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2 <!DOCTYPE chapter PUBLIC "-//Samba-Team//DTD DocBook V4.2-Based Variant V1.0//EN" "http://www.samba.org/samba/DTD/samba-doc">
3 <chapter id="domain-member">
11 <author>&person.gd;<contrib>LDAP updates</contrib></author>
14 <title>Domain Membership</title>
17 <indexterm><primary>domain member</primary></indexterm>
18 <indexterm><primary>machine trust account</primary></indexterm>
19 <indexterm><primary>domain security</primary></indexterm>
20 Domain membership is a subject of vital concern. Samba must be able to
21 participate as a member server in a Microsoft domain security context, and
22 Samba must be capable of providing domain machine member trust accounts;
23 otherwise it would not be able to offer a viable option for many users.
27 <indexterm><primary>domain membership</primary></indexterm>
28 <indexterm><primary>misinformation</primary></indexterm>
29 This chapter covers background information pertaining to domain membership,
30 the Samba configuration for it, and MS Windows client procedures for joining a
31 domain. Why is this necessary? Because both are areas in which there exists
32 within the current MS Windows networking world, and particularly in the
33 UNIX/Linux networking and administration world, a considerable level of
34 misinformation, incorrect understanding, and lack of knowledge. Hopefully
35 this chapter will fill the voids.
39 <title>Features and Benefits</title>
42 <indexterm><primary>domain security</primary></indexterm>
43 <indexterm><primary>single sign-on</primary></indexterm>
44 <indexterm><primary>SSO</primary></indexterm>
45 MS Windows workstations and servers that want to participate in domain security need to
46 be made domain members. Participating in domain security is often called
47 <emphasis>single sign-on</emphasis>, or <acronym>SSO</acronym> for short. This
48 chapter describes the process that must be followed to make a workstation
49 (or another server &smbmdash; be it an <application>MS Windows NT4/200x</application>
50 server) or a Samba server a member of an MS Windows domain security context.
54 <indexterm><primary>native member</primary></indexterm>
55 <indexterm><primary>ADS</primary></indexterm>
56 <indexterm><primary>domain control</primary></indexterm>
57 <indexterm><primary>Server Type</primary><secondary>Domain Member</secondary></indexterm>
58 Samba-3 can join an MS Windows NT4-style domain as a native member server, an
59 MS Windows Active Directory domain as a native member server, or a Samba domain
60 control network. Domain membership has many advantages:
65 <indexterm><primary>SAM</primary></indexterm>
66 MS Windows workstation users get the benefit of SSO.
70 <indexterm><primary>access rights</primary></indexterm>
71 <indexterm><primary>file ownership</primary></indexterm>
72 <indexterm><primary>access controls</primary></indexterm>
73 <indexterm><primary>SAM</primary></indexterm>
74 Domain user access rights and file ownership/access controls can be set
75 from the single Domain Security Account Manager (SAM) database
76 (works with domain member servers as well as with MS Windows workstations
77 that are domain members).
81 <indexterm><primary>domain members</primary></indexterm>
82 <indexterm><primary>network logon</primary></indexterm>
83 Only <application>MS Windows NT4/200x/XP Professional</application>
84 workstations that are domain members can use network logon facilities.
88 <indexterm><primary>domain member</primary></indexterm>
89 <indexterm><primary>policy files</primary></indexterm>
90 <indexterm><primary>NTConfig.POL</primary></indexterm>
91 <indexterm><primary>desktop profiles</primary></indexterm>
92 Domain member workstations can be better controlled through the use of
93 policy files (<filename>NTConfig.POL</filename>) and desktop profiles.
97 <indexterm><primary>logon script</primary></indexterm>
98 <indexterm><primary>transparent access</primary></indexterm>
99 <indexterm><primary>application servers</primary></indexterm>
100 Through the use of logon scripts, users can be given transparent access to network
101 applications that run off application servers.
105 <indexterm><primary>user access management</primary></indexterm>
106 <indexterm><primary>SAM</primary></indexterm>
107 <indexterm><primary>LDAP</primary></indexterm>
108 <indexterm><primary>ADS</primary></indexterm>
109 Network administrators gain better application and user access management
110 abilities because there is no need to maintain user accounts on any network
111 client or server other than the central domain database
112 (either NT4/Samba SAM-style domain, NT4 domain that is backend-ed with an
113 LDAP directory, or via an Active Directory infrastructure).
119 <sect1 id="machine-trust-accounts">
120 <title>MS Windows Workstation/Server Machine Trust Accounts</title>
123 <indexterm><primary>Machine Trust Accounts</primary></indexterm>
124 <indexterm><primary>authenticate</primary></indexterm>
125 <indexterm><primary>domain controller</primary></indexterm>
126 <indexterm><primary>rogue user</primary></indexterm>
127 A Machine Trust Account is an account that is used to authenticate a client machine (rather than a user) to
128 the domain controller server. In Windows terminology, this is known as a <quote>computer account.</quote> The
129 purpose of the machine trust account is to prevent a rogue user and domain controller from colluding to gain
130 access to a domain member workstation.
134 <indexterm><primary>machine trust account</primary><secondary>password</secondary></indexterm>
135 <indexterm><primary>shared secret</primary></indexterm>
136 <indexterm><primary>unauthorized</primary></indexterm>
137 <indexterm><primary>Windows NT/200x/XP Professional</primary></indexterm>
138 <indexterm><primary>Windows 9x/Me/XP Home</primary></indexterm>
139 The password of a Machine Trust Account acts as the shared secret for secure communication with the domain
140 controller. This is a security feature to prevent an unauthorized machine with the same NetBIOS name from
141 joining the domain, participating in domain security operations, and gaining access to domain user/group
142 accounts. Windows NT/200x/XP Professional clients use machine trust accounts, but Windows 9x/Me/XP Home
143 clients do not. Hence, a Windows 9x/Me/XP Home client is never a true member of a domain because it does not
144 possess a Machine Trust Account, and, thus, has no shared secret with the domain controller.
148 <indexterm><primary>Windows Registry</primary></indexterm>
149 <indexterm><primary>PDC</primary></indexterm>
150 <indexterm><primary>ADS</primary></indexterm>
151 <indexterm><primary>Machine Trust Account</primary></indexterm>
152 A Windows NT4 PDC stores each Machine Trust Account in the Windows Registry.
153 The introduction of MS Windows 2000 saw the introduction of Active Directory,
154 the new repository for Machine Trust Accounts. A Samba PDC, however, stores
155 each Machine Trust Account in two parts,
160 <indexterm><primary>domain security account</primary></indexterm>
161 <indexterm><primary>account information</primary></indexterm>
162 <indexterm><primary>backend database</primary></indexterm>
163 A domain security account (stored in the <smbconfoption name="passdb backend"/>) that has been configured in
164 the &smb.conf; file. The precise nature of the account information that is stored depends on the type of
165 backend database that has been chosen.
