draft-ietf-dnsext-nsid-02.txt   rfc5001.txt 
Network Working Group R. Austein Network Working Group R. Austein
Internet-Draft ISC Request for Comments: 5001 ISC
Expires: December 22, 2006 June 20, 2006 Category: Standards Track August 2007
DNS Name Server Identifier Option (NSID)
draft-ietf-dnsext-nsid-02
Status of this Memo
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Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2006). Copyright (C) The IETF Trust (2007).
Abstract Abstract
With the increased use of DNS anycast, load balancing, and other With the increased use of DNS anycast, load balancing, and other
mechanisms allowing more than one DNS name server to share a single mechanisms allowing more than one DNS name server to share a single
IP address, it is sometimes difficult to tell which of a pool of name IP address, it is sometimes difficult to tell which of a pool of name
servers has answered a particular query. While existing ad-hoc servers has answered a particular query. While existing ad-hoc
mechanism allow an operator to send follow-up queries when it is mechanisms allow an operator to send follow-up queries when it is
necessary to debug such a configuration, the only completely reliable necessary to debug such a configuration, the only completely reliable
way to obtain the identity of the name server which responded is to way to obtain the identity of the name server that responded is to
have the name server include this information in the response itself. have the name server include this information in the response itself.
This note defines a protocol extension to support this functionality. This note defines a protocol extension to support this functionality.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Reserved Words . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Reserved Words . . . . . . . . . . . . . . . . . . . . . . 3
2. Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2. Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. Resolver Behavior . . . . . . . . . . . . . . . . . . . . 4 2.1. Resolver Behavior . . . . . . . . . . . . . . . . . . . . 3
2.2. Name Server Behavior . . . . . . . . . . . . . . . . . . . 4 2.2. Name Server Behavior . . . . . . . . . . . . . . . . . . . 3
2.3. The NSID Option . . . . . . . . . . . . . . . . . . . . . 4 2.3. The NSID Option . . . . . . . . . . . . . . . . . . . . . 4
2.4. Presentation Format . . . . . . . . . . . . . . . . . . . 5 2.4. Presentation Format . . . . . . . . . . . . . . . . . . . 4
3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 6 3. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3.1. The NSID Payload . . . . . . . . . . . . . . . . . . . . . 6 3.1. The NSID Payload . . . . . . . . . . . . . . . . . . . . . 4
3.2. NSID Is Not Transitive . . . . . . . . . . . . . . . . . . 8 3.2. NSID Is Not Transitive . . . . . . . . . . . . . . . . . . 7
3.3. User Interface Issues . . . . . . . . . . . . . . . . . . 9 3.3. User Interface Issues . . . . . . . . . . . . . . . . . . 7
3.4. Truncation . . . . . . . . . . . . . . . . . . . . . . . . 9 3.4. Truncation . . . . . . . . . . . . . . . . . . . . . . . . 8
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
5. Security Considerations . . . . . . . . . . . . . . . . . . . 12 5. Security Considerations . . . . . . . . . . . . . . . . . . . 9
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 13 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 9
7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 14 7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7.1. Normative References . . . . . . . . . . . . . . . . . . . 14 7.1. Normative References . . . . . . . . . . . . . . . . . . . 9
7.2. Informative References . . . . . . . . . . . . . . . . . . 14 7.2. Informative References . . . . . . . . . . . . . . . . . . 10
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . . 15
Intellectual Property and Copyright Statements . . . . . . . . . . 16
1. Introduction 1. Introduction
With the increased use of DNS anycast, load balancing, and other With the increased use of DNS anycast, load balancing, and other
mechanisms allowing more than one DNS name server to share a single mechanisms allowing more than one DNS name server to share a single
IP address, it is sometimes difficult to tell which of a pool of name IP address, it is sometimes difficult to tell which of a pool of name
servers has answered a particular query. servers has answered a particular query.
Existing ad-hoc mechanisms allow an operator to send follow-up Existing ad-hoc mechanisms allow an operator to send follow-up
queries when it is necessary to debug such a configuration, but there queries when it is necessary to debug such a configuration, but there
are situations in which this is not a totally satisfactory solution, are situations in which this is not a totally satisfactory solution,
since anycast routing may have changed, or the server pool in since anycast routing may have changed, or the server pool in
question may be behind some kind of extremely dynamic load balancing question may be behind some kind of extremely dynamic load balancing
hardware. Thus, while these ad-hoc mechanisms are certainly better hardware. Thus, while these ad-hoc mechanisms are certainly better
than nothing (and have the advantage of already being deployed), a than nothing (and have the advantage of already being deployed), a
better solution seems desirable. better solution seems desirable.
