< draft-ietf-6man-multicast-addr-arch-update-05.txt		draft-ietf-6man-multicast-addr-arch-update-06.txt >
	6man Working Group M. Boucadair		6man Working Group M. Boucadair
	Internet-Draft France Telecom		Internet-Draft France Telecom
	Updates: 3306,3956,4291 (if approved) S. Venaas		Updates: 3306,3956,4291 (if approved) S. Venaas
	Intended status: Standards Track Cisco		Intended status: Standards Track Cisco
	Expires: December 20, 2014 June 18, 2014		Expires: January 5, 2015 July 04, 2014
	Updates to the IPv6 Multicast Addressing Architecture		Updates to the IPv6 Multicast Addressing Architecture
	draft-ietf-6man-multicast-addr-arch-update-05		draft-ietf-6man-multicast-addr-arch-update-06
	Abstract		Abstract
	This document updates the IPv6 multicast addressing architecture by		This document updates the IPv6 multicast addressing architecture by
	re-defining the reserved bits as generic flag bits. The document		re-defining the reserved bits as generic flag bits. The document
	provides also some clarifications related to the use of these flag		provides also some clarifications related to the use of these flag
	bits.		bits.
	This document updates RFC 3956, RFC 3306 and RFC 4291.		This document updates RFC 3956, RFC 3306 and RFC 4291.
	skipping to change at page 1, line 42 ¶		skipping to change at page 1, line 42 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on December 20, 2014.		This Internet-Draft will expire on January 5, 2015.
	Copyright Notice		Copyright Notice
	Copyright (c) 2014 IETF Trust and the persons identified as the		Copyright (c) 2014 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		(http://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
	2. Addressing Architecture Update . . . . . . . . . . . . . . . 2		2. Addressing Architecture Update . . . . . . . . . . . . . . . 3
	3. Flag Bits: A Recommendation . . . . . . . . . . . . . . . . . 3		3. Flag Bits: A Recommendation . . . . . . . . . . . . . . . . . 3
	4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 3		4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 4
	4.1. RFC 3306 . . . . . . . . . . . . . . . . . . . . . . . . 3		4.1. RFC 3306 . . . . . . . . . . . . . . . . . . . . . . . . 4
			4.1.1. Update #1 . . . . . . . . . . . . . . . . . . . . . . 4
			4.1.2. Update #2 . . . . . . . . . . . . . . . . . . . . . . 5
	4.2. RFC 3956 . . . . . . . . . . . . . . . . . . . . . . . . 6		4.2. RFC 3956 . . . . . . . . . . . . . . . . . . . . . . . . 6
			4.2.1. Update #1 . . . . . . . . . . . . . . . . . . . . . . 6
			4.2.2. Update #2 . . . . . . . . . . . . . . . . . . . . . . 6
			4.2.3. Update #3 . . . . . . . . . . . . . . . . . . . . . . 8
			4.2.4. Update #4 . . . . . . . . . . . . . . . . . . . . . . 8
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 8		6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8		7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
	8. Normative References . . . . . . . . . . . . . . . . . . . . 8		8. References . . . . . . . . . . . . . . . . . . . . . . . . . 9
			8.1. Normative References . . . . . . . . . . . . . . . . . . 9
			8.2. Informative References . . . . . . . . . . . . . . . . . 9
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
	1. Introduction		1. Introduction
	This document updates the IPv6 addressing architecture [RFC4291] by		This document updates the IPv6 addressing architecture [RFC4291] by
	re-defining reserved bits as generic flag bits (Section 2). The		re-defining reserved bits as generic flag bits (Section 2). The
	document provides also some clarifications related to the use of		document provides also some clarifications related to the use of
	these flag bits (Section 3).		these flag bits (Section 3).
