draft-ietf-idr-rfc8203bis-08.txt   rfc9003.txt 
IDR J. Snijders Internet Engineering Task Force (IETF) J. Snijders
Internet-Draft NTT Request for Comments: 9003 NTT
Obsoletes: 8203 (if approved) J. Heitz Obsoletes: 8203 J. Heitz
Updates: 4486 (if approved) Cisco Updates: 4486 Cisco
Intended status: Standards Track J. Scudder Category: Standards Track J. Scudder
Expires: April 17, 2021 Juniper ISSN: 2070-1721 Juniper
A. Azimov A. Azimov
Yandex Yandex
October 14, 2020 January 2021
Extended BGP Administrative Shutdown Communication Extended BGP Administrative Shutdown Communication
draft-ietf-idr-rfc8203bis-08
Abstract Abstract
This document enhances the BGP Cease NOTIFICATION message This document enhances the BGP Cease NOTIFICATION message
"Administrative Shutdown" and "Administrative Reset" subcodes for "Administrative Shutdown" and "Administrative Reset" subcodes for
operators to transmit a short freeform message to describe why a BGP operators to transmit a short free-form message to describe why a BGP
session was shutdown or reset. This document updates RFC 4486 and session was shut down or reset. This document updates RFC 4486 and
obsoletes RFC 8203 by defining an Extended BGP Administrative obsoletes RFC 8203 by defining an Extended BGP Administrative
Shutdown Communication of up to 255 octets to improve communication Shutdown Communication of up to 255 octets to improve communication
using multibyte character sets. using multibyte character sets.
Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This is an Internet Standards Track document.
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months This document is a product of the Internet Engineering Task Force
and may be updated, replaced, or obsoleted by other documents at any (IETF). It represents the consensus of the IETF community. It has
time. It is inappropriate to use Internet-Drafts as reference received public review and has been approved for publication by the
material or to cite them other than as "work in progress." Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
This Internet-Draft will expire on April 17, 2021. Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9003.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
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publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction
2. Shutdown Communication . . . . . . . . . . . . . . . . . . . 2 1.1. Requirements Language
3. Operational Considerations . . . . . . . . . . . . . . . . . 3 2. Shutdown Communication
4. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4 3. Operational Considerations
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 4. Error Handling
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 6. Security Considerations
7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7. References
7.2. Informative References . . . . . . . . . . . . . . . . . 6 7.1. Normative References
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 6 7.2. Informative References
Appendix B. Changes to RFC 8203 . . . . . . . . . . . . . . . . 6 Appendix A. Changes to RFC 8203
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7 Acknowledgements
Authors' Addresses
1. Introduction 1. Introduction
It can be troublesome for an operator to correlate a BGP-4 [RFC4271] It can be troublesome for an operator to correlate a BGP-4 [RFC4271]
session teardown in the network with a notice that was transmitted session teardown in the network with a notice that was transmitted
via offline methods such as email or telephone calls. This document via offline methods, such as email or telephone calls. This document
updates [RFC4486] by specifying a mechanism to transmit a short updates [RFC4486] by specifying a mechanism to transmit a short free-
freeform UTF-8 [RFC3629] message as part of a Cease NOTIFICATION form UTF-8 [RFC3629] message as part of a Cease NOTIFICATION message
message [RFC4271] to inform the peer why the BGP session is being [RFC4271] to inform the peer why the BGP session is being shut down
shutdown or reset. This document obsoletes [RFC8203]; the specific or reset. This document obsoletes [RFC8203]; the specific
differences and rationale are discussed in detail in Appendix B. differences and rationale are discussed in detail in Appendix A.
1.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2. Shutdown Communication 2. Shutdown Communication
If a BGP speaker decides to terminate its session with a BGP If a BGP speaker decides to terminate its session with a BGP
neighbor, and it sends a NOTIFICATION message with the Error Code neighbor, and it sends a NOTIFICATION message with the Error Code
"Cease" and Error Subcode "Administrative Shutdown" or "Cease" and Error Subcode "Administrative Shutdown" or
"Administrative Reset" [RFC4486], it MAY include a UTF-8 encoded "Administrative Reset" [RFC4486], it MAY include a UTF-8-encoded
string. The contents of the string are at the operator's discretion. string. The contents of the string are at the operator's discretion.
