draft-josefsson-dns-url-10.txt   draft-josefsson-dns-url-11.txt 
Network Working Group S. Josefsson Network Working Group S. Josefsson
Expires: March 3, 2005 Expires: August 11, 2005
Domain Name System Uniform Resource Identifiers Domain Name System Uniform Resource Identifiers
draft-josefsson-dns-url-10 draft-josefsson-dns-url-11
Status of this Memo Status of this Memo
This document is an Internet-Draft and is subject to all provisions This document is an Internet-Draft and is subject to all provisions
of section 3 of RFC 3667. By submitting this Internet-Draft, each of section 3 of RFC 3667. By submitting this Internet-Draft, each
author represents that any applicable patent or other IPR claims of author represents that any applicable patent or other IPR claims of
which he or she is aware have been or will be disclosed, and any of which he or she is aware have been or will be disclosed, and any of
which he or she become aware will be disclosed, in accordance with which he or she become aware will be disclosed, in accordance with
RFC 3668. RFC 3668.
skipping to change at page 1, line 35 skipping to change at page 1, line 35
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt. http://www.ietf.org/ietf/1id-abstracts.txt.
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This Internet-Draft will expire on March 3, 2005. This Internet-Draft will expire on August 11, 2005.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2004). Copyright (C) The Internet Society (2005).
Abstract Abstract
This document define Uniform Resource Identifiers for Domain Name This document define Uniform Resource Identifiers for Domain Name
System resources. System resources.
Table of Contents Table of Contents
1. Introduction and Background . . . . . . . . . . . . . . . . . 3 1. Introduction and Background . . . . . . . . . . . . . . . . . 3
2. DNS URI Registration . . . . . . . . . . . . . . . . . . . . . 4 2. Usage Model . . . . . . . . . . . . . . . . . . . . . . . . . 4
3. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 3. DNS URI Registration . . . . . . . . . . . . . . . . . . . . . 5
4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 4. Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 5. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9
6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9 6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
6.1 Normative References . . . . . . . . . . . . . . . . . . . . 9 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
6.2 Informative References . . . . . . . . . . . . . . . . . . . 9 8. Copying conditions . . . . . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . 10 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
A. Revision Changes . . . . . . . . . . . . . . . . . . . . . . . 10 9.1 Normative References . . . . . . . . . . . . . . . . . . . . 10
A.1 Changes since -06 . . . . . . . . . . . . . . . . . . . . 10 9.2 Informative References . . . . . . . . . . . . . . . . . . . 10
A.2 Changes since -07 . . . . . . . . . . . . . . . . . . . . 10 Author's Address . . . . . . . . . . . . . . . . . . . . . . . 11
A.3 Changes since -08 . . . . . . . . . . . . . . . . . . . . 11 A. Revision Changes . . . . . . . . . . . . . . . . . . . . . . . 11
A.4 Changes since -09 . . . . . . . . . . . . . . . . . . . . 11 A.1 Changes since -06 . . . . . . . . . . . . . . . . . . . . 11
Intellectual Property and Copyright Statements . . . . . . . . 12 A.2 Changes since -07 . . . . . . . . . . . . . . . . . . . . 11
A.3 Changes since -08 . . . . . . . . . . . . . . . . . . . . 12
A.4 Changes since -09 . . . . . . . . . . . . . . . . . . . . 12
A.5 Changes since -10 . . . . . . . . . . . . . . . . . . . . 12
Intellectual Property and Copyright Statements . . . . . . . . 13
1. Introduction and Background 1. Introduction and Background
The Domain Name System (DNS) [1][2] is a widely deployed system used The Domain Name System (DNS) [1][2] is a widely deployed system used
to, among other things, translate host names into IP addresses. to, among other things, translate host names into IP addresses.
Recent work has added support for storing certificates and Recent work has added support for storing certificates and
certificate revocation lists (CRLs) in the DNS [9]. Several certificate revocation lists (CRLs) in the DNS [9]. Several
protocols use Uniform Resource Locators (URLs) to point at protocols use Uniform Resource Locators (URLs) to point at
certificates and CRLs. By defining a Uniform Resource Identifier certificates and CRLs. By defining a Uniform Resource Identifier
(URI) scheme for DNS resources, such protocols can reference (URI) scheme for DNS resources, such protocols can reference
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The DNS URI scheme defined here can be used to reference any data The DNS URI scheme defined here can be used to reference any data
stored in the DNS, and is not limited to certificates or CRLs. The stored in the DNS, and is not limited to certificates or CRLs. The
purpose of this specification is to define a generic DNS URI, not to purpose of this specification is to define a generic DNS URI, not to
specify a solution only for certificates stored in the DNS. specify a solution only for certificates stored in the DNS.