Given that a DNS query is an idempotent operation with no retained Given that a DNS query is an idempotent operation with no retained
state, it would appear that the only completely reliable way to state, it would appear that the only completely reliable way to
obtain the identity of the name server which responded to a obtain the identity of the name server that responded to a particular
particular query is to have that name server include identifying query is to have that name server include identifying information in
information in the response itself. This note defines a protocol the response itself. This note defines a protocol enhancement to
enhancement to achieve this. achieve this.
1.1. Reserved Words 1.1. Reserved Words
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 [RFC2119]. document are to be interpreted as described in [RFC2119].
2. Protocol 2. Protocol
This note uses an EDNS [RFC2671] option to signal the resolver's This note uses an EDNS [RFC2671] option to signal the resolver's
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presence of an NSID option in a query is a request that the name presence of an NSID option in a query is a request that the name
server which receives the query identify itself. If the name server server which receives the query identify itself. If the name server
side of a recursive name server receives an NSID request, the client side of a recursive name server receives an NSID request, the client
is asking the recursive name server to identify itself; if the is asking the recursive name server to identify itself; if the
resolver side of the recursive name server wishes to receive resolver side of the recursive name server wishes to receive
identifying information, it is free to add NSID requests in its own identifying information, it is free to add NSID requests in its own
queries, but that is a separate matter. queries, but that is a separate matter.
2.2. Name Server Behavior 2.2. Name Server Behavior
A name server which understands the NSID option and chooses to honor A name server that understands the NSID option and chooses to honor a
a particular NSID request responds by including identifying particular NSID request responds by including identifying information
information in a NSID option (Section 2.3) in an EDNS OPT pseudo-RR in a NSID option (Section 2.3) in an EDNS OPT pseudo-RR in the
in the response message. response message.
The name server MUST ignore any NSID payload data that might be The name server MUST ignore any NSID payload data that might be
present in the query message. present in the query message.
The NSID option is not transitive. A name server MUST NOT send an The NSID option is not transitive. A name server MUST NOT send an
NSID option back to a resolver which did not request it. In NSID option back to a resolver which did not request it. In
particular, while a recursive name server may choose to add an NSID particular, while a recursive name server may choose to add an NSID
option when sending a query, this has no effect on the presence or option when sending a query, this has no effect on the presence or
absence of the NSID option in the recursive name server's response to absence of the NSID option in the recursive name server's response to
the original client. the original client.
As stated in Section 2.1, this mechanism is not restricted to As stated in Section 2.1, this mechanism is not restricted to
authoritative name servers; the semantics are intended to be equally authoritative name servers; the semantics are intended to be equally
applicable to recursive name servers. applicable to recursive name servers.
2.3. The NSID Option 2.3. The NSID Option
The OPTION-CODE for the NSID option is [TBD]. The OPTION-CODE for the NSID option is 3.
The OPTION-DATA for the NSID option is an opaque byte string the The OPTION-DATA for the NSID option is an opaque byte string, the
semantics of which are deliberately left outside the protocol. See semantics of which are deliberately left outside the protocol. See
Section 3.1 for discussion. Section 3.1 for discussion.
2.4. Presentation Format 2.4. Presentation Format
User interfaces MUST read and write the content of the NSID option as User interfaces MUST read and write the contents of the NSID option
a sequence of hexadecimal digits, two digits per payload octet. as a sequence of hexadecimal digits, two digits per payload octet.
The NSID payload is binary data. Any comparison between NSID The NSID payload is binary data. Any comparison between NSID
payloads MUST be a comparison of the raw binary data. Copy payloads MUST be a comparison of the raw binary data. Copy
operations MUST NOT assume that the raw NSID payload is null- operations MUST NOT assume that the raw NSID payload is null-
terminated. Any resemblance between raw NSID payload data and any terminated. Any resemblance between raw NSID payload data and any
form of text is purely a convenience, and does not change the form of text is purely a convenience, and does not change the
underlying nature of the payload data. underlying nature of the payload data.
See Section 3.3 for discussion. See Section 3.3 for discussion.
3. Discussion 3. Discussion
This section discusses certain aspects of the protocol and explains This section discusses certain aspects of the protocol and explains
considerations that led to the chosen design. considerations that led to the chosen design.
3.1. The NSID Payload 3.1. The NSID Payload
The syntax and semantics of the content of the NSID option is The syntax and semantics of the content of the NSID option are
deliberately left outside the scope of this specification. deliberately left outside the scope of this specification.
