slapd — Stand-alone LDAP Daemon


slapd [-4|-6] [-T {acl|a[dd]|auth|c[at]| d[n]|i[ndex]|p[asswd]|s[chema]|t[est]}] [-d debug-level] [-f slapd-config-file] [-F slapd-config-directory] [-h URLs] [-n service-name] [-s syslog-level] [-l syslog-local-user] [-o option[=value]] [-r directory] [-u user] [-g group] [-c cookie]


Slapd is the stand-alone LDAP daemon. It listens for LDAP connections on any number of ports (default 389), responding to the LDAP operations it receives over these connections. slapd is typically invoked at boot time, usually out of /etc/rc.local. Upon startup, slapd normally forks and disassociates itself from the invoking tty. If configured in the config file (or config directory), the slapd process will print its process ID (see getpid(2)) to a .pid file, as well as the command line options during invocation to an .args file (see slapd.conf(5)). If the -d flag is given, even with a zero argument, slapd will not fork and disassociate from the invoking tty.

See the "OpenLDAP Administrator's Guide" for more details on slapd.



Listen on IPv4 addresses only.


Listen on IPv6 addresses only.

-T tool

Run in Tool mode. The tool argument selects whether to run as slapadd, slapcat, slapdn, slapindex, slappasswd, slapschema, or slaptest (slapacl and slapauth need the entire acl and auth option value to be spelled out, as a is reserved to slapadd). This option should be the first option specified when it is used; any remaining options will be interpreted by the corresponding  slap tool program, according to the respective man pages. Note that these tool programs will usually be symbolic links to slapd. This option is provided for situations where symbolic links  are not provided or not usable.

-d debug-level

Turn on debugging as defined by debug-level. If this option is specified, even with a zero argument, slapd will not fork or disassociate from the invoking terminal.  Some general operation and status messages are printed for any value of debug-level. debug-level is taken as a bit string, with each bit corresponding to a different kind of debugging information.  See <ldap_log.h> for details. Comma-separated arrays of friendly names can be specified to select debugging output of the corresponding debugging information. All the names recognized by the loglevel directive  described in slapd.conf(5) are supported. If debug-level is ?, a list of installed debug-levels is printed, and slapd exits.

Remember that if you turn on packet logging, packets containing bind passwords will be output, so if you redirect the log to a logfile, that file should be read-protected.

-s syslog-level

This option tells slapd at what debug-level debugging statements should be logged to the syslog(8) facility. The value syslog-level can be set to any value or combination allowed by the -d switch. Slapd logs all messages selected by syslog-level  at the syslog(3) severity debug-level DEBUG, on the unit specified with -l.

-n service-name

Specifies the service name for logging and other purposes.  Defaults to basename of argv[0], i.e.: "slapd".

-l syslog-local-user

Selects the local user of the syslog(8) facility. Value can be LOCAL0, through LOCAL7, as well as USER and DAEMON. The default is LOCAL4. However, this option is only permitted on systems that support local users with the syslog(8) facility. Logging to syslog(8) occurs at the "DEBUG" severity debug-level.

-f slapd-config-file

Specifies the slapd configuration file. The default is /etc/openldap/slapd.conf.

-F slapd-config-directory

Specifies the slapd configuration directory. The default is /etc/openldap/slapd.d. If both -f and -F are specified, the config file will be read and converted to config directory format and written to the specified directory. If neither option is specified, slapd will attempt to read the default config directory before trying to use the default config file. If a valid config directory exists then the default config file is ignored. All of the slap tools that use the config options observe this same behavior.

-h URLlist

slapd will by default serve ldap:/// (LDAP over TCP on all interfaces on default LDAP port).  That is,  it will bind using INADDR_ANY and port 389. The -h option may be used to specify LDAP (and other scheme) URLs to serve. For example, if slapd is given -h "ldap:// ldaps:/// ldapi:///", it will listen on for LDAP, for LDAP over TLS, and LDAP over IPC (Unix domain sockets).  Host represents INADDR_ANY (any interface). A space separated list of URLs is expected.  The URLs should be of the LDAP, LDAPS, or LDAPI schemes, and generally without a DN or other optional parameters (excepting as discussed below). Support for the latter two schemes depends on selected configuration  options.  Hosts may be specified by name or IPv4 and IPv6 address formats. Ports, if specified, must be numeric.  The default ldap:// port is 389 and the default ldaps:// port is 636.

