draft-ietf-6man-multicast-addr-arch-update-01.txt		draft-ietf-6man-multicast-addr-arch-update-02.txt
	6man Working Group M. Boucadair		6man Working Group M. Boucadair
	Internet-Draft France Telecom		Internet-Draft France Telecom
	Updates: 3306,3956,4607,4291 (if approved) S. Venaas		Updates: 3306,3956,4291 (if approved) S. Venaas
	Intended status: Standards Track Cisco		Intended status: Standards Track Cisco
	Expires: November 24, 2013 May 23, 2013		Expires: April 21, 2014 October 18, 2013
	Updates to the IPv6 Multicast Addressing Architecture		Updates to the IPv6 Multicast Addressing Architecture
	draft-ietf-6man-multicast-addr-arch-update-01		draft-ietf-6man-multicast-addr-arch-update-02
	Abstract		Abstract
	This document updates the IPv6 multicast addressing architecture by		This document updates the IPv6 multicast addressing architecture by
	defining the 17-20 reserved bits as generic flag bits. The document		defining the 17-20 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, RFC 4607 and RFC 4291.		This document updates RFC 3956, RFC 3306 and RFC 4291.
	Requirements Language		Requirements Language
	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 RFC 2119 [RFC2119].		document are to be interpreted as described in RFC 2119 [RFC2119].
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	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 November 24, 2013.		This Internet-Draft will expire on April 21, 2014.
	Copyright Notice		Copyright Notice
	Copyright (c) 2013 IETF Trust and the persons identified as the		Copyright (c) 2013 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
	skipping to change at page 2, line 21		skipping to change at page 2, line 21
	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 . . . . . . . . . . . . . . . 2
	3. Clarifications . . . . . . . . . . . . . . . . . . . . . . . 3		3. Clarifications . . . . . . . . . . . . . . . . . . . . . . . 3
	3.1. Flag Bits . . . . . . . . . . . . . . . . . . . . . . . . 3		3.1. Flag Bits . . . . . . . . . . . . . . . . . . . . . . . . 3
	3.2. IANA Assigned SSM Block . . . . . . . . . . . . . . . . . 4
	4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 4		4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 4
	4.1. RFC3306 . . . . . . . . . . . . . . . . . . . . . . . . . 4		4.1. RFC 3306 . . . . . . . . . . . . . . . . . . . . . . . . 4
	4.2. RFC3956 . . . . . . . . . . . . . . . . . . . . . . . . . 6		4.2. RFC 3956 . . . . . . . . . . . . . . . . . . . . . . . . 5
	4.3. RFC4607 . . . . . . . . . . . . . . . . . . . . . . . . . 8		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9		6. Security Considerations . . . . . . . . . . . . . . . . . . . 8
	6. Security Considerations . . . . . . . . . . . . . . . . . . . 9		7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 8
	7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9		8. Normative References . . . . . . . . . . . . . . . . . . . . 8
	8. Normative References . . . . . . . . . . . . . . . . . . . . 9		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
	1. Introduction		1. Introduction
	This document updates the IPv6 multicast addressing architecture		This document updates the IPv6 multicast addressing architecture
	[RFC4291] by defining the 17-20 reserved bits as generic flag bits		[RFC4291] by defining the 17-20 reserved bits as generic flag bits
	(Section 2). The document provides also some clarifications related		(Section 2). The document provides also some clarifications related
	to the use of these flag bits (Section 3.1) and also about IANA		to the use of these flag bits (Section 3.1).
	assigned SSM blocks (Section 3.2).
	This document updates [RFC3956], [RFC3306], [RFC4607] and [RFC4291].		This document updates [RFC3956], [RFC3306], and [RFC4291].
	2. Addressing Architecture Update		2. Addressing Architecture Update
	Bits 17-20 of a multicast address are defined in [RFC3956] and		Bits 17-20 of a multicast address are defined in [RFC3956] and
	[RFC3306] as reserved bits. This document defines these bits as		[RFC3306] as reserved bits. This document defines these bits as
	generic flag bits so that they apply to any multicast address.		generic flag bits so that they apply to any multicast address.