	This document updates [RFC3956], [RFC3306], and [RFC4291]. These		This document updates [RFC3956], [RFC3306], and [RFC4291]. These
	skipping to change at page 3, line 9 ¶		skipping to change at page 3, line 20 ¶
	they apply to any multicast address. These bits are referred to as		they apply to any multicast address. These bits are referred to as
	ff2 (flag field 2) while the flgs bits in [RFC4291][RFC3956] are		ff2 (flag field 2) while the flgs bits in [RFC4291][RFC3956] are
	renamed to ff1 (flag field 1).		renamed to ff1 (flag field 1).
	Within this document, flag bits denote both ff1 and ff2.		Within this document, flag bits denote both ff1 and ff2.
	Defining the bits 17-20 as flags for all IPv6 multicast addresses		Defining the bits 17-20 as flags for all IPv6 multicast addresses
	allows addresses to be treated in a more uniform and generic way, and		allows addresses to be treated in a more uniform and generic way, and
	allows for these bits to be defined in the future for different		allows for these bits to be defined in the future for different
	purposes, irrespective of the specific type of multicast address.		purposes, irrespective of the specific type of multicast address.
			For the record, this design choice was initially triggered by
			specification in [I-D.ietf-mboned-64-multicast-address-format] which
			proposed for associating a meaning with one of the reserved bits.
			Moreover, [I-D.ietf-mboned-64-multicast-address-format] considered
			also the use of the last remaining flag in ff1 but that approach was
			abandoned because it is not clear at this stage whether there is
			other usage scenarios of the flag.
	Section 4 specifies the updated structure of the addressing		Section 4 specifies the updated structure of the addressing
	architecture.		architecture.
	Further specification documents may define a meaning for these flag		Further specification documents may define a meaning for these flag
	bits.		bits.
	3. Flag Bits: A Recommendation		3. Flag Bits: A Recommendation
	Some implementations and specification documents do not treat the		Some implementations and specification documents do not treat the
	flag bits as separate bits but tend to use their combined value as a		flag bits as separate bits but tend to use their combined value as a
	4-bit integer. This practice is a hurdle for assigning a meaning to		4-bit integer. This practice is a hurdle for assigning a meaning to
	the remaining flag bits. Below are listed some examples for		the remaining flag bits. Below are listed some examples for
	illustration purposes:		illustration purposes:
	o the reading of [RFC3306] may lead to conclude that ff3x::/32 is		o the reading of [RFC3306] may lead to conclude that ff3x::/32 is
	the only allowed SSM IPv6 prefix block.		the only allowed Source Specific Multicast (SSM) IPv6 prefix
			block.
	o [RFC3956] states only ff70::/12 applies to Embedded-RP.		o [RFC3956] states only ff70::/12 applies to Embedded-RP.
	Particularly, implementations should not treat the fff0::/12 range		Particularly, implementations should not treat the fff0::/12 range
	as Embedded-RP.		as Embedded-RP.
	To avoid such confusion and to unambiguously associate a meaning with		To avoid such confusion and to unambiguously associate a meaning with
	the remaining flags, the following requirement is made:		the remaining flags, the following requirement is made:
	Implementations MUST treat flag bits as separate bits.		Implementations MUST treat flag bits as separate bits.
	4. RFC Updates		4. RFC Updates
	4.1. RFC 3306		4.1. RFC 3306
			4.1.1. Update #1
	This document changes Section 4 of [RFC3306] as follows:		This document changes Section 4 of [RFC3306] as follows:
	OLD:		OLD:
	| 8 | 4 | 4 | 8 | 8 | 64 | 32 |		| 8 | 4 | 4 | 8 | 8 | 64 | 32 |
	+--------+----+----+--------+--------+----------------+----------+		+--------+----+----+--------+--------+----------------+----------+
	|11111111|flgs|scop|reserved| plen | network prefix | group ID |		|11111111|flgs|scop|reserved| plen | network prefix | group ID |
	+--------+----+----+--------+--------+----------------+----------+		+--------+----+----+--------+--------+----------------+----------+
	+-+-+-+-+		+-+-+-+-+
	skipping to change at page 4, line 26 ¶		skipping to change at page 4, line 38 ¶
	address as defined in [ADDRARCH].		address as defined in [ADDRARCH].
	o P = 1 indicates a multicast address that is assigned based		o P = 1 indicates a multicast address that is assigned based
	on the network prefix.		on the network prefix.
	o If P = 1, T MUST be set to 1, otherwise the setting of the T		o If P = 1, T MUST be set to 1, otherwise the setting of the T
	bit is defined in Section 2.7 of [ADDRARCH].		bit is defined in Section 2.7 of [ADDRARCH].