Chosing the NSID content is a prerogative of the server Choosing the NSID content is a prerogative of the server
administrator. The server server administrator might chose to encode administrator. The server administrator might choose to encode the
the NSID content in such a way that the server operator (or clients NSID content in such a way that the server operator (or clients
authorized by the server operator) can decode the NSID content to authorized by the server operator) can decode the NSID content to
obtain more information than other clients can. Alternatively, the obtain more information than other clients can. Alternatively, the
server operator might choose unencoded NSID content that is equally server operator might choose unencoded NSID content that is equally
meaningful to any client. meaningful to any client.
This section describe some of the kinds of data that server This section describes some of the kinds of data that server
administrators might choose to provide as the content of the NSID administrators might choose to provide as the content of the NSID
option, and explains the reasoning behind specifying a simple opaque option, and explains the reasoning behind specifying a simple opaque
byte string in Section 2.3. byte string in Section 2.3.
There are several possibilities for the payload of the NSID option: There are several possibilities for the payload of the NSID option:
o It could be the "real" name of the specific name server within the o It could be the "real" name of the specific name server within the
name server pool. name server pool.
o It could be the "real" IP address (IPv4 or IPv6) of the name o It could be the "real" IP address (IPv4 or IPv6) of the name
server within the name server pool. server within the name server pool.
o It could be some sort of pseudo-random number generated in a o It could be some sort of pseudo-random number generated in a
predictable fashion somehow using the server's IP address or name predictable fashion somehow using the server's IP address or name
as a seed value. as a seed value.
o It could be some sort of probabilisticly unique identifier o It could be some sort of probabilistically unique identifier
initially derived from some sort of random number generator then initially derived from some sort of random number generator then
preserved across reboots of the name server. preserved across reboots of the name server.
o It could be some sort of dynamicly generated identifier so that o It could be some sort of dynamically generated identifier so that
only the name server operator could tell whether or not any two only the name server operator could tell whether or not any two
queries had been answered by the same server. queries had been answered by the same server.
o It could be a blob of signed data, with a corresponding key which o It could be a blob of signed data, with a corresponding key which
might (or might not) be available via DNS lookups. might (or might not) be available via DNS lookups.
o It could be a blob of encrypted data, the key for which could be o It could be a blob of encrypted data, the key for which could be
restricted to parties with a need to know (in the opinion of the restricted to parties with a need to know (in the opinion of the
server operator). server operator).
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o Using a hash or pseudo-random number can provide a fixed length o Using a hash or pseudo-random number can provide a fixed length
value that the resolver can use to tell two name servers apart value that the resolver can use to tell two name servers apart
without necessarily being able to tell where either one of them without necessarily being able to tell where either one of them
"really" is, but makes debugging more difficult if one happens to "really" is, but makes debugging more difficult if one happens to
be in a friendly open environment. Furthermore, hashing might not be in a friendly open environment. Furthermore, hashing might not
add much value, since a hash based on an IPv4 address still only add much value, since a hash based on an IPv4 address still only
involves a 32-bit search space, and DNS names used for servers involves a 32-bit search space, and DNS names used for servers
that operators might have to debug at 4am tend not to be very that operators might have to debug at 4am tend not to be very
random. random.
o Probabilisticly unique identifiers have similar properties to o Probabilistically unique identifiers have properties similar to
hashed identifiers, but (given a sufficiently good random number hashed identifiers, but (given a sufficiently good random number
generator) are immune to the search space issues. However, the generator) are immune to the search space issues. However, the
strength of this approach is also its weakness: there is no strength of this approach is also its weakness: there is no
algorithmic transformation by which even the server operator can algorithmic transformation by which even the server operator can
associate name server instances with identifiers while debugging, associate name server instances with identifiers while debugging,
which might be annoying. This approach also requires the name which might be annoying. This approach also requires the name
server instance to preserve the probabilisticly unique identifier server instance to preserve the probabilistically unique
across reboots, but this does not appear to be a serious identifier across reboots, but this does not appear to be a
restriction, since authoritative nameservers almost always have serious restriction, since authoritative nameservers almost always
some form of nonvolatile storage in any case, and in the rare case have some form of non-volatile storage. In the rare case of a
of a name server that does not have any way to store such an name server that does not have any way to store such an
identifier, nothing terrible will happen if the name server just identifier, nothing terrible will happen if the name server
generates a new identifier every time it reboots. generates a new identifier every time it reboots.
