Provided by: slapd_2.4.28-1.1ubuntu4_amd64 bug

NAME

       slapd.conf - configuration file for slapd, the stand-alone LDAP daemon

SYNOPSIS

       /etc/ldap/slapd.conf

DESCRIPTION

       The  file /etc/ldap/slapd.conf contains configuration information for the slapd(8) daemon.
       This  configuration  file  is  also  used  by  the  SLAPD  tools  slapacl(8),  slapadd(8),
       slapauth(8), slapcat(8), slapdn(8), slapindex(8), and slaptest(8).

       The  slapd.conf  file  consists  of a series of global configuration options that apply to
       slapd as a whole (including all backends), followed  by  zero  or  more  database  backend
       definitions  that  contain  information specific to a backend instance.  The configuration
       options are case-insensitive; their value, on a case by case basis, may be case-sensitive.

       The general format of slapd.conf is as follows:

           # comment - these options apply to every database
           <global configuration options>
           # first database definition & configuration options
           database <backend 1 type>
           <configuration options specific to backend 1>
           # subsequent database definitions & configuration options
           ...

       As many backend-specific sections as desired may  be  included.   Global  options  can  be
       overridden  in  a  backend (for options that appear more than once, the last appearance in
       the slapd.conf file is used).

       If a line begins with white space, it is considered a continuation of the  previous  line.
       No physical line should be over 2000 bytes long.

       Blank  lines  and  comment  lines  beginning  with  a  `#'  character  are ignored.  Note:
       continuation lines are unwrapped before comment processing is applied.

       Arguments on configuration lines are separated by white space.  If  an  argument  contains
       white  space, the argument should be enclosed in double quotes.  If an argument contains a
       double quote (`"') or a backslash character (`\'), the character should be preceded  by  a
       backslash character.

       The   specific   configuration  options  available  are  discussed  below  in  the  Global
       Configuration Options, General Backend Options, and General  Database  Options.   Backend-
       specific  options  are  discussed  in  the  slapd-<backend>(5) manual pages.  Refer to the
       "OpenLDAP Administrator's Guide" for more details on the slapd configuration file.

GLOBAL CONFIGURATION OPTIONS

       Options described in this section apply to all backends, unless specifically overridden in
       a  backend  definition.  Arguments  that  should  be  replaced by actual text are shown in
       brackets <>.

       access to <what> [ by <who> <access> <control> ]+
              Grant access (specified  by  <access>)  to  a  set  of  entries  and/or  attributes
              (specified by <what>) by one or more requestors (specified by <who>).  If no access
              controls are present, the  default  policy  allows  anyone  and  everyone  to  read
              anything  but  restricts  updates to rootdn.  (e.g., "access to * by * read").  The
              rootdn  can  always  read  and  write  EVERYTHING!   See  slapd.access(5)  and  the
              "OpenLDAP's Administrator's Guide" for details.

       allow <features>
              Specify  a  set  of  features  (separated  by white space) to allow (default none).
              bind_v2 allows acceptance of LDAPv2 bind requests.  Note  that  slapd(8)  does  not
              truly  implement LDAPv2 (RFC 1777), now Historic (RFC 3494).  bind_anon_cred allows
              anonymous  bind  when  credentials  are  not  empty  (e.g.   when  DN  is   empty).
              bind_anon_dn  allows  unauthenticated  (anonymous)  bind  when  DN  is  not  empty.
              update_anon allows unauthenticated (anonymous) update operations  to  be  processed
              (subject  to  access  controls  and other administrative limits).  proxy_authz_anon
              allows unauthenticated (anonymous) proxy  authorization  control  to  be  processed
              (subject to access controls, authorization and other administrative limits).

       argsfile <filename>
              The  (absolute)  name  of  a  file  that  will hold the slapd server's command line
              (program name and options).

       attributeoptions [option-name]...
              Define tagging attribute options or option tag/range prefixes.   Options  must  not
              end  with  `-',  prefixes must end with `-'.  The `lang-' prefix is predefined.  If
              you use the attributeoptions directive, `lang-' will no longer be defined  and  you
              must specify it explicitly if you want it defined.

              An  attribute  description  with  a  tagging  option is a subtype of that attribute
              description without the option.  Except for that, options defined this way have  no
              special  semantics.   Prefixes defined this way work like the `lang-' options: They
              define a prefix for tagging options starting with the  prefix.   That  is,  if  you
              define  the prefix `x-foo-', you can use the option `x-foo-bar'.  Furthermore, in a
              search or compare, a prefix or range name (with a trailing `-') matches all options
              starting  with  that  name,  as  well  as  the  option with the range name sans the
              trailing `-'.  That is, `x-foo-bar-' matches `x-foo-bar' and `x-foo-bar-baz'.

              RFC 4520 reserves options beginning  with  `x-'  for  private  experiments.   Other
              options  should  be  registered with IANA, see RFC 4520 section 3.5.  OpenLDAP also
              has the `binary' option built in, but this is a  transfer  option,  not  a  tagging
              option.

       attributetype    ( <oid>   [NAME <name>]   [DESC <description>]   [OBSOLETE]   [SUP <oid>]
              [EQUALITY <oid>] [ORDERING <oid>] [SUBSTR <oid>]  [SYNTAX <oidlen>]  [SINGLE-VALUE]
              [COLLECTIVE] [NO-USER-MODIFICATION] [USAGE <attributeUsage>] )
              Specify  an  attribute type using the LDAPv3 syntax defined in RFC 4512.  The slapd
              parser extends the RFC 4512 definition by allowing string forms as well as  numeric
              OIDs  to  be  used  for  the  attribute  OID  and  attribute  syntax OID.  (See the
              objectidentifier description.)

       authid-rewrite<cmd> <args>
              Used by the authentication framework to convert simple user names  to  an  LDAP  DN
              used  for authorization purposes.  Its purpose is analogous to that of authz-regexp
              (see below).  The prefix authid- is followed by a set of rules analogous  to  those
              described  in  slapo-rwm(5)  for  data  rewriting  (replace  the  rwm-  prefix with
              authid-).  authid-rewrite<cmd> and authz-regexp rules should not be intermixed.

       authz-policy <policy>
              Used to specify which rules to use for Proxy  Authorization.   Proxy  authorization
              allows  a  client  to  authenticate to the server using one user's credentials, but
              specify a different identity to use for authorization and access control  purposes.
              It essentially allows user A to login as user B, using user A's password.  The none
              flag disables proxy authorization. This is the default setting.  The from flag will
              use rules in the authzFrom attribute of the authorization DN.  The to flag will use
              rules in the authzTo attribute of the authentication DN.  The any  flag,  an  alias
              for  the  deprecated  value of both, will allow any of the above, whatever succeeds
              first (checked in to, from sequence.  The all flag requires both authorizations  to
              succeed.