	The reserved field MUST be zero.		The reserved field MUST be zero.
			Note: [ADDRARCH] is a reference listed in [RFC3306]. [ADDRARCH]
			has been since obsoleted by [RFC4291].
	NEW:		NEW:
	| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |		| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
	+--------+----+----+----+----+--------+----------------+----------+		+--------+----+----+----+----+--------+----------------+----------+
	|11111111|ff1 |scop|ff2 |rsvd| plen | network prefix | group ID |		|11111111|ff1 |scop|ff2 |rsvd| plen | network prefix | group ID |
	+--------+----+----+----+----+--------+----------------+----------+		+--------+----+----+----+----+--------+----------------+----------+
	+-+-+-+-+		+-+-+-+-+
	ff1 (flag field 1) is a set of 4 flags: |X|Y|P|T|		ff1 (flag field 1) is a set of 4 flags: |X|Y|P|T|
	+-+-+-+-+		+-+-+-+-+
	skipping to change at page 5, line 31 ¶		skipping to change at page 5, line 31 ¶
	on the network prefix.		on the network prefix.
	o If P = 1, T MUST be set to 1, otherwise the setting of the T		o If P = 1, T MUST be set to 1, otherwise the setting of the T
	bit is defined in Section 2.7 of [RFC4291].		bit is defined in Section 2.7 of [RFC4291].
	+-+-+-+-+		+-+-+-+-+
	ff2 (flag field 2) is a set of 4 flags: |r|r|r|r|		ff2 (flag field 2) is a set of 4 flags: |r|r|r|r|
	+-+-+-+-+		+-+-+-+-+
	where "rrrr" are for future assignment as additional flag bits.		where "rrrr" are for future assignment as additional flag bits.
			r bits MUST each be set to 0.
	Flag bits denote both ff1 and ff2.		Flag bits denote both ff1 and ff2.
			4.1.2. Update #2
	This document changes Section 6 of [RFC3306] as follows:		This document changes Section 6 of [RFC3306] as follows:
	OLD:		OLD:
	These settings create an SSM range of FF3x::/32 (where 'x' is any		These settings create an SSM range of FF3x::/32 (where 'x' is any
	valid scope value). The source address field in the IPv6 header		valid scope value). The source address field in the IPv6 header
	identifies the owner of the multicast address.		identifies the owner of the multicast address.
	NEW:		NEW:
	If the flag bits in ff1 are set to 0011, these settings create an		If the flag bits in ff1 are set to 0011, these settings create an
	SSM range of ff3x::/32 (where 'x' is any valid scope value). The		SSM range of ff3x::/32 (where 'x' is any valid scope value). The
	source address field in the IPv6 header identifies the owner of		source address field in the IPv6 header identifies the owner of
	the multicast address. ff3x::/32 is not the only allowed SSM		the multicast address. ff3x::/32 is not the only allowed SSM
	prefix range. For example if the most significant flag bit in ff1		prefix range. For example if the most significant flag bit in ff1
	is set, then we would get the SSM range ffbx::/32.		is set, then we would get the SSM range ffbx::/32.
