PC World Komputer 1998 July & August/Pcwk78a98.iso/Wtestowe/Clico/UNIX/SAMBA/SMB_SOL2.Z/SMB_SOL2/docs/DOMAIN.txt

Text File | 1997-08-27 | 16.8 KB | 366 lines

Contributor:    Samba Team
Updated:    August 25, 1997

Subject:    Network Logons and Roving Profiles
===========================================================================

A domain and a workgroup are exactly the same thing in terms of network
traffic, except for the client logon sequence. Some kind of distributed
authentication database is associated with a domain (there are quite a few
choices) and this adds so much flexibility that many people think of a
domain as a completely different entity to a workgroup. From Samba's
point of view a client connecting to a service presents an authentication
token, and it if it is valid they have access. Samba does not care what
mechanism was used to generate that token in the first place.

The SMB client logging on to a domain has an expectation that every other
server in the domain should accept the same authentication information.
However the network browsing functionality of domains and workgroups is
identical and is explained in BROWSING.txt.

There are some implementation differences: Windows 95 can be a member of
both a workgroup and a domain, but Windows NT cannot. Windows 95 also
has the concept of an "alternative workgroup". Samba can only be a
member of a single workgroup or domain, although this is due to change
with a future version when nmbd will be split into two daemons, one
for WINS and the other for browsing (NetBIOS.txt explains what WINS is.)

Issues related to the single-logon network model are discussed in this
document.  Samba supports domain logons, network logon scripts, and user
profiles.  The support is still experimental, but it seems to work.

The support is also not complete.  Samba does not yet support the sharing
of the Windows NT-style SAM database with other systems.  However this is
only one way of having a shared user database: exactly the same effect can
be achieved by having all servers in a domain share a distributed NIS,
Kerberos or other authentication database. These other options may or may
not involve changes to the client software, that depends on the combination
of client OS, server OS and authentication protocol.

When an SMB client in a domain wishes to logon it broadcast 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 very stupid) to create a domain where the user
database is not shared between servers, ie 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.

Another thing commonly associated with single-logon domains is remote
administration over the SMB protocol.  Again, there is no reason why this
cannot be implemented with an underlying username database which is
different from the Windows NT SAM.  Support for the Remote Administration
Protocol is planned for a future release of Samba.

The domain support works for WfWg, and Win95 clients.  Support for Windows
NT and OS/2 clients is still being worked on and is still experimental.
Support for profiles is confirmed as working for Win95, NT 4.0 and NT 3.51,
although NT Workstation requires manual configuration of user accounts with
NT's "User Manager for Domains", and no automatic profile location support
is available using samba, although it has been confirmed as possible to use
an NT server to specify that the location of profiles is on a samba server.

The help of an NT server can be enlisted, both for profile storage and
for user authentication.  For details on user authentication, see
security_level.txt.  For details on profile storage, see below.


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.


Configuration Instructions:    Network Logons
==========================================

To use domain logons and profiles you need to do the following:


1) Setup nmbd and smbd by configuring smb.conf so that Samba is
   acting as the master browser. See <your OS>_INSTALL.txt and BROWSING.txt
   for details.

2) Setup a WINS server (see NetBIOS.txt) and configure all your clients
   to use that WINS service.  [lkcl 12jul97 - problems occur where
   clients do not pick up the profiles properly unless they are using a
   WINS server.  this is still under investigation].

3) Create a share called [netlogon] in your smb.conf. This share should
   be readable by all users, and probably should not be writeable. This
   share will hold your network logon scripts, and the CONFIG.POL file
   (Note: for details on the CONFIG.POL file, how to use it, what it is,
   refer to the Microsoft Windows NT Administration documentation.
   The format of these files is not known, so you will need to use
   Microsoft tools).

For example I have used:

   [netlogon]
    path = /data/dos/netlogon
    writeable = no
    guest ok = no

Note that it is important that this share is not writeable by ordinary
users, in a secure environment: ordinary users should not be allowed
to modify or add files that another user's computer would then download
when they log in.

4) in the [global] section of smb.conf set the following:

   domain logons = yes
   logon script = %U.bat

The choice of batch file is, of course, up to you. The above would
give each user a separate batch file as the %U will be changed to
their username automatically. The other standard % macros may also be
used. You can make the batch files come from a subdirectory by using
something like:

   logon script = scripts\%U.bat

5) create the batch files to be run when the user logs in. If the batch
   file doesn't exist then no batch file will be run.

In the batch files you need to be careful to use DOS style cr/lf line
endings. If you don't then DOS may get confused. I suggest you use a
DOS editor to remotely edit the files if you don't know how to produce
DOS style files under unix.