              The  rules  are mechanisms to specify which identities are allowed to perform proxy
              authorization.  The authzFrom attribute in an entry specifies which other users are
              allowed  to  proxy login to this entry. The authzTo attribute in an entry specifies
              which other users this user can authorize as.  Use of authzTo rules can  be  easily
              abused  if  users  are  allowed  to  write  arbitrary values to this attribute.  In
              general the authzTo attribute must be protected with ACLs such that only privileged
              users can modify it.  The value of authzFrom and authzTo describes an identity or a
              set of identities; it can take five forms:

                     ldap:///<base>??[<scope>]?<filter>
                     dn[.<dnstyle>]:<pattern>
                     u[.<mech>[/<realm>]]:<pattern>
                     group[/objectClass[/attributeType]]:<pattern>
                     <pattern>

                     <dnstyle>:={exact|onelevel|children|subtree|regex}

              The first form is a valid LDAP URI where the <host>:<port>,  the  <attrs>  and  the
              <extensions>  portions  must be absent, so that the search occurs locally on either
              authzFrom or authzTo.  The second form is a DN, with the optional  style  modifiers
              exact,  onelevel,  children,  and subtree for exact, onelevel, children and subtree
              matches, which cause <pattern> to be normalized according to the  DN  normalization
              rules,  or  the  special regex style, which causes the <pattern> to be treated as a
              POSIX  (''extended'')  regular  expression,  as  discussed   in   regex(7)   and/or
              re_format(7).  A pattern of * means any non-anonymous DN.  The third form is a SASL
              id, with the optional fields <mech> and  <realm>  that  allow  to  specify  a  SASL
              mechanism, and eventually a SASL realm, for those mechanisms that support one.  The
              need to allow the specification of a mechanism is  still  debated,  and  users  are
              strongly  discouraged  to  rely  on  this  possibility.  The fourth form is a group
              specification,  consisting  of  the  keyword  group,  optionally  followed  by  the
              specification of the group objectClass and member attributeType.  The group with DN
              <pattern> is searched with base scope, and in case of  match,  the  values  of  the
              member   attributeType   are   searched   for   the  asserted  DN.   For  backwards
              compatibility, if no identity type is provided, i.e. only <pattern> is present,  an
              exact  DN is assumed; as a consequence, <pattern> is subjected to DN normalization.
              Since the interpretation of authzFrom and authzTo can impact  security,  users  are
              strongly  encouraged  to  explicitly set the type of identity specification that is
              being used.  A subset of these rules can be used as third arg in  the  authz-regexp
              statement  (see  below); significantly, the URI, provided it results in exactly one
              entry, and the dn.exact:<dn> forms.

       authz-regexp <match> <replace>
              Used by the authentication framework to convert simple user names, such as provided
              by  SASL  subsystem,  or  extracted  from  certificates  in case of cert-based SASL
              EXTERNAL, or provided within the RFC 4370 "proxied authorization"  control,  to  an
              LDAP DN used for authorization purposes.  Note that the resulting DN need not refer
              to an existing entry to be considered valid.   When  an  authorization  request  is
              received  from  the  SASL  subsystem,  the  SASL USERNAME, REALM, and MECHANISM are
              taken, when available, and combined into a name of the form

                     UID=<username>[[,CN=<realm>],CN=<mechanism>],CN=auth

              This  name  is  then  compared  against  the  match  POSIX  (''extended'')  regular
              expression,  and  if the match is successful, the name is replaced with the replace
              string.  If there are wildcard strings in the match  regular  expression  that  are
              enclosed in parenthesis, e.g.

                     UID=([^,]*),CN=.*

              then  the  portion  of  the  name  that  matched the wildcard will be stored in the
              numbered  placeholder  variable  $1.  If  there  are  other  wildcard  strings   in
              parenthesis,  the  matching  strings  will  be  in  $2,  $3,  etc.  up  to  $9. The
              placeholders can then be used in the replace string, e.g.

                     UID=$1,OU=Accounts,DC=example,DC=com

              The replaced name can be either a DN, i.e. a string prefixed by "dn:", or  an  LDAP
              URI.  If the latter, the server will use the URI to search its own database(s) and,
              if the search returns exactly one entry, the name is replaced by  the  DN  of  that
              entry.    The  LDAP URI must have no hostport, attrs, or extensions components, but
              the filter is mandatory, e.g.

                     ldap:///OU=Accounts,DC=example,DC=com??one?(UID=$1)

              The protocol portion of the URI must be strictly ldap.  Note that  this  search  is
              subject  to  access  controls.  Specifically, the authentication identity must have
              "auth" access in the subject.

              Multiple authz-regexp options can be given in the configuration file to  allow  for
              multiple  matching  and  replacement patterns. The matching patterns are checked in
              the order they appear in the file, stopping at the first successful match.

       concurrency <integer>
              Specify a desired level of concurrency.  Provided to the underlying  thread  system
              as a hint.  The default is not to provide any hint.

       conn_max_pending <integer>
              Specify  the  maximum  number  of  pending  requests  for an anonymous session.  If
              requests are submitted faster than the server can process them, they will be queued
              up  to  this limit. If the limit is exceeded, the session is closed. The default is
              100.

       conn_max_pending_auth <integer>
              Specify the maximum number of pending requests for an authenticated  session.   The
              default is 1000.

       defaultsearchbase <dn>
              Specify  a default search base to use when client submits a non-base search request
              with an empty base DN.  Base scoped search requests with an empty base DN  are  not
              affected.

       disallow <features>
              Specify  a  set  of features (separated by white space) to disallow (default none).
              bind_anon disables acceptance of anonymous bind requests.  Note that  this  setting
              does  not  prohibit  anonymous directory access (See "require authc").  bind_simple
              disables simple (bind) authentication.   tls_2_anon  disables  forcing  session  to
              anonymous  status  (see also tls_authc) upon StartTLS operation receipt.  tls_authc
              disallows  the  StartTLS  operation  if  authenticated   (see   also   tls_2_anon).
              proxy_authz_non_critical  disables  acceptance of the proxied authorization control
              (RFC4370) when criticality is FALSE.  dontusecopy_non_critical disables  acceptance
              of the dontUseCopy control (a work in progress) when criticality is FALSE.

       ditcontentrule   ( <oid>   [NAME <name>]   [DESC <description>]   [OBSOLETE]  [AUX <oids>]
              [MUST <oids>] [MAY <oids>] [NOT <oids>] )
              Specify an DIT Content Rule using the LDAPv3 syntax defined in RFC 4512.  The slapd
              parser  extends the RFC 4512 definition by allowing string forms as well as numeric
              OIDs to be used  for  the  attribute  OID  and  attribute  syntax  OID.   (See  the
              objectidentifier description.)

       gentlehup { on | off }
              A  SIGHUP  signal  will  only  cause  a  'gentle' shutdown-attempt: Slapd will stop
              listening for new connections, but will not close the connections  to  the  current
              clients.   Future  write  operations  return  unwilling-to-perform,  though.  Slapd
              terminates when all clients have closed their connections (if they ever do),  or  -
              as  before  -  if  it receives a SIGTERM signal.  This can be useful if you wish to
              terminate the server and start a new slapd server with  another  database,  without
              disrupting  the currently active clients.  The default is off.  You may wish to use
              idletimeout along with this option.

       idletimeout <integer>
              Specify the number of seconds to  wait  before  forcibly  closing  an  idle  client
              connection.   A  idletimeout of 0 disables this feature.  The default is 0. You may
              also want to set the writetimeout option.

       include <filename>
              Read additional configuration information from the  given  file  before  continuing
              with the next line of the current file.

       index_intlen <integer>
              Specify  the  key length for ordered integer indices. The most significant bytes of
              the binary integer will be used for index keys.  The  default  value  is  4,  which
              provides exact indexing for 31 bit values.  A floating point representation is used
              to index too large values.

       index_substr_if_minlen <integer>
              Specify the minimum length for subinitial and subfinal indices. An attribute  value
              must  have  at  least this many characters in order to be processed by the indexing
              functions. The default is 2.

       index_substr_if_maxlen <integer>
              Specify the maximum length for subinitial and  subfinal  indices.  Only  this  many
              characters  of  an attribute value will be processed by the indexing functions; any
              excess characters are ignored. The default is 4.

       index_substr_any_len <integer>
              Specify the length used for subany indices. An attribute value must have  at  least
              this  many  characters  in order to be processed. Attribute values longer than this
              length will be processed in segments of this length. The default is 4.  The  subany
              index  will  also  be used in subinitial and subfinal index lookups when the filter
              string is longer than the index_substr_if_maxlen value.

       index_substr_any_step <integer>
              Specify the steps used in subany index lookups. This value sets the offset for  the
              segments  of  a  filter  string  that  are processed for a subany index lookup. The
              default is 2. For example, with the default values,  a  search  using  this  filter
              "cn=*abcdefgh*" would generate index lookups for "abcd", "cdef", and "efgh".

