Network Working Group S. Bellovin
Request for Comments: 4278 AT&T Labs Research
Category: Informational A. Zinin
Alcatel
January 2006
Standards Maturity Variance Regarding the TCP MD5 Signature Option
(RFC 2385) and the BGP-4 Specification
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 (2006).
Abstract
The IETF Standards Process requires that all normative references for
a document be at the same or higher level of standardization. RFC
2026 section 9.1 allows the IESG to grant a variance to the standard
practices of the IETF. This document explains why the IESG is
considering doing so for the revised version of the BGP-4
specification, which refers normatively to RFC 2385, "Protection of
BGP Sessions via the TCP MD5 Signature Option". RFC 2385 will remain
at the Proposed Standard level.
1. Introduction
The IETF Standards Process [RFC2026] requires that all normative
references for a document be at the same or higher level of
standardization. RFC 2026 section 9.1 allows the IESG to grant a
variance to the standard practices of the IETF. Pursuant to that, it
is considering publishing the updated BGP-4 specification [RFC4271]
as Draft Standard, despite the normative reference to [RFC2385],
"Protection of BGP Sessions via the TCP MD5 Signature Option". RFC
2385 will remain a Proposed Standard. (Note that although the title
of [RFC2385] includes the word "signature", the technology described
in it is commonly known as a Message Authentication Code or MAC, and
should not be confused with digital signature technologies.)
[RFC2385], which is widely implemented, is the only transmission
security mechanism defined for BGP-4. Other possible mechanisms,
such as IPsec [RFC2401] and TLS [RFC2246], are rarely, if ever, used
Bellovin & Zinin Informational [Page 1]RFC 4278 Standards Maturity Variance: RFC 2385 and BGP-4 January 2006
for this purpose. Given the long-standing requirement for security
features in protocols, it is not possible to advance BGP-4 without a
mandated security mechanism.
The conflict of maturity levels between specifications would normally
be resolved by advancing the specification being referred to along
the standards track, to the level of maturity that the referring
specification needs to achieve. However, in the particular case
considered here, the IESG believes that [RFC2385], though adequate
for BGP deployments at this moment, is not strong enough for general
use, and thus should not be progressed along the standards track. In
this situation, the IESG believes that variance procedure should be
used to allow the updated BGP-4 specification to be published as
Draft Standard.
The following sections of the document give detailed explanations of
the statements above.
2. Draft Standard Requirements
The requirements for Proposed Standards and Draft Standards are given
in [RFC2026]. For Proposed Standards, [RFC2026] warns that:
Implementors should treat Proposed Standards as immature
specifications. It is desirable to implement them in order to
gain experience and to validate, test, and clarify the
specification. However, since the content of Proposed Standards
may be changed if problems are found or better solutions are
identified, deploying implementations of such standards into a
disruption-sensitive environment is not recommended.
In other words, it is considered reasonable for flaws to be
discovered in Proposed Standards.
The requirements for Draft Standards are higher:
A Draft Standard must be well-understood and known to be quite
stable, both in its semantics and as a basis for developing an
implementation.
In other words, any document that has known deficiencies should not
be promoted to Draft Standard.
Bellovin & Zinin Informational [Page 2]RFC 4278 Standards Maturity Variance: RFC 2385 and BGP-4 January 20063. The TCP MD5 Signature Option
[RFC2385], despite its 1998 publication date, describes a Message
Authentication Code (MAC) that is considerably older. It utilizes a
datatracker.ietf.org