	4.2. RFC 3956		4.2. RFC 3956
			4.2.1. Update #1
	This document changes Section 2 of [RFC3956] as follows:		This document changes Section 2 of [RFC3956] as follows:
	OLD:		OLD:
	As described in [RFC3306], the multicast address format is as		As described in [RFC3306], the multicast address format is as
	follows:		follows:
	| 8 | 4 | 4 | 8 | 8 | 64 | 32 |		| 8 | 4 | 4 | 8 | 8 | 64 | 32 |
	+--------+----+----+--------+----+----------------+----------+		+--------+----+----+--------+----+----------------+----------+
	|11111111|flgs|scop|reserved|plen| network prefix | group ID |		|11111111|flgs|scop|reserved|plen| network prefix | group ID |
	skipping to change at page 6, line 41 ¶		skipping to change at page 6, line 43 ¶
	+-+-+-+-+		+-+-+-+-+
	ff1 (flag field 1) is a set of four flags: |X|R|P|T|		ff1 (flag field 1) is a set of four flags: |X|R|P|T|
	+-+-+-+-+		+-+-+-+-+
	X may be set to 0 or 1.		X may be set to 0 or 1.
	+-+-+-+-+		+-+-+-+-+
	ff2 (flag field 2) is a set of 4 flags: |r|r|r|r|		ff2 (flag field 2) is a set of 4 flags: |r|r|r|r|
	+-+-+-+-+		+-+-+-+-+
	where "rrrr" are for future assignment as additional flag bits.		where "rrrr" are for future assignment as additional flag bits.
			r bits MUST each be set to 0.
	Flag bits denote both ff1 and ff2.		Flag bits denote both ff1 and ff2.
			4.2.2. Update #2
	This document changes Section 3 of [RFC3956] as follows:		This document changes Section 3 of [RFC3956] as follows:
	OLD:		OLD:
	| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |		| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
	+--------+----+----+----+----+----+----------------+----------+		+--------+----+----+----+----+----+----------------+----------+
	|11111111|flgs|scop|rsvd|RIID|plen| network prefix | group ID |		|11111111|flgs|scop|rsvd|RIID|plen| network prefix | group ID |
	+--------+----+----+----+----+----+----------------+----------+		+--------+----+----+----+----+----+----------------+----------+
	+-+-+-+-+		+-+-+-+-+
	flgs is a set of four flags: |0|R|P|T|		flgs is a set of four flags: |0|R|P|T|
	skipping to change at page 7, line 40 ¶		skipping to change at page 7, line 40 ¶
	| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |		| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
	+--------+----+----+----+----+----+----------------+----------+		+--------+----+----+----+----+----+----------------+----------+
	|11111111|ff1 |scop|ff2 |RIID|plen| network prefix | group ID |		|11111111|ff1 |scop|ff2 |RIID|plen| network prefix | group ID |
	+--------+----+----+----+----+----+----------------+----------+		+--------+----+----+----+----+----+----------------+----------+
	+-+-+-+-+		+-+-+-+-+
	ff1 is a set of four flags: |X|R|P|T|		ff1 is a set of four flags: |X|R|P|T|
	+-+-+-+-+		+-+-+-+-+
	X may be set to 0 or 1.		X may be set to 0 or 1.
	R = 1 indicates a multicast address that embeds the address of the		R = 1 indicates a multicast address that embeds the address of the
	RP. P MUST be set to 1, and consequently T MUST be set to 1,		RP. Then P MUST be set to 1, and consequently T MUST be set to 1,
	according to [RFC3306], as this is a special case of unicast-prefix		according to [RFC3306], as this is a special case of unicast-prefix
	based addresses. This implies that for instance prefixes ff70::/12		based addresses. This implies that, for instance, prefixes ff70::/12
	and fff0::/12 are embedded RP prefixes. The behavior is unspecified		and fff0::/12 are embedded RP prefixes. The behavior is unspecified
	if P or T is not set to 1. When the R-bit is set, the last 4 bits of		if P or T is not set to 1. When the R-bit is set, the last 4 bits of
	the field that were reserved in [RFC3306] are interpreted as		the field that were reserved in [RFC3306] are interpreted as
	embedding the RP interface ID, as specified in this memo.		embedding the RP interface ID, as specified in this memo.