       Note:  Indexing  support  depends  on  the particular backend in use. Also, changing these
       settings will generally require deleting any indices that depend on these  parameters  and
       recreating them with slapindex(8).

       ldapsyntax ( <oid> [DESC <description>] [X-SUBST <substitute-syntax>] )
              Specify  an  LDAP  syntax  using  the LDAPv3 syntax defined in RFC 4512.  The slapd
              parser extends the RFC 4512 definition by allowing string forms as well as  numeric
              OIDs  to  be used for the syntax OID.  (See the objectidentifier description.)  The
              slapd parser also honors the X-SUBST extension  (an  OpenLDAP-specific  extension),
              which  allows  to  use  the ldapsyntax statement to define a non-implemented syntax
              along with another syntax, the extension value substitute-syntax, as its  temporary
              replacement.   The  substitute-syntax  must  be  defined.   This  allows  to define
              attribute types that make use of non-implemented syntaxes using the correct  syntax
              OID.   Unless  X-SUBST  is  used,  this  configuration statement would result in an
              error, since no handlers would be associated to the resulting syntax structure.

       listener-threads <integer>
              Specify the number of threads to use for the connection manager.  The default is  1
              and  this is typically adequate for up to 16 CPU cores.  The value should be set to
              a power of 2.

       localSSF <SSF>
              Specifies the Security Strength Factor (SSF) to be given local LDAP sessions,  such
              as  those  to  the  ldapi://  listener.  For a description of SSF values, see sasl-
              secprops's minssf option description.  The default is 71.

       logfile <filename>
              Specify a file for recording debug log messages. By default these messages only  go
              to  stderr and are not recorded anywhere else. Specifying a logfile copies messages
              to both stderr and the logfile.

       loglevel <integer> [...]
              Specify the level at which debugging statements and operation statistics should  be
              syslogged  (currently  logged to the syslogd(8) LOG_LOCAL4 facility).  They must be
              considered subsystems rather than increasingly verbose log levels.   Some  messages
              with  higher  priority  are logged regardless of the configured loglevel as soon as
              any logging is configured.  Log levels are additive, and available levels are:
                     1      (0x1 trace) trace function calls
                     2      (0x2 packets) debug packet handling
                     4      (0x4 args) heavy trace debugging (function args)
                     8      (0x8 conns) connection management
                     16     (0x10 BER) print out packets sent and received
                     32     (0x20 filter) search filter processing
                     64     (0x40 config) configuration file processing
                     128    (0x80 ACL) access control list processing
                     256    (0x100 stats) connections, LDAP operations, results (recommended)
                     512    (0x200 stats2) stats log entries sent
                     1024   (0x400 shell) print communication with shell backends
                     2048   (0x800 parse) entry parsing

                     16384  (0x4000 sync) LDAPSync replication
                     32768  (0x8000 none) only messages that get logged whatever log level is set
              The desired log level can be input as a single integer  that  combines  the  (ORed)
              desired  levels,  both in decimal or in hexadecimal notation, as a list of integers
              (that are ORed internally), or as a list  of  the  names  that  are  shown  between
              brackets, such that

                  loglevel 129
                  loglevel 0x81
                  loglevel 128 1
                  loglevel 0x80 0x1
                  loglevel acl trace

              are equivalent.  The keyword any can be used as a shortcut to enable logging at all
              levels  (equivalent  to  -1).   The  keyword  none,  or  the   equivalent   integer
              representation,  causes those messages that are logged regardless of the configured
              loglevel to be logged.  In fact, if loglevel is set to 0, no logging occurs, so  at
              least the none level is required to have high priority messages logged.

              The  loglevel  defaults  to stats.  This level should usually also be included when
              using other loglevels, to help analyze the logs.

       moduleload <filename>
              Specify the name of a dynamically loadable module to load. The filename may  be  an
              absolute path name or a simple filename. Non-absolute names are searched for in the
              directories specified by the modulepath option.  This  option  and  the  modulepath
              option are only usable if slapd was compiled with --enable-modules.

       modulepath <pathspec>
              Specify a list of directories to search for loadable modules. Typically the path is
              colon-separated  but  this  depends  on  the  operating  system.   The  default  is
              /usr/lib/ldap, which is where the standard OpenLDAP install will place its modules.

       objectclass ( <oid> [NAME <name>] [DESC <description>] [OBSOLETE] [SUP <oids>] [{ ABSTRACT
              | STRUCTURAL | AUXILIARY }] [MUST <oids>] [MAY <oids>] )
              Specify an objectclass using the LDAPv3 syntax defined  in  RFC  4512.   The  slapd
              parser  extends the RFC 4512 definition by allowing string forms as well as numeric
              OIDs to be used for the object class OID.  (See the objectidentifier  description.)
              Object classes are "STRUCTURAL" by default.

       objectidentifier <name> { <oid> | <name>[:<suffix>] }
              Define a string name that equates to the given OID. The string can be used in place
              of the numeric OID in objectclass and attribute definitions. The name can  also  be
              used with a suffix of the form ":xx" in which case the value "oid.xx" will be used.

       password-hash <hash> [<hash>...]
              This  option  configures  one  or  more  hashes  to  be  used in generation of user
              passwords stored in the userPassword attribute during processing of  LDAP  Password
              Modify  Extended  Operations  (RFC 3062).  The <hash> must be one of {SSHA}, {SHA},
              {SMD5}, {MD5}, {CRYPT}, and {CLEARTEXT}.  The default is {SSHA}.

              {SHA} and {SSHA} use the SHA-1 algorithm (FIPS 160-1), the latter with a seed.

              {MD5} and {SMD5} use the MD5 algorithm (RFC 1321), the latter with a seed.

              {CRYPT} uses the crypt(3).

              {CLEARTEXT} indicates that the new password should  be  added  to  userPassword  as
              clear text.

              Note  that  this  option  does  not  alter the normal user applications handling of
              userPassword during LDAP Add, Modify, or other LDAP operations.

       password-crypt-salt-format <format>
              Specify the format of the salt passed to crypt(3) when generating {CRYPT} passwords
              (see  password-hash)  during processing of LDAP Password Modify Extended Operations
              (RFC 3062).

