/etc/user.map: |
|||
SAMDOM\domain users:x:10000: |
|||
!root = SAMDOM\Administrator SAMDOM\administrator Administrator administrator |
|||
Do not give Administrator a uidNumber attribute, this will turn Administrator into a normal Unix user, without the required permissions & rights it needs. |
|||
= |
=== Assigning File Permissions to Domain Users and Groups === |
||
The name service switch (NSS) library enables you to use domain user accounts and groups in commands. For example to set the owner of a file to the <code>demo01</code> domain user and the group to the <code>Domain Users</code> domain group, enter: |
|||
''If you have setup this Domain Member as a server providing file shares or print services, you may want to skip this part, By following this part, you will allow domain users to logon locally to the hosts console.'' |
|||
# chown "SAMDOM\\demo01:SAMDOM\\domain users" file.txt |
|||
== General information == |
|||
'''Important note:''' Before you start changing your PAM configuration: |
|||
* make sure you know what you're doing! |
|||
* before you start, login within a second terminal and keep it open until everything works as expected. Otherwise, you may lockout yourself and won't be able to login again! |
|||
If you have compiled Samba, you need to add a symbolic links. See [[Pam_winbind_Link|pam_winbind Link]] for OS specific information, where to place it. Samba package installations usually place the file directly in the right folder or have a link included. |
|||
= Setting up Additional Services on the Domain Member = |
|||
On a Samba domain member, you can additionally set up: |
|||
* File shares to act as a file server. For details, see [[Samba_File_Serving|Samba File Serving]]. |
|||
* Print services to act as a print server. For details, see [[Print_Server_Support|Print Server Support]]. |
|||
* PAM authentication of domain users for local services. For details, see [[Authenticating_Domain_Users_Using_PAM|Authenticating Domain Users Using PAM]]. |
|||
== Configure PAM == |
|||
'''Note:''' Whenever your distribution ship tools to configure PAM, it's recommended to use them, instead of manually editing the configuration files! |
|||
* Red Hat based OS: authconfig/authconfig-tui |
|||
* Debian based OS: pam-auth-update |
|||
* SUSE based OS: yast |
|||
For manual changes: Typically the PAM configuration files are located in /etc/pam.d/ Depending on your distribution, the filename(s) may differ. E. g. on RHEL, you configure system login authentication in /etc/pam.d/password-auth-ac: |
|||
#%PAM-1.0 |
|||
auth required pam_env.so |
|||
auth sufficient pam_unix.so nullok try_first_pass |
|||
auth requisite pam_succeed_if.so uid >= 1000 quiet_success |
|||
auth sufficient pam_winbind.so use_first_pass # <-- add this line |
|||
auth required pam_deny.so |
|||
account required pam_unix.so broken_shadow |
|||
account sufficient pam_localuser.so |
|||
account sufficient pam_succeed_if.so uid < 1000 quiet |
|||
account [default=bad success=ok user_unknown=ignore] pam_winbind.so # <-- add this line |
|||
account required pam_permit.so |
|||
password requisite pam_cracklib.so try_first_pass retry=3 type= |
|||
password sufficient pam_unix.so sha512 shadow nullok try_first_pass use_authtok |
|||
password sufficient pam_winbind.so use_authtok # <-- add this line |
|||
password required pam_deny.so |
|||
session optional pam_keyinit.so revoke |
|||
session required pam_limits.so |
|||
session [success=1 default=ignore] pam_succeed_if.so service in crond quiet use_uid |
|||
session required pam_unix.so |
|||
= Troubleshooting = |
|||
For additional information about PAM configuration and settings used in the example above, please consult the [http://www.linux-pam.org PAM] documentation and the manpages of pam.conf and pam_winbind. |
|||
For details, see [[Troubleshooting_Samba_Domain_Members|Troubleshooting Samba Domain Members]]. |
|||
== Verify domain user login == |
|||
Try to login on the local console with a domain user account: |
|||
CentOS Linux 7 (Core) |
|||
Kernel 3.10.0-229.11.1.el.7.x86_64 on an x86_64 |
|||
M1 login: demo01 |
|||
Password: Passw0rd |
|||
[demo01@M1 ~]$ _ |
|||
= Setting up additional services = |
|||
---- |
|||
Now you have successfully made your host be a Domain Member, you can, as on a Windows OS, additionally [[File_sharing|share directories (file server)]] or act as an [[Setup_a_Samba_print_server|print server]]. |
|||
[[Category:Active Directory]] |
|||
[[Category:Domain Members]] |
|||
[[Category:NT4 Domains]] |
Revision as of 14:11, 22 March 2018
Introduction
A Samba domain member is a Linux machine joined to a domain that is running Samba and does not provide domain services, such as an NT4 primary domain controller (PDC) or Active Directory (AD) domain controller (DC).