169 <indexterm><primary>smbpasswd</primary></indexterm>
170 <indexterm><primary>UNIX login ID</primary></indexterm>
171 <indexterm><primary>UID</primary></indexterm>
172 <indexterm><primary>LanMan</primary></indexterm>
173 <indexterm><primary>NT-encrypted password</primary></indexterm>
174 <indexterm><primary>UNIX user identifier</primary><see>UID</see></indexterm>
175 The older format of this data is the <filename>smbpasswd</filename> database
176 that contains the UNIX login ID, the UNIX user identifier (UID), and the
177 LanMan and NT-encrypted passwords. There is also some other information in
178 this file that we do not need to concern ourselves with here.
182 <indexterm><primary>database</primary></indexterm>
183 <indexterm><primary>ldapsam</primary></indexterm>
184 <indexterm><primary>smbpasswd</primary></indexterm>
185 <indexterm><primary>account controls</primary></indexterm>
186 The two newer database types are called ldapsam and tdbsam. Both store considerably more data than the older
187 <filename>smbpasswd</filename> file did. The extra information enables new user account controls to be
192 <indexterm><primary>UNIX account</primary></indexterm>
193 <indexterm><primary>/etc/passwd</primary></indexterm>
194 A corresponding UNIX account, typically stored in <filename>/etc/passwd</filename>. Work is in progress to
195 allow a simplified mode of operation that does not require UNIX user accounts, but this has not been a feature
196 of the early releases of Samba-3, and is not currently planned for release either.
203 <indexterm><primary>Machine Trust Accounts</primary><secondary>creating</secondary></indexterm>
204 There are three ways to create Machine Trust Accounts:
209 <indexterm><primary>manual UNIX account creation</primary></indexterm>
210 Manual creation from the UNIX/Linux command line. Here, both the Samba and
211 corresponding UNIX account are created by hand.
215 <indexterm><primary>Server Manager</primary></indexterm>
216 <indexterm><primary>Nexus toolkit</primary></indexterm>
217 Using the MS Windows NT4 Server Manager, either from an NT4 domain member
218 server or using the Nexus toolkit available from the Microsoft Web site.
219 This tool can be run from any MS Windows machine as long as the user is
220 logged on as the administrator account.
224 <indexterm><primary>Machine Trust Account</primary></indexterm>
225 <indexterm><primary>joined client</primary></indexterm>
226 <quote>On-the-fly</quote> creation. The Samba Machine Trust Account is automatically
227 created by Samba at the time the client is joined to the domain.
228 (For security, this is the recommended method.) The corresponding UNIX
229 account may be created automatically or manually.
234 <indexterm><primary>enforcing</primary></indexterm>
235 <indexterm><primary>machine trust account</primary><secondary>creation</secondary></indexterm>
236 Neither MS Windows NT4/200x/XP Professional, nor Samba, provide any method for enforcing the method of machine
237 trust account creation. This is a matter of the administrator's choice.
241 <title>Manual Creation of Machine Trust Accounts</title>
244 <indexterm><primary>/etc/passwd</primary></indexterm>
245 <indexterm><primary></primary></indexterm>
246 <indexterm><primary>useradd</primary></indexterm>
247 <indexterm><primary>vipw</primary></indexterm>
248 The first step in manually creating a Machine Trust Account is to manually
249 create the corresponding UNIX account in <filename>/etc/passwd</filename>.
250 This can be done using <command>vipw</command> or another <quote>adduser</quote> command
251 that is normally used to create new UNIX accounts. The following is an example for
252 a Linux-based Samba server:
254 &rootprompt;<userinput>/usr/sbin/useradd -g machines -d /var/lib/nobody \
255 -c <replaceable>"machine nickname"</replaceable> \
256 -s /bin/false <replaceable>machine_name</replaceable>$ </userinput>
258 &rootprompt;<userinput>passwd -l <replaceable>machine_name</replaceable>$</userinput>
263 <indexterm><primary>primary group</primary></indexterm>
264 <indexterm><primary>GID</primary></indexterm>
265 <indexterm><primary>machine accounts</primary></indexterm>
266 In the example above there is an existing system group <quote>machines</quote> which is used
267 as the primary group for all machine accounts. In the following examples the <quote>machines</quote> group
272 <indexterm><primary>chpass</primary></indexterm>
273 <indexterm><primary>BSD</primary></indexterm>
274 On *BSD systems, this can be done using the <command>chpass</command> utility:
276 &rootprompt;<userinput>chpass -a \
277 '<replaceable>machine_name</replaceable>$:*:101:100::0:0:Windows <replaceable>machine_name</replaceable>:/dev/null:/sbin/nologin'</userinput>
282 <indexterm><primary>/etc/passwd</primary></indexterm>
283 <indexterm><primary>$</primary></indexterm>
284 <indexterm><primary>null shell</primary></indexterm>
285 <indexterm><primary>home directory</primary></indexterm>
286 The <filename>/etc/passwd</filename> entry will list the machine name
287 with a <quote>$</quote> appended, and will not have a password, will have a null shell and no
288 home directory. For example, a machine named <quote>doppy</quote> would have an
289 <filename>/etc/passwd</filename> entry like this:
291 doppy$:x:505:100:<replaceable>machine_nickname</replaceable>:/dev/null:/bin/false
296 <indexterm><primary>machine_nickname</primary></indexterm>
297 <indexterm><primary>machine_name</primary></indexterm>
298 <indexterm><primary>Machine Trust Account</primary></indexterm>
299 in which <replaceable>machine_nickname</replaceable> can be any
300 descriptive name for the client, such as BasementComputer.
301 <replaceable>machine_name</replaceable> absolutely must be the NetBIOS
302 name of the client to be joined to the domain. The <quote>$</quote> must be
303 appended to the NetBIOS name of the client or Samba will not recognize
304 this as a Machine Trust Account.
