rfc8203.txt   draft-ietf-idr-rfc8203bis-08.txt >
Internet Engineering Task Force (IETF) J. Snijders IDR J. Snijders
Request for Comments: 8203 NTT Internet-Draft NTT
Updates: 4486 J. Heitz Obsoletes: 8203 (if approved) J. Heitz
Category: Standards Track Cisco Updates: 4486 (if approved) Cisco
ISSN: 2070-1721 J. Scudder Intended status: Standards Track J. Scudder
Juniper Expires: April 17, 2021 Juniper
July 2017 A. Azimov
Yandex
October 14, 2020
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 freeform message to describe why a BGP
session was shutdown or reset. This document updates RFC 4486. session was shutdown or reset. This document updates RFC 4486 and
obsoletes RFC 8203 by defining an Extended BGP Administrative
Shutdown Communication of up to 255 octets to improve communication
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 is an Internet Standards Track document. This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
This document is a product of the Internet Engineering Task Force Internet-Drafts are working documents of the Internet Engineering
(IETF). It represents the consensus of the IETF community. It has Task Force (IETF). Note that other groups may also distribute
received public review and has been approved for publication by the working documents as Internet-Drafts. The list of current Internet-
Internet Engineering Steering Group (IESG). Further information on Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata, Internet-Drafts are draft documents valid for a maximum of six months
and how to provide feedback on it may be obtained at and may be updated, replaced, or obsoleted by other documents at any
http://www.rfc-editor.org/info/rfc8203. time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on April 17, 2021.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2020 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
(http://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
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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
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. Shutdown Communication . . . . . . . . . . . . . . . . . . . 2 2. Shutdown Communication . . . . . . . . . . . . . . . . . . . 2
3. Operational Considerations . . . . . . . . . . . . . . . . . 3 3. Operational Considerations . . . . . . . . . . . . . . . . . 3
4. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4 4. Error Handling . . . . . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
7.1. Normative References . . . . . . . . . . . . . . . . . . 5 7.1. Normative References . . . . . . . . . . . . . . . . . . 5
7.2. Informative References . . . . . . . . . . . . . . . . . 5 7.2. Informative References . . . . . . . . . . . . . . . . . 6
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 6 Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6 Appendix B. Changes to RFC 8203 . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
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
freeform UTF-8 [RFC3629] message as part of a Cease NOTIFICATION freeform UTF-8 [RFC3629] message as part of a Cease NOTIFICATION
message [RFC4271] to inform the peer why the BGP session is being message [RFC4271] to inform the peer why the BGP session is being
shutdown or reset. shutdown or reset. This document obsoletes [RFC8203]; the specific
differences and rationale are discussed in detail in Appendix B.
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 an 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 | ... \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ / +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ /
skipping to change at page 3, line 25 skipping to change at page 3, line 25
\ \ \ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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. The length value MUST range from 0 Communication field in octets. When the length value is zero, no
to 128 inclusive. When the length value is zero, no Shutdown Shutdown Communication field follows.
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. value. This field is not NUL terminated. UTF-8 "Shortest Form"
encoding is REQUIRED to guard against the technical issues
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
skipping to change at page 4, line 8 skipping to change at page 4, line 8
"[TICKET-1-1438367390] software upgrade; back in 2 hours" "[TICKET-1-1438367390] software upgrade; back in 2 hours"
"[TICKET-1-1438367390]" is a ticket reference with significance to "[TICKET-1-1438367390]" is a ticket reference with significance to
both the sender and receiver, followed by a brief human-readable both the sender and receiver, followed by a brief human-readable
message regarding the reason for the BGP session shutdown followed by message regarding the reason for the BGP session shutdown followed by
an indication about the length of the maintenance. The receiver can an indication about the length of the maintenance. The receiver can
now use the string 'TICKET-1-1438367390' to search in their email now use the string 'TICKET-1-1438367390' to search in their email
archive to find more details. archive to find more details.
If a Shutdown Communication longer than 128 octets is sent to a BGP
speaker that implements [RFC8203], then that speaker will treat it as
an error, the consequence of which should be a log message.
If a Shutdown Communication of any length is sent to a BGP speaker
that implements neither [RFC8203] nor this specification, then that
speaker will treat it as an error, the consequence of which should be
a log message.
In any case, a receiver of a NOTIFICATION message is unable to
acknowledge the receipt and correct understanding of any Shutdown
Communication.
Operators should not rely on Shutdown Communications as their sole
form of communication with their peer for important events.
If it is known that the peer BGP speaker supports this specification,
then a Shutdown Communication that is not longer than 255 octets MAY
be sent. Otherwise, a Shutdown Communication MAY be sent, but it
SHOULD NOT be longer than 128 octets.