              This string needs to be in sprintf(3) format and may include one (and only one)  %s
              conversion.  This conversion will be substituted with a string of random characters
              from [A-Za-z0-9./].   For  example,  "%.2s"  provides  a  two  character  salt  and
              "$1$%.8s"  tells  some  versions of crypt(3) to use an MD5 algorithm and provides 8
              random characters of salt.  The default is "%s", which provides  31  characters  of
              salt.

       pidfile <filename>
              The  (absolute)  name  of  a file that will hold the slapd server's process ID (see
              getpid(2)).

       referral <url>
              Specify the referral to pass back when slapd(8) cannot find  a  local  database  to
              handle a request.  If specified multiple times, each url is provided.

       require <conditions>
              Specify  a  set of conditions (separated by white space) to require (default none).
              The directive may be specified  globally  and/or  per-database;  databases  inherit
              global conditions, so per-database specifications are additive.  bind requires bind
              operation prior to directory operations.  LDAPv3 requires session to be using  LDAP
              version  3.   authc  requires  authentication  prior to directory operations.  SASL
              requires SASL authentication prior to directory operations.  strong requires strong
              authentication  prior to directory operations.  The strong keyword allows protected
              "simple" authentication as well as  SASL  authentication.   none  may  be  used  to
              require  no  conditions  (useful  to  clear  out  globally  set conditions within a
              particular database); it must occur first in the list of conditions.

       reverse-lookup on | off
              Enable/disable client name unverified reverse lookup (default is  off  if  compiled
              with --enable-rlookups).

       rootDSE <file>
              Specify the name of an LDIF(5) file containing user defined attributes for the root
              DSE.  These attributes are returned in addition to the attributes normally produced
              by slapd.

              The root DSE is an entry with information about the server and its capabilities, in
              operational attributes.  It has the empty DN, and can be read with e.g.:
                  ldapsearch -x -b "" -s base "+"
              See RFC 4512 section 5.1 for details.

       sasl-auxprops <plugin> [...]
              Specify which auxprop plugins to use for authentication  lookups.  The  default  is
              empty,  which  just uses slapd's internal support. Usually no other auxprop plugins
              are needed.

       sasl-host <fqdn>
              Used to specify the fully qualified domain name used for SASL processing.

       sasl-realm <realm>
              Specify SASL realm.  Default is empty.

       sasl-secprops <properties>
              Used to specify Cyrus SASL security properties.  The none flag (without  any  other
              properties)  causes  the  flag  properties  default,  "noanonymous,noplain",  to be
              cleared.  The noplain  flag  disables  mechanisms  susceptible  to  simple  passive
              attacks.  The noactive flag disables mechanisms susceptible to active attacks.  The
              nodict flag disables mechanisms susceptible to  passive  dictionary  attacks.   The
              noanonymous flag disables mechanisms which support anonymous login.  The forwardsec
              flag require forward secrecy between sessions.   The  passcred  require  mechanisms
              which  pass  client credentials (and allow mechanisms which can pass credentials to
              do so).  The minssf=<factor> property specifies  the  minimum  acceptable  security
              strength  factor  as  an  integer  approximate  to  effective  key  length used for
              encryption.  0 (zero) implies no protection, 1 implies integrity  protection  only,
              56  allows  DES  or  other  weak  ciphers,  112  allows triple DES and other strong
              ciphers, 128 allows RC4, Blowfish and other modern strong ciphers.  The default  is
              0.  The maxssf=<factor> property specifies the maximum acceptable security strength
              factor as an integer (see  minssf  description).   The  default  is  INT_MAX.   The
              maxbufsize=<size> property specifies the maximum security layer receive buffer size
              allowed.  0 disables security layers.  The default is 65536.

       schemadn <dn>
              Specify the distinguished name for the subschema subentry that controls the entries
              on this server.  The default is "cn=Subschema".

       security <factors>
              Specify  a  set  of security strength factors (separated by white space) to require
              (see sasl-secprops's minssf option for a description of security strength factors).
              The directive may be specified globally and/or per-database.  ssf=<n> specifies the
              overall security strength factor.  transport=<n> specifies the  transport  security
              strength  factor.   tls=<n>  specifies  the TLS security strength factor.  sasl=<n>
              specifies the SASL security strength factor.  update_ssf=<n> specifies the  overall
              security  strength  factor  to require for directory updates.  update_transport=<n>
              specifies the transport security strength factor to require for directory  updates.
              update_tls=<n>  specifies the TLS security strength factor to require for directory
              updates.  update_sasl=<n> specifies the SASL security strength  factor  to  require
              for  directory  updates.   simple_bind=<n>  specifies  the security strength factor
              required for simple username/password  authentication.   Note  that  the  transport
              factor  is  measure of security provided by the underlying transport, e.g. ldapi://
              (and eventually IPSEC).  It is not normally used.

       serverID <integer> [<URL>]
              Specify an integer ID from 0 to 4095 for this  server  (limited  to  3  hexadecimal
              digits).   The  ID may also be specified as a hexadecimal ID by prefixing the value
              with "0x".  These IDs are required when  using  multimaster  replication  and  each
              master  must  have a unique ID. Note that this requirement also applies to separate
              masters contributing to a glued set of databases.  If the  URL  is  provided,  this
              directive   may   be  specified  multiple  times,  providing  a  complete  list  of
              participating servers and their IDs. The fully qualified hostname  of  each  server
              should  be used in the supplied URLs. The IDs are used in the "replica id" field of
              all CSNs generated by the specified server. The default value is zero.  Example:

            serverID 1

       sizelimit {<integer>|unlimited}

       sizelimit size[.{soft|hard|unchecked}]=<integer> [...]
              Specify the maximum number of entries to  return  from  a  search  operation.   The
              default  size limit is 500.  Use unlimited to specify no limits.  The second format
              allows a fine grain setting of the size limits.  Extra args can  be  added  on  the
              same line.  See limits for an explanation of the different flags.

       sockbuf_max_incoming <integer>
              Specify  the maximum incoming LDAP PDU size for anonymous sessions.  The default is
              262143.

       sockbuf_max_incoming_auth <integer>
              Specify the maximum incoming LDAP PDU size for authenticated sessions.  The default
              is 4194303.

       sortvals <attr> [...]
              Specify a list of multi-valued attributes whose values will always be maintained in
              sorted order. Using this option will allow Modify, Compare, and filter  evaluations
              on  these  attributes  to  be  performed more efficiently. The resulting sort order
              depends on the attributes' syntax and matching rules  and  may  not  correspond  to
              lexical order or any other recognizable order.

       tcp-buffer [listener=<URL>] [{read|write}=]<size>
              Specify  the  size  of  the TCP buffer.  A global value for both read and write TCP
              buffers related to any listener is  defined,  unless  the  listener  is  explicitly
              specified,  or  either  the  read  or  write  qualifiers  are used.  See tcp(7) for
              details.  Note that some OS-es implement automatic TCP buffer tuning.

       threads <integer>
              Specify the maximum size of the primary  thread  pool.   The  default  is  16;  the
              minimum value is 2.

       timelimit {<integer>|unlimited}

       timelimit time[.{soft|hard}]=<integer> [...]
              Specify  the  maximum number of seconds (in real time) slapd will spend answering a
              search request.  The default time limit is  3600.   Use  unlimited  to  specify  no
              limits.   The  second format allows a fine grain setting of the time limits.  Extra
              args can be added on the same line.  See limits for an explanation of the different
              flags.

       tool-threads <integer>
              Specify  the  maximum  number  of  threads to use in tool mode.  This should not be
              greater than the number of CPUs in the system.  The default is 1.

       writetimeout <integer>
              Specify the number of seconds to wait before forcibly closing a connection with  an
              outstanding  write.  This  allows recovery from various network hang conditions.  A
              writetimeout of 0 disables this feature.  The default is 0.