The Cease NOTIFICATION message with a Shutdown Communication is The Cease NOTIFICATION message with a Shutdown Communication is
encoded as below: encoded as below:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Code 6 | Subcode | Length | ... \ | Error Code 6 | Subcode | Length | ... \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /
\ \ \ \
/ ... Shutdown Communication ... / / ... Shutdown Communication ... /
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1 Figure 1
Subcode: the Error Subcode value MUST be one of the following Subcode: The Error Subcode value MUST be one of the following
values: 2 ("Administrative Shutdown") or 4 ("Administrative values: 2 ("Administrative Shutdown") or 4 ("Administrative
Reset"). Reset").
Length: this 8-bit field represents the length of the Shutdown Length: This 8-bit field represents the length of the Shutdown
Communication field in octets. When the length value is zero, no Communication field in octets. When the length value is zero, no
Shutdown Communication field follows. Shutdown Communication field follows.
Shutdown Communication: to support international characters, the Shutdown Communication: To support international characters, the
Shutdown Communication field MUST be encoded using UTF-8. A Shutdown Communication field MUST be encoded using UTF-8. A
receiving BGP speaker MUST NOT interpret invalid UTF-8 sequences. receiving BGP speaker MUST NOT interpret invalid UTF-8 sequences.
Note that when the Shutdown Communication contains multibyte Note that when the Shutdown Communication contains multibyte
characters, the number of characters will be less than the length characters, the number of characters will be less than the length
value. This field is not NUL terminated. UTF-8 "Shortest Form" value. This field is not NUL terminated. UTF-8 "Shortest Form"
encoding is REQUIRED to guard against the technical issues encoding is REQUIRED to guard against the technical issues
outlined in [UTR36]. outlined in [UTR36].
Mechanisms concerning the reporting of information contained in the Mechanisms concerning the reporting of information contained in the
Shutdown Communication are implementation specific but SHOULD include Shutdown Communication are implementation specific but SHOULD include
methods such as Syslog [RFC5424]. methods such as syslog [RFC5424].
3. Operational Considerations 3. Operational Considerations
Operators are encouraged to use the Shutdown Communication to inform Operators are encouraged to use the Shutdown Communication to inform
their peers of the reason for the shutdown of the BGP session and their peers of the reason for the shutdown of the BGP session and
include out-of-band reference materials. An example of a useful include out-of-band reference materials. An example of a useful
Shutdown Communication would be: Shutdown Communication would be:
"[TICKET-1-1438367390] software upgrade; back in 2 hours" "[TICKET-1-1438367390] software upgrade; back in 2 hours"
skipping to change at page 4, line 22 skipping to change at line 162
If a Shutdown Communication of any length is sent to a BGP speaker If a Shutdown Communication of any length is sent to a BGP speaker
that implements neither [RFC8203] nor this specification, then that that implements neither [RFC8203] nor this specification, then that
speaker will treat it as an error, the consequence of which should be speaker will treat it as an error, the consequence of which should be
a log message. a log message.
In any case, a receiver of a NOTIFICATION message is unable to In any case, a receiver of a NOTIFICATION message is unable to
acknowledge the receipt and correct understanding of any Shutdown acknowledge the receipt and correct understanding of any Shutdown
Communication. Communication.
Operators should not rely on Shutdown Communications as their sole Operators should not rely on Shutdown Communications as their sole
form of communication with their peer for important events. form of communication with their peers for important events.
If it is known that the peer BGP speaker supports this specification, If it is known that the peer BGP speaker supports this specification,
then a Shutdown Communication that is not longer than 255 octets MAY then a Shutdown Communication that is not longer than 255 octets MAY
be sent. Otherwise, a Shutdown Communication MAY be sent, but it be sent. Otherwise, a Shutdown Communication MAY be sent, but it
SHOULD NOT be longer than 128 octets. SHOULD NOT be longer than 128 octets.