	Figure 1 and Figure 2 show the updated structure of the addressing		Figure 1 and Figure 2 show the updated structure of the addressing
	architecture. The first diagram shows the update of the base IPv6		architecture. The first diagram shows the update of the base IPv6
	addressing architecture, and the second shows the update of so-called		addressing architecture, and the second shows the update of so-called
	Embedded-RP.		Embedded-RP.
	skipping to change at page 3, line 19		skipping to change at page 3, line 14
	+--------+----+----+----------------------------------------------+		+--------+----+----+----------------------------------------------+
	NEW:		NEW:
	| 8 | 4 | 4 | 4 | 108 bits |		| 8 | 4 | 4 | 4 | 108 bits |
	+--------+----+----+----------------------------------------------+		+--------+----+----+----------------------------------------------+
	|11111111|flgs|scop|flgs| group ID |		|11111111|flgs|scop|flgs| group ID |
	+--------+----+----+----+-----------------------------------------+		+--------+----+----+----+-----------------------------------------+
	Figure 1: Updated IPv6 Multicast Addressing Architecture		Figure 1: Updated IPv6 Multicast Addressing Architecture
	OLD (RFC3956):		OLD (RFC 3956):
	| 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 |
	+--------+----+----+----+----+--------+----------------+----------+		+--------+----+----+----+----+--------+----------------+----------+
	NEW:		NEW:
	| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |		| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
	+--------+----+----+----+----+--------+----------------+----------+		+--------+----+----+----+----+--------+----------------+----------+
	|11111111|flgs|scop|flgs|RIID| plen | network prefix | group ID |		|11111111|flgs|scop|flgs|RIID| plen | network prefix | group ID |
	+--------+----+----+----+----+--------+----------------+----------+		+--------+----+----+----+----+--------+----------------+----------+
	skipping to change at page 3, line 50		skipping to change at page 3, line 45
	3. Clarifications		3. Clarifications
	3.1. Flag Bits		3.1. Flag Bits
	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 [RFC4607] 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 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 recommendation 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.
	3.2. IANA Assigned SSM Block
	Another issue related to SSM is the IANA assigned SSM address block.
	Per [RFC4607], ff3x::4000:0001 through ff3x::7fff:fff is the block
	for IANA assignments (http://www.iana.org/assignments/ipv6-multicast-
	addresses/ipv6-multicast-addresses.xml). However, IANA assignments
	are permanent addresses and should not have the transient bit set.
	Quoting from [RFC4607]:
	"T = 1 indicates a non-permanently-assigned ("transient")
	multicast address.".
	4. RFC Updates		4. RFC Updates
	4.1. RFC3306		4.1. RFC 3306
	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 5, line 27		skipping to change at page 5, line 12
	X and Y may each be set to 0 or 1.		X and Y may each be set to 0 or 1.
	o P = 0 indicates a multicast address that is not assigned		o P = 0 indicates a multicast address that is not assigned
	based on the network prefix. This indicates a multicast		based on the network prefix. This indicates a multicast
	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 T is set according to the definition in Section 2.7		o If P = 1, T MUST be set to 1, otherwise the setting of the T
	of [ADDRARCH]. Unicast-Prefix-based addresses would		bit is defined in Section 2.7 of [ADDRARCH].
	typically not be IANA assigned, so in most cases T would
	be set to 1.
	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:
	T flag is set according to whether the addresses are assigned by		If the flag bits are set to 0011, these settings create an SSM
	IANA.		range of ff3x::/32 (where 'x' is any valid scope value). The
			source address field in the IPv6 header identifies the owner of
	If the flag bits are to 0011, these settings create an SSM range		the multicast address. ff3x::/32 is not the only allowed SSM
	of ff3x::/32 (where 'x' is any valid scope value). The source		prefix range. For example if the most significant flag bit is
	address field in the IPv6 header identifies the owner of the		set, then we would get the SSM range ffbx::/32.
	multicast address. ff3x::/32 is not the only allowed SSM prefix
	range. For example, ff2x::/32 would be IANA assigned SSM
	addresses.
	4.2. RFC3956		4.2. RFC 3956
	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 |
	+--------+----+----+--------+----+----------------+----------+		+--------+----+----+--------+----+----------------+----------+
	Where flgs are "0011". (The first two bits are as yet undefined,		Where flgs are "0011". (The first two bits are as yet undefined,
	sent as zero and ignored on receipt.)		sent as zero and ignored on receipt.)
	NEW:		NEW:
	As described in [RFC3306], the multicast address format is as		The multicast address format is as
	follows:		follows:
	| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |		| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
	+--------+----+----+---------+----+----------------+----------+		+--------+----+----+---------+----+----------------+----------+
	|11111111|flgs|scop|flgs|rsvd|plen| network prefix | group ID |		|11111111|flgs|scop|flgs|rsvd|plen| network prefix | group ID |
	+--------+----+----+---------+----+----------------+----------+		+--------+----+----+---------+----+----------------+----------+
	+-+-+-+-+		+-+-+-+-+
	flgs is a set of four flags: |X|R|P|T|		flgs is a set of four flags: |X|R|P|T|
	+-+-+-+-+		+-+-+-+-+
	skipping to change at page 7, line 37		skipping to change at page 7, line 11
	| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |		| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
	+--------+----+----+----+----+----+----------------+----------+		+--------+----+----+----+----+----+----------------+----------+
	|11111111|flgs|scop|flgs|RIID|plen| network prefix | group ID |		|11111111|flgs|scop|flgs|RIID|plen| network prefix | group ID |
	+--------+----+----+----+----+----+----------------+----------+		+--------+----+----+----+----+----+----------------+----------+
	+-+-+-+-+		+-+-+-+-+
	flgs is a set of four flags: |X|R|P|T|		flgs 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 RP.		R = 1 indicates a multicast address that embeds the address of the RP.