308 <indexterm><primary>UNIX account</primary></indexterm>
309 <indexterm><primary>Samba account</primary></indexterm>
310 <indexterm><primary>Machine Trust Account</primary><secondary>password</secondary></indexterm>
311 Now that the corresponding UNIX account has been created, the next step is to create
312 the Samba account for the client containing the well-known initial
313 Machine Trust Account password. This can be done using the
314 <command>smbpasswd</command> command
317 &rootprompt;<userinput>smbpasswd -a -m <replaceable>machine_name</replaceable></userinput>
322 <indexterm><primary>machine_name</primary></indexterm>
323 <indexterm><primary>NetBIOS name</primary></indexterm>
324 <indexterm><primary>RID</primary></indexterm>
325 <indexterm><primary>UID</primary></indexterm>
326 where <replaceable>machine_name</replaceable> is the machine's NetBIOS
327 name. The RID of the new machine account is generated from the UID of
328 the corresponding UNIX account.
332 <title>Join the client to the domain immediately</title>
335 <indexterm><primary>Machine Trust Account</primary></indexterm>
336 <indexterm><primary>PDC</primary></indexterm>
337 <indexterm><primary>Server Manager</primary></indexterm>
338 <indexterm><primary>changes password</primary></indexterm>
339 <indexterm><primary>NetBIOS name</primary></indexterm>
340 Manually creating a Machine Trust Account using this method is the
341 equivalent of creating a Machine Trust Account on a Windows NT PDC using
342 <indexterm><primary>Server Manager</primary></indexterm>
343 the <application>Server Manager</application>. From the time at which the
344 account is created to the time the client joins the domain and
345 changes the password, your domain is vulnerable to an intruder joining
346 your domain using a machine with the same NetBIOS name. A PDC inherently
347 trusts members of the domain and will serve out a large degree of user
348 information to such clients. You have been warned!
354 <title>Managing Domain Machine Accounts using NT4 Server Manager</title>
357 <indexterm><primary>machine trust accounts</primary></indexterm>
358 <indexterm><primary>automatic account creation</primary></indexterm>
359 <indexterm><primary>Server Manager</primary></indexterm>
360 A working <smbconfoption name="add machine script"/> is essential
361 for machine trust accounts to be automatically created. This applies no matter whether
362 you use automatic account creation or the NT4 Domain Server Manager.
366 <indexterm><primary>SRVTOOLS.EXE</primary></indexterm>
367 <indexterm><primary>SrvMgr.exe</primary></indexterm>
368 <indexterm><primary>UsrMgr.exe</primary></indexterm>
369 <indexterm><primary>domain management tools</primary></indexterm>
370 If the machine from which you are trying to manage the domain is an
371 <application>MS Windows NT4 workstation or MS Windows 200x/XP Professional</application>,
372 the tool of choice is the package called <command>SRVTOOLS.EXE</command>.
373 When executed in the target directory it will unpack <command>SrvMgr.exe</command>
374 and <command>UsrMgr.exe</command> (both are domain management tools for MS Windows NT4 workstation).
378 <indexterm><primary>Nexus.exe</primary></indexterm>
379 <indexterm><primary>Microsoft Windows 9x/Me</primary></indexterm>
380 If your workstation is a <application>Microsoft Windows 9x/Me</application> family product,
381 you should download the <command>Nexus.exe</command> package from the Microsoft Web site.
382 When executed from the target directory, it will unpack the same tools but for use on
387 Further information about these tools may be obtained from Knowledge Base articles
388 <ulink url="http://support.microsoft.com/default.aspx?scid=kb;en-us;173673">173673</ulink>, and
389 <ulink url="http://support.microsoft.com/default.aspx?scid=kb;en-us;172540">172540</ulink>
393 <indexterm><primary>srvmgr.exe</primary></indexterm>
394 <indexterm><primary>Server Manager for Domains</primary></indexterm>
395 Launch the <command>srvmgr.exe</command> (Server Manager for Domains) and follow these steps:
399 <title>Server Manager Account Machine Account Management</title>
401 From the menu select <guimenu>Computer</guimenu>.
405 Click <guimenuitem>Select Domain</guimenuitem>.
409 Click the name of the domain you wish to administer in the
410 <guilabel>Select Domain</guilabel> panel and then click
411 <guibutton>OK</guibutton>.
415 Again from the menu select <guimenu>Computer</guimenu>.
419 Select <guimenuitem>Add to Domain</guimenuitem>.
423 In the dialog box, click the radio button to
424 <guilabel>Add NT Workstation of Server</guilabel>, then
425 enter the machine name in the field provided, and click the
426 <guibutton>Add</guibutton> button.
433 <title>On-the-Fly Creation of Machine Trust Accounts</title>
436 <indexterm><primary>Machine Trust Account</primary><secondary>creation</secondary></indexterm>
437 The third (and recommended) way of creating Machine Trust Accounts is simply to allow the Samba server to
438 create them as needed when the client is joined to the domain.
442 <indexterm><primary>Machine Trust Account</primary><secondary>UNIX account</secondary></indexterm>
443 <indexterm><primary>UNIX account</primary></indexterm>
444 <indexterm><primary>add machine script</primary></indexterm>
445 Since each Samba Machine Trust Account requires a corresponding UNIX account, a method
446 for automatically creating the UNIX account is usually supplied; this requires configuration of the
447 add machine script option in &smb.conf;. This method is not required; however, corresponding UNIX
448 accounts may also be created manually.
453 <indexterm><primary>useradd</primary></indexterm>
454 <indexterm><primary>Red Hat Linux</primary></indexterm>
455 Here is an example for a Red Hat Linux system:
457 <smbconfsection name="[global]"/>
458 <smbconfoption name="add machine script">/usr/sbin/useradd -d /var/lib/nobody -g 100 -s /bin/false -M %u</smbconfoption>
464 <sect2><title>Making an MS Windows Workstation or Server a Domain Member</title>
467 The procedure for making an MS Windows workstation or server a member of the domain varies
468 with the version of Windows.
472 <title>Windows 200x/XP Professional Client</title>
475 <indexterm><primary>domain member</primary></indexterm>
476 <indexterm><primary>machine trust account</primary><secondary>create privilege</secondary></indexterm>
477 <indexterm><primary>privileges</primary></indexterm>
478 <indexterm><primary>root</primary></indexterm>
479 When the user elects to make the client a domain member, Windows 200x prompts for
480 an account and password that has privileges to create machine accounts in the domain.
484 A Samba administrator account (i.e., a Samba account that has <literal>root</literal> privileges on the
485 Samba server) must be entered here; the operation will fail if an ordinary user account is given.
486 The necessary privilege can be assured by creating a Samba SAM account for <literal>root</literal> or
487 by granting the <literal>SeMachineAccountPrivilege</literal> privilege to the user account.
