From d069dacb6e17866dd5d3862e1837a9cae008644f Mon Sep 17 00:00:00 2001 From: Jelmer Vernooij Date: Fri, 15 Aug 2003 18:26:34 +0000 Subject: Regenerate docs (This used to be commit dc33e94161e4fc1ca6bf66a321c708c89bb276e3) --- docs/htmldocs/samba-pdc.html | 510 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 510 insertions(+) create mode 100644 docs/htmldocs/samba-pdc.html (limited to 'docs/htmldocs/samba-pdc.html') diff --git a/docs/htmldocs/samba-pdc.html b/docs/htmldocs/samba-pdc.html new file mode 100644 index 0000000000..aab2d4207c --- /dev/null +++ b/docs/htmldocs/samba-pdc.html @@ -0,0 +1,510 @@ +Chapter 5. Domain Control

Chapter 5. Domain Control

John H. Terpstra

Samba Team

Gerald (Jerry) Carter

Samba Team

David Bannon

Samba Team

The Essence of Learning:  +There are many who approach MS Windows networking with incredible misconceptions. +That's OK, because it gives the rest of us plenty of opportunity to be of assistance. +Those who really want help would be well advised to become familiar with information +that is already available. +

+The reader is advised NOT to tackle this section without having first understood +and mastered some basics. MS Windows networking is not particularly forgiving of +misconfiguration. Users of MS Windows networking are likely to complain +of persistent niggles that may be caused by a broken network configuration. +To a great many people however, MS Windows networking starts with a domain controller +that in some magical way is expected to solve all ills. +

Figure 5.1. An Example Domain

An Example Domain

+From the Samba mailing list one can readily identify many common networking issues. +If you are not clear on the following subjects, then it will do much good to read the +sections of this HOWTO that deal with it. These are the most common causes of MS Windows +networking problems: +

  • Basic TCP/IP configuration

  • NetBIOS name resolution

  • Authentication configuration

  • User and Group configuration

  • Basic File and Directory Permission Control in UNIX/Linux

  • Understanding of how MS Windows clients interoperate in a network + environment

+Do not be put off; on the surface of it MS Windows networking seems so simple that anyone +can do it. In fact, it is not a good idea to set up an MS Windows network with +inadequate training and preparation. But let's get our first indelible principle out of the +way: It is perfectly OK to make mistakes! In the right place and at +the right time, mistakes are the essence of learning. It is very much +not ok to make mistakes that cause loss of productivity and impose an avoidable financial +burden on an organisation. +

+Where is the right place to make mistakes? Only out of harm's way! If you are going to +make mistakes, then please do this on a test network, away from users and in such a way as +to not inflict pain on others. Do your learning on a test network. +

Features and Benefits

+What is the key benefit of Microsoft Domain security? +

+In a word, Single Sign On, or SSO for short. To many, this is the holy +grail of MS Windows NT and beyond networking. SSO allows users in a well designed network +to log onto any workstation that is a member of the domain that their user account is in +(or in a domain that has an appropriate trust relationship with the domain they are visiting) +and they will be able to log onto the network and access resources (shares, files, and printers) +as if they are sitting at their home (personal) workstation. This is a feature of the Domain +security protocols. +

+The benefits of Domain security are available to those sites that deploy a Samba PDC. +A Domain provides a unique network security identifier (SID). Domain user and group security +identifiers are comprised of the network SID plus a relative identifier (RID) that is unique to +the account. User and Group SIDs (the network SID plus the RID) can be used to create Access Control +Lists (ACLs) attached to network resources to provide organizational access control. UNIX systems +know only of local security identifiers. +

Note

+Network clients of an MS Windows Domain security environment must be Domain members to be +able to gain access to the advanced features provided. Domain membership involves more than just +setting the workgroup name to the Domain name. It requires the creation of a Domain trust account +for the workstation (called a machine account). Please refer to the chapter on +setting up samba as a domain member for more information. +

+The following functionalities are new to the Samba-3 release: +

  • + Windows NT4 domain trusts +

  • + Adding users via the User Manager for Domains. This can be done on any MS Windows + client using the Nexus toolkit that is available from Microsoft's web site. + Samba-3 supports the use of the Microsoft Management Console for user management. +

