winbindd - Name Service Switch daemon for resolving names from NT


   winbindd [-D|--daemon] [-F|--foreground] [-S|--stdout]
    [-i|--interactive] [-d <debug level>] [-s <smb config file>]
    [-n|--no-caching] [--no-process-group]


   This program is part of the samba(7) suite.

   winbindd is a daemon that provides a number of services to the Name
   Service Switch capability found in most modern C libraries, to
   arbitrary applications via PAM and ntlm_auth and to Samba itself.

   Even if winbind is not used for nsswitch, it still provides a service
   to smbd, ntlm_auth and the PAM module, by managing
   connections to domain controllers. In this configuration the idmap
   config * : range parameter is not required. (This is known as `netlogon
   proxy only mode'.)

   The Name Service Switch allows user and system information to be
   obtained from different databases services such as NIS or DNS. The
   exact behaviour can be configured through the /etc/nsswitch.conf file.
   Users and groups are allocated as they are resolved to a range of user
   and group ids specified by the administrator of the Samba system.

   The service provided by winbindd is called `winbind' and can be used to
   resolve user and group information from a Windows NT server. The
   service can also provide authentication services via an associated PAM

   The pam_winbind module supports the auth, account and password
   module-types. It should be noted that the account module simply
   performs a getpwnam() to verify that the system can obtain a uid for
   the user, as the domain controller has already performed access
   control. If the libnss_winbind library has been correctly installed, or
   an alternate source of names configured, this should always succeed.

   The following nsswitch databases are implemented by the winbindd

       This feature is only available on IRIX. User information
       traditionally stored in the hosts(5) file and used by
       gethostbyname(3) functions. Names are resolved through the WINS
       server or by broadcast.

       User information traditionally stored in the passwd(5) file and
       used by getpwent(3) functions.

       Group information traditionally stored in the group(5) file and
       used by getgrent(3) functions.

   For example, the following simple configuration in the
   /etc/nsswitch.conf file can be used to initially resolve user and group
   information from /etc/passwd and /etc/group and then from the Windows
   NT server.

       passwd:         files winbind
       group:          files winbind
       ## only available on IRIX: use winbind to resolve hosts:
       # hosts:        files dns winbind
       ## All other NSS enabled systems should use like this:
       hosts:          files dns wins

   The following simple configuration in the /etc/nsswitch.conf file can
   be used to initially resolve hostnames from /etc/hosts and then from
   the WINS server.

       hosts:         files wins


       If specified, this parameter causes the server to operate as a
       daemon. That is, it detaches itself and runs in the background on
       the appropriate port. This switch is assumed if winbindd is
       executed on the command line of a shell.

       If specified, this parameter causes the main winbindd process to
       not daemonize, i.e. double-fork and disassociate with the terminal.
       Child processes are still created as normal to service each
       connection request, but the main process does not exit. This
       operation mode is suitable for running winbindd under process
       supervisors such as supervise and svscan from Daniel J. Bernstein's
       daemontools package, or the AIX process monitor.

       If specified, this parameter causes winbindd to log to standard
       output rather than a file.

       level is an integer from 0 to 10. The default value if this
       parameter is not specified is 0.

       The higher this value, the more detail will be logged to the log
       files about the activities of the server. At level 0, only critical
       errors and serious warnings will be logged. Level 1 is a reasonable
       level for day-to-day running - it generates a small amount of
       information about operations carried out.

       Levels above 1 will generate considerable amounts of log data, and
       should only be used when investigating a problem. Levels above 3
       are designed for use only by developers and generate HUGE amounts
       of log data, most of which is extremely cryptic.

       Note that specifying this parameter here will override the log
       level parameter in the smb.conf file.

       Prints the program version number.

   -s|--configfile=<configuration file>
       The file specified contains the configuration details required by
       the server. The information in this file includes server-specific
       information such as what printcap file to use, as well as
       descriptions of all the services that the server is to provide. See
       smb.conf for more information. The default configuration file name
       is determined at compile time.

       Base directory name for log/debug files. The extension ".progname"
       will be appended (e.g. log.smbclient, log.smbd, etc...). The log
       file is never removed by the client.

       Set the smb.conf(5) option "<name>" to value "<value>" from the
       command line. This overrides compiled-in defaults and options read
       from the configuration file.

       Print a summary of command line options.

       Display brief usage message.

       Tells winbindd to not become a daemon and detach from the current
       terminal. This option is used by developers when interactive
       debugging of winbindd is required.  winbindd also logs to standard
       output, as if the -S parameter had been given.

       Disable some caching. This means winbindd will often have to wait
       for a response from the domain controller before it can respond to
       a client and this thus makes things slower. The results will
       however be more accurate, since results from the cache might not be
       up-to-date. This might also temporarily hang winbindd if the DC
       doesn't respond. This does not disable the samlogon cache, which is
       required for group membership tracking in trusted environments.

       Do not create a new process group for winbindd.


   Users and groups on a Windows NT server are assigned a security id
   (SID) which is globally unique when the user or group is created. To
   convert the Windows NT user or group into a unix user or group, a
   mapping between SIDs and unix user and group ids is required. This is
   one of the jobs that winbindd performs.

