В итоге имеем конфигурацию:
AuthName "Restricted access" AuthType Basic AuthLDAPEnabled on AuthzLDAPAuthoritative off AuthLDAPURL "ldap://server.local:3268/DC=SERVER,DC=LOCAL?sAMAccountName?sub"AuthLDAPBindDN "secretname@server.local" AuthLDAPBindPassword "Password" Require group CN=neededgroup,OU=Group,DC=Server,DC=Local