4. Error Handling 4. Error Handling
If a Shutdown Communication with an invalid UTF-8 sequence is If a Shutdown Communication with an invalid UTF-8 sequence is
received, a message indicating this event SHOULD be logged for the received, a message indicating this event SHOULD be logged for the
attention of the operator. An erroneous or malformed Shutdown attention of the operator. An erroneous or malformed Shutdown
Communication itself MAY be logged in a hexdump format. Communication itself MAY be logged in a hexdump format.
5. IANA Considerations 5. IANA Considerations
IANA is requested to reference this document at subcode IANA has referenced this document at subcodes "Administrative
"Administrative Shutdown", and at subcode "Administrative Reset" in Shutdown" and "Administrative Reset" in the "BGP Cease NOTIFICATION
the "BGP Cease NOTIFICATION message subcodes" registry under the message subcodes" registry under the "Border Gateway Protocol (BGP)
"Border Gateway Protocol (BGP) Parameters" group in addition to Parameters" group in addition to [RFC4486].
[RFC4486].
6. Security Considerations 6. Security Considerations
This document uses UTF-8 encoding for the Shutdown Communication. This document uses UTF-8 encoding for the Shutdown Communication.
There are a number of security issues with Unicode. Implementers and There are a number of security issues with Unicode. Implementers and
operators are advised to review Unicode Technical Report #36 [UTR36] operators are advised to review Unicode Technical Report #36 [UTR36]
to learn about these issues. UTF-8 "Shortest Form" encoding is to learn about these issues. UTF-8 "Shortest Form" encoding is
REQUIRED to guard against the technical issues outlined in [UTR36]. REQUIRED to guard against the technical issues outlined in [UTR36].
As BGP Shutdown Communications are likely to appear in syslog output, As BGP Shutdown Communications are likely to appear in syslog output,
there is a risk that carefully constructed Shutdown Communication there is a risk that carefully constructed Shutdown Communication
might be formatted by receiving systems in a way to make them appear might be formatted by receiving systems in a way to make them appear
as additional syslog messages. The 255 octet length limit on the BGP as additional syslog messages. The 255-octet length limit on the BGP
Shutdown Communication may help limit the ability to mount such an Shutdown Communication may help limit the ability to mount such an
attack. attack.
Users of this mechanism should be aware that unless a transport that Users of this mechanism should be aware that unless a transport that
provides integrity is used for the BGP session in question, a provides integrity is used for the BGP session in question, a
Shutdown Communication message could be forged. Unless a transport Shutdown Communication message could be forged. Unless a transport
that provides confidentiality is used, a Shutdown Communication that provides confidentiality is used, a Shutdown Communication
message could be snooped by an attacker. These issues are common to message could be snooped by an attacker. These issues are common to
any BGP message but may be of greater interest in the context of this any BGP message, but they may be of greater interest in the context
proposal since the information carried in the message is generally of this proposal since the information carried in the message is
expected to be used for human-to-human communication. Refer to the generally expected to be used for human-to-human communication.
related considerations in [RFC4271] and [RFC4272]. Refer to the related considerations in [RFC4271] and [RFC4272].
Users of this mechanism should consider applying data minimization Users of this mechanism should consider applying data minimization
practices as outlined in Section 6.1 of [RFC6973] because a received practices as outlined in Section 6.1 of [RFC6973] because a received
Shutdown Communication may be used at the receiver's discretion. Shutdown Communication may be used at the receiver's discretion.
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
skipping to change at page 6, line 26 skipping to change at line 259
Morris, J., Hansen, M., and R. Smith, "Privacy Morris, J., Hansen, M., and R. Smith, "Privacy
Considerations for Internet Protocols", RFC 6973, Considerations for Internet Protocols", RFC 6973,
DOI 10.17487/RFC6973, July 2013, DOI 10.17487/RFC6973, July 2013,
<https://www.rfc-editor.org/info/rfc6973>. <https://www.rfc-editor.org/info/rfc6973>.
[RFC8203] Snijders, J., Heitz, J., and J. Scudder, "BGP [RFC8203] Snijders, J., Heitz, J., and J. Scudder, "BGP
Administrative Shutdown Communication", RFC 8203, Administrative Shutdown Communication", RFC 8203,
DOI 10.17487/RFC8203, July 2017, DOI 10.17487/RFC8203, July 2017,
<https://www.rfc-editor.org/info/rfc8203>. <https://www.rfc-editor.org/info/rfc8203>.
