Hi I try to connect my Freeradius to a Zimbra LDAP server with multidomain. In Zimbra, the LDAP tree is something like : "ou=people,dc=domain,dc=tld". I have some domains in ".fr" and some other in ".org". If I configure with the basedn = "dc=fr", Freeradius works well for all the domains in ".fr". But if I try to allow all my domains (with a basedn=""), Freeradius don't accept to authenticate the users. In the logs, when there is a reject, I can see : [ldap-inner-tunnel] performing user authorization for XXXXX [ldap-inner-tunnel] expand: (mail=%{User-Name}) -> (mail=XXXXX.fr) [ldap-inner-tunnel] expand: -> [ldap-inner-tunnel] unable to create basedn. ++[ldap-inner-tunnel] returns invalid Invalid user: [XXXXX.fr] (from client localhost port 0 via TLS tunnel) I found a topic in the list http://freeradius.1045715.n5.nabble.com/Sending-null-BaseDN-td5716006.html in 2012, but there is no solution. I am on a Debian stable Freeradius 2.1.12 Thanks a lot. Dom