6) Use smbclient with the -U option for some users to make sure that
   the \\server\NETLOGON share is available, the batch files are
   visible and they are readable by the users.

7) you will probabaly find that your clients automatically mount the
   \\SERVER\NETLOGON share as drive z: while logging in. You can put
   some useful programs there to execute from the batch files.

NOTE: You must be using "security = user" or "security = server" for
domain logons to work correctly.  Share level security won't work
correctly.



Configuration Instructions:    Setting up Roaming User Profiles
================================================================

In the [global] section of smb.conf set the following (for example):

  logon path = \\profileserver\profileshare\profilepath\%U\moreprofilepath

The default for this option is \\%L\%U, namely \\sambaserver\username,
The \\L%\%U services is created automatically by the [homes] service.

If you are using a samba server for the profiles, you _must_ make the
share specified in the logon path browseable.  Windows 95 appears to
check that it can see the share and any subdirectories within that share
specified by the logon path option, rather than just connecting straight
away.  It also attempts to create the components of the full path for
you.  If the creation of any component fails, or if it cannot see any
component of the path, the profile creation / reading fails.


Windows 95
----------

When a user first logs in on Windows 95, the file user.DAT is created,
as are folders "Start Menu", "Desktop", "Programs" and "Nethood".
These directories and their contents will be merged with the local
versions stored in c:\windows\profiles\username on subsequent logins,
taking the most recent from each.  You will need to use the [global]
options "preserve case = yes", "short case preserve = yes" and
"case sensitive = no" in order to maintain capital letters in shortcuts
in any of the profile folders.

The user.DAT file contains all the user's preferences.  If you wish to
enforce a set of preferences, rename their user.DAT file to user.MAN,
and deny them write access to this file.

2) On the Windows 95 machine, go to Control Panel | Passwords and
   select the User Profiles tab.  Select the required level of
   roaming preferences.  Press OK, but do _not_ allow the computer
   to reboot.

3) On the Windows 95 machine, go to Control Panel | Network |
   Client for Microsoft Networks | Preferences.  Select 'Log on to
   NT Domain'.  Then, ensure that the Primary Logon is 'Client for
   Microsoft Networks'.  Press OK, and this time allow the computer
   to reboot.

Under Windows 95, Profiles are downloaded from the Primary Logon.
If you have the Primary Logon as 'Client for Novell Networks', then
the profiles and logon script will be downloaded from your Novell
Server.  If you have the Primary Logon as 'Windows Logon', then the
profiles will be loaded from the local machine - a bit against the
concept of roaming profiles, if you ask me.

You will now find that the Microsoft Networks Login box contains
[user, password, domain] instead of just [user, password].  Type in
the samba server's domain name (or any other domain known to exist,
but bear in mind that the user will be authenticated against this
domain and profiles downloaded from it, if that domain logon server
supports it), user name and user's password.

Once the user has been successfully validated, the Windows 95 machine
will inform you that 'The user has not logged on before' and asks you
if you wish to save the user's preferences?  Select 'yes'.

Once the Windows 95 client comes up with the desktop, you should be able
to examine the contents of the directory specified in the "logon path"
on the samba server and verify that the "Desktop", "Start Menu",
"Programs" and "Nethood" folders have been created.

These folders will be cached locally on the client, and updated when
the user logs off (if you haven't made them read-only by then :-).
You will find that if the user creates further folders or short-cuts,
that the client will merge the profile contents downloaded with the
contents of the profile directory already on the local client, taking
the newest folders and short-cuts from each set.

If you have made the folders / files read-only on the samba server,
then you will get errors from the w95 machine on logon and logout, as
it attempts to merge the local and the remote profile.  Basically, if
you have any errors reported by the w95 machine, check the unix file
permissions and ownership rights on the profile directory contents,
on the samba server.


If you have problems creating user profiles, you can reset the user's
local desktop cache, as shown below.  When this user then next logs in,
they will be told that they are logging in "for the first time".


1) instead of logging in under the [user, password, domain] dialog],
   press escape.

2) run the regedit.exe program, and look in:

     HKEY_LOCAL_MACHINE\Windows\CurrentVersion\ProfileList

   you will find an entry, for each user, of ProfilePath.  Note the
   contents of this key (likely to be c:\windows\profiles\username),
   then delete the key ProfilePath for the required user.

   [Exit the registry editor].

3) WARNING - before deleting the contents of the directory listed in
   the ProfilePath (this is likely to be c:\windows\profiles\username),
   ask them if they have any important files stored on their desktop
   or in their start menu.  delete the contents of the directory
   ProfilePath (making a backup if any of the files are needed).