  • + Introduces replaceable and multiple user account (authentication) + back ends. In the case where the back end is placed in an LDAP database, + Samba-3 confers the benefits of a back end that can be distributed, replicated, + and is highly scalable. +

  • + Implements full Unicode support. This simplifies cross locale internationalisation + support. It also opens up the use of protocols that Samba-2.2.x had but could not use due + to the need to fully support Unicode. +

+The following functionalities are NOT provided by Samba-3: +

  • + SAM replication with Windows NT4 Domain Controllers + (i.e. a Samba PDC and a Windows NT BDC or vice versa). This means samba + cannot operate as a BDC when the PDC is Microsoft-based or + replicate account data to Windows-BDC's. +

  • + Acting as a Windows 2000 Domain Controller (i.e. Kerberos and + Active Directory) - In point of fact, Samba-3 DOES have some + Active Directory Domain Control ability that is at this time + purely experimental AND that is certain + to change as it becomes a fully supported feature some time + during the Samba-3 (or later) life cycle. However, Active Directory is + more then just SMB - it's also LDAP, Kerberos, DHCP and other protocols + (with proprietary extensions, of course). +

+Windows 9x / Me / XP Home clients are not true members of a domain for reasons outlined +in this chapter. The protocol for support of Windows 9x / Me style network (domain) logons +is completely different from NT4 / Win2k type domain logons and has been officially supported +for some time. These clients use the old LanMan Network Logon facilities that are supported +in Samba since approximately the Samba-1.9.15 series. +

+Samba-3 has an implementation of group mapping between Windows NT groups +and UNIX groups (this is really quite complicated to explain in a short space). This is +discussed more fully in the chapter on group mapping. +

+Samba-3, like an MS Windows NT4 PDC or a Windows 200x Active Directory, needs to store +user and machine trust account information in a suitable backend data store. +Refer to the section on machine trust accounts. With Samba-3 there can be multiple +back-ends for this. A complete discussion of account database backends can be found in +the chapter on Account Information Databases. +

Basics of Domain Control

+Over the years, public perceptions of what Domain Control really is has taken on an +almost mystical nature. Before we branch into a brief overview of Domain Control, +there are three basic types of domain controllers: +

Domain Controller Types

  • Primary Domain Controller

  • Backup Domain Controller

  • ADS Domain Controller

+The Primary Domain Controller or PDC plays an important role in the MS +Windows NT4. In Windows 200x Domain Control architecture this role is held by domain controllers. +There is folk lore that dictates that because of it's role in the MS Windows +network, the domain controllers should be the most powerful and most capable machine in the network. +As strange as it may seem to say this here, good over all network performance dictates that +the entire infrastructure needs to be balanced. It is advisable to invest more in Stand-Alone +(or Domain Member) servers than in the domain controllers. +

+In the case of MS Windows NT4 style domains, it is the PDC that initiates a new Domain Control database. +This forms a part of the Windows registry called the SAM (Security Account Manager). It plays a key +part in NT4 type domain user authentication and in synchronisation of the domain authentication +database with Backup Domain Controllers. +

+With MS Windows 200x Server based Active Directory domains, one domain controller initiates a potential +hierarchy of domain controllers, each with their own area of delegated control. The master domain +controller has the ability to override any down-stream controller, but a down-line controller has +control only over it's down-line. With Samba-3 this functionality can be implemented using an +LDAP based user and machine account back end. +

+New to Samba-3 is the ability to use a back-end database that holds the same type of data as +the NT4 style SAM (Security Account Manager) database (one of the registry files). +[1] +

+The Backup Domain Controller or BDC plays a key role in servicing network +authentication requests. The BDC is biased to answer logon requests in preference to the PDC. +On a network segment that has a BDC and a PDC the BDC will be most likely to service network +logon requests. The PDC will answer network logon requests when the BDC is too busy (high load). +A BDC can be promoted to a PDC. If the PDC is on line at the time that a BDC is promoted to +PDC, the previous PDC is automatically demoted to a BDC. With Samba-3 this is NOT an automatic +operation; the PDC and BDC must be manually configured and changes need to be made likewise. +