491 <indexterm><primary>administrator account</primary></indexterm>
492 <indexterm><primary>/etc/passwd</primary></indexterm>
493 For security reasons, the password for this administrator account should be set
494 to a password that is other than that used for the root user in <filename>/etc/passwd</filename>.
498 <indexterm><primary>account</primary></indexterm>
499 <indexterm><primary>create domain member</primary></indexterm>
500 <indexterm><primary>root</primary></indexterm>
501 <indexterm><primary>map</primary></indexterm>
502 The name of the account that is used to create domain member machine trust accounts can be
503 anything the network administrator may choose. If it is other than <constant>root</constant>,
504 then this is easily mapped to <constant>root</constant> in the file named in the &smb.conf; parameter
505 <smbconfoption name="username map">/etc/samba/smbusers</smbconfoption>.
509 <indexterm><primary>administrator account</primary></indexterm>
510 <indexterm><primary>encryption key</primary></indexterm>
511 <indexterm><primary>machine trust account</primary></indexterm>
512 The session key of the Samba administrator account acts as an encryption key for setting the password of the machine trust
513 account. The Machine Trust Account will be created on-the-fly, or updated if it already exists.
518 <title>Windows NT4 Client</title>
521 <indexterm><primary>Machine Trust Account</primary></indexterm>
522 <indexterm><primary>Create a Computer Account</primary></indexterm>
523 <indexterm><primary>join the machine</primary></indexterm>
524 If the Machine Trust Account was created manually, on the
525 Identification Changes menu enter the domain name, but do not
526 check the box <guilabel>Create a Computer Account in the Domain</guilabel>.
527 In this case, the existing Machine Trust Account is used to join the machine
532 <indexterm><primary>Machine Trust Account</primary></indexterm>
533 <indexterm><primary>on the fly</primary></indexterm>
534 <indexterm><primary>Computer Account</primary></indexterm>
535 <indexterm><primary>administrator account</primary></indexterm>
536 If the Machine Trust Account is to be created on the fly, on the Identification Changes menu enter the domain
537 name and check the box <guilabel>Create a Computer Account in the Domain</guilabel>. In this case, joining
538 the domain proceeds as above for Windows 2000 (i.e., you must supply a Samba administrator account when
544 <title>Samba Client</title>
547 <indexterm><primary></primary></indexterm>
548 Joining a Samba client to a domain is documented in <link linkend="domain-member-server">the next section</link>.
555 <sect1 id="domain-member-server">
556 <title>Domain Member Server</title>
559 <indexterm><primary>domain security</primary></indexterm>
560 <indexterm><primary>security context</primary></indexterm>
561 <indexterm><primary>authentication regime</primary></indexterm>
562 <indexterm><primary>ADS</primary></indexterm>
563 This mode of server operation involves the Samba machine being made a member
564 of a domain security context. This means by definition that all user
565 authentication will be done from a centrally defined authentication regime.
566 The authentication regime may come from an NT3/4-style (old domain technology)
567 server, or it may be provided from an Active Directory server (ADS) running on
568 MS Windows 2000 or later.
573 <indexterm><primary>authentication</primary><secondary>backend</secondary></indexterm>
574 <indexterm><primary>distributed directory</primary></indexterm>
575 <indexterm><primary>LDAP</primary></indexterm>
576 <indexterm><primary>OpenLDAP</primary></indexterm>
577 <indexterm><primary>iPlanet</primary></indexterm>
578 <indexterm><primary>Sun</primary></indexterm>
579 <indexterm><primary>Novell</primary></indexterm>
580 <indexterm><primary>e-Directory</primary></indexterm>
581 Of course it should be clear that the authentication backend itself could be
582 from any distributed directory architecture server that is supported by Samba.
583 This can be LDAP (from OpenLDAP), or Sun's iPlanet, or Novell e-Directory
589 <indexterm><primary>LDAP</primary></indexterm>
590 <indexterm><primary>identity management</primary></indexterm>
591 <indexterm><primary>machine authentication</primary></indexterm>
592 When Samba is configured to use an LDAP or other identity management and/or
593 directory service, it is Samba that continues to perform user and machine
594 authentication. It should be noted that the LDAP server does not perform
595 authentication handling in place of what Samba is designed to do.
599 <indexterm><primary>create a domain machine account</primary></indexterm>
600 <indexterm><primary>domain member server</primary></indexterm>
601 <indexterm><primary>join the domain</primary></indexterm>
602 Please refer to <link linkend="samba-pdc">Domain Control</link>, for more information regarding
603 how to create a domain machine account for a domain member server as well as for
604 information on how to enable the Samba domain member machine to join the domain
605 and be fully trusted by it.
609 <title>Joining an NT4-type Domain with Samba-3</title>
611 <para><link linkend="assumptions">Assumptions</link> lists names that are used in the remainder of this chapter.</para>
613 <table frame="all" id="assumptions"><title>Assumptions</title>
615 <colspec align="right"/>
616 <colspec align="left"/>
619 <entry>Samba DMS NetBIOS name:</entry><entry>SERV1</entry>
622 <entry>Windows 200x/NT domain name:</entry><entry>&example.workgroup;</entry>
625 <entry>Domain's PDC NetBIOS name:</entry><entry>DOMPDC</entry>
628 <entry>Domain's BDC NetBIOS names:</entry><entry>DOMBDC1 and DOMBDC2</entry>
635 <indexterm><primary></primary></indexterm>
636 First, you must edit your &smb.conf; file to tell Samba it should now use domain security.
640 <indexterm><primary>security = user</primary></indexterm>
641 <indexterm><primary>standalone server</primary></indexterm>
642 <indexterm><primary>domain member server</primary></indexterm>
643 <indexterm><primary>domain security</primary></indexterm>
644 Change (or add) your <smbconfoption name="security"/> line in the [global] section
645 of your &smb.conf; to read:
647 <smbconfoption name="security">domain</smbconfoption>
649 Note that if the parameter <parameter>security = user</parameter> is used, this machine would function as a
650 standalone server and not as a domain member server. Domain security mode causes Samba to work within the
651 domain security context.