TLS OPTIONS

       If slapd is built with support for Transport Layer Security, there are  more  options  you
       can specify.

       TLSCipherSuite <cipher-suite-spec>
              Permits  configuring  what  ciphers  will  be  accepted  and  the preference order.
              <cipher-suite-spec> should be a cipher specification for the  TLS  library  in  use
              (OpenSSL, GnuTLS, or Mozilla NSS).  Example:

                     OpenSSL:
                            TLSCipherSuite HIGH:MEDIUM:+SSLv2

                     GnuTLS:
                            TLSCiphersuite SECURE256:!AES-128-CBC

              To check what ciphers a given spec selects in OpenSSL, use:

                   openssl ciphers -v <cipher-suite-spec>

              With  GnuTLS  the  available specs can be found in the manual page of gnutls-cli(1)
              (see the description of the option --priority).

              In older  versions  of  GnuTLS,  where  gnutls-cli  does  not  support  the  option
              --priority, you can obtain the — more limited — list of ciphers by calling:

                   gnutls-cli -l

              When  using  Mozilla  NSS,  the  OpenSSL  cipher  suite specifications are used and
              translated into the format used internally by Mozilla NSS.  There isn't an easy way
              to  list the cipher suites from the command line.  The authoritative list is in the
              source code for Mozilla NSS in the file sslinfo.c in the structure
                      static const SSLCipherSuiteInfo suiteInfo[]

       TLSCACertificateFile <filename>
              Specifies  the  file  that  contains  certificates  for  all  of  the   Certificate
              Authorities  that slapd will recognize.  The certificate for the CA that signed the
              server certificate must be included among these certificates. If the signing CA was
              not  a  top-level  (root) CA, certificates for the entire sequence of CA's from the
              signing CA to the top-level CA should be present. Multiple certificates are  simply
              appended to the file; the order is not significant.

       TLSCACertificatePath <path>
              Specifies  the path of a directory that contains Certificate Authority certificates
              in separate individual files. Usually only one of this or the  TLSCACertificateFile
              is used. This directive is not supported when using GnuTLS.

              When  using  Mozilla  NSS,  <path> may contain a Mozilla NSS cert/key database.  If
              <path> contains a Mozilla NSS cert/key database and CA cert  files,  OpenLDAP  will
              use the cert/key database and will ignore the CA cert files.

       TLSCertificateFile <filename>
              Specifies the file that contains the slapd server certificate.

              When   using   Mozilla   NSS,   if   using  a  cert/key  database  (specified  with
              TLSCACertificatePath), TLSCertificateFile specifies the name of the certificate  to
              use:
                   TLSCertificateFile Server-Cert
              If  using  a  token  other than the internal built in token, specify the token name
              first, followed by a colon:
                   TLSCertificateFile my hardware device:Server-Cert
              Use certutil -L to list the certificates by name:
                   certutil -d /path/to/certdbdir -L

       TLSCertificateKeyFile <filename>
              Specifies the file that contains the slapd server  private  key  that  matches  the
              certificate stored in the TLSCertificateFile file.  Currently, the private key must
              not be protected with a password, so it  is  of  critical  importance  that  it  is
              protected carefully.

              When  using  Mozilla  NSS,  TLSCertificateKeyFile specifies the name of a file that
              contains  the  password  for  the  key   for   the   certificate   specified   with
              TLSCertificateFile.   The  modutil  command  can  be  used  to  turn  off  password
              protection  for  the  cert/key  database.   For  example,  if  TLSCACertificatePath
              specifes /etc/openldap/certdb as the location of the cert/key database, use modutil
              to change the password to the empty string:
                   modutil -dbdir /etc/openldap/certdb -changepw 'NSS Certificate DB'
              You must have the old password, if any.   Ignore  the  WARNING  about  the  running
              browser.  Press 'Enter' for the new password.

       TLSDHParamFile <filename>
              This  directive  specifies  the  file  that  contains parameters for Diffie-Hellman
              ephemeral key exchange.  This is required in order to use a DSA certificate on  the
              server. If multiple sets of parameters are present in the file, all of them will be
              processed.  Note that setting this option may also enable Anonymous  Diffie-Hellman
              key  exchanges  in  certain non-default cipher suites.  You should append "!ADH" to
              your cipher suites if  you  have  changed  them  from  the  default,  otherwise  no
              certificate  exchanges  or  verification  will  be  done.  When  using GnuTLS these
              parameters are always generated  randomly  so  this  directive  is  ignored.   This
              directive is ignored when using Mozilla NSS.

       TLSRandFile <filename>
              Specifies the file to obtain random bits from when /dev/[u]random is not available.
              Generally set to the name  of  the  EGD/PRNGD  socket.   The  environment  variable
              RANDFILE  can also be used to specify the filename.  This directive is ignored with
              GnuTLS and Mozilla NSS.

       TLSVerifyClient <level>
              Specifies what checks to perform on client certificates in an incoming TLS session,
              if any.  The <level> can be specified as one of the following keywords:

              never  This is the default.  slapd will not ask the client for a certificate.

              allow  The  client  certificate  is  requested.  If no certificate is provided, the
                     session proceeds normally.  If a bad certificate is  provided,  it  will  be
                     ignored and the session proceeds normally.

              try    The  client  certificate  is  requested.  If no certificate is provided, the
                     session proceeds normally.  If a bad certificate is provided, the session is
                     immediately terminated.

              demand | hard | true
                     These  keywords  are  all equivalent, for compatibility reasons.  The client
                     certificate  is  requested.   If  no  certificate  is  provided,  or  a  bad
                     certificate is provided, the session is immediately terminated.

                     Note  that  a  valid client certificate is required in order to use the SASL
                     EXTERNAL authentication mechanism with a  TLS  session.   As  such,  a  non-
                     default  TLSVerifyClient  setting  must  be  chosen  to enable SASL EXTERNAL
                     authentication.

       TLSCRLCheck <level>
              Specifies if the Certificate Revocation List (CRL) of the  CA  should  be  used  to
              verify   if   the   client  certificates  have  not  been  revoked.  This  requires
              TLSCACertificatePath parameter to be set. This directive is ignored with GnuTLS and
              Mozilla NSS.  <level> can be specified as one of the following keywords:

              none   No CRL checks are performed

              peer   Check the CRL of the peer certificate

              all    Check the CRL for a whole certificate chain

       TLSCRLFile <filename>
              Specifies  a file containing a Certificate Revocation List to be used for verifying
              that certificates have not been revoked. This directive is only  valid  when  using
              GnuTLS and Mozilla NSS.

GENERAL BACKEND OPTIONS

       Options  in  this  section  only apply to the configuration file section for the specified
       backend.  They are supported by every type of backend.

       backend <databasetype>
              Mark the beginning of a backend definition. <databasetype> should be  one  of  bdb,
              config,  dnssrv,  hdb, ldap, ldif, meta, monitor, null, passwd, perl, relay, shell,
              or sql, depending on which backend will serve the database.

GENERAL DATABASE OPTIONS

       Options in this section only apply to the configuration file section for the  database  in
       which  they  are  defined.   They  are  supported by every type of backend.  Note that the
       database and at least one suffix option are mandatory for each database.

       database <databasetype>
              Mark the beginning of a new database instance definition. <databasetype> should  be
              one  of  bdb,  config,  dnssrv, hdb, ldap, ldif, meta, monitor, null, passwd, perl,
              relay, shell, or sql, depending on which backend will serve the database.

