rfc3088.txt

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       c: searchRequest {
           base="CN=subordinate,DC=example,DC=net"
           scope=base
           filter=(objectClass=*)
           ManageDSAit
       }

       s: searchResult {
           noSuchObject
           matchedDN="DC=example,DC=net"
       }

5. Using the Service

   Servers may be configured to refer superior requests to
   <ldap://root.openldap.org:389>.

   Though clients may use the service directly, this is not encouraged.
   Clients should use a local service and only use this service when
   referred to it.

   The service supports LDAPv3 and LDAPv2+ [LDAPv2+] clients over
   TCP/IPv4.  Future incarnations of this service may support TCP/IPv6
   or other transport/internet protocols.



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RFC 3088                 OpenLDAP Root Service                April 2001


6. Lessons Learned

6.1. Scaling / Reliability

   This service currently runs on a single host.  This host and
   associated network resources are not yet exhausted.  If they do
   become exhausted, we believe we can easily scale to meet the demand
   through common distributed load balancing technics.  The service can
   also easily be duplicated locally.

6.2. Protocol interoperability

   This service has able avoided known interoperability issues in
   supporting variants of LDAP.

6.2.1. LDAPv3

   The server implements all features of LDAPv3 [RFC2251] necessary to
   provide the service.

6.2.2. LDAPv2

   LDAPv2 [RFC1777] does not support the return of referrals and hence
   may not be referred to this service.  Though a LDAPv2 client could
   connect and issue requests to this service, the client would treat
   any referral returned to it as an unknown error.

6.2.3. LDAPv2+

   LDAPv2+ [LDAPv2+] provides a number of extensions to LDAPv2,
   including referrals.  LDAPv2+, like LDAPv3, does not require a bind
   operation before issuing of other operations.  As the referral
   representation differ between LDAPv2+ and LDAPv3, the service returns
   LDAPv3 referrals in this case.  However, as commonly deployed LDAPv2+
   clients issue bind requests (for compatibility with LDAPv2 servers),
   this has not generated any interoperability issues (yet).

   A future incarnation of this service may drop support for LDAPv2+
   (and LDAPv2).

6.2.4. CLDAP

   CLDAP [RFC1798] does not support the return of referrals and hence is
   not supported.







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RFC 3088                 OpenLDAP Root Service                April 2001


7. Security Considerations

   This service provides information to "anonymous" clients.  This
   information is derived from the public directories, namely the Domain
   Name System.

   The use of authentication would require clients to disclose
   information to the service.  This would be an unnecessary invasion of
   privacy.

   The lack of encryption allows eavesdropping upon client requests and
   responses.  A later incarnation of this service may support
   encryption (such as via Start TLS [RFC2830]).

   Information integrity protection is not provided by the service.  The
   service is subject to varies forms of DNS spoofing and attacks.  LDAP
   session or operation integrity would provide false sense of security
   concerning the integrity of DNS information.  A later incarnation of
   this service may support DNSSEC and provide integrity protection (via
   SASL, TLS, or IPSEC).

   The service is subject to a variety of denial of service attacks.
   The service is capable of blocking access by a number of factors.
   This capability have yet to be used and likely would be ineffective
   in preventing sophisticated attacks.  Later incarnations of this
   service will likely need better protection from such attacks.

8. Conclusions

   DNS is good glue.  By leveraging of the Domain Name System, global
   LDAP directories may be built without requiring a protocol specific
   registration infrastructures.

   In addition, use of DNS service location allows global directories to
   be built "ad hoc".  That is, anyone with a domain name can
   participate.  There is no requirement that the superior domain
   participate.

9. Additional Information

   Additional information about the OpenLDAP Project and the OpenLDAP
   Root Service can be found at <http://www.openldap.org/>.









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RFC 3088                 OpenLDAP Root Service                April 2001


10. Author's Address

   Kurt Zeilenga
   OpenLDAP Foundation

   EMail: [e-mail]

11. Acknowledgments

   Internet hosting for this experiment is provided by the Internet
   Software Consortium <http://www.isc.org/>.  Computing resources were
   provided by Net Boolean Incorporated <http://www.boolean.net/>.  This
   experiment would not have been possible without the contributions of
   numerous volunteers of the open source community.  Mechanisms
   described in this document are based upon those introduced in
   [RFC2247] and [LOCATE].

References

   [RFC1034]  Mockapetris, P., "Domain Names - Concepts and Facilities",
              STD 13, RFC 1034, November 1987.

   [RFC1777]  Yeong, W., Howes, T. and S. Kille, "Lightweight Directory
              Access Protocol", RFC 1777, March 1995.

   [RFC1798]  Young, A., "Connection-less Lightweight Directory Access
              Protocol", RFC 1798, June 1995.

   [RFC2119]  Bradner, S., "Key Words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2247]  Kille, S., Wahl, M., Grimstad, A., Huber, R. and S.
              Sataluri, "Using Domains in LDAP/X.500 Distinguished
              Names", RFC 2247, January 1998.

   [RFC2251]  Wahl, M., Howes, T. and S. Kille, "Lightweight Directory
              Access Protocol (v3)", RFC 2251, December 1997.

   [RFC2253]  Wahl, M., Kille, S. and T. Howes, "Lightweight Directory
              Access Protocol (v3): UTF-8 String Representation of
              Distinguished Names", RFC 2253, December 1997.

   [RFC2255]  Howes, T. and M. Smith, "The LDAP URL Format", RFC 2255,
              December 1997.

   [RFC2782]  Gulbrandsen, A., Vixie, P. and L. Esibov, "A DNS RR for
              specifying the location of services (DNS SRV)", RFC 2782,
              February 2000.



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   [RFC2829]  Wahl, M., Alvestrand, H., Hodges, J. and R. Morgan,
              "Authentication Methods for LDAP", RFC 2829, May 2000.

   [RFC2830]  Hodges, J., Morgan, R. and M. Wahl, "Lightweight Directory
              Access Protocol (v3): Extension for Transport Layer
              Security", RFC 2830, May 2000.

   [LOCATE]   IETF LDAPext WG, "Discovering LDAP Services with DNS",
              Work in Progress.

   [LDAPv2+]  University of Michigan LDAP Team, "Referrals within the
              LDAPv2 Protocol", August 1996.

   [NAMEDREF] Zeilenga, K. (editor), "Named Subordinate References in
              LDAP Directories", Work in Progress.

   [X500]     ITU-T Rec. X.500, "The Directory: Overview of Concepts,
              Models and Service",  1993.

































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RFC 3088                 OpenLDAP Root Service                April 2001


Full Copyright Statement

   Copyright (C) The Internet Society (2001).  All Rights Reserved.

   This document and translations of it may be copied and furnished to
   others, and derivative works that comment on or otherwise explain it
   or assist in its implementation may be prepared, copied, published
   and distributed, in whole or in part, without restriction of any
   kind, provided that the above copyright notice and this paragraph are
   included on all such copies and derivative works.  However, this
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Acknowledgement

   Funding for the RFC Editor function is currently provided by the
   Internet Society.



















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