655 Next change the <smbconfoption name="workgroup"/> line in the <smbconfsection name="[global]"/>
658 <smbconfoption name="workgroup">&example.workgroup;</smbconfoption>
660 This is the name of the domain we are joining.
664 <indexterm><primary>authenticate</primary></indexterm>
665 <indexterm><primary>PDC</primary></indexterm>
666 You must also have the parameter <smbconfoption name="encrypt passwords"/>
667 set to <constant>yes</constant> in order for your users to authenticate to the NT PDC.
668 This is the default setting if this parameter is not specified. There is no need to specify this
669 parameter, but if it is specified in the &smb.conf; file, it must be set to <constant>Yes</constant>.
673 <indexterm><primary>PDC</primary></indexterm>
674 <indexterm><primary>BDC</primary></indexterm>
675 <indexterm><primary>authenticate users</primary></indexterm>
676 <indexterm><primary>domain controllers</primary></indexterm>
677 Finally, add (or modify) a <smbconfoption name="password server"/> line in the [global]
680 <smbconfoption name="password server">DOMPDC DOMBDC1 DOMBDC2</smbconfoption>
682 These are the PDC and BDCs Samba
683 will attempt to contact in order to authenticate users. Samba will
684 try to contact each of these servers in order, so you may want to
685 rearrange this list in order to spread out the authentication load
686 among Domain Controllers.
690 <indexterm><primary>list of domain controllers</primary></indexterm>
691 <indexterm><primary>mechanism</primary></indexterm>
692 <indexterm><primary>broadcast-based name resolution</primary></indexterm>
693 <indexterm><primary>DNS name resolution</primary></indexterm>
694 Alternatively, if you want smbd to determine automatically the list of domain controllers to use for
695 authentication, you may set this line to be:
697 <smbconfoption name="password server">*</smbconfoption>
699 <indexterm><primary>WINS</primary></indexterm>
700 This method allows Samba to use exactly the same mechanism that NT does. The
701 method either uses broadcast-based name resolution, performs a WINS database
702 lookup in order to find a domain controller against which to authenticate,
703 or locates the domain controller using DNS name resolution.
707 To join the domain, run this command:
708 <indexterm><primary>net</primary><secondary>rpc</secondary><tertiary>join</tertiary></indexterm>
710 &rootprompt;<userinput>net rpc join -S DOMPDC -U<replaceable>Administrator%password</replaceable></userinput>
715 <indexterm><primary>NetBIOS name</primary></indexterm>
716 <indexterm><primary>PDC</primary></indexterm>
717 <indexterm><primary>WINS lookup</primary></indexterm>
718 <indexterm><primary>NetBIOS broadcast</primary></indexterm>
719 If the <option>-S DOMPDC</option> argument is not given, the domain name will be obtained from &smb.conf; and
720 the NetBIOS name of the PDC will be obtained either using a WINS lookup or via NetBIOS broadcast based name
725 <indexterm><primary>joining the domain</primary></indexterm>
726 <indexterm><primary>PDC</primary></indexterm>
727 <indexterm><primary>Administrator%password</primary></indexterm>
728 <indexterm><primary>Joined domain</primary></indexterm>
729 The machine is joining the domain DOM, and the PDC for that domain (the only machine
730 that has write access to the domain SAM database) is DOMPDC; therefore, use the <option>-S</option>
731 option. The <replaceable>Administrator%password</replaceable> is the login name and
732 password for an account that has the necessary privilege to add machines to the
733 domain. If this is successful, you will see the following message in your terminal window.
734 Where the older NT4-style domain architecture is used:
736 <computeroutput>Joined domain DOM.</computeroutput>
741 <indexterm><primary>net</primary><secondary>ads</secondary><tertiary>join</tertiary></indexterm>
742 <indexterm><primary>ADS</primary></indexterm>
743 <indexterm><primary>join the ADS domain</primary></indexterm>
744 Where Active Directory is used, the command used to join the ADS domain is:
746 &rootprompt; net ads join -U<replaceable>Administrator%password</replaceable>
748 And the following output is indicative of a successful outcome:
750 <computeroutput>Joined SERV1 to realm MYREALM.</computeroutput>
755 Refer to the <command>net</command> man page and to <link linkend="NetCommand">the chapter on remote
756 administration</link> for further information.
760 <indexterm><primary>join the domain</primary></indexterm>
761 <indexterm><primary>create machine trust account</primary></indexterm>
762 <indexterm><primary>PDC</primary></indexterm>
763 This process joins the server to the domain without separately having to create the machine
764 trust account on the PDC beforehand.
768 <indexterm><primary>machine account password</primary><secondary>change protocol</secondary></indexterm>
769 <indexterm><primary>random machine account password</primary></indexterm>
770 <indexterm><primary>/usr/local/samba/private/secrets.tdb</primary></indexterm>
771 <indexterm><primary>/etc/samba/secrets.tdb</primary></indexterm>
772 This command goes through the machine account password change protocol, then writes the new (random) machine
773 account password for this Samba server into a file in the same directory in which a smbpasswd file would be
774 normally stored. The trust account information that is needed by the DMS is written into the file
775 <filename>/usr/local/samba/private/secrets.tdb</filename> or <filename>/etc/samba/secrets.tdb</filename>.
779 <indexterm><primary>domain-level security</primary></indexterm>
780 <indexterm><primary>shadow password file</primary></indexterm>
781 This file is created and owned by root and is not readable by any other user. It is
782 the key to the domain-level security for your system and should be treated as carefully
783 as a shadow password file.
787 <indexterm><primary>Samba daemons</primary></indexterm>
788 <indexterm><primary>distribution</primary></indexterm>
789 <indexterm><primary>/etc/init.d/samba</primary></indexterm>
790 Finally, restart your Samba daemons and get ready for clients to begin using domain
791 security. The way you can restart your Samba daemons depends on your distribution,
792 but in most cases the following will suffice:
794 &rootprompt;/etc/init.d/samba restart
802 <sect1 id="ads-member">
803 <title>Samba ADS Domain Membership</title>
806 <indexterm significance="preferred"><primary>Active Directory</primary></indexterm>
807 <indexterm significance="preferred"><primary>ADS</primary><see>Active Directory</see></indexterm>