              LDAP operations, even subtree searches, normally access only  one  database.   That
              can  be  changed by gluing databases together with the subordinate keyword.  Access
              controls and some overlays can also involve multiple databases.

       add_content_acl on | off
              Controls whether Add operations will perform ACL checks on the content of the entry
              being  added. This check is off by default. See the slapd.access(5) manual page for
              more details on ACL requirements for Add operations.

       extra_attrs <attrlist>
              Lists what attributes need to be added to search requests.  Local storage  backends
              return the entire entry to the frontend.  The frontend takes care of only returning
              the requested attributes that are allowed by ACLs.  However, features  like  access
              checking and so may need specific attributes that are not automatically returned by
              remote storage backends, like proxy backends and so on.  <attrlist> is  a  list  of
              attributes  that  are  needed  for  internal  purposes  and  thus always need to be
              collected, even when not explicitly requested by clients.

       hidden on | off
              Controls whether the database will be used to answer queries. A  database  that  is
              hidden  will  never be selected to answer any queries, and any suffix configured on
              the database will be ignored in checks  for  conflicts  with  other  databases.  By
              default, hidden is off.

       lastmod on | off
              Controls   whether   slapd   will   automatically   maintain   the   modifiersName,
              modifyTimestamp, creatorsName, and createTimestamp attributes for entries. It  also
              controls  the  entryCSN  and entryUUID attributes, which are needed by the syncrepl
              provider. By default, lastmod is on.

       limits <selector> <limit> [<limit> [...]]
              Specify time and size limits based on the operation's initiator or  base  DN.   The
              argument <selector> can be any of

                     anonymous | users | [<dnspec>=]<pattern> | group[/oc[/at]]=<pattern>

              with

                     <dnspec> ::= dn[.<type>][.<style>]

                     <type>  ::= self | this

                     <style> ::= exact | base | onelevel | subtree | children | regex | anonymous

              DN  type self is the default and means the bound user, while this means the base DN
              of the operation.  The term anonymous matches  all  unauthenticated  clients.   The
              term  users  matches  all  authenticated  clients; otherwise an exact dn pattern is
              assumed unless otherwise specified by qualifying the (optional) key string dn  with
              exact  or  base  (which are synonyms), to require an exact match; with onelevel, to
              require exactly one level of depth match; with subtree, to allow any level of depth
              match, including the exact match; with children, to allow any level of depth match,
              not including the exact match; regex explicitly requires the (default) match  based
              on  POSIX  (''extended'')  regular  expression pattern.  Finally, anonymous matches
              unbound operations; the pattern field is ignored.  The same behavior is obtained by
              using  the  anonymous  form  of  the  <selector>  clause.  The term group, with the
              optional objectClass oc and attributeType at fields, followed by pattern, sets  the
              limits  for any DN listed in the values of the at attribute (default member) of the
              oc group objectClass (default groupOfNames) whose DN exactly matches pattern.

              The currently supported limits are size and time.

              The syntax for time limits is time[.{soft|hard}]=<integer>, where  integer  is  the
              number of seconds slapd will spend answering a search request.  If no time limit is
              explicitly requested by the client, the soft limit is used; if the  requested  time
              limit  exceeds the hard limit, the value of the limit is used instead.  If the hard
              limit is set to the keyword soft, the soft limit is used in either case; if  it  is
              set  to  the  keyword  unlimited, no hard limit is enforced.  Explicit requests for
              time limits smaller or equal to the hard limit are honored.  If no limit  specifier
              is set, the value is assigned to the soft limit, and the hard limit is set to soft,
              to preserve the original behavior.

              The syntax for size limits is size[.{soft|hard|unchecked}]=<integer>, where integer
              is  the maximum number of entries slapd will return answering a search request.  If
              no size limit is explicitly requested by the client, the soft limit is used; if the
              requested  size  limit  exceeds  the  hard  limit,  the  value of the limit is used
              instead.  If the hard limit is set to the keyword soft, the soft limit is  used  in
              either  case;  if  it  is  set to the keyword unlimited, no hard limit is enforced.
              Explicit requests for size limits smaller or equal to the hard limit  are  honored.
              The  unchecked  specifier sets a limit on the number of candidates a search request
              is allowed to examine.  The rationale behind it is that searches  for  non-properly
              indexed  attributes  may result in large sets of candidates, which must be examined
              by slapd(8) to determine  whether  they  match  the  search  filter  or  not.   The
              unchecked  limit  provides  a  means  to  drop such operations before they are even
              started.  If the selected candidates exceed the unchecked limit,  the  search  will
              abort  with  Unwilling to perform.  If it is set to the keyword unlimited, no limit
              is applied (the default).  If it is  set  to  disabled,  the  search  is  not  even
              performed;  this  can be used to disallow searches for a specific set of users.  If
              no limit specifier is set, the value is assigned to the soft limit,  and  the  hard
              limit is set to soft, to preserve the original behavior.

              In  case  of no match, the global limits are used.  The default values are the same
              as for sizelimit and timelimit; no limit is set on unchecked.

              If pagedResults control is requested, the hard  size  limit  is  used  by  default,
              because the request of a specific page size is considered an explicit request for a
              limitation on the number of entries  to  be  returned.   However,  the  size  limit
              applies  to  the  total  count  of entries returned within the search, and not to a
              single  page.   Additional  size  limits   may   be   enforced;   the   syntax   is
              size.pr={<integer>|noEstimate|unlimited},  where integer is the max page size if no
              explicit limit is set; the keyword noEstimate inhibits the server from returning an
              estimate  of  the total number of entries that might be returned (note: the current
              implementation does not return any estimate).  The keyword unlimited indicates that
              no   limit   is  applied  to  the  pagedResults  control  page  size.   The  syntax
              size.prtotal={<integer>|unlimited|disabled} allows to set  a  limit  on  the  total
              number  of  entries that a pagedResults control allows to return.  By default it is
              set to the hard limit.  When set, integer is the max number  of  entries  that  the
              whole  search  with  pagedResults  control  can  return.   Use  unlimited  to allow
              unlimited number of  entries  to  be  returned,  e.g.  to  allow  the  use  of  the
              pagedResults control as a means to circumvent size limitations on regular searches;
              the keyword disabled disables the control, i.e. no paged results can  be  returned.
              Note  that  the  total  number of entries returned when the pagedResults control is
              requested cannot exceed the hard size limit of regular searches unless extended  by
              the prtotal switch.