+With MS Windows NT4, it is an install time decision what type of machine the server will be. +It is possible to change the promote a BDC to a PDC and vice versa only, but the only way +to convert a domain controller to a domain member server or a stand-alone server is to +reinstall it. The install time choices offered are: +

  • Primary Domain Controller - The one that seeds the domain SAM

  • Backup Domain Controller - One that obtains a copy of the domain SAM

  • Domain Member Server - One that has NO copy of the domain SAM, rather it obtains authentication from a Domain Controller for all access controls.

  • Stand-Alone Server - One that plays NO part is SAM synchronisation, has it's own authentication database and plays no role in Domain security.

+With MS Windows 2000 the configuration of domain control is done after the server has been +installed. Samba-3 is capable of acting fully as a native member of a Windows 200x server +Active Directory domain. +

+New to Samba-3 is the ability to function fully as an MS Windows NT4 style Domain Controller, +excluding the SAM replication components. However, please be aware that Samba-3 support the +MS Windows 200x domain control protocols also. +

+At this time any appearance that Samba-3 is capable of acting as an +Domain Controller in native ADS mode is limited and experimental in nature. +This functionality should not be used until the Samba-Team offers formal support for it. +At such a time, the documentation will be revised to duly reflect all configuration and +management requirements. Samba can act as a NT4-style DC in a Windows 2000/XP +environment. However, there are certain compromises: + +

  • No machine policy files

  • No Group Policy Objects

  • No synchronously executed AD logon scripts

  • Can't use ANY Active Directory management tools to manage users and machines

  • Registry changes tattoo the main registry, while with AD they do NOT. ie: Leave permanent changes in effect

  • Without AD you can not peprform the function of exporting specific applications to specific users or groups

+

Preparing for Domain Control

+There are two ways that MS Windows machines may interact with each other, with other servers, +and with Domain Controllers: Either as Stand-Alone systems, more commonly +called Workgroup members, or as full participants in a security system, +more commonly called Domain members. +

+It should be noted that Workgroup membership involve no special configuration +other than the machine being configured so that the network configuration has a commonly used name +for it's workgroup entry. It is not uncommon for the name WORKGROUP to be used for this. With this +mode of configuration there are NO machine trust accounts and any concept of membership as such +is limited to the fact that all machines appear in the network neighbourhood to be logically +grouped together. Again, just to be clear: workgroup mode does not involve any security machine +accounts. +

+Domain member machines have a machine account in the Domain accounts database. A special procedure +must be followed on each machine to affect Domain membership. This procedure, which can be done +only by the local machine Administrator account, will create the Domain machine account (if +if does not exist), and then initializes that account. When the client first logs onto the +Domain it triggers a machine password change. +

Note

+When running a Domain all MS Windows NT / 200x / XP Professional clients should be configured +as full Domain Members - IF A SECURE NETWORK IS WANTED. If the machine is NOT made a member of the +Domain, then it will operate like a workgroup (stand-alone) machine. Please refer to +the chapter on domain membership for information regarding HOW to make your MS Windows clients Domain members. +

+The following are necessary for configuring Samba-3 as an MS Windows NT4 style PDC for MS Windows +NT4 / 200x / XP clients. +

  • Configuration of basic TCP/IP and MS Windows Networking

  • Correct designation of the Server Role (security = user)

  • Consistent configuration of Name Resolution (See chapter on Network Browsing and on + Integrating Unix into Windows networks)

  • Domain logons for Windows NT4 / 200x / XP Professional clients

  • Configuration of Roaming Profiles or explicit configuration to force local profile usage

  • Configuration of Network/System Policies

  • Adding and managing domain user accounts

  • Configuring MS Windows client machines to become domain members

+The following provisions are required to serve MS Windows 9x / Me Clients: +

  • Configuration of basic TCP/IP and MS Windows Networking

  • Correct designation of the Server Role (security = user)

  • Network Logon Configuration (Since Windows 9x / XP Home are not technically domain + members, they do not really participate in the security aspects of Domain logons as such)

  • Roaming Profile Configuration

  • Configuration of System Policy handling

  • Installation of the Network driver "Client for MS Windows Networks" and configuration + to log onto the domain

  • Placing Windows 9x / Me clients in user level security - if it is desired to allow + all client share access to be controlled according to domain user / group identities.

