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
	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
	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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