Data browsers may support DNS URIs by forming DNS queries and render Data browsers may support DNS URIs by forming DNS queries and render
DNS responses using HTML [13], similar to what is commonly done for DNS responses using HTML [13], similar to what is commonly done for
FTP [5] resources. FTP [5] resources.
The core part of this document is the URI Registration Template in
accordance with [12].
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [6]. document are to be interpreted as described in RFC 2119 [6].
2. DNS URI Registration 2. Usage Model
The reader is referred to section 1 of [4] for an in-depth discussion
of URI classifications. In particular, the reader is assumed to be
familiar with the "name" vs "locator" distinction. This section
describe how the DNS URI scheme is intended to be used, and outline
future work that may be required to use URIs with the DNS for some
applications.
The URI scheme described in this document focus on the data stored in
the DNS. As such, there is no provision to specify any of the fields
in the actual DNS protocol. This is intentional, so that the URI may
be used even in situations where the DNS protocol is not used
directly. Two examples for this is zone file editors and DNS-related
configuration files, which may use this URI scheme to identify data.
The application would not use the DNS protocol to resolve the URIs.
A limitation of this design is that it do not accommodate all
protocol parameters within the DNS protocol. It is expected that for
certain applications, a more detailed URI syntax that map more
closely to the DNS protocol may be required. However, such an URI
definition is not included in this document. This document specify a
URI that is primarily intended to name DNS resources, but it can also
be used to locate said resources for simple (but common)
applications.
3. DNS URI Registration
The section contain the registration template for the DNS URI scheme
in accordance with [12].
URL scheme name: "dns". URL scheme name: "dns".
URL scheme syntax: A DNS URI designate a DNS resource record set, URL scheme syntax: A DNS URI designate a DNS resource record set,
referenced by domain name, class, type and optionally the authority. referenced by domain name, class, type and optionally the authority.
The DNS URI follows the generic syntax from RFC 2396 [4], and is The DNS URI follows the generic syntax from RFC 3986 [4], and is
described using ABNF [3]. Strings are not case sensitive and free described using ABNF [3]. Strings are not case sensitive and free
insertion of linear-white-space is not permitted. insertion of linear-white-space is not permitted.
dnsurl = "dns:" [ "//" dnsauthority "/" ] dnsname ["?" dnsquery] dnsurl = "dns:" [ "//" dnsauthority "/" ]
dnsname ["?" dnsquery]
dnsauthority = hostport dnsauthority = host [ ":" port ]
; See RFC 2396 for "hostport" definition. ; See RFC 3986 for the
; definition of "host" and "port".
dnsname = *pchar dnsname = *pchar
; See RFC 2396 for "pchar" definition. ; See RFC 3986 for the
; definition of "pchar".
; The "dnsname" field may be a "relative" ; The "dnsname" field may be a
; or "absolute" name, as per RFC 1034 ; "relative" or "absolute" name,
; section 3.1. ; as per RFC 1034 section 3.1.
; Note further that an empty "dnsname" ; Note further that an empty
; value is to be interpreted as the ; "dnsname" value is to be
; root itself. See below on relative ; interpreted as the root itself.
; dnsname's. ; See below on relative dnsname's.
dnsquery = dnsqueryelement [";" dnsquery] dnsquery = dnsqueryelement [";" dnsquery]
dnsqueryelement = ( "CLASS=" dnsclassval ) / ( "TYPE=" dnstypeval ) dnsqueryelement = ( "CLASS=" dnsclassval ) / ( "TYPE=" dnstypeval )
; Each clause MUST NOT be used more than ; Each clause MUST NOT be used more
; once. ; than once.
dnsclassval = 1*digit / "IN" / "CH" / ... dnsclassval = 1*digit / "IN" / "CH" / ...
; Any IANA registered DNS class expressed ; Any IANA registered DNS class
; as mnemonic or as decimal integer. ; expressed as mnemonic or as
; decimal integer.
dnstypeval = 1*digit / "A" / "NS" / "MD" / ... dnstypeval = 1*digit / "A" / "NS" / "MD" / ...
; Any IANA registered DNS type expressed ; Any IANA registered DNS type
; as mnemonic or as decimal integer. ; expressed as mnemonic or as
; decimal integer.
