.TH SLAPO-CHAIN 5 "RELEASEDATE" "OpenLDAP LDVERSION"
.\" Copyright 1998-2005 The OpenLDAP Foundation, All Rights Reserved.
.\" Copying restrictions apply.  See the COPYRIGHT file.
.\" $OpenLDAP$
.SH NAME
slapo-chain \- chain overlay
.SH SYNOPSIS
ETCDIR/slapd.conf
.SH DESCRIPTION
The
.B chain
overlay to
.BR slapd (8)
allows automatic referral chasing.
Any time a referral is returned (except for bind operations),
it is chased by using an instance of the ldap backend.
If operations are performed with an identity (i.e. after a bind),
the referrals are chased with the 
.B acl-authcDN 
(if any; see
.BR slapd-ldap (5)
for details), with the original identity asserted by means of the
.B proxyAuthz
control (see \fIdraft-weltman-ldapv3-proxy\fP for details).

.LP 
The config directives that are specific to the
.B chain
overlay can be prefixed by
.BR chain\- ,
to avoid conflicts with directives specific to the underlying database
or to other stacked overlays.

.LP
There are no chain overlay specific directives; however, directives 
related to the instance of the ldap backend that is implicitly 
instantiated by the overlay may assume a special meaning when used 
in conjuction with this overlay.
.TP
.B overlay chain
This directive adds the chain overlay to the current backend.
The chain overlay may be used with any backend but is intended 
for use with local storage backends that may return referrals.
It is useless in conjunction with the ldap and meta backends
because they exploit the libldap specific referral chase feature.
.TP
.B chain-uri <ldapuri>
This directive instructs the underlying ldap database about which
URI to contact to follow referrals.
If not given, the referral itself is parsed, and the protocol/host/port
portions are used to establish a connection.

.LP
Directives for configuring the underlying ldap database must also be given, 
as shown here:
.LP
.RS
.nf
chain-acl-authcDN	cn=Auth,dc=example,dc=com
chain-acl-passwd	secret
.fi
.RE
.LP
Any valid directives for the ldap database may be used; see
.BR slapd-ldap (5)
for details.
.SH FILES
.TP
ETCDIR/slapd.conf
default slapd configuration file
.SH SEE ALSO
.BR slapd.conf (5),
.BR slapd\-ldap (5),
.BR slapd (8).
.SH AUTHOR
Originally implemented by Howard Chu.