Connection-less Lightweight Directory Access Protocol (CLDAP) to Historic Status
Why the connection-less flavour of LDAP never caught on, and why RFC 1798 was retired to Historic.
Zeilenga, K., "Connection-less Lightweight Directory Access Protocol (CLDAP) to Historic Status", RFC 3352, DOI 10.17487/RFC3352, March 2003, <https://www.rfc-editor.org/info/rfc3352>.
@misc{rfc3352,
series = {Request for Comments},
number = 3352,
howpublished = {RFC 3352},
publisher = {RFC Editor},
doi = {10.17487/RFC3352},
url = {https://www.rfc-editor.org/info/rfc3352},
author = {K. Zeilenga},
title = {{Connection-less Lightweight Directory Access Protocol (CLDAP) to Historic Status}},
pagetotal = 4,
year = 2003,
month = mar,
} RFC text
Contents
Network Working Group K. Zeilenga
Request for Comments: 3352 OpenLDAP Foundation
Obsoletes: 1798 March 2003
Category: Informational
Connection-less Lightweight Directory Access Protocol (CLDAP)
to Historic Status
Status of this Memo
This memo provides information for the Internet community. It does
not specify an Internet standard of any kind. Distribution of this
memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2003). All Rights Reserved.
Abstract
The Connection-less Lightweight Directory Access Protocol (CLDAP)
technical specification, RFC 1798, was published in 1995 as a
Proposed Standard. This document discusses the reasons why the CLDAP
technical specification has not been furthered on the Standard Track.
This document recommends that RFC 1798 be moved to Historic status.
1. Background
Connection-less Lightweight Directory Access Protocol (CLDAP)
[RFC1798] was published in 1995 as a Proposed Standard. The protocol
was targeted at applications which require lookup of small amounts of
information held in the directory. The protocol avoids the overhead
of establishing (and closing) a connection and the session bind and
unbind operations needed in connection-oriented directory access
protocols. The CLDAP was designed to complement version 2 of the
Lightweight Directory Access Protocol (LDAPv2) [RFC1777], now
Historic [HISTORIC].
In the seven years since its publication, CLDAP has not become widely
deployed on the Internet. There are a number of probable reasons for
this:
- Limited functionality:
+ anonymous only,
+ read only,
+ small result sizes only, and
- Insufficient security capabilities:
+ no integrity protection,
+ no confidentiality protection
- Inadequate internationalization support;
- Insufficient extensibility; and
- Lack of multiple independently developed implementations.
The CLDAP technical specification has normative references to
multiple obsolete technical specifications including X.501(88),
X.511(88), RFC 1487 (the predecessor to RFC 1777, the now Historic
LDAPv2 technical specification). Unless the technical specification
were to be updated, CLDAP cannot remain on the standards track
because of the Normative reference to a Historic RFC.
The community recognized in the mid-1990s that CLDAP needed to be
updated. In response to this, the IETF chartered the LDAP Extensions
Working Group (LDAPext WG) in 1997 to undertake this update. The
LDAPext WG is concluding without producing an update to CLDAP.
Currently, there is no standardization effort to update CLDAP.
It should be noted that the community still has interest in
developing a "connection-less" directory access protocol. However,
based on operational experience, has determined that further
experimentation is necessary to address outstanding technical issues.
In particular, security considerations associated with
"connection-less" services need to be addressed.
2. Recommendation
As there is no viable standardization effort to update CLDAP as
necessary to keep it on the standards track and the community
currently considers this an area requiring further experimentation,
RFC 1798 must be moved to Historic status.
It is recommended that those interested in connection-less access to
X.500-based directory services experiment with [LDAPUDP] and other
alternatives which might become available.
3. Security Considerations
The security of the Internet will not be impacted by the retirement
of CLDAP.
4. Acknowledgment
The author would like to thank the designers of CLDAP for their
contribution to the Internet community.
5. Normative References
[HISTORIC] Zeilenga, K., "Lightweight Directory Access Protocol
version 2 (LDAPv2) to Historic Status", RFC 3494, February
2003.
[CLDAP] Young, A. "Connection-less Lightweight Directory Access
Protocol," RFC 1798, June 1995.
6. Informative References
[LDAPUDP] Johansson, L. and R. Hedberg, "Lightweight Directory
Access Protocol over UDP/IP," Work in Progress.
[RFC1777] Yeong, W., Howes, T. and S. Kille, "Lightweight Directory
Access Protocol", RFC 1777, March 1995.
[RFC3377] Hodges, J. and R. Morgan, "Lightweight Directory Access
Protocol (v3): Technical Specification", RFC 3377,
September 2002.
[X501] The Directory: Models. CCITT Recommendation X.501 ISO/IEC
JTC 1/SC21; International Standard 9594-2, 1988.
[X511] The Directory: Abstract Service Definition. CCITT
Recommendation X.511, ISO/IEC JTC 1/SC21; International
Standard 9594-3, 1988.
7. Author's Address
Kurt D. Zeilenga
OpenLDAP Foundation
EMail: Kurt@OpenLDAP.org
8. Full Copyright Statement
Copyright (C) The Internet Society (2003). All Rights Reserved.
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Acknowledgement
Funding for the RFC Editor function is currently provided by the
Internet Society.
AI ELI5
On this page
§1What CLDAP Was
Connection-less LDAP (CLDAP, RFC 1798) was published in 1995 as a Proposed Standard. It targeted applications that look up small amounts of information held in a directory. It skipped the cost of opening and closing a connection, and the bind and unbind operations that connection-oriented directory protocols need.
It was designed to complement version 2 of the Lightweight Directory Access Protocol (LDAPv2, RFC 1777), which is itself now Historic.
CLDAP was a way to ask a quick question without first knocking, saying hello and signing in. Like shouting a question across the street instead of making a phone call.
§2Why It Did Not Take Off
Seven years after publication, the memo says CLDAP had not become widely deployed on the Internet. It lists probable reasons:
- Limited functionality: anonymous only, read only, and small result sizes only.
- Insufficient security: no integrity protection and no confidentiality protection.
- Inadequate internationalization support and insufficient extensibility.
- A lack of multiple independently developed implementations.
There was also a standards-process problem. The specification has normative references to several obsolete specifications, including RFC 1487, the predecessor of RFC 1777. Without an update, it could not remain on the standards track because of the normative reference to a Historic RFC.
It could only ask, never change anything, and anyone could listen in. Few people built it, and its old rule book pointed at other rule books that had been thrown out.
§3The Recommendation
The IETF chartered the LDAP Extensions Working Group in 1997 to update CLDAP. That group was concluding without producing an update, and no standardization effort remained. The community still wanted a connection-less directory protocol, but considered further experimentation necessary, in particular on the security issues of connection-less services.
The memo therefore says RFC 1798 must be moved to Historic status. It suggests that people interested in connection-less access to X.500-based directory services experiment with LDAP over UDP and other alternatives.
Nobody was going to fix it, so it goes on the history shelf. People who still like the idea are told to try new versions instead.