  • Adding and managing domain user accounts

Note

+Roaming Profiles and System/Network policies are advanced network administration topics +that are covered in the Profile Management and +Policy Management chapters of this document. However, these are not +necessarily specific to a Samba PDC as much as they are related to Windows NT networking concepts. +

+A Domain Controller is an SMB/CIFS server that: +

  • + Registers and advertises itself as a Domain Controller (through NetBIOS broadcasts + as well as by way of name registrations either by Mailslot Broadcasts over UDP broadcast, + to a WINS server over UDP unicast, or via DNS and Active Directory) +

  • + Provides the NETLOGON service (actually a collection of services that runs over + a number of protocols. These include the LanMan Logon service, the Netlogon service, + the Local Security Account service, and variations of them) +

  • + Provides a share called NETLOGON +

+For Samba to provide these is rather easy to configure. Each Samba Domain Controller must provide +the NETLOGON service which Samba calls the domain logons functionality +(after the name of the parameter in the smb.conf file). Additionally, one (1) server in a Samba-3 +Domain must advertise itself as the domain master browser[2]. This causes the Primary Domain Controller +to claim domain specific NetBIOS name that identifies it as a domain master browser for its given +domain/workgroup. Local master browsers in the same domain/workgroup on broadcast-isolated subnets +then ask for a complete copy of the browse list for the whole wide area network. Browser clients +will then contact their local master browser, and will receive the domain-wide browse list, +instead of just the list for their broadcast-isolated subnet. +

Domain Control - Example Configuration

+The first step in creating a working Samba PDC is to understand the parameters necessary +in smb.conf. An example smb.conf for acting as a PDC can be found in the example +for being a PDC. +

+

Example 5.1. smb.conf for being a PDC

[global]
netbios name = BELERIAND
workgroup = MIDEARTH
passdb backend = ldapsam, guest
os level = 33
preferred master = yes
domain master = yes
local master = yes
security = user
encrypt passwords = yes
domain logons = yes
logon path = \\%N\profiles\%u
logon drive = H:
logon home = \\homeserver\%u\winprofile
logon script = logon.cmd
[netlogon]
path = /var/lib/samba/netlogon
read only = yes
write list = ntadmin
[profiles]
path = /var/lib/samba/profiles
read only = no
create mask = 0600
directory mask = 0700

+

+The basic options shown above are explained as follows: +

passdb backend

+ This contains all the user and group account information. Acceptable values for a PDC + are: smbpasswd, tdbsam, ldapsam. The 'guest' entry provides needed + default accounts.

+ Where is is intended to use backup domain controllers (BDCs) the only logical choice is + to use LDAP so that the passdb backend can be distributed. The tdbsam and smbpasswd files + can not effectively be distributed and therefore should not be used. +

Domain Control Parameters

+ The parameters os level, preferred master, domain master, security, + encrypt passwords, domain logons play a central role in assuring domain + control and network logon support.

+ The os level must be set at or above a value of 32. A domain controller + must be the domain master browser, must be set in user mode security, + must support Microsoft compatible encrypted passwords, and must provide the network logon + service (domain logons). Encrypted passwords must be enabled, for more details on how + to do this, refer to the chapter on account information databases. +

Environment Parameters

+ The parameters logon path, logon home, logon drive, logon script are + environment support settings that help to facilitate client logon operations and that help + to provide automated control facilities to ease network management overheads. Please refer + to the man page information for these parameters. +

NETLOGON Share

+ The NETLOGON share plays a central role in domain logon and domain membership support. + This share is provided on all Microsoft domain controllers. It is used to provide logon + scripts, to store Group Policy files (NTConfig.POL), as well as to locate other common + tools that may be needed for logon processing. This is an essential share on a domain controller. +

