# $OpenLDAP$
-# Copyright 1999-2000, The OpenLDAP Foundation, All Rights Reserved.
+# Copyright 1999-2008 The OpenLDAP Foundation, All Rights Reserved.
# COPYING RESTRICTIONS APPLY, see COPYRIGHT.
H1: Constructing a Distributed Directory Service
and {{superior}} knowledge information.
!else
{{slapd}} supports {{subordinate}} and {{superior}} knowledge information.
+Subordinate knowledge information is held in {{EX:referral}}
+objects ({{REF:RFC3296}}).
!endif
The server uses this information to generate referrals and
search continuations to subordinate servers.
-For those familiar with X.500, a {{named referral}} object is
+For those familiar with {{TERM:X.500}}, a {{named referral}} object is
similar to an X.500 knowledge reference held in a {{subr}}
{{TERM:DSE}}.
The server uses this information to generate referrals to
management operations.
-For those familiar with X.500, this use of the {{EX:ref}} attribute
-is similar to an X.500 knowledge reference held in a
+For those familiar with {{TERM:X.500}}, this use of the {{EX:ref}}
+attribute is similar to an X.500 knowledge reference held in a
{{immSupr}} {{TERM:DSE}}.
!endif
H2: Superior Knowledge Information
-Superior knowledge information may be specified using the
-{{EX:referral}} directive. The value is a list of {{TERM:URI}}s
-referring to superior directory services. For servers without
-immediate superiors, such as for {{EX:a.example.net}} in the example
-above, the server can be configured to use a directory service with
-{{global knowledge}}, such as the {{OpenLDAP Root Service}}
+Superior knowledge information may be specified using the {{EX:referral}}
+directive. The value is a list of {{TERM:URI}}s referring to
+superior directory services. For servers without immediate superiors,
+such as for {{EX:a.example.net}} in the example above, the server
+can be configured to use a directory service with {{global knowledge}},
+such as the {{OpenLDAP Root Service}}
({{URL:http://www.openldap.org/faq/index.cgi?file=393}}).
> referral ldap://root.openldap.org/
> referral ldap://a.example.net/
-The server uses this information to generate referrals for
-operations acting upon entries not within or subordinate
-to any of the naming contexts held by the server.
+The server uses this information to generate referrals for operations
+acting upon entries not within or subordinate to any of the naming
+contexts held by the server.
-For those familiar with X.500, this use of the {{EX:ref}} attribute
-is similar to an X.500 knowledge reference held in a
+For those familiar with {{TERM:X.500}}, this use of the {{EX:ref}}
+attribute is similar to an X.500 knowledge reference held in a
{{Supr}} {{TERM:DSE}}.
Note: the {{EX:ref}} attribute is operational and must be explicitly
requested when desired in search results.
+Note: the use of referrals to construct a Distributed Directory Service is
+extremely clumsy and not well supported by common clients. If an existing
+installation has already been built using referrals, the use of the
+{{chain}} overlay to hide the referrals will greatly improve the usability
+of the Directory system. A better approach would be to use explicitly
+defined local and proxy databases in {{subordinate}} configurations to
+provide a seamless view of the Distributed Directory.