   This will have the effect of removing the local (read-only hidden
   system file) user.DAT in their profile directory, as well as the
   local "desktop", "nethood", "start menu" and "programs" folders.

4) search for the user's .PWL password-cacheing file in the c:\windows
   directory, and delete it.

5) log off the windows 95 client.

6) check the contents of the profile path (see "logon path" described
   above), and delete the user.DAT or user.MAN file for the user,
   making a backup if required.


If all else fails, increase samba's debug log levels to between 3 and 10,
and / or run a packet trace program such as tcpdump or netmon.exe, and
look for any error reports.

If you have access to an NT server, then first set up roaming profiles
and / or netlogons on the NT server.  Make a packet trace, or examine
the example packet traces provided with NT server, and see what the
differences are with the equivalent samba trace.


Windows NT Workstation 4.0
--------------------------

When a user first logs in to a Windows NT Workstation, the profile
NTuser.MAN is created.  The "User Manager for Domains" can be used
to specify the location of the profile.  Samba cannot be a domain
logon server for NT, therefore you will need to manually configure
each and every account.  [lkcl 10aug97 - i tried setting the path
in each account to \\samba-server\homes\profile, and discovered that
this fails for some reason.  you have to have \\samba-server\user\profile,
where user is the username created from the [homes] share].

The entry for the NT 4.0 profile is a _directory_ not a file.  The NT
help on profiles mentions that a directory is also created with a .PDS
extension.  The user, while logging in, must have write permission to
create the full profile path (and the folder with the .PDS extension)
[lkcl 10aug97 - i found that the creation of the .PDS directory failed,
and had to create these manually for each user, with a shell script.
also, i presume, but have not tested, that the full profile path must
be browseable just as it is for w95, due to the manner in which they
attempt to create the full profile path: test existence of each path
component; create path component].

In the profile directory, NT creates more folders than 95.  It creates
"Application Data" and others, as well as "Desktop", "Nethood",
"Start Menu" and "Programs".  The profile itself is stored in a file
NTuser.DAT.  Nothing appears to be stored in the .PDS directory, and
its purpose is currently unknown.

You can use the System Control Panel to copy a local profile onto
a samba server (see NT Help on profiles: it is also capable of firing
up the correct location in the System Control Panel for you).  The
NT Help file also mentions that renaming NTuser.DAT to NTuser.MAN
turns a profile into a mandatory one.

[lkcl 10aug97 - i notice that NT Workstation tells me that it is
downloading a profile from a slow link.  whether this is actually the
case, or whether there is some configuration issue, as yet unknown,
that makes NT Workstation _think_ that the link is a slow one is a
matter to be resolved].

[lkcl 20aug97 - after samba digest correspondance, one user found, and
another confirmed, that profiles cannot be loaded from a samba server
unless "security = user" and "encrypted passwords = yes" (see the file
ENCRYPTION.txt) or "security = server" and "password server = ip.address.
of.yourNTserver" are used.  either of these options will allow the NT
workstation to access the samba server using LAN manager encrypted
passwords, without the user intervention normally required by NT
workstation for clear-text passwords].

[lkcl 25aug97 - more comments received about NT profiles: the case of
the profile _matters_.  the file _must_ be called NTuser.DAT or, for
a mandatory profile, NTuser.MAN].


Windows NT Server
-----------------

Following the instructions for NT Workstation, there is nothing to stop
you specifying any path that you like for the location of users' profiles.
Therefore, you could specify that the profile be stored on a samba server,
or any other SMB server, as long as that SMB server supports encrypted
passwords.



Sharing Profiles between W95 and NT Workstation 4.0
---------------------------------------------------

The default logon path is \\%L\U%.  NT Workstation will attempt to create
a directory "\\samba-server\username.PDS" if you specify the logon path
as "\\samba-server\username" with the NT User Manager.  Therefore, you
will need to specify (for example) "\\samba-server\username\profile".
NT 4.0 will attempt to create "\\samba-server\username\profile.PDS", which
is more likely to succeed.

If you then want to share the same Start Menu / Desktop with W95, you will
need to specify "logon path = \\samba-server\username\profile" [lkcl 10aug97
this has its drawbacks: i created a shortcut to telnet.exe, which attempts
to run from the c:\winnt\system32 directory.  this directory is obviously
unlikely to exist on a W95 host].

If you have this set up correctly, you will find separate user.DAT and
NTuser.DAT files in the same profile directory.

[lkcl 25aug97 - there are some issues to resolve with downloading of
NT profiles, probably to do with time/date stamps.  i have found that
NTuser.DAT is never updated on the workstation after the first time that
it is copied to the local workstation profile directory.  this is in
contrast to w95, where it _does_ transfer / update profiles correctly].