Installation guide
260 Chapter 18. Lightweight Directory Access Protocol (LDAP)
18.3. LDAP Terminology
An entry is one unit in an LDAP directory. Each entry is identified by its unique Distinguished Name
(DN).
Each entry has attributes, which are pieces of information directly associated with the entry. For
example, an organization could be an LDAP entry. Attributes associated with the organization might
be its fax number, its address, and so on. People can also be entries in the LDAP directory. Common
attributes for people include the person’s telephone numbers and email addresses.
Some attributes are required, while other attributes are optional. An objectclass definition sets which
attributes are required and which are not for each entry. Objectclass definitions are found in various
schema files, located in the /etc/openldap/schema/ directory.
The LDAP Data Interchange Format (LDIF) is an ASCII text format for LDAP entries. Files that
import or export data to and from LDAP servers must be in LDIF format. An LDIF entry looks
similar to the following example:
[
id ]
dn: distinguished name
attrtype : attrvalue
attrtype : attrvalue
attrtype : attrvalue
An entry can contain as many attrtype : attrvalue pairs as needed. A blank line indicates
the end of an entry.
Caution
All attrtype and attrvalue pairs must be defined in a corresponding schema file to use
this information.
Any value enclosed within a and a is a variable and can be set whenever a new LDAP entry is
created, except for
id . The id is a number determined by the application you use to edit the
entry.
Note
You should never need to edit an LDIF entry by hand. Instead use an LDAP client application, such
as the ones listed in Section 18.2.
18.4. OpenLDAP Configuration Files
OpenLDAP configuration files are installed into the /etc/openldap/ directory. The following is a
brief list highlighting the most important directories and files:
• /etc/openldap/schema/ directory — This subdirectory contains the schema used by the slapd
daemon. See Section 18.4.2 for more information about this directory.
• /etc/openldap/ldap.conf — This is the configuration file for all client applications which use
the OpenLDAP libraries. These include, but are not limited to, Sendmail, Pine, Balsa, Evolution,
and Gnome Meeting.