For LDAP over IPC, name is the name of the socket, and no port is required, nor allowed; note that directory separators must be  URL-encoded, like any other characters that are special to URLs;  so the socket


must be specified as


The default location for the IPC socket is /var/run/ldapi

The listener permissions are indicated by "x-mod=-rwxrwxrwx", "x-mod=0777" or "x-mod=777", where any  of the "rwx" can be "-" to suppress the related permission, while any  of the "7" can be any legal octal digit, according to chmod(1). The listeners can take advantage of the "x-mod" extension to apply rough limitations to operations, e.g. allow read operations ("r", which applies to search and compare), write operations ("w",  which applies to add, delete, modify and modrdn), and execute operations ("x", which means bind is required). "User" permissions apply to authenticated users, while "other" apply to anonymous users; "group" permissions are ignored. For example, "ldap:///????x-mod=-rw-------" means that read and write is only allowed for authenticated connections, and bind is required for all operations. This feature is experimental, and requires to be manually enabled at configure time.

-r directory

Specifies a directory to become the root directory.  slapd will change the current working directory to this directory and then chroot(2) to this directory.  This is done after opening listeners but before reading any configuration file or initializing any backend.  When used as a security mechanism, it should be used in conjunction with -u and -g options.

-u user

slapd will run slapd with the specified user name or id, and that user's supplementary group access list as set with initgroups(3).  The group ID is also changed to this user's gid, unless the -g option is used to override.  Note when used with -r, slapd will use the user database in the change root environment.

Note that on some systems, running as a non-privileged user will prevent passwd back-ends from accessing the encrypted passwords.  Note also that any shell back-ends will run as the specified non-privileged user.

-g group

slapd will run with the specified group name or id.  Note when used with -r, slapd will use the group database in the change root environment.

-c cookie

This option provides a cookie for the syncrepl replication consumer. The cookie is a comma separated list of name=value pairs. Currently supported syncrepl cookie fields are rid, sid, and csn. rid identifies a replication thread within the consumer server and is used to find the syncrepl specification in slapd.conf(5) or slapd-config(5) having the matching replication identifier in its definition. The rid must be provided in order for any other specified values to be used. sid is the server id in a multi-master/mirror-mode configuration. csn is the commit sequence number received by a previous synchronization and represents the state of the consumer replica content which the syncrepl engine will synchronize to the current provider content. In case of mirror-mode or multi-master replication agreement, multiple csn values, semicolon separated, can appear. Use only the rid part to force a full reload.

-o option[=value]

This option provides a generic means to specify options without the need to reserve a separate letter for them.

It supports the following options:


When SLP support is compiled into slapd, disable it (off),
enable it by registering at SLP DAs without specific SLP attributes (on), or with specific SLP attributes slp-attrs that must be an SLP attribute list definition according to the SLP standard.

For example, "slp=(tree=production),(server-type=OpenLDAP),(server-version=2.4.15)" registers at SLP DAs with the three SLP attributes tree, server-type and server-version that have the values given above. This allows one to specifically query the SLP DAs for LDAP servers holding the production tree in case multiple trees are available.


To start slapd and have it fork and detach from the terminal and start serving the LDAP databases defined in the default config file, just type:


To start slapd with an alternate configuration file, and turn on voluminous debugging which will be printed on standard error, type:

	slapd -f /var/tmp/slapd.conf -d 255

To test whether the configuration file is correct or not, type:

	slapd -Tt

See Also

ldap(3), slapd.conf(5), slapd-config(5), slapd.access(5), slapacl(8), slapadd(8), slapauth(8), slapcat(8), slapdn(8), slapindex(8), slappasswd(8), slapschema(8), slaptest(8).

"OpenLDAP Administrator's Guide" (




OpenLDAP Software is developed and maintained by The OpenLDAP Project <>. OpenLDAP Software is derived from the University of Michigan LDAP 3.3 Release.  

Referenced By

ldap(3), ldap_sync(3), slapacl(8), slapadd(8), slapauth(8), slapcat(8), slapd.access(5), slapd.backends(5), slapd-bdb(5), slapd.conf(5), slapd-config(5), slapd-dnssrv(5), slapd-ldap(5), slapd-ldif(5), slapd-mdb(5), slapd-meta(5), slapd-monitor(5), slapdn(8), slapd-ndb(5), slapd-null(5), slapd.overlays(5), slapd-passwd(5), slapd-perl(5), slapd.plugin(5), slapd-relay(5), slapd_selinux(8), slapd-shell(5), slapd-sock(5), slapd-sql(5), slapindex(8), slapo-chain(5), slapo-dds(5), slapo-dynlist(5), slapo-memberof(5), slapo-pbind(5), slapo-pcache(5), slapo-retcode(5), slapo-rwm(5), slappasswd(8), slapschema(8), slaptest(8).

2018/12/19 OpenLDAP 2.4.47