On a Samba domain member, you can:
- Use domain users and groups in local ACLs on files and directories.
- Set up shares to act as a file server.
- Set up printing services to act as a print server.
- Configure PAM to enable domain users to log on locally or to authenticate to local installed services.
For details about setting up a Samba NT4 domain or Samba AD, see Domain Control.
Preparing the Installation
General Preparation
- Verify that no Samba processes are running:
# ps ax | egrep "samba|smbd|nmbd|winbindd"
- If the output lists any
samba
,smbd
,nmbd
, orwinbindd
processes, shut down the processes.
- If you previously run a Samba installation on this host:
- Remove the existing
smb.conf
file. To list the path to the file, enter:
- Remove the existing
# 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:
- Remove all Samba database files, such as
# smbd -b | egrep "LOCKDIR|STATEDIR|CACHEDIR|PRIVATE_DIR" LOCKDIR: /usr/local/samba/var/lock/ STATEDIR: /usr/local/samba/var/locks/ CACHEDIR: /usr/local/samba/var/cache/ PRIVATE_DIR: /usr/local/samba/private/
- Starting with a clean environment helps you to prevent confusion, and no files from your previous Samba installation are mixed with your new domain member installation.
Preparing a Domain Member to Join an Active Directory Domain
Configuring DNS
For details, see Linux and Unix DNS Configuration.
Configuring Kerberos
Samba supports Heimdal and MIT Kerberos back ends. To configure Kerberos on the domain member, set the following in your /etc/krb5.conf
file:
[libdefaults] default_realm = SAMDOM.EXAMPLE.COM dns_lookup_realm = false dns_lookup_kdc = true
The previous example configures Kerberos for the SAMDOM.EXAMPLE.COM
realm.
The Samba teams recommends not setting further parameters in the /etc/krb5.conf
file.
Configuring Time Synchronisation
Kerberos requires a synchronised time on all domain members. Thus it is recommended to set up an NTP client. For further details, see Configuring Time Synchronisation on a Unix Domain Member.
Local Host Name Resolution
When you join the host to the domain, Samba tries to register the host name in the AD DNS zone. For this, the net
utility must be able to resolve the host name using DNS or using a correct entry in the /etc/hosts
file.
To verify that your host name resolves correctly, use the getent hosts
command. For example:
# getent hosts M1 10.99.0.5 M1.samdom.example.com M1
The host name and FQDN must not resolve to the 127.0.0.1
IP address or any other IP address other than the one used on the LAN interface of the domain member.
If no output is displayed or the host is resolved to the wrong IP address and you are not using dhcp, set the correct entry in the /etc/hosts
file. For example:
127.0.0.1 localhost 10.99.0.5 M1.samdom.example.com M1
If you are using dhcp, check that /etc/hosts
only contains the '127.0.0.1' line shown above. If you continue to have problems, contact the sysadmin who controls your DHCP server.
- On debian related systems you will also see the line
127.0.1.1 hostname
in /etc/hosts, remove it before you install samba. - Please keep the line :
127.0.0.1 localhost
if you need to add aliases to the machine hostname, add them to the end of the line that starts with the machines ipaddress, not the 127.0.0.1 line.
Preparing a Domain Member to Join an NT4 Domain
For joining a host to an NT4 domain, no preparation is required.
Installing Samba
For details, see Installing Samba.
Install a maintained Samba version. For details, see Samba Release Planning. |
Configuring Samba
Setting up a Basic smb.conf
File
When Setting up smb.conf on a Unix domain member, you will need to make a few decisions.
- Do you require users and groups to have the same IDs everywhere, including Samba AD DCs ?
- Do you only want your users and groups to have the same IDs on Unix domain members ?
After making your decision, you will have another decision to make, this decision could affect what you think you have already decided.
- Do you want or need individual users to have different login shells and/or Unix home directory paths ?
If you need your users to have different login shells and/or Unix home directory paths, or you want them to have the same ID everywhere, you will need to use the winbind 'ad' backend and add RFC2307 attributes to AD.