808 <indexterm><primary>KDC</primary></indexterm>
809 <indexterm><primary>Kerberos</primary></indexterm>
810 This is a rough guide to setting up Samba-3 with Kerberos authentication against a
811 Windows 200x KDC. A familiarity with Kerberos is assumed.
815 <title>Configure &smb.conf;</title>
818 You must use at least the following three options in &smb.conf;:
822 <smbconfoption name="realm">your.kerberos.REALM</smbconfoption>
823 <smbconfoption name="security">ADS</smbconfoption>
824 <smbconfcomment>The following parameter need only be specified if present.</smbconfcomment>
825 <smbconfcomment>The default setting if not present is Yes.</smbconfcomment>
826 <smbconfoption name="encrypt passwords">yes</smbconfoption>
830 <indexterm><primary>ADS</primary></indexterm>
831 <indexterm><primary>realm</primary></indexterm>
832 <indexterm><primary>DNS</primary></indexterm>
833 <indexterm><primary>ADS DC</primary></indexterm>
834 <indexterm><primary>password server</primary></indexterm>
835 In case samba cannot correctly identify the appropriate ADS server using the realm name, use the
836 <smbconfoption name="password server"/> option in &smb.conf;:
838 <smbconfoption name="password server">your.kerberos.server</smbconfoption>
840 The most common reason for which Samba may not be able to locate the ADS domain controller is a consequence of
841 sites maintaining some DNS servers on UNIX systems without regard for the DNS requirements of the ADS
842 infrastructure. There is no harm in specifying a preferred ADS domain controller using the <parameter>password
847 <indexterm><primary>smbpasswd</primary></indexterm>
848 <indexterm><primary>authenticated</primary></indexterm>
849 You do <emphasis>not</emphasis> need an smbpasswd file, and older clients will be authenticated as
850 if <smbconfoption name="security">domain</smbconfoption>, although it will not do any harm and
851 allows you to have local users not in the domain.
857 <title>Configure <filename>/etc/krb5.conf</filename></title>
860 <indexterm><primary>/etc/krb5.conf</primary></indexterm>
861 <indexterm><primary>Kerberos</primary><secondary>/etc/krb5.conf</secondary></indexterm>
862 <indexterm><primary>MIT</primary></indexterm>
863 <indexterm><primary>Heimdal</primary></indexterm>
864 With both MIT and Heimdal Kerberos, it is unnecessary to configure the <filename>/etc/krb5.conf</filename>,
865 and it may be detrimental.
869 <indexterm><primary>ADS</primary></indexterm>
870 <indexterm><primary>SRV records</primary></indexterm>
871 <indexterm><primary>DNS zon</primary></indexterm>
872 <indexterm><primary>KDC</primary></indexterm>
873 <indexterm><primary>_kerberos.REALM.NAME</primary></indexterm>
874 Microsoft ADS automatically create SRV records in the DNS zone
875 <parameter>_kerberos._tcp.REALM.NAME</parameter> for each KDC in the realm. This is part
876 of the installation and configuration process used to create an Active Directory domain.
877 A KDC is a Kerberos Key Distribution Center and forms an integral part of the Microsoft
878 active directory infrastructure.
882 <indexterm><primary>kinit</primary></indexterm>
883 <indexterm><primary>DES-CBC-MD5</primary></indexterm>
884 <indexterm><primary>DES-CBC-CRC</primary></indexterm>
885 <indexterm><primary>encryption types</primary></indexterm>
886 <indexterm><primary>kerberos</primary></indexterm>
887 <indexterm><primary>Windows 2000</primary></indexterm>
888 UNIX systems can use kinit and the DES-CBC-MD5 or DES-CBC-CRC encryption types to authenticate to the Windows
889 2000 KDC. For further information regarding Windows 2000 ADS kerberos interoperability please refer to the
890 Microsoft Windows 2000 Kerberos <ulink
891 url="http://www.microsoft.com/windows2000/techinfo/planning/security/kerbsteps.asp">Interoperability</ulink>
892 guide. Another very useful document that may be referred to for general information regarding Kerberos
893 interoperability is <ulink url="http://www.ietf.org/rfc/rfc1510.txt?number=1510">RFC1510</ulink>. This RFC
894 explains much of the magic behind the operation of Kerberos.
898 <indexterm><primary>MIT</primary></indexterm>
899 <indexterm><primary>KRB5</primary></indexterm>
900 <indexterm><primary>SRV records</primary></indexterm>
901 <indexterm><primary>krb5.conf</primary></indexterm>
902 <indexterm><primary>DNS lookup</primary></indexterm>
903 <indexterm><primary>libraries</primary></indexterm>
904 MIT's, as well as Heimdal's, recent KRB5 libraries default to checking for SRV records, so they will
905 automatically find the KDCs. In addition, <filename>krb5.conf</filename> only allows specifying
906 a single KDC, even there if there may be more than one. Using the DNS lookup allows the KRB5
907 libraries to use whichever KDCs are available.
911 <indexterm><primary>krb5.conf</primary></indexterm>
912 When manually configuring <filename>krb5.conf</filename>, the minimal configuration is:
915 default_realm = YOUR.KERBEROS.REALM
916 dns_lookup_kdc = true
919 .kerberos.server = YOUR.KERBEROS.REALM
924 If you must specify the KDC directly, the minimal configuration is:
927 default_realm = YOUR.KERBEROS.REALM
930 YOUR.KERBEROS.REALM = {
931 kdc = your.kerberos.server
935 .kerberos.server = YOUR.KERBEROS.REALM
940 <indexterm><primary>KDC</primary></indexterm>
941 <indexterm><primary>kinit</primary></indexterm>
942 Test your config by doing a <userinput>kinit
943 <replaceable>USERNAME</replaceable>@<replaceable>REALM</replaceable></userinput> and
944 making sure that your password is accepted by the Win2000 KDC.
948 <indexterm><primary>realm</primary></indexterm>
949 <indexterm><primary>uppercase</primary></indexterm>
950 <indexterm><primary>KDC</primary></indexterm>
951 The realm must be in uppercase or you will get a <quote><errorname>Cannot find KDC for
952 requested realm while getting initial credentials</errorname></quote> error (Kerberos
957 <indexterm><primary>synchronize</primary></indexterm>
958 <indexterm><primary>credentials</primary></indexterm>
959 <indexterm><primary>time difference</primary></indexterm>
960 <indexterm><primary>clock skew</primary></indexterm>
961 Time between the two servers must be synchronized. You will get a <quote><errorname>kinit(v5): Clock skew too
962 great while getting initial credentials</errorname></quote> if the time difference (clock skew) is more than five minutes.