   As winbindd users and groups are resolved from a server, user and group
   ids are allocated from a specified range. This is done on a first come,
   first served basis, although all existing users and groups will be
   mapped as soon as a client performs a user or group enumeration
   command. The allocated unix ids are stored in a database and will be

   WARNING: The SID to unix id database is the only location where the
   user and group mappings are stored by winbindd. If this store is
   deleted or corrupted, there is no way for winbindd to determine which
   user and group ids correspond to Windows NT user and group rids.


   Configuration of the winbindd daemon is done through configuration
   parameters in the smb.conf(5) file. All parameters should be specified
   in the [global] section of smb.conf.

   *   winbind separator

   *   idmap config * : range

   *   idmap config * : backend

   *   winbind cache time

   *   winbind enum users

   *   winbind enum groups

   *   template homedir

   *   template shell

   *   winbind use default domain

   *   winbind: rpc only Setting this parameter forces winbindd to use RPC
       instead of LDAP to retrieve information from Domain Controllers.


   To setup winbindd for user and group lookups plus authentication from a
   domain controller use something like the following setup. This was
   tested on an early Red Hat Linux box.

   In /etc/nsswitch.conf put the following:

       passwd: files winbind
       group:  files winbind

   In /etc/pam.d/* replace the
    auth lines with something like this:

       auth  required    /lib/security/
       auth  required   /lib/security/
       auth  sufficient  /lib/security/
       auth  required    /lib/security/ \
                         use_first_pass shadow nullok

       The PAM module pam_unix has recently replaced the module pam_pwdb.
       Some Linux systems use the module pam_unix2 in place of pam_unix.

   Note in particular the use of the sufficient keyword and the
   use_first_pass keyword.

   Now replace the account lines with this:

   account required /lib/security/

   The next step is to join the domain. To do that use the net program
   like this:

   net join -S PDC -U Administrator

   The username after the -U can be any Domain user that has administrator
   privileges on the machine. Substitute the name or IP of your PDC for

   Next copy to /lib and to
   /lib/security. A symbolic link needs to be made from
   /lib/ to /lib/ If you are using an
   older version of glibc then the target of the link should be

   Finally, setup a smb.conf(5) containing directives like the following:

            winbind separator = +
               winbind cache time = 10
               template shell = /bin/bash
               template homedir = /home/%D/%U
               idmap config * : range = 10000-20000
               workgroup = DOMAIN
               security = domain
               password server = *

   Now start winbindd and you should find that your user and group
   database is expanded to include your NT users and groups, and that you
   can login to your unix box as a domain user, using the DOMAIN+user
   syntax for the username. You may wish to use the commands getent passwd
   and getent group to confirm the correct operation of winbindd.


   The following notes are useful when configuring and running winbindd:

   nmbd(8) must be running on the local machine for winbindd to work.

   PAM is really easy to misconfigure. Make sure you know what you are
   doing when modifying PAM configuration files. It is possible to set up
   PAM such that you can no longer log into your system.

   If more than one UNIX machine is running winbindd, then in general the
   user and groups ids allocated by winbindd will not be the same. The
   user and group ids will only be valid for the local machine, unless a
   shared idmap config * : backend is configured.

   If the Windows NT SID to UNIX user and group id mapping file is damaged
   or destroyed then the mappings will be lost.


   The following signals can be used to manipulate the winbindd daemon.

       Reload the smb.conf(5) file and apply any parameter changes to the
       running version of winbindd. This signal also clears any cached
       user and group information. The list of other domains trusted by
       winbindd is also reloaded.

       The SIGUSR2 signal will cause winbindd to write status information
       to the winbind log file.

       Log files are stored in the filename specified by the log file


       Name service switch configuration file.

       The UNIX pipe over which clients communicate with the winbindd
       program. For security reasons, the winbind client will only attempt
       to connect to the winbindd daemon if both the /tmp/.winbindd
       directory and /tmp/.winbindd/pipe file are owned by root.

       The UNIX pipe over which 'privileged' clients communicate with the
       winbindd program. For security reasons, access to some winbindd
       functions - like those needed by the ntlm_auth utility - is
       restricted. By default, only users in the 'root' group will get
       this access, however the administrator may change the group
       permissions on $LOCKDIR/winbindd_privileged to allow programs like
       'squid' to use ntlm_auth. Note that the winbind client will only
       attempt to connect to the winbindd daemon if both the
       $LOCKDIR/winbindd_privileged directory and
       $LOCKDIR/winbindd_privileged/pipe file are owned by root.

       Implementation of name service switch library.

       Storage for the Windows NT rid to UNIX user/group id mapping. The
       lock directory is specified when Samba is initially compiled using
       the --with-lockdir option. This directory is by default

       Storage for cached user and group information.


   This man page is correct for version 3 of the Samba suite.


   nsswitch.conf(5), samba(7), wbinfo(1), ntlm_auth(8), smb.conf(5),


   The original Samba software and related utilities were created by
   Andrew Tridgell. Samba is now developed by the Samba Team as an Open
   Source project similar to the way the Linux kernel is developed.

   wbinfo and winbindd were written by Tim Potter.

   The conversion to DocBook for Samba 2.2 was done by Gerald Carter. The
   conversion to DocBook XML 4.2 for Samba 3.0 was done by Alexander


Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.

Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.

Free Software

Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.

Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.

Free Books

The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.

Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.


Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.

Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.