PROFILE Share

+ This share is used to store user desktop profiles. Eash user must have a directory at the root + of this share. This directory must be write enabled for the user and must be globally read enabled. + Samba-3 has a VFS module called 'fake_permissions' that may be installed on this share. This will + allow a Samba administrator to make the directory read only to everyone. Of course this is useful + only after the profile has been properly created. +

Note

+The above parameters make for a full set of parameters that may define the server's mode +of operation. The following smb.conf parameters are the essentials alone: +

+

netbios name = BELERIAND
workgroup = MIDEARTH
domain logons = Yes
domain master = Yes
security = User

+

+The additional parameters shown in the longer listing above just makes for +more complete explanation. +

Samba ADS Domain Control

+Samba-3 is not, and can not act as, an Active Directory Server. It can not truly function as +an Active Directory Primary Domain Controller. The protocols for some of the functionality +the Active Directory Domain Controllers has been partially implemented on an experimental +only basis. Please do NOT expect Samba-3 to support these protocols. Do not depend +on any such functionality either now or in the future. The Samba-Team may remove these +experimental features or may change their behaviour. This is mentioned for the benefit of those +who have discovered secret capabilities in samba-3 and who have asked when this functionality will be +completed. The answer is: Maybe or maybe never! +

+To be sure: Samba-3 is designed to provide most of the functionality that Microsoft Windows NT4 style +domain controllers have. Samba-3 does NOT have all the capabilities of Windows NT4, but it does have +a number of features that Windows NT4 domain contollers do not have. In short, Samba-3 is not NT4 and it +is not Windows Server 200x and it is not an Active Directory server. We hope this is plain and simple +enough for all to understand. +

Domain and Network Logon Configuration

+The subject of Network or Domain Logons is discussed here because it forms +an integral part of the essential functionality that is provided by a Domain Controller. +

Domain Network Logon Service

+All Domain Controllers must run the netlogon service (domain logons +in Samba). One Domain Controller must be configured with domain master = Yes +(the Primary Domain Controller); on ALL Backup Domain Controllers domain master = No +must be set. +

Example Configuration

Example 5.2. smb.conf for being a PDC

[global]
domain logons = Yes
domain master = (Yes on PDC, No on BDCs)
[netlogon]
comment = Network Logon Service
path = /var/lib/samba/netlogon
guest ok = Yes
browseable = No

The Special Case of MS Windows XP Home Edition

Note

+MS Windows XP Home Edition does not have the ability to join any type of Domain +security facility. Unlike, MS Windows 9x / Me, MS Windows XP Home Edition also completely +lacks the ability to log onto a network. +

+To be completely clear: If you want MS Windows XP Home Edition to integrate with your +MS Windows NT4 or Active Directory Domain security understand - IT CAN NOT BE DONE. +Your only choice is to buy the upgrade pack from MS Windows XP Home Edition to +MS Windows XP Professional. +

+Now that this has been said, please do NOT ask the mailing list, or email any of the +Samba-Team members with your questions asking how to make this work. It can't be done. +If it can be done, then to do so would violate your software license agreement with +Microsoft, and we recommend that you do not do that. +

The Special Case of Windows 9x / Me

+A domain and a workgroup are exactly the same in terms of network +browsing. The difference is that a distributable authentication +database is associated with a domain, for secure login access to a +network. Also, different access rights can be granted to users if they +successfully authenticate against a domain logon server. Samba-3 does this +now in the same way that MS Windows NT/2K. +

+The SMB client logging on to a domain has an expectation that every other +server in the domain should accept the same authentication information. +Network browsing functionality of domains and workgroups is identical and +is explained in this documentation under the browsing discussions. +It should be noted, that browsing is totally orthogonal to logon support. +

+Issues related to the single-logon network model are discussed in this +section. Samba supports domain logons, network logon scripts, and user +profiles for MS Windows for workgroups and MS Windows 9X/ME clients +which are the focus of this section. +

+When an SMB client in a domain wishes to logon, it broadcasts requests for a +logon server. The first one to reply gets the job, and validates its +password using whatever mechanism the Samba administrator has installed. +It is possible (but ill advised ) to create a domain where the user +database is not shared between servers, i.e. they are effectively workgroup +servers advertising themselves as participating in a domain. This +demonstrates how authentication is quite different from but closely +involved with domains. +