966 <indexterm><primary>clock skew</primary></indexterm>
967 <indexterm><primary>Kerberos</primary></indexterm>
968 Clock skew limits are configurable in the Kerberos protocols. The default setting is five minutes.
972 <indexterm><primary>Kerberos</primary></indexterm>
973 <indexterm><primary>Create the Computer Account</primary></indexterm>
974 <indexterm><primary>Testing Server Setup</primary></indexterm>
975 <indexterm><primary></primary></indexterm>
976 If all you want is Kerberos support in &smbclient;, then you can skip directly to <link
977 linkend="ads-test-smbclient">Testing with &smbclient;</link> now. <link
978 linkend="ads-create-machine-account">Create the Computer Account</link> and <link
979 linkend="ads-test-server">Testing Server Setup</link> are needed only if you want Kerberos support for &smbd;
985 <sect2 id="ads-create-machine-account">
986 <title>Create the Computer Account</title>
989 <indexterm><primary>write permission</primary></indexterm>
990 <indexterm><primary>Samba private directory</primary></indexterm>
991 <indexterm><primary>Administrator account</primary></indexterm>
992 <indexterm><primary>ADS</primary></indexterm>
993 As a user who has write permission on the Samba private directory (usually root), run:
995 &rootprompt; <userinput>net ads join -U Administrator%password</userinput>
997 The Administrator account can be any account that has been designated in the ADS domain security settings with
998 permission to add machines to the ADS domain. It is, of course, a good idea to use an account other than Administrator.
999 On the UNIX/Linux system, this command must be executed by an account that has UID=0 (root).
1003 <indexterm><primary>ADS</primary></indexterm>
1004 <indexterm><primary>machine trust account</primary></indexterm>
1005 <indexterm><primary>organizational unit</primary></indexterm>
1006 <indexterm><primary>ADS manager</primary></indexterm>
1007 <indexterm><primary>kinit</primary></indexterm>
1008 <indexterm><primary>net</primary><secondary>ads</secondary><tertiary>join</tertiary></indexterm>
1009 When making a Windows client a member of an ADS domain within a complex organization, you
1010 may want to create the machine trust account within a particular organizational unit. Samba-3 permits
1011 this to be done using the following syntax:
1013 &rootprompt; <userinput>kinit Administrator@your.kerberos.REALM</userinput>
1014 &rootprompt; <userinput>net ads join createcomputer="organizational_unit"</userinput>
1016 Your ADS manager will be able to advise what should be specified for the "organizational_unit" parameter.
1020 <indexterm><primary>organizational directory</primary></indexterm>
1021 <indexterm><primary>machine trust account</primary></indexterm>
1022 <indexterm><primary>container</primary></indexterm>
1023 <indexterm><primary>ADS</primary></indexterm>
1024 For example, you may want to create the machine trust account in a container called <quote>Servers</quote>
1025 under the organizational directory <quote>Computers/BusinessUnit/Department,</quote> like this:
1027 &rootprompt; <userinput>net ads join "Computers/BusinessUnit/Department/Servers"</userinput>
1029 This command will place the Samba server machine trust account in the container
1030 <literal>Computers/BusinessUnit/Department/Servers</literal>. The container should exist in the ADS directory
1031 before executing this command. Please note that forward slashes must be used, because backslashes are both
1032 valid characters in an OU name and used as escapes for other characters. If you need a backslash in an OU
1033 name, it may need to be quadrupled to pass through the shell escape and ldap escape.
1037 <title>Possible Errors</title>
1041 <varlistentry><term><errorname>ADS support not compiled in</errorname></term>
1043 <indexterm><primary>config.cache</primary></indexterm>
1044 <indexterm><primary>Kerberos</primary></indexterm>
1045 <indexterm><primary>headers files</primary></indexterm>
1046 Samba must be reconfigured (remove config.cache) and recompiled (make clean all install) after the
1047 Kerberos libraries and headers files are installed.
1048 </para></listitem></varlistentry>
1050 <varlistentry><term><errorname>net ads join prompts for user name</errorname></term>
1052 <indexterm><primary>kinit</primary></indexterm>
1053 <indexterm><primary>rights</primary></indexterm>
1054 You need to login to the domain using <userinput>kinit
1055 <replaceable>USERNAME</replaceable>@<replaceable>REALM</replaceable></userinput>.
1056 <replaceable>USERNAME</replaceable> must be a user who has rights to add a machine to the domain.
1057 </para></listitem></varlistentry>
1065 <sect2 id="ads-test-server">
1066 <title>Testing Server Setup</title>
1069 <indexterm><primary>successful join</primary></indexterm>
1070 <indexterm><primary>computer account</primary></indexterm>
1071 <indexterm><primary>ADS</primary></indexterm>
1072 If the join was successful, you will see a new computer account with the
1073 NetBIOS name of your Samba server in Active Directory (in the <quote>Computers</quote>
1074 folder under Users and Computers.
1078 <indexterm><primary>Windows 2000</primary></indexterm>
1079 <indexterm><primary>net</primary><secondary>use</secondary></indexterm>
1080 <indexterm><primary>DES-CBC-MD5</primary></indexterm>
1081 On a Windows 2000 client, try <userinput>net use * \\server\share</userinput>. It should be possible
1082 to login with Kerberos without needing to know a password. If this fails, then run
1083 <userinput>klist tickets</userinput>. Did you get a ticket for the server? Does it have
1084 an encryption type of DES-CBC-MD5?
1088 <indexterm><primary>DES-CBC-MD5</primary></indexterm>
1089 <indexterm><primary>ARCFOUR-HMAC-MD5</primary></indexterm>
1090 <indexterm><primary>encoding</primary></indexterm>
1091 Samba can use both DES-CBC-MD5 encryption as well as ARCFOUR-HMAC-MD5 encoding.
1096 <sect2 id="ads-test-smbclient">
1097 <title>Testing with &smbclient;</title>
1100 <indexterm><primary>smbclient</primary></indexterm>
1101 <indexterm><primary>Kerberos</primary></indexterm>
1102 <indexterm><primary>Kerberos authentication</primary></indexterm>
1103 On your Samba server try to login to a Windows 2000 server or your Samba
1104 server using &smbclient; and Kerberos. Use &smbclient; as usual, but
1105 specify the <option>-k</option> option to choose Kerberos authentication.
1111 <title>Notes</title>
1114 <indexterm><primary>administrator password</primary></indexterm>
1115 <indexterm><primary>change password</primary></indexterm>
1116 <indexterm><primary>encryption types</primary></indexterm>
1117 You must change the administrator password at least once after installing a domain controller,
1118 to create the right encryption types.