o Using an arbitrary octet string gives name server operators yet o Using an arbitrary octet string gives name server operators yet
another thing to configure, or mis-configure, or forget to another setting to configure, or mis-configure, or forget to
configure. Having all the nodes in an anycast name server configure. Having all the nodes in an anycast name server
constellation identify themselves as "My Name Server" would not be constellation identify themselves as "My Name Server" would not be
particularly useful. particularly useful.
o A signed blob is not particularly useful as an NSID payload unless
the signed data is dynamic and includes some kind of replay
protection, such as a timestamp or some kind of data identifying
the requestor. Signed blobs that meet these criteria could
conceivably be useful in some situations but would require
detailed security analysis beyond the scope of this document.
o A static encrypted blob would not be particularly useful, as it
would be subject to replay attacks and would, in effect, just be a
random number to any party that does not possess the decryption
key. Dynamic encrypted blobs could conceivably be useful in some
situations but, as with signed blobs, dynamic encrypted blobs
would require detailed security analysis beyond the scope of this
document.
Given all of the issues listed above, there does not appear to be a Given all of the issues listed above, there does not appear to be a
single solution that will meet all needs. Section 2.3 therefore single solution that will meet all needs. Section 2.3 therefore
defines the NSID payload to be an opaque byte string and leaves the defines the NSID payload to be an opaque byte string and leaves the
choice up to the implementor and name server operator. The following choice of payload up to the implementor and name server operator.
guidelines may be useful to implementors and server operators:
The following guidelines may be useful to implementors and server
operators:
o Operators for whom divulging the unicast address is an issue could o Operators for whom divulging the unicast address is an issue could
use the raw binary representation of a probabilisticly unique use the raw binary representation of a probabilistically unique
random number. This should probably be the default implementation random number. This should probably be the default implementation
behavior. behavior.
o Operators for whom divulging the unicast address is not an issue o Operators for whom divulging the unicast address is not an issue
could just use the raw binary representation of a unicast address could just use the raw binary representation of a unicast address
for simplicity. This should only be done via an explicit for simplicity. This should only be done via an explicit
configuration choice by the operator. configuration choice by the operator.
o Operators who really need or want the ability to set the NSID o Operators who really need or want the ability to set the NSID
payload to an arbitrary value could do so, but this should only be payload to an arbitrary value could do so, but this should only be
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In cases where the name server operator derives the NSID payload from In cases where the name server operator derives the NSID payload from
textual data, a textual form such as US-ASCII or UTF-8 strings might textual data, a textual form such as US-ASCII or UTF-8 strings might
at first glance seem easier for a user to deal with. There are, at first glance seem easier for a user to deal with. There are,
however, a number of complex issues involving internationalized text however, a number of complex issues involving internationalized text
which, if fully addressed here, would require a set of rules which, if fully addressed here, would require a set of rules
significantly longer than the rest of this specification. See significantly longer than the rest of this specification. See
[RFC2277] for an overview of some of these issues. [RFC2277] for an overview of some of these issues.
It is much more important for the NSID payload data to be passed It is much more important for the NSID payload data to be passed
unambiguously from server administrator to user and back again than unambiguously from server administrator to user and back again than
it is for the payload data data to be pretty while in transit. In it is for the payload data to be pretty while in transit. In
particular, it's critical that it be straightforward for a user to particular, it's critical that it be straightforward for a user to
cut and paste an exact copy of the NSID payload output by a debugging cut and paste an exact copy of the NSID payload output by a debugging
tool into other formats such as email messages or web forms without tool into other formats such as email messages or web forms without
distortion. Hexadecimal strings, while ugly, are also robust. distortion. Hexadecimal strings, while ugly, are also robust.
3.4. Truncation 3.4. Truncation
In some cases, adding the NSID option to a response message may In some cases, adding the NSID option to a response message may
trigger message truncation. This specification does not change the trigger message truncation. This specification does not change the
rules for DNS message truncation in any way, but implementors will rules for DNS message truncation in any way, but implementors will
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specification never requires name servers to truncate response specification never requires name servers to truncate response
messages. messages.
By definition, a resolver that requests NSID responses also supports By definition, a resolver that requests NSID responses also supports
EDNS, so a resolver that requests NSID responses can also use the EDNS, so a resolver that requests NSID responses can also use the
"sender's UDP payload size" field of the OPT pseudo-RR to signal a "sender's UDP payload size" field of the OPT pseudo-RR to signal a
receive buffer size large enough to make truncation unlikely. receive buffer size large enough to make truncation unlikely.
4. IANA Considerations 4. IANA Considerations
This mechanism requires allocation of one ENDS option code for the IANA has allocated EDNS option code 3 for the NSID option
NSID option (Section 2.3). (Section 2.3).