              The  limits  statement  is  typically used to let an unlimited number of entries be
              returned by  searches  performed  with  the  identity  used  by  the  consumer  for
              synchronization  purposes  by  means  of  the RFC 4533 LDAP Content Synchronization
              protocol (see syncrepl for details).

       maxderefdepth <depth>
              Specifies the maximum number of aliases to dereference when trying  to  resolve  an
              entry, used to avoid infinite alias loops. The default is 15.

       mirrormode on | off
              This  option puts a replica database into "mirror" mode.  Update operations will be
              accepted from any user, not just  the  updatedn.   The  database  must  already  be
              configured  as  a  syncrepl consumer before this keyword may be set. This mode also
              requires a serverID (see above) to be configured.  By default, mirrormode is off.

       monitoring on | off
              This option enables database-specific  monitoring  in  the  entry  related  to  the
              current  database in the "cn=Databases,cn=Monitor" subtree of the monitor database,
              if the monitor database is enabled.  Currently, only the BDB and the HDB  databases
              provide database-specific monitoring.  The default depends on the backend type.

       overlay <overlay-name>
              Add  the  specified  overlay  to  this database. An overlay is a piece of code that
              intercepts database operations in order to extend  or  change  them.  Overlays  are
              pushed  onto  a stack over the database, and so they will execute in the reverse of
              the order in which they were  configured  and  the  database  itself  will  receive
              control  last  of all. See the slapd.overlays(5) manual page for an overview of the
              available overlays.  Note that all of the database's  regular  settings  should  be
              configured before any overlay settings.

       readonly on | off
              This  option  puts  the database into "read-only" mode.  Any attempts to modify the
              database will return an "unwilling to perform" error.  By default, readonly is off.

       restrict <oplist>
              Specify a whitespace separated list of operations that are restricted.  If  defined
              inside  a  database  specification,  restrictions  apply  only  to  that  database,
              otherwise they are global.  Operations can be any of add,  bind,  compare,  delete,
              extended[=<OID>], modify, rename, search, or the special pseudo-operations read and
              write, which respectively summarize read and write operations.  The use of restrict
              write  is  equivalent  to  readonly on (see above).  The extended keyword allows to
              indicate the OID of the specific operation to be restricted.

       rootdn <dn>
              Specify  the  distinguished  name  that  is  not  subject  to  access  control   or
              administrative  limit restrictions for operations on this database.  This DN may or
              may not be associated with an entry.  An empty root DN (the default)  specifies  no
              root  access is to be granted.  It is recommended that the rootdn only be specified
              when needed (such as when initially populating  a  database).   If  the  rootdn  is
              within a namingContext (suffix) of the database, a simple bind password may also be
              provided using the rootpw directive. Many optional  features,  including  syncrepl,
              require the rootdn to be defined for the database.

       rootpw <password>
              Specify a password (or hash of the password) for the rootdn.  The password can only
              be set if the rootdn is within the namingContext (suffix) of  the  database.   This
              option  accepts  all  RFC  2307  userPassword  formats  known  to  the  server (see
              password-hash description) as well as cleartext.   slappasswd(8)  may  be  used  to
              generate   a  hash  of  a  password.   Cleartext  and  {CRYPT}  passwords  are  not
              recommended.  If empty (the default), authentication of the root  DN  is  by  other
              means (e.g. SASL).  Use of SASL is encouraged.

       suffix <dn suffix>
              Specify  the  DN  suffix  of  queries that will be passed to this backend database.
              Multiple suffix lines can be given and at least one is required for  each  database
              definition.

              If  the  suffix  of one database is "inside" that of another, the database with the
              inner suffix must come first in the configuration file.  You may also want to  glue
              such databases together with the subordinate keyword.

       subordinate [advertise]
              Specify  that  the  current  backend  database  is a subordinate of another backend
              database. A subordinate  database may have only one suffix. This option may be used
              to  glue  multiple  databases  into  a  single namingContext.  If the suffix of the
              current database is within the  namingContext  of  a  superior  database,  searches
              against the superior database will be propagated to the subordinate as well. All of
              the databases associated with a single namingContext should have identical rootdns.
              Behavior  of other LDAP operations is unaffected by this setting. In particular, it
              is not possible to use moddn to move an  entry  from  one  subordinate  to  another
              subordinate within the namingContext.

              If  the optional advertise flag is supplied, the naming context of this database is
              advertised in the root DSE. The default is to hide this database context,  so  that
              only the superior context is visible.

              If  the slap tools slapcat(8), slapadd(8), or slapindex(8) are used on the superior
              database, any glued subordinates that support these tools are opened as well.

              Databases that are glued together  should  usually  be  configured  with  the  same
              indices  (assuming  they  support indexing), even for attributes that only exist in
              some of these  databases.  In  general,  all  of  the  glued  databases  should  be
              configured  as similarly as possible, since the intent is to provide the appearance
              of a single directory.

              Note that the subordinate functionality  is  implemented  internally  by  the  glue
              overlay  and  as  such  its  behavior  will interact with other overlays in use. By
              default, the glue overlay is automatically configured as the last  overlay  on  the
              superior  backend.  Its  position  on  the  backend can be explicitly configured by
              setting  an  overlay  glue  directive  at  the  desired  position.  This   explicit
              configuration  is  necessary  e.g.  when using the syncprov overlay, which needs to
              follow glue in order to work over all of the glued databases. E.g.
                   database bdb
                   suffix dc=example,dc=com
                   ...
                   overlay glue
                   overlay syncprov

       sync_use_subentry
              Store the syncrepl contextCSN in a subentry instead of the  context  entry  of  the
              database.  The  subentry's  RDN will be "cn=ldapsync". By default the contextCSN is
              stored in the context entry.

       syncrepl  rid=<replica  ID>  provider=ldap[s]://<hostname>[:port]   searchbase=<base   DN>
              [type=refreshOnly|refreshAndPersist]      [interval=dd:hh:mm:ss]     [retry=[<retry
              interval>  <#  of  retries>]+]  [filter=<filter  str>]  [scope=sub|one|base|subord]
              [attrs=<attr    list>]    [attrsonly]    [sizelimit=<limit>]    [timelimit=<limit>]
              [schemachecking=on|off]       [network-timeout=<seconds>]       [timeout=<seconds>]
              [bindmethod=simple|sasl]   [binddn=<dn>]   [saslmech=<mech>]   [authcid=<identity>]
              [authzid=<identity>] [credentials=<passwd>] [realm=<realm>] [secprops=<properties>]
              [keepalive=<idle>:<probes>:<interval>]   [starttls=yes|critical]  [tls_cert=<file>]
              [tls_key=<file>]             [tls_cacert=<file>]             [tls_cacertdir=<path>]
              [tls_reqcert=never|allow|try|demand]                    [tls_ciphersuite=<ciphers>]
              [tls_crlcheck=none|peer|all]   [suffixmassage=<real   DN>]   [logbase=<base    DN>]
              [logfilter=<filter str>] [syncdata=default|accesslog|changelog]
              Specify  the current database as a replica which is kept up-to-date with the master
              content by establishing the current slapd(8) as a replication consumer site running
              a  syncrepl  replication  engine.   The replica content is kept synchronized to the
              master content using the  LDAP  Content  Synchronization  protocol.  Refer  to  the
              "OpenLDAP   Administrator's  Guide"  for  detailed  information  on  setting  up  a
              replicated slapd directory service using the syncrepl replication engine.

              rid identifies the current syncrepl directive within the replication consumer site.
              It  is  a  non-negative  integer  not  greater  than  999 (limited to three decimal
              digits).

              provider specifies the replication provider site containing the master  content  as
              an  LDAP URI. If <port> is not given, the standard LDAP port number (389 or 636) is
              used.

              The content of the syncrepl replica is defined using a search specification as  its
              result  set.  The  consumer  slapd  will send search requests to the provider slapd
              according  to  the  search  specification.  The   search   specification   includes
              searchbase, scope, filter, attrs, attrsonly, sizelimit, and timelimit parameters as
              in the normal search specification.  The scope defaults to sub, the filter defaults
              to  (objectclass=*),  while there is no default searchbase. The attrs list defaults
              to "*,+" to return all user and operational attributes, and attrsonly is  unset  by
              default.   The  sizelimit  and  timelimit  only  accept  "unlimited"  and  positive
              integers, and both default to "unlimited".  The sizelimit and timelimit  parameters
              define  a  consumer  requested  limitation  on  the  number  of entries that can be
              returned by the LDAP Content Synchronization operation; as such, it is intended  to
              implement  partial  replication based on the size of the replicated database and on
              the time required by the synchronization.  Note, however,  that  any  provider-side
              limits  for the replication identity will be enforced by the provider regardless of
              the limits requested by the LDAP Content Synchronization operation, much  like  for
              any other search operation.