4. Error Handling 4. Error Handling
If a Shutdown Communication with an invalid Length value, or an If a Shutdown Communication with an invalid UTF-8 sequence is
invalid UTF-8 sequence is received, a message indicating this event received, a message indicating this event SHOULD be logged for the
SHOULD be logged for the attention of the operator. An erroneous or attention of the operator. An erroneous or malformed Shutdown
malformed Shutdown Communication itself MAY be logged in a hexdump Communication itself MAY be logged in a hexdump format.
format.
5. IANA Considerations 5. IANA Considerations
IANA references this document (in addition to [RFC4486]) for subcodes IANA is requested to reference this document at subcode
"Administrative Shutdown" (2) and "Administrative Reset" (4) in the "Administrative Shutdown", and at subcode "Administrative Reset" in
"Cease NOTIFICATION message subcodes" registry under the "Border the "BGP Cease NOTIFICATION message subcodes" registry under the
Gateway Protocol (BGP) Parameters" group. "Border Gateway Protocol (BGP) Parameters" group in addition to
[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. To limit the ability to mount such an as additional syslog messages. The 255 octet length limit on the BGP
attack, the BGP Shutdown Communication is limited to 128 octets in Shutdown Communication may help limit the ability to mount such an
length. 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 may be of greater interest in the context of this
proposal since the information carried in the message is generally proposal since the information carried in the message is generally
expected to be used for human-to-human communication. Refer to the expected to be used for human-to-human communication. Refer to the
related considerations in [RFC4271] and [RFC4272]. related considerations in [RFC4271] and [RFC4272].
skipping to change at page 5, line 12 skipping to change at page 5, line 33
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
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO [RFC3629] Yergeau, F., "UTF-8, a transformation format of ISO
10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November 10646", STD 63, RFC 3629, DOI 10.17487/RFC3629, November
2003, <http://www.rfc-editor.org/info/rfc3629>. 2003, <https://www.rfc-editor.org/info/rfc3629>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271, Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006, DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>. <https://www.rfc-editor.org/info/rfc4271>.
[RFC4486] Chen, E. and V. Gillet, "Subcodes for BGP Cease [RFC4486] Chen, E. and V. Gillet, "Subcodes for BGP Cease
Notification Message", RFC 4486, DOI 10.17487/RFC4486, Notification Message", RFC 4486, DOI 10.17487/RFC4486,
April 2006, <http://www.rfc-editor.org/info/rfc4486>. April 2006, <https://www.rfc-editor.org/info/rfc4486>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <http://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
7.2. Informative References 7.2. Informative References
[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006, RFC 4272, DOI 10.17487/RFC4272, January 2006,
<http://www.rfc-editor.org/info/rfc4272>. <https://www.rfc-editor.org/info/rfc4272>.
[RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424, [RFC5424] Gerhards, R., "The Syslog Protocol", RFC 5424,
DOI 10.17487/RFC5424, March 2009, DOI 10.17487/RFC5424, March 2009,
<http://www.rfc-editor.org/info/rfc5424>. <https://www.rfc-editor.org/info/rfc5424>.
[RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J., [RFC6973] Cooper, A., Tschofenig, H., Aboba, B., Peterson, J.,
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,
<http://www.rfc-editor.org/info/rfc6973>. <https://www.rfc-editor.org/info/rfc6973>.
[UTR36] Davis, M., Ed. and M. Suignard, Ed., "Unicode Security [RFC8203] Snijders, J., Heitz, J., and J. Scudder, "BGP
Administrative Shutdown Communication", RFC 8203,
DOI 10.17487/RFC8203, July 2017,
<https://www.rfc-editor.org/info/rfc8203>.
[UTR36] Davis, M. and M. Suignard, "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/>.
Acknowledgements Appendix A. 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 rights to the IETF their work on [RFC4486] and granting the related BCP 78 rights to the
Trust per BCP 78. IETF Trust.
The authors would like to acknowledge Misha Grishin (MSK-IX) for
raising awareness that [RFC8203]'s length specification was
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 Communications
Theodorus Majofskistraat 100 Theodorus Majofskistraat 100
Amsterdam 1065 SZ Amsterdam 1065 SZ
The Netherlands The Netherlands
Email: job@ntt.net Email: job@ntt.net
skipping to change at line 266 skipping to change at page 7, line 39
Email: jheitz@cisco.com Email: jheitz@cisco.com
John Scudder John Scudder
Juniper Networks Juniper Networks
1194 N. Mathilda Ave 1194 N. Mathilda Ave
Sunnyvale, CA 94089 Sunnyvale, CA 94089
United States of America United States of America
Email: jgs@juniper.net Email: jgs@juniper.net
Alexander Azimov
Yandex
Email: a.e.azimov@gmail.com
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