1122 <indexterm><primary>_kerberos._udp</primary></indexterm>
1123 <indexterm><primary>_ldap._tcp</primary></indexterm>
1124 <indexterm><primary>default DNS setup</primary></indexterm>
1125 Windows 200x does not seem to create the <parameter>_kerberos._udp</parameter> and
1126 <parameter>_ldap._tcp</parameter> in the default DNS setup. Perhaps this will be fixed later in service packs.
1133 <title>Sharing User ID Mappings between Samba Domain Members</title>
1136 <indexterm><primary>maps UNIX users and groups</primary></indexterm>
1137 <indexterm><primary>UID</primary></indexterm>
1138 <indexterm><primary>GID</primary></indexterm>
1139 <indexterm><primary>SID</primary></indexterm>
1140 Samba maps UNIX users and groups (identified by UIDs and GIDs) to Windows users and groups (identified by SIDs).
1141 These mappings are done by the <parameter>idmap</parameter> subsystem of Samba.
1145 <indexterm><primary>mappings</primary></indexterm>
1146 <indexterm><primary>CIFS</primary></indexterm>
1147 <indexterm><primary>NFS</primary></indexterm>
1148 In some cases it is useful to share these mappings between Samba domain members,
1149 so <emphasis>name->id</emphasis> mapping is identical on all machines.
1150 This may be needed in particular when sharing files over both CIFS and NFS.
1154 <indexterm><primary>LDAP</primary></indexterm>
1155 <indexterm><primary>ldap idmap suffix</primary></indexterm>
1156 To use the <emphasis>LDAP</emphasis> <parameter>ldap idmap suffix</parameter>, set:
1160 <smbconfoption name="ldap idmap suffix">ou=Idmap</smbconfoption>
1164 See the &smb.conf; man page entry for the <smbconfoption name="ldap idmap suffix"></smbconfoption>
1165 parameter for further information.
1169 <indexterm><primary>smbpasswd</primary></indexterm>
1170 <indexterm><primary>LDAP administrative password</primary></indexterm>
1171 <indexterm><primary>secrets.tdb</primary></indexterm>
1172 Do not forget to specify also the <smbconfoption name="ldap admin dn"/>
1173 and to make certain to set the LDAP administrative password into the <filename>secrets.tdb</filename> using:
1175 &rootprompt; smbpasswd -w ldap-admin-password
1177 In place of <literal>ldap-admin-password</literal>, substitute the LDAP administration password for your
1184 <title>Common Errors</title>
1187 <indexterm><primary>domain member</primary></indexterm>
1188 <indexterm><primary>machine trust accounts</primary></indexterm>
1189 In the process of adding/deleting/re-adding domain member machine trust accounts, there are
1190 many traps for the unwary player and many <quote>little</quote> things that can go wrong.
1191 It is particularly interesting how often subscribers on the Samba mailing list have concluded
1192 after repeated failed attempts to add a machine account that it is necessary to <quote>reinstall</quote>
1193 MS Windows on the machine. In truth, it is seldom necessary to reinstall because of this type
1194 of problem. The real solution is often quite simple, and with an understanding of how MS Windows
1195 networking functions, it is easy to overcome.
1199 <title>Cannot Add Machine Back to Domain</title>
1202 <indexterm><primary>machine trust account</primary></indexterm>
1203 <indexterm><primary>already exists</primary></indexterm>
1204 <quote>A Windows workstation was reinstalled. The original domain machine trust
1205 account was deleted and added immediately. The workstation will not join the domain if I use
1206 the same machine name. Attempts to add the machine fail with a message that the machine already
1207 exists on the network &smbmdash; I know it does not. Why is this failing?</quote>
1211 <indexterm><primary>NetBIOS name cache</primary></indexterm>
1212 <indexterm><primary>nbtstat</primary></indexterm>
1213 The original name is still in the NetBIOS name cache and must expire after machine account
1214 deletion before adding that same name as a domain member again. The best advice is to delete
1215 the old account and then add the machine with a new name. Alternately, the name cache can be flushed and
1216 reloaded with current data using the <command>nbtstat</command> command on the Windows client:
1218 &dosprompt; nbtstat -R
1225 <title>Adding Machine to Domain Fails</title>
1228 <indexterm><primary>PDC</primary></indexterm>
1229 <indexterm><primary>fails</primary></indexterm>
1230 <quote>Adding a Windows 200x or XP Professional machine to the Samba PDC Domain fails with a
1231 message that says, <errorname>"The machine could not be added at this time, there is a network problem.
1232 Please try again later."</errorname> Why?</quote>
1236 <indexterm><primary>check logs</primary></indexterm>
1237 You should check that there is an <smbconfoption name="add machine script"/> in your &smb.conf;
1238 file. If there is not, please add one that is appropriate for your OS platform. If a script
1239 has been defined, you will need to debug its operation. Increase the <smbconfoption name="log level"></smbconfoption>
1240 in the &smb.conf; file to level 10, then try to rejoin the domain. Check the logs to see which
1241 operation is failing.
1245 Possible causes include:
1250 <indexterm><primary>script</primary></indexterm>
1251 <indexterm><primary>path specified</primary></indexterm>
1252 The script does not actually exist, or could not be located in the path specified.
1256 <indexterm><primary>UNIX system account</primary></indexterm>
1257 <indexterm><primary>Samba SAM account</primary></indexterm>
1258 <emphasis>Corrective action:</emphasis> Fix it. Make sure when run manually
1259 that the script will add both the UNIX system account and the Samba SAM account.
1263 <indexterm><primary>UNIX system account</primary></indexterm>
1264 <indexterm><primary>/etc/passwd</primary></indexterm>
1265 The machine could not be added to the UNIX system accounts file <filename>/etc/passwd</filename>.
1269 <indexterm><primary>legal UNIX system account name</primary></indexterm>
1270 <indexterm><primary>uppercase</primary></indexterm>
1271 <emphasis>Corrective action:</emphasis> Check that the machine name is a legal UNIX
1272 system account name. If the UNIX utility <command>useradd</command> is called,
1273 then make sure that the machine name you are trying to add can be added using this
1274 tool. <command>Useradd</command> on some systems will not allow any uppercase characters
1275 nor will it allow spaces in the name.
1280 <indexterm><primary>backend database</primary></indexterm>
1281 <indexterm><primary>UNIX system account</primary></indexterm>
1282 <indexterm><primary>Samba backend database</primary></indexterm>
1283 The <smbconfoption name="add machine script"/> does not create the
1284 machine account in the Samba backend database; it is there only to create a UNIX system
1285 account to which the Samba backend database account can be mapped.