The RFC2307 attributes are not added automatically when users or groups are created. |
The ID numbers found on a DC (numbers in the 3000000 range) are NOT rfc2307 attributes They cannot and will not be used on Unix Domain Members, if you want to have the same ID numbers everywhere, you must add uidNumber & gidNumber attributes to AD and use the winbind 'ad' backend on Unix Domain Members. If you do decide to add uidNumber & gidNumber attributes to AD, you do not need to use numbers in the 3000000 range and in fact it would definitely be a good idea to use a different range. |
If your users will only use the Samba AD DC for authentication and will not store data on it or log into it, you can use the the winbind 'rid' backend, this calculates the user and group IDs from the Windows RID, if you use the same [global] section of the smb.conf on every Unix domain member, you will get the same IDs. If you use the 'rid' backend you do not need to add anything to AD and in fact, any RFC2307 attributes will be ignored. When using the 'rid' backend you must set the 'template shell' and 'template homedir' parameters in smb.conf, these are global settings and everyone gets the same login shell and Unix home directory path, unlike the RFC2307 attributes where you can set individual Unix home directory paths and shells.
There is another way of setting up Samba, this is where you require your users and groups to have the same ID everywhere, but only need your users to have the same login shell and use the same Unix home directory path. You can do this by using the winbind 'ad' backend and using the template lines in smb.conf. This way you only have to add uidNumber & gidNumbers attributes to AD.
Having decided which winbind backend to use, you now have a further decision to make, the ranges to use with 'idmap config' in smb.conf. By default on a Unix domain member, there are multiple blocks of users & groups:
- The local system users & groups: These will be from 0-999
- The local Unix users and groups: These start at 1000
- The 'well Known SIDs': ????
- The DOMAIN users and groups: ADUC, by default, starts these at 10000
- Trusted domains: ????
- Anything that isn't a 'well Known SID' or a member of DOMAIN or a trusted domain: ????
As you can see from the above, you shouldn't set either the '*' or 'DOMAIN' ranges to start at 999 or less, as they would interfere with the local system users & groups. You also should leave a space for any local Unix users & groups, so starting the 'idmap config' ranges at 3000 seems to be a good compromise.
You need to decide how large your 'DOMAIN' is likely to grow to and you also need to know if you have any trusted domains or if you may need to have any in future.
Bearing the above information in mind, you could set the 'idmap config' ranges to the following:
Domain Range *
3000-7999 DOMAIN
10000-999999
You could also have any trusted domains starting at:
Domain Range TRUSTED
1000000-9999999
If you set the '*' range above the 'DOMAIN' range, the ranges will conflict if the 'Domain' grows to the point that the next ID would be the same as the '*' range start ID.
With the above suggested ranges, no range will overlap or interfere with another.
You may also have seen examples of the '*' range being used for everything, this is not recommended and should not be used.
Before joining the domain, configure the domain member's smb.conf
file:
- To locate the file, enter:
# smbd -b | grep CONFIGFILE CONFIGFILE: /usr/local/samba/etc/smb.conf
- After reading this wikipage, edit the
smb.conf
file and use this example configuration as a basis to set yours, do not just 'cut & paste' it:
[global]
security = ADS
workgroup = SAMDOM
realm = SAMDOM.EXAMPLE.COM
log file = /var/log/samba/%m.log
log level = 1
# Default ID mapping configuration for local BUILTIN accounts
# and groups on a domain member. The default (*) domain:
# - must not overlap with any domain ID mapping configuration!
# - must use a read-write-enabled back end, such as tdb
.
# - Adding just this is not enough
# - You must set a DOMAIN backend configuration, see below
idmap config * : backend = tdb
idmap config * : range = 3000-7999
- For information on the parameters, see the
smb.conf(5)
man page.
- You must add an ID mapping configuration, for each domain that you want Samba to be aware of, to the
[global]
section of yoursmb.conf
file. - You must click on one of the following hyperlinks to find information about the Samba domain back ends:
Back End Documentation Man Page ad
idmap config ad idmap_ad(8)
rid
idmap config rid idmap_rid(8)
autorid
idmap config autorid idmap_autorid(8)
hash
idmap config hash idmap_hash(8)
ldap
idmap config ldap idmap_ldap(8)
nss
idmap config nss idmap_nss(8)
Add an additional ID mapping configuration for every domain. The ID ranges of the default ( *
) domain and other domains configured in thesmb.conf
file must not overlap.
Mapping the Domain Administrator Account to the Local root
User
Samba enables you to map domain accounts to a local account. Use this feature to execute file operations on the domain member's file system as a different user than the account that requested the operation on the client.