Unless specified in the URI, the authority ("dnsauthority") is Unless specified in the URI, the authority ("dnsauthority") is
assumed to be locally known, the class ("dnsclassval") to be the assumed to be locally known, the class ("dnsclassval") to be the
Internet class ("IN"), and the type ("dnstypeval") to be the Address Internet class ("IN"), and the type ("dnstypeval") to be the Address
type ("A"). These default values match the typical use of DNS; to type ("A"). These default values match the typical use of DNS; to
look up addresses for host names. look up addresses for host names.
A dnsquery element MUST NOT contain more than one occurance of the A dnsquery element MUST NOT contain more than one occurance of the
"CLASS" and "TYPE" fields. For example, both "CLASS" and "TYPE" fields. For example, both
"dns:example?TYPE=A;TYPE=TXT" and "dns:example?TYPE=A;TYPE=A" are "dns:example?TYPE=A;TYPE=TXT" and "dns:example?TYPE=A;TYPE=A" are
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usage. The previous paragraph only illustrate how DNS URIs are usage. The previous paragraph only illustrate how DNS URIs are
resolved using the DNS protocol. resolved using the DNS protocol.
A client MAY want to check that it understands the dnsclassval and A client MAY want to check that it understands the dnsclassval and
dnstypeval before sending a query, so that it will be able to dnstypeval before sending a query, so that it will be able to
understand the response. However, a typical example of a client that understand the response. However, a typical example of a client that
would not need to check dnsclassval and dnstypeval would be a proxy, would not need to check dnsclassval and dnstypeval would be a proxy,
that would just treat the received answer as opaque data. that would just treat the received answer as opaque data.
Character encoding considerations: The characters are encoded as per Character encoding considerations: The characters are encoded as per
the "URI Generic Syntax" RFC [4]. The DNS protocol do not consider RFC 3986 [4]. The DNS protocol do not consider character sets, it
character sets, it simply transports opaque data. In particular, the simply transports opaque data. In particular, the "dnsname" field of
"dnsname" field of the DNS URI is to be considered an the DNS URI is to be considered an internationalized domain name
internationalized domain name (IDN) unaware domain name slot, in the (IDN) unaware domain name slot, in the terminology of [15]. The
terminology of [15]. The considerations for "hostport" are discussed considerations for "host" and "port" are discussed in [4]
in [4]
Because "." is used as the DNS label separator, an escaping mechanism Because "." is used as the DNS label separator, an escaping mechanism
is required to encode a "." that is part of a DNS label. The is required to encode a "." that is part of a DNS label. The
escaping mechanism is described in section 5.1 of RFC 1035. For escaping mechanism is described in section 5.1 of RFC 1035. For
example, a DNS label of "exa.mple" can be escaped as "exa\.mple" or example, a DNS label of "exa.mple" can be escaped as "exa\.mple" or
"exa\046mple". However, the URI specification disallow the "\" "exa\046mple". However, the URI specification disallow the "\"
character from occuring directly in URIs, so it must be escaped as character from occuring directly in URIs, so it must be escaped as
"%5c". The single DNS label "exa.mple" is thus encoded as "%5c". The single DNS label "exa.mple" is thus encoded as
"exa%5c.mple". The same mechanism can be used to encode other "exa%5c.mple". The same mechanism can be used to encode other
characters, for example "?" and ";". Note that "." and "%2e" are characters, for example "?" and ";". Note that "." and "%2e" are
equivalent within dnsname, and are interchangable. equivalent within dnsname, and are interchangable.
This URI specification allows all possible domain names to be encoded This URI specification allows all possible domain names to be encoded
(of course following the encoding rules of [4]), however certain (of course following the encoding rules of [4]), however certain
applications may restrict the set of valid characters and care should applications may restrict the set of valid characters. Care should
be taken so that invalid characters in these contexts does not cause be taken so that invalid characters in these contexts does not cause
harm. In particular, host names in the DNS have certain harm. In particular, host names in the DNS have certain
restrictions. It is up to these application to limit this subset, restrictions. It is up to these application to limit this subset,
this URI scheme places no restrictions. this URI scheme places no restrictions.
Intended usage: Whenever DNS resources are useful to reference by Intended usage: Whenever DNS resources are useful to reference by
protocol independent identifiers, often when the data is more protocol independent identifiers, often when the data is more
important than the access method. Since software in general has important than the access method. Since software in general has
coped without this so far, it is not anticipated to be implemented coped without this so far, it is not anticipated to be implemented
widely, nor migrated to by existing systems, but specific solutions widely, nor migrated to by existing systems, but specific solutions
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[2]. [2].