+Using these features you can make your clients verify their logon via +the Samba server; make clients run a batch file when they logon to +the network and download their preferences, desktop and start menu. +

+MS Windows XP Home edition is NOT able to join a domain and does not permit +the use of domain logons. +

+Before launching into the configuration instructions, it is +worthwhile to look at how a Windows 9x/ME client performs a logon: +

  1. + The client broadcasts (to the IP broadcast address of the subnet it is in) + a NetLogon request. This is sent to the NetBIOS name DOMAIN<#1c> at the + NetBIOS layer. The client chooses the first response it receives, which + contains the NetBIOS name of the logon server to use in the format of + \\SERVER. +

  2. + The client then connects to that server, logs on (does an SMBsessetupX) and + then connects to the IPC$ share (using an SMBtconX). +

  3. + The client then does a NetWkstaUserLogon request, which retrieves the name + of the user's logon script. +

  4. + The client then connects to the NetLogon share and searches for said script + and if it is found and can be read, is retrieved and executed by the client. + After this, the client disconnects from the NetLogon share. +

  5. + The client then sends a NetUserGetInfo request to the server, to retrieve + the user's home share, which is used to search for profiles. Since the + response to the NetUserGetInfo request does not contain much more than + the user's home share, profiles for Win9X clients MUST reside in the user + home directory. +

  6. + The client then connects to the user's home share and searches for the + user's profile. As it turns out, you can specify the user's home share as + a sharename and path. For example, \\server\fred\.winprofile. + If the profiles are found, they are implemented. +

  7. + The client then disconnects from the user's home share, and reconnects to + the NetLogon share and looks for CONFIG.POL, the policies file. If this is + found, it is read and implemented. +

+The main difference between a PDC and a Windows 9x logon server configuration is that +

  • + Password encryption is not required for a Windows 9x logon server. But note + that beginning with MS Windows 98 the default setting is that plain-text + password support is disabled. It can be re-enabled with the registry + changes that are documented in the chapter on Policies. +

  • + Windows 9x/ME clients do not require and do not use machine trust accounts. +

+A Samba PDC will act as a Windows 9x logon server; after all, it does provide the +network logon services that MS Windows 9x / Me expect to find. +

Note

+Use of plain-text passwords is strongly discouraged. Where used they are easily detected +using a sniffer tool to examine network traffic. +

Security Mode and Master Browsers

+There are a few comments to make in order to tie up some +loose ends. There has been much debate over the issue of whether +or not it is ok to configure Samba as a Domain Controller in security +modes other than USER. The only security mode +which will not work due to technical reasons is SHARE +mode security. DOMAIN and SERVER +mode security are really just a variation on SMB user level security. +

+Actually, this issue is also closely tied to the debate on whether +or not Samba must be the domain master browser for its workgroup +when operating as a DC. While it may technically be possible +to configure a server as such (after all, browsing and domain logons +are two distinctly different functions), it is not a good idea to do +so. You should remember that the DC must register the DOMAIN<#1b> NetBIOS +name. This is the name used by Windows clients to locate the DC. +Windows clients do not distinguish between the DC and the DMB. +A DMB is a Domain Master Browser - see Domain Master Browser. +For this reason, it is very wise to configure the Samba DC as the DMB. +

+Now back to the issue of configuring a Samba DC to use a mode other +than security = user. If a Samba host is configured to use +another SMB server or DC in order to validate user connection +requests, then it is a fact that some other machine on the network +(the password server) knows more about the user than the Samba host. +99% of the time, this other host is a domain controller. Now +in order to operate in domain mode security, the workgroup parameter +must be set to the name of the Windows NT domain (which already +has a domain controller). If the domain does NOT already have a Domain Controller +then you do not yet have a Domain! +

+Configuring a Samba box as a DC for a domain that already by definition has a +PDC is asking for trouble. Therefore, you should always configure the Samba DC +to be the DMB for its domain and set security = user. +This is the only officially supported mode of operation. +