[UTR36] Davis, M. and M. Suignard, "Unicode Security [UTR36] Davis, M., Ed. and M. Suignard, Ed., "Unicode Security
Considerations", Unicode Technical Report #36, August Considerations", Unicode Technical Report #36, August
2010, <http://unicode.org/reports/tr36/>. 2010, <http://unicode.org/reports/tr36/>.
Appendix A. Acknowledgements Appendix A. Changes to RFC 8203
The maximum permitted length was changed from 128 to 255.
Feedback from operators based in regions that predominantly use
multibyte character sets showed that messages similar in meaning to
what can be sent in other languages using single-byte encoding failed
to fit within the length constraints as specified by [RFC8203]. For
example, the phrase "Planned work to add switch to stack. Completion
time - 30 minutes" has a length of 65 bytes. Its translation in
Russian has a length of 139 bytes.
If a Shutdown Communication message longer than 128 octets is sent to
a BGP speaker that implements [RFC8203], then that speaker will bring
it to the attention of an operator but will otherwise process the
NOTIFICATION message as normal.
Acknowledgements
The authors would like to gratefully acknowledge Tom Scholl, David The authors would like to gratefully acknowledge Tom Scholl, David
Freedman, Jared Mauch, Jeff Haas, Peter Hessler, Bruno Decraene, John Freedman, Jared Mauch, Jeff Haas, Peter Hessler, Bruno Decraene, John
Heasley, Peter van Dijk, Arjen Zonneveld, James Bensley, Susan Hares, Heasley, Peter van Dijk, Arjen Zonneveld, James Bensley, Susan Hares,
Saku Ytti, Lou Berger, Alvaro Retana, and Adam Roach. Saku Ytti, Lou Berger, Alvaro Retana, and Adam Roach.
The authors would like to thank Enke Chen and Vincent Gillet for The authors would like to thank Enke Chen and Vincent Gillet for
their work on [RFC4486] and granting the related BCP 78 rights to the their work on [RFC4486] and granting the related BCP 78 rights to the
IETF Trust. IETF Trust.
The authors would like to acknowledge Misha Grishin (MSK-IX) for The authors would like to acknowledge Misha Grishin (MSK-IX) for
raising awareness that [RFC8203]'s length specification was raising awareness that the length specification of [RFC8203] was
insufficient in context of multibyte character sets. insufficient in context of multibyte character sets.
Appendix B. Changes to RFC 8203
The maximum permitted length was changed from 128 to 255.
Feedback from operators based in regions which predominantly use
multibyte character sets, showed that messages similar in meaning to
what can be send in other languages in using single-byte encoding,
failed to fit within the Length constraints as specified by
[RFC8203]. For example, the phrase: 'Planned work to add switch to
stack. Completion time - 30 minutes' has length 65 bytes. Its
translation in Russian has length 139 bytes.
If a Shutdown Communication message longer than 128 octets is sent to
a BGP speaker that implements [RFC8203], then that speaker will bring
it to the attention of an operator, but will otherwise process the
NOTIFICATION message as normal.
Authors' Addresses Authors' Addresses
Job Snijders Job Snijders
NTT Communications NTT Ltd.
Theodorus Majofskistraat 100 Theodorus Majofskistraat 100
Amsterdam 1065 SZ 1065 SZ Amsterdam
The Netherlands Netherlands
Email: job@ntt.net Email: job@ntt.net
Jakob Heitz Jakob Heitz
Cisco Cisco
170 West Tasman Drive 170 West Tasman Drive
San Jose, CA 95134 San Jose, CA 95134
United States of America United States of America
Email: jheitz@cisco.com Email: jheitz@cisco.com
John Scudder John Scudder
Juniper Networks Juniper Networks
1194 N. Mathilda Ave 1133 Innovation Way
Sunnyvale, CA 94089 Sunnyvale, CA 94089
United States of America United States of America
Email: jgs@juniper.net Email: jgs@juniper.net
Alexander Azimov Alexander Azimov
Yandex Yandex
Ulitsa Lva Tolstogo 16
Moscow
119021
Russian Federation
Email: a.e.azimov@gmail.com Email: a.e.azimov@gmail.com
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