	P MUST be set to 1 according to [RFC3306], as this is a special case of		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 based addresses. This implies that for instance prefixes		unicast-prefix based addresses. This implies that for instance prefixes
	ff70::/12 and fff0::/12 are embedded RP prefixes, but all multicast		ff70::/12 and fff0::/12 are embedded RP prefixes, but all multicast
	addresses with the R-bit set to 1 MUST be treated as Embedded RP		addresses with the R-bit set to 1 MUST be treated as Embedded RP
	addresses. The behavior is unspecified if P is not set to 1. When the		addresses. The behavior is unspecified if P or T is not set to 1. When the
	R-bit is set, the last 4 bits of the previously reserved field are		R-bit is set, the last 4 bits of the previously reserved field are
	interpreted as embedding the RP interface ID, as specified in this memo.		interpreted as embedding the RP interface ID, as specified in this memo.
	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 set to 1 when using the embedding in this		It MUST have P-bit and T-bit both set to 1 when using the
	document as it is a prefix-based address.		embedding in this document as it is a prefix-based address.
	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.
	4.3. RFC4607
	This document changes the abstract of [RFC4607] as follows:
	OLD:
	IP version 4 (IPv4) addresses in the 232/8 (232.0.0.0 to
	232.255.255.255) range are designated as source-specific multicast
	(SSM) destination addresses and are reserved for use by source-
	specific applications and protocols. For IP version 6 (IPv6), the
	address prefix FF3x::/32 is currently reserved for source-specific
	multicast use but others may be reserved in the future. This
	document defines an extension to the Internet network service that
	applies to datagrams sent to SSM addresses and defines the host
	and router requirements to support this extension.
	NEW:
	IP version 4 (IPv4) addresses in the 232/8 (232.0.0.0 to
	232.255.255.255) range are designated as source-specific multicast
	(SSM) destination addresses and are reserved for use by source-
	specific applications and protocols. For IP version 6 (IPv6), the
	address prefix ff3x::/32 is currently reserved for source-specific
	multicast use but others may be reserved in the future. This
	document defines an extension to the Internet network service that
	applies to datagrams sent to SSM addresses and defines the host
	and router requirements to support this extension.
	This document changes Section 1 of [RFC4607] as follows:
	OLD:
	For IPv6, the address prefix FF3x::/32 is reserved for source-
	specific multicast use, where 'x' is any valid scope identifier,
	by [IPv6-UBM]. Using the terminology of [IPv6-UBM], all SSM
	addresses must have P=1, T=1, and plen=0. [IPv6-MALLOC] mandates
	that the network prefix field of an SSM address also be set to
	zero, hence all SSM addresses fall in the FF3x::/96 range. Future
	documents may allow a non-zero network prefix field if, for
	instance, a new IP- address-to-MAC-address mapping is defined.
	Thus, address allocation should occur within the FF3x::/96 range,
	but a system should treat all of FF3x::/32 as SSM addresses, to
	allow for compatibility with possible future uses of the network
	prefix field.
	NEW:
	For IPv6, all SSM addresses must have P=1 and plen=0 while T-bit
	is set according to whether the addresses are assigned by IANA
	[I-D.ietf-6man-multicast-addr-arch-update]. In particular, a
	system should treat all of ff3x::/32 and ff2x::/32 as SSM
	addresses, to allow for compatibility with possible future uses of
	the network prefix field. Other SSM prefixes can be defined in
	the future.
	5. IANA Considerations		5. IANA Considerations
	This document may require IANA updates. However, at this point it is		This document may require IANA updates. However, at this point it is
	not clear exactly what these updates may be.		not clear exactly what these updates may be.
	6. Security Considerations		6. Security Considerations
	Security considerations discussed in [RFC3956], [RFC3306], [RFC4607]		Security considerations discussed in [RFC3956], [RFC3306] and
	and [RFC4291] MUST be taken into account.		[RFC4291] MUST be taken into account.
	7. Acknowledgements		7. Acknowledgements
	Many thanks to B. Haberman for the discussions prior to the		Many thanks to B. Haberman for the discussions prior to the
	publication of this document.		publication of this document.
	8. Normative References		8. 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.
	[RFC4607] Holbrook, H. and B. Cain, "Source-Specific Multicast for
	IP", RFC 4607, August 2006.
	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. 26 change blocks.
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