Mapping the domain administrator to the local root account is optional. Only configure the mapping if the domain administrator must be able to execute file operations on the domain member using root permissions. You should be aware that mapping Administrator to the root account will not allow you to log onto Unix domain members as Administrator . |
To map the domain administrator to the local root
account:
- Add the following parameter to the
[global]
section of yoursmb.conf
file:
username map = /usr/local/samba/etc/user.map
- Create the
/usr/local/samba/etc/user.map
file with the following content:
!root = SAMDOM\Administrator
When using the ad
ID mapping back end, do not set theuidNumber
attribute for the domain administrator account. If the account has the attribute set, the value overrides the local UID0
of theroot
user and thus the mapping fails.
For further details, see username map
parameter in the smb.conf(5)
man page.
Joining the Domain
- To join the host to an Active Directory (AD), enter:
# net ads join -U administrator Enter administrator's password: Passw0rd Using short domain name -- SAMDOM Joined 'M1' to dns domain 'samdom.example.com'
- To join the host to an NT4 domain, enter:
# net rpc join -U administrator Enter administrator's password: Passw0rd Joined domain SAMDOM.
Do not provision or join a domain member using the samba-tool utility. These options are unsupported and can cause problems with your AD replication. The options will be removed from samba-tool in a future release. |
If you have problems joining the domain, check your configuration. For further help, see Troubleshooting Samba Domain Members.
Configuring the Name Service Switch
To enable the name service switch (NSS) library to make domain users and groups available to the local system:
- Append the
winbind
entry to the following databases in the/etc/nsswitch.conf
file:
passwd: files winbind group: files winbind
- Keep the
files
entry as first source for both databases. This enables NSS to look up domain users and groups from the/etc/passwd
and/etc/group
files before querying the Winbind service.
- Keep the
- Do not add the
winbind
entry to the NSSshadow
database. This can cause thewbinfo
utility fail.
- Do not add the
Do not use the same user names in the local /etc/passwd
file as in the domain.
- If you compiled Samba, add symbolic links from the
libnss_winbind
library to the operating system's library path. For details, see libnss_winbind Links. If you used packages to install Samba, the link is usually created automatically.
Starting the Services
To start the services on a domain member:
- Start the
winbindd
service to enable the name service switch (NSS) library to look up domain users and groups:
# winbindd
- If you set up file shares or printer services on the domain member, additionally start the
smbd
andnmbd
service:
# smbd # nmbd
You must not start the samba
service on a domain member. This service is required only on Active Directory (AD) domain controllers (DC).
Samba does not provide System V init scripts, systemd
, upstart
, or service files for other init services.
- If you installed Samba using packages, use the script or service configuration file provided by the package to start Samba.
- If you built Samba, see your distribution's documentation for how to create a script or configuration to start services.
Testing the Winbindd Connectivity
Sending a Winbindd Ping
To verify if the Winbindd service is able to connect to Active Directory (AD) Domain Controllers (DC) or a primary domain controller (PDC), enter:
# wbinfo --ping-dc checking the NETLOGON for domain[SAMDOM] dc connection to "DC.SAMDOM.EXAMPLE.COM" succeeded
If the previous command fails, verify:
- That the
winbindd
service is running. - Your
smb.conf
file is set up correctly.
Using Domain Accounts and Groups in Operating System Commands
Looking up Domain Users and Groups
The libnss_winbind
library enables you to look up domain users and groups. For example:
- To look up the domain user
SAMDOM\demo01
:
# getent passwd SAMDOM\\demo01 SAMDOM\demo01:*:10000:10000:demo01:/home/demo01:/bin/bash
- To look up the domain group
Domain Users
:
# getent group "SAMDOM\\Domain Users" SAMDOM\domain users:x:10000:
Assigning File Permissions to Domain Users and Groups
The name service switch (NSS) library enables you to use domain user accounts and groups in commands. For example to set the owner of a file to the demo01
domain user and the group to the Domain Users
domain group, enter:
# chown "SAMDOM\\demo01:SAMDOM\\domain users" file.txt
Setting up Additional Services on the Domain Member
On a Samba domain member, you can additionally set up:
- File shares to act as a file server. For details, see Samba File Serving.
- Print services to act as a print server. For details, see Print Server Support.
- PAM authentication of domain users for local services. For details, see Authenticating Domain Users Using PAM.
Troubleshooting
For details, see Troubleshooting Samba Domain Members.