When using a ldap server under Active directory server you get the following error:

Unable to connect to aus.namehidden.com: javax.naming.NamingException: [LDAP:
error code 1 - 00000000: LdapErr: DSID-0C090627, comment: In order to perform
this operation a successful bind must be completed on the connection., data 0,
vece�]; remaining name ''

It seems like a user name and password is required to first bind with the server.

(Hudson version 1.660)