LDAP authentication

Hi could you help me with LDAP integration?

For example,  there is a user in the directory

cn=john,dc=example,dc=com

ldap connection url: ldap://localhost:1389/dc=example,dc=com

when I press "test connection" I able to test it only using fully qualified name "cn=john,dc=example,dc=com"

what creditnails should be used to log-in into youtrack as "john"?

I tested many combinations without success :-(

and was unable to find any valuable information about that

I using Sun's ldap server  OpenDS