			4.2.3. Update #3
	This document changes Section 4 of [RFC3956] as follows:		This document changes Section 4 of [RFC3956] as follows:
	OLD:		OLD:
	It MUST be a multicast address with "flgs" set to 0111, that is,		It MUST be a multicast address with "flgs" set to 0111, that is,
	to be of the prefix FF70::/12,		to be of the prefix FF70::/12,
	NEW:		NEW:
	It MUST be a multicast address with R-bit set to 1.		It MUST be a multicast address with R-bit set to 1.
	It MUST have P-bit and T-bit both set to 1 when using the		It MUST have P-bit and T-bit both set to 1 when using the
	embedding in this document as it is a prefix-based address.		embedding in this document as it is a prefix-based address.
			4.2.4. Update #4
	This document changes Section 7.1 of [RFC3956] as follows:		This document changes Section 7.1 of [RFC3956] as follows:
	OLD:		OLD:
	To avoid loops and inconsistencies, for addresses in the range		To avoid loops and inconsistencies, for addresses in the range
	FF70::/12, the Embedded-RP mapping MUST be considered the longest		FF70::/12, the Embedded-RP mapping MUST be considered the longest
	possible match and higher priority than any other mechanism.		possible match and higher priority than any other mechanism.
	NEW:		NEW:
	To avoid loops and inconsistencies, for addresses with R-bit set		To avoid loops and inconsistencies, for addresses with R-bit set
	to 1, the Embedded-RP mapping MUST be considered the longest		to 1, the Embedded-RP mapping MUST be considered the longest
	possible match and higher priority than any other mechanism.		possible match and higher priority than any other mechanism.
	5. IANA Considerations		5. IANA Considerations
	This document does not require any action from IANA.		This document does not require any action from IANA.
	6. Security Considerations		6. Security Considerations
	Security considerations discussed in [RFC3956], [RFC3306] and		The same security considerations as those discussed in [RFC3956],
	[RFC4291] MUST be taken into account.		[RFC3306] and [RFC4291] are to be taken into account.
	7. Acknowledgements		7. Acknowledgements
	Special thanks to Brian Haberman for the discussions prior to the		Special thanks to Brian Haberman for the discussions prior to the
	publication of this document.		publication of this document.
	Many thanks to Jouni Korhonen and Tatuya Jinmei their review.		Many thanks to Jouni Korhonen, Tatuya Jinmei, Charlie Kaufman, and
			Ben Campbell for their review.
	8. Normative References		8. References
			8.1. 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, March 1997.		Requirement Levels", BCP 14, RFC 2119, March 1997.
	[RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6		[RFC3306] Haberman, B. and D. Thaler, "Unicast-Prefix-based IPv6
	Multicast Addresses", RFC 3306, August 2002.		Multicast Addresses", RFC 3306, August 2002.
	[RFC3956] Savola, P. and B. Haberman, "Embedding the Rendezvous		[RFC3956] Savola, P. and B. Haberman, "Embedding the Rendezvous
	Point (RP) Address in an IPv6 Multicast Address", RFC		Point (RP) Address in an IPv6 Multicast Address", RFC
	3956, November 2004.		3956, November 2004.
	[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing		[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
	Architecture", RFC 4291, February 2006.		Architecture", RFC 4291, February 2006.
	[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6		[RFC5952] Kawamura, S. and M. Kawashima, "A Recommendation for IPv6
	Address Text Representation", RFC 5952, August 2010.		Address Text Representation", RFC 5952, August 2010.
			8.2. Informative References
			[I-D.ietf-mboned-64-multicast-address-format]
			Boucadair, M., Qin, J., Lee, Y., Venaas, S., Li, X., and
			M. Xu, "IPv6 Multicast Address With Embedded IPv4
			Multicast Address", draft-ietf-mboned-64-multicast-
			address-format-05 (work in progress), April 2013.
	Authors' Addresses		Authors' Addresses
	Mohamed Boucadair		Mohamed Boucadair
	France Telecom		France Telecom
	Rennes 35000		Rennes 35000
	France		France
	Email: mohamed.boucadair@orange.com		Email: mohamed.boucadair@orange.com
	Stig Venaas		Stig Venaas
End of changes. 24 change blocks.
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