Interaction with Binary Labels [11], or other extended label types, Interaction with Binary Labels [11], or other extended label types,
has not been analyzed. However, they appear to be infrequently used has not been analyzed. However, they appear to be infrequently used
in practice. in practice.
Contact: simon@josefsson.org Contact: simon@josefsson.org
Author/Change Controller: simon@josefsson.org Author/Change Controller: simon@josefsson.org
3. Examples 4. Examples
A DNS URI is of the following general form. This is intended to A DNS URI is of the following general form. This is intended to
illustrate, not define, the scheme. illustrate, not define, the scheme.
dns:[//authority/]domain[?CLASS=class;TYPE=type] dns:[//authority/]domain[?CLASS=class;TYPE=type]
The following illustrate a URI for a resource with the absolute name The following illustrate a URI for a resource with the absolute name
"www.example.org.", the Internet (IN) class and the Address (A) type: "www.example.org.", the Internet (IN) class and the Address (A) type:
dns:www.example.org.?clAsS=IN;tYpE=A dns:www.example.org.?clAsS=IN;tYpE=A
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The following illustrate a URI for a resource with the name The following illustrate a URI for a resource with the name
"ftp.example.org", in the Internet (IN) class and the address (A) "ftp.example.org", in the Internet (IN) class and the address (A)
type, but from the DNS authority 192.168.1.1 instead of the default type, but from the DNS authority 192.168.1.1 instead of the default
authority: authority:
dns://192.168.1.1/ftp.example.org?type=A dns://192.168.1.1/ftp.example.org?type=A
The following illustrate various escaping techniques. The owner name The following illustrate various escaping techniques. The owner name
would be "world wide web.example\.domain.org" where "\." denote the would be "world wide web.example\.domain.org" where "\." denote the
character "." as part of a label, and "." denote the label separator: character "." as part of a label, and "." denote the label
separator:
dns:world%20wide%20web.example%5c.domain.example?TYPE=TXT dns:world%20wide%20web.example%5c.domain.example?TYPE=TXT
The following illustrate a strange, but valid, DNS resource: The following illustrate a strange, but valid, DNS resource:
dns://fw.example.org/*.%20%00.example?type=TXT dns://fw.example.org/*.%20%00.example?type=TXT
4. Security Considerations 5. Acknowledgments
Thanks to Stuart Cheshire, Donald Eastlake, Pasi Eronen, Ted Hardie,
Peter Koch, Andrew Main, Larry Masinter, Michael Mealling, Steve
Mattson, and Paul Vixie for comments and suggestions. The author
acknowledges the RSA Laboratories for supporting the work that led to
this document.
6. Security Considerations
If a DNS URI references domains in the Internet DNS environment, both If a DNS URI references domains in the Internet DNS environment, both
the URI itself and the information referenced by the URI is public the URI itself and the information referenced by the URI is public
information. If a DNS URI is used within an "internal" DNS information. If a DNS URI is used within an "internal" DNS
environment, both the DNS URI and the data is referenced should be environment, both the DNS URI and the data is referenced should be
handled using the same considerations that apply to DNS data in the handled using the same considerations that apply to DNS data in the
environment. environment.
If information referenced by DNS URIs are used to make security If information referenced by DNS URIs are used to make security
decisions (examples of such data include, but is not limited to, decisions (examples of such data include, but is not limited to,
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the URI "dns:www.example.org?secret=value" without knowing what the the URI "dns:www.example.org?secret=value" without knowing what the
"secret=value" dnsqueryelement means), a covert channel used to "secret=value" dnsqueryelement means), a covert channel used to
"leak" information may be enabled. The implications of covert "leak" information may be enabled. The implications of covert
channels should be understood by applications that accepts unknown channels should be understood by applications that accepts unknown
dnsqueryelement values. dnsqueryelement values.
Slight variations, such as difference between upper and lower case in Slight variations, such as difference between upper and lower case in
the dnsname field, can be used as a covert channel to leak the dnsname field, can be used as a covert channel to leak
information. information.
5. IANA Considerations 7. IANA Considerations
The IANA is asked to register the DNS URI scheme, using the template The IANA is asked to register the DNS URI scheme, using the template
in section 2, in accordance with RFC 2717 [12]. in section 2, in accordance with RFC 2717 [12].