Common Errors

'$' cannot be included in machine name

+A 'machine account', (typically) stored in /etc/passwd, +takes the form of the machine name with a '$' appended. FreeBSD (and other BSD +systems?) won't create a user with a '$' in their name. +

+The problem is only in the program used to make the entry. Once made, it works perfectly. +Create a user without the '$'. Then use vipw to edit the entry, adding +the '$'. Or create the whole entry with vipw if you like; make sure you use a unique User ID! +

Note

+The UNIX tool vipw is a common tool for directly editting the /etc/passwd file. +

Joining domain fails because of existing machine account

I get told "You already have a connection to the Domain...." +or "Cannot join domain, the credentials supplied conflict with an +existing set.." when creating a machine trust account.

+This happens if you try to create a machine trust account from the +machine itself and already have a connection (e.g. mapped drive) +to a share (or IPC$) on the Samba PDC. The following command +will remove all network drive connections: +

+C:\> net use * /d
+

+Further, if the machine is already a 'member of a workgroup' that +is the same name as the domain you are joining (bad idea) you will +get this message. Change the workgroup name to something else, it +does not matter what, reboot, and try again. +

The system can not log you on (C000019B)....

I joined the domain successfully but after upgrading +to a newer version of the Samba code I get the message, The system +can not log you on (C000019B), Please try again or consult your +system administrator when attempting to logon.” +

+This occurs when the domain SID stored in the secrets.tdb database +is changed. The most common cause of a change in domain SID is when +the domain name and/or the server name (NetBIOS name) is changed. +The only way to correct the problem is to restore the original domain +SID or remove the domain client from the domain and rejoin. The domain +SID may be reset using either the net or rpcclient utilities. +

+The reset or change the domain SID you can use the net command as follows: + +

+root# net getlocalsid 'OLDNAME'
+root# net setlocalsid 'SID'
+

+

+Workstation machine trust accounts work only with the Domain (or network) SID. If this SID changes +then domain members (workstations) will not be able to log onto the domain. The original Domain SID +can be recovered from the secrets.tdb file. The alternative is to visit each workstation to re-join +it to the domain. +

The machine trust account not accessible

+ “When I try to join the domain I get the message The machine account +for this computer either does not exist or is not accessible. What's +wrong?” +

+This problem is caused by the PDC not having a suitable machine trust account. +If you are using the add machine script method to create +accounts then this would indicate that it has not worked. Ensure the domain +admin user system is working. +

+Alternatively if you are creating account entries manually then they +have not been created correctly. Make sure that you have the entry +correct for the machine trust account in smbpasswd file on the Samba PDC. +If you added the account using an editor rather than using the smbpasswd +utility, make sure that the account name is the machine NetBIOS name +with a '$' appended to it ( i.e. computer_name$ ). There must be an entry +in both /etc/passwd and the smbpasswd file. +

+Some people have also reported +that inconsistent subnet masks between the Samba server and the NT +client can cause this problem. Make sure that these are consistent +for both client and server. +

Account disabled

When I attempt to login to a Samba Domain from a NT4/W2K workstation, + I get a message about my account being disabled.

+Enable the user accounts with smbpasswd -e username +, this is normally done as an account is created. +

Domain Controller Unavailable

Until a few minutes after Samba has started, clients get the error "Domain Controller Unavailable"

+ A domain controller has to announce on the network who it is. This usually takes a while. +

Can not log onto domain member workstation after joining domain

After successfully joining the domain user logons fail with one of two messages:

One to the effect that the domain controller can not be found, the other claiming that the + account does not exist in the domain or that the password is incorrect.

This may be due to incompatible settings between + the Windows client and the Samba-3 server for schannel (secure channel) settings + or smb signing settings. Check your samba settings for + client schannel, server schannel, client signing, server signing by executing: + testparm -v | more and looking for the value of these parameters. +

+ Also use the Microsoft Management Console - Local Security Settings. This tool is available from the + Control Panel. The Policy settings are found in the Local Policies / Securty Options area and are prefixed by + Secure Channel: ..., and Digitally sign .... +

+ It is important that these be set consistently with the Samba-3 server settings. +

-- cgit