5. Security Considerations 5. Security Considerations
This document describes a channel signaling mechanism, intended This document describes a channel signaling mechanism intended
primarily for debugging. Channel signaling mechanisms are outside primarily for debugging. Channel signaling mechanisms are outside
the scope of DNSSEC per se. Applications that require integrity the scope of DNSSEC, per se. Applications that require integrity
protection for the data being signaled will need to use a channel protection for the data being signaled will need to use a channel
security mechanism such as TSIG [RFC2845]. security mechanism such as TSIG [RFC2845].
Section 3.1 discusses a number of different kinds of information that Section 3.1 discusses a number of different kinds of information that
a name server operator might choose to provide as the value of the a name server operator might choose to provide as the value of the
NSID option. Some of these kinds of information are security NSID option. Some of these kinds of information are security
sensitive in some environments. This specification deliberately sensitive in some environments. This specification deliberately
leaves the syntax and semantics of the NSID option content up to the leaves the syntax and semantics of the NSID option content up to the
implementation and the name server operator. implementation and the name server operator.
Two of the possible kinds of payload data discussed in Section 3.1
involve a digital signature and encryption, respectively. While this
specification discusses some of the pitfalls that might lurk for
careless users of these kinds of payload data, full analysis of the
issues that would be involved in these kinds of payload data would
require knowledge of the content to be signed or encrypted,
algorithms to be used, and so forth, which is beyond the scope of
this document. Implementors should seek competent advice before
attempting to use these kinds of NSID payloads.
6. Acknowledgements 6. Acknowledgements
Joe Abley, Harald Alvestrand, Dean Anderson, Mark Andrews, Roy Thanks to: Joe Abley, Harald Alvestrand, Dean Anderson, Mark Andrews,
Arends, Steve Bellovin, Alex Bligh, Randy Bush, David Conrad, John Roy Arends, Steve Bellovin, Alex Bligh, Randy Bush, David Conrad,
Dickinson, Johan Ihren, Daniel Karrenberg, Peter Koch, William John Dickinson, Alfred Hoenes, Johan Ihren, Daniel Karrenberg, Peter
Leibzon, Ed Lewis, Thomas Narten, Mike Patton, Geoffrey Sisson, Koch, William Leibzon, Ed Lewis, Thomas Narten, Mike Patton, Geoffrey
Andrew Sullivan, Mike StJohns, Paul Vixie, Sam Weiler, and Suzanne Sisson, Andrew Sullivan, Mike StJohns, Tom Taylor, Paul Vixie, Sam
Woolf, none of whom are responsible for what the author did with Weiler, and Suzanne Woolf, none of whom are responsible for what the
their comments and suggestions. Apologies to anyone inadvertently author did with their comments and suggestions. Apologies to anyone
omitted from the above list. inadvertently omitted from the above list.
7. References 7. References
7.1. Normative References 7.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", RFC 2119, BCP 14, March 1997. Requirement Levels", RFC 2119, BCP 14, March 1997.
[RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)", [RFC2671] Vixie, P., "Extension Mechanisms for DNS (EDNS0)",
RFC 2671, August 1999. RFC 2671, August 1999.
skipping to change at page 15, line 13 skipping to change at page 10, line 22
Languages", RFC 2277, BCP 18, January 1998. Languages", RFC 2277, BCP 18, January 1998.
Author's Address Author's Address
Rob Austein Rob Austein
ISC ISC
950 Charter Street 950 Charter Street
Redwood City, CA 94063 Redwood City, CA 94063
USA USA
Email: sra@isc.org EMail: sra@isc.org
Intellectual Property Statement Full Copyright Statement
Copyright (C) The IETF Trust (2007).
This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF
THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED
WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
Intellectual Property
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.
skipping to change at page 16, line 29 skipping to change at page 11, line 45
such proprietary rights by implementers or users of this such proprietary rights by implementers or users of this
specification can be obtained from the IETF on-line IPR repository at specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr. http://www.ietf.org/ipr.
The IETF invites any interested party to bring to its attention any The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. ietf-ipr@ietf.org.
Disclaimer of Validity Acknowledgement
This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET
ENGINEERING TASK FORCE DISCLAIM ALL WARRANTIES, EXPRESS OR IMPLIED,
INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE
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Copyright Statement
Copyright (C) The Internet Society (2006). This document is subject
to the rights, licenses and restrictions contained in BCP 78, and
except as set forth therein, the authors retain all their rights.
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.
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