Acknowledgments 8. Copying conditions
Thanks to Stuart Cheshire, Donald Eastlake, Pasi Eronen, Ted Hardie, Regarding this entire document or any portion of it, the author makes
Peter Koch, Andrew Main, Larry Masinter, Michael Mealling, Steve no guarantees and is not responsible for any damage resulting from
Mattson, and Paul Vixie for comments and suggestions. The author its use. The author grants irrevocable permission to anyone to use,
acknowledges the RSA Laboratories for supporting the work that led to modify, and distribute it in any way that does not diminish the
this document. rights of anyone else to use, modify, and distribute it, provided
that redistributed derivative works do not contain misleading author
or version information. Derivative works need not be licensed under
similar terms.
6. References 9. References
6.1 Normative References 9.1 Normative References
[1] Mockapetris, P., "Domain names - concepts and facilities", STD [1] Mockapetris, P., "Domain names - concepts and facilities", STD
13, RFC 1034, November 1987. 13, RFC 1034, November 1987.
[2] Mockapetris, P., "Domain names - implementation and [2] Mockapetris, P., "Domain names - implementation and
specification", STD 13, RFC 1035, November 1987. specification", STD 13, RFC 1035, November 1987.
[3] Crocker, D. and P. Overell, "Augmented BNF for Syntax [3] Crocker, D. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", RFC 2234, November 1997. Specifications: ABNF", RFC 2234, November 1997.
[4] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource [4] Berners-Lee, T., Fielding, R. and L. Masinter, "Uniform Resource
Identifiers (URI): Generic Syntax", RFC 2396, August 1998. Identifier (URI): Generic Syntax", STD 66, RFC 3986, January
2005.
6.2 Informative References 9.2 Informative References
[5] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9, [5] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9,
RFC 959, October 1985. RFC 959, October 1985.
[6] Bradner, S., "Key words for use in RFCs to Indicate Requirement [6] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997. Levels", BCP 14, RFC 2119, March 1997.
[7] Callas, J., Donnerhacke, L., Finney, H. and R. Thayer, "OpenPGP [7] Callas, J., Donnerhacke, L., Finney, H. and R. Thayer, "OpenPGP
Message Format", RFC 2440, November 1998. Message Format", RFC 2440, November 1998.
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Simplified introduction. Discuss relative and absolute dnsname's. Simplified introduction. Discuss relative and absolute dnsname's.
Clarify that empty dnsname correspond to the root. Change so that Clarify that empty dnsname correspond to the root. Change so that
dns:foo?TYPE=A;TYPE=TXT is invalid, instead of meaning TYPE=A. The dns:foo?TYPE=A;TYPE=TXT is invalid, instead of meaning TYPE=A. The
underspecified extension mechanism was dropped; now only TYPE= and underspecified extension mechanism was dropped; now only TYPE= and
CLASS= are permitted. Remove background discussion of why the CLASS= are permitted. Remove background discussion of why the
dnsname field is made a IDN unaware domain name slot. Use standard dnsname field is made a IDN unaware domain name slot. Use standard
DNS escaping (i.e, "\." for ".") instead of broken approach that DNS escaping (i.e, "\." for ".") instead of broken approach that
violated the URI specification. Improve examples. Add security violated the URI specification. Improve examples. Add security
considerations. considerations.
A.5 Changes since -10
Add section "Usage Model". Move acknowledgements, as per rfc2223bis.
Add permissive copying condition. Updates to align with RFC 3986.
Intellectual Property Statement Intellectual Property Statement
The IETF takes no position regarding the validity or scope of any The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights or other rights that might be claimed to Intellectual Property Rights or other rights that might be claimed to
pertain to the implementation or use of the technology described in pertain to the implementation or use of the technology described in
this document or the extent to which any license under such rights this document or the extent to which any license under such rights
might or might not be available; nor does it represent that it has might or might not be available; nor does it represent that it has
made any independent effort to identify any such rights. Information made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79. found in BCP 78 and BCP 79.
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This document and the information contained herein are provided on an This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED, ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Copyright Statement Copyright Statement
Copyright (C) The Internet Society (2004). This document is subject Copyright (C) The Internet Society (2005). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights. except as set forth therein, the authors retain all their rights.
Acknowledgment Acknowledgment
Funding for the RFC Editor function is currently provided by the Funding for the RFC Editor function is currently provided by the
Internet Society. Internet Society.
 End of changes. 

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