              The  LDAP  Content  Synchronization  protocol  has  two  operation  types.   In the
              refreshOnly operation, the next synchronization search  operation  is  periodically
              rescheduled at an interval time (specified by interval parameter; 1 day by default)
              after each synchronization operation finishes.  In the refreshAndPersist operation,
              a synchronization search remains persistent in the provider slapd.  Further updates
              to the master replica will generate searchResultEntry to the consumer slapd as  the
              search responses to the persistent synchronization search.

              If  an  error  occurs  during  replication,  the consumer will attempt to reconnect
              according to the retry parameter which is a list of the <retry interval> and <#  of
              retries>  pairs.  For example, retry="60 10 300 3" lets the consumer retry every 60
              seconds for the first 10 times and then retry every 300  seconds  for  the  next  3
              times  before  stop  retrying. The `+' in <# of retries> means indefinite number of
              retries until success.  If no retry was  specified,  by  default  syncrepl  retries
              every hour forever.

              The  schema  checking  can be enforced at the LDAP Sync consumer site by turning on
              the schemachecking parameter. The default is off.  Schema checking  on  means  that
              replicated  entries  must  have  a structural objectClass, must obey to objectClass
              requirements in terms of required/allowed attributes, and  that  naming  attributes
              and distinguished values must be present.  As a consequence, schema checking should
              be off when partial replication is used.

              The network-timeout parameter sets how long the consumer will wait to  establish  a
              network  connection  to the provider. Once a connection is established, the timeout
              parameter determines how long the consumer will wait for the initial  Bind  request
              to complete. The defaults for these parameters come from ldap.conf(5).

              A  bindmethod of simple requires the options binddn and credentials and should only
              be used when  adequate  security  services  (e.g.  TLS  or  IPSEC)  are  in  place.
              REMEMBER:  simple  bind  credentials  must  be  in cleartext!  A bindmethod of sasl
              requires the option  saslmech.   Depending  on  the  mechanism,  an  authentication
              identity  and/or  credentials  can be specified using authcid and credentials.  The
              authzid parameter may be used  to  specify  an  authorization  identity.   Specific
              security  properties  (as with the sasl-secprops keyword above) for a SASL bind can
              be set with the secprops option. A non default SASL realm can be set with the realm
              option.  The identity used for synchronization by the consumer should be allowed to
              receive an unlimited number of entries  in  response  to  a  search  request.   The
              provider,  other  than  allow authentication of the syncrepl identity, should grant
              that identity appropriate access privileges to the data that  is  being  replicated
              (access directive), and appropriate time and size limits.  This can be accomplished
              by either allowing unlimited sizelimit and timelimit, or by setting an  appropriate
              limits  statement  in  the  consumer's  configuration (see sizelimit and limits for
              details).

              The keepalive parameter sets the values of idle, probes, and interval used to check
              whether  a  socket  is  alive;  idle is the number of seconds a connection needs to
              remain idle before TCP starts sending  keepalive  probes;  probes  is  the  maximum
              number of keepalive probes TCP should send before dropping the connection; interval
              is interval in seconds between individual  keepalive  probes.   Only  some  systems
              support  the  customization  of  these  values;  the keepalive parameter is ignored
              otherwise, and system-wide settings are used.

              The starttls  parameter  specifies  use  of  the  StartTLS  extended  operation  to
              establish a TLS session before Binding to the provider. If the critical argument is
              supplied, the session will be aborted if the StartTLS request fails. Otherwise  the
              syncrepl  session  continues  without  TLS.  The  tls_reqcert  setting  defaults to
              "demand" and the other TLS settings default to the  same  as  the  main  slapd  TLS
              settings.

              The  suffixmassage  parameter  allows  the  consumer  to pull entries from a remote
              directory whose DN suffix differs from the local  directory.  The  portion  of  the
              remote  entries'  DNs  that  matches  the  searchbase  will  be  replaced  with the
              suffixmassage DN.

              Rather than replicating  whole  entries,  the  consumer  can  query  logs  of  data
              modifications. This mode of operation is referred to as delta syncrepl. In addition
              to the  above  parameters,  the  logbase  and  logfilter  parameters  must  be  set
              appropriately  for the log that will be used. The syncdata parameter must be set to
              either "accesslog" if the log conforms to the  slapo-accesslog(5)  log  format,  or
              "changelog"  if  the log conforms to the obsolete changelog format. If the syncdata
              parameter is omitted or set to "default" then the log parameters are ignored.

       updatedn <dn>
              This option is only applicable in a slave database.  It specifies the DN  permitted
              to  update  (subject to access controls) the replica.  It is only needed in certain
              push-mode replication scenarios.  Generally, this DN should not be the same as  the
              rootdn used at the master.

       updateref <url>
              Specify  the  referral  to  pass back when slapd(8) is asked to modify a replicated
              local database.  If specified multiple times, each url is provided.

DATABASE-SPECIFIC OPTIONS

       Each database may allow specific configuration options; they are documented separately  in
       the  backends'  manual  pages.  See  the  slapd.backends(5) manual page for an overview of
       available backends.

EXAMPLES

       Here is a short example of a configuration file:

              include   /etc/ldap/schema/core.schema
              pidfile   /var/run/slapd.pid

              # Subtypes of "name" (e.g. "cn" and "ou") with the
              # option ";x-hidden" can be searched for/compared,
              # but are not shown.  See slapd.access(5).
              attributeoptions x-hidden lang-
              access to attrs=name;x-hidden by * =cs

              # Protect passwords.  See slapd.access(5).
              access    to attrs=userPassword  by * auth
              # Read access to other attributes and entries.
              access    to *  by * read

              database  bdb
              suffix    "dc=our-domain,dc=com"
              # The database directory MUST exist prior to
              # running slapd AND should only be accessible
              # by the slapd/tools. Mode 0700 recommended.
              directory /var/lib/ldap
              # Indices to maintain
              index     objectClass  eq
              index     cn,sn,mail   pres,eq,approx,sub

              # We serve small clients that do not handle referrals,
              # so handle remote lookups on their behalf.
              database  ldap
              suffix    ""
              uri       ldap://ldap.some-server.com/
              lastmod   off

       "OpenLDAP Administrator's Guide" contains a longer annotated example  of  a  configuration
       file.  The original /etc/ldap/slapd.conf is another example.

FILES

       /etc/ldap/slapd.conf
              default slapd configuration file

SEE ALSO

       ldap(3),     gnutls-cli(1),     slapd-config(5),    slapd.access(5),    slapd.backends(5),
       slapd.overlays(5), slapd.plugin(5),  slapd.replog(5),  slapd(8),  slapacl(8),  slapadd(8),
       slapauth(8), slapcat(8), slapdn(8), slapindex(8), slappasswd(8), slaptest(8).

       "OpenLDAP Administrator's Guide" (http://www.OpenLDAP.org/doc/admin/)

ACKNOWLEDGEMENTS

       OpenLDAP    Software    is    developed   and   maintained   by   The   OpenLDAP   Project
       <http://www.openldap.org/>.  OpenLDAP Software is derived from University of Michigan LDAP
       3.3 Release.