< draft-ietf-6man-multicast-addr-arch-update-00.txt		draft-ietf-6man-multicast-addr-arch-update-01.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: 3306,3956,4607,4291 (if approved) S. Venaas
	Intended status: Standards Track Cisco		Intended status: Standards Track Cisco
	Expires: October 10, 2013 April 08, 2013		Expires: November 24, 2013 May 23, 2013
	Updates to the IPv6 Multicast Addressing Architecture		Updates to the IPv6 Multicast Addressing Architecture
	draft-ietf-6man-multicast-addr-arch-update-00		draft-ietf-6man-multicast-addr-arch-update-01
	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, RFC 4607 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 October 10, 2013.		This Internet-Draft will expire on November 24, 2013.
	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 22 ¶		skipping to change at page 2, line 22 ¶
	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		3.2. IANA Assigned SSM Block . . . . . . . . . . . . . . . . . 4
	4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4		4. RFC Updates . . . . . . . . . . . . . . . . . . . . . . . . . 4
	5. Security Considerations . . . . . . . . . . . . . . . . . . . 4		4.1. RFC3306 . . . . . . . . . . . . . . . . . . . . . . . . . 4
	6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4		4.2. RFC3956 . . . . . . . . . . . . . . . . . . . . . . . . . 6
	7. Normative References . . . . . . . . . . . . . . . . . . . . 4		4.3. RFC4607 . . . . . . . . . . . . . . . . . . . . . . . . . 8
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
			6. Security Considerations . . . . . . . . . . . . . . . . . . . 9
			7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 9
			8. Normative References . . . . . . . . . . . . . . . . . . . . 9
			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) and also about IANA
	assigned SSM blocks (Section 3.2).		assigned SSM blocks (Section 3.2).
	This document updates [RFC3956], [RFC3306], [RFC4607] and [RFC4291].		This document updates [RFC3956], [RFC3306], [RFC4607] and [RFC4291].
	skipping to change at page 4, line 4 ¶		skipping to change at page 4, line 11 ¶
	o the reading of [RFC4607] may lead to conclude that ff3x::/32 is		o the reading of [RFC4607] 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 recommendation is made
	Implementations MUST treat flag bits as separate bits.		Implementations MUST treat flag bits as separate bits.
	3.2. IANA Assigned SSM Block		3.2. IANA Assigned SSM Block
	Another issue related to SSM is the IANA assigned SSM address 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		Per [RFC4607], ff3x::4000:0001 through ff3x::7fff:fff is the block
	for IANA assignments (http://www.iana.org/assignments/ipv6-multicast-		for IANA assignments (http://www.iana.org/assignments/ipv6-multicast-
	addresses/ipv6-multicast-addresses.xml). However, IANA assignments		addresses/ipv6-multicast-addresses.xml). However, IANA assignments
	are permanent addresses and should not have the transient bit set.		are permanent addresses and should not have the transient bit set.
	Quoting from [RFC4607]:		Quoting from [RFC4607]:
	"T = 1 indicates a non-permanently-assigned ("transient")		"T = 1 indicates a non-permanently-assigned ("transient")
	multicast address.".		multicast address.".
	4. IANA Considerations		4. RFC Updates
			4.1. RFC3306
			This document changes Section 4 of [RFC3306] as follows:
			OLD:
			| 8 | 4 | 4 | 8 | 8 | 64 | 32 |
			+--------+----+----+--------+--------+----------------+----------+
			|11111111|flgs|scop|reserved| plen | network prefix | group ID |
			+--------+----+----+--------+--------+----------------+----------+
			+-+-+-+-+
			flgs is a set of 4 flags: |0|0|P|T|
			+-+-+-+-+
			o P = 0 indicates a multicast address that is not assigned
			based on the network prefix. This indicates a multicast
			address as defined in [ADDRARCH].
			o P = 1 indicates a multicast address that is assigned based
			on the network prefix.
			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].
			The reserved field MUST be zero.
			NEW:
			| 8 | 4 | 4 | 8 | 8 | 64 | 32 |
			+--------+----+----+--------+--------+----------------+----------+
			|11111111|flgs|scop|reserved| plen | network prefix | group ID |
			+--------+----+----+--------+--------+----------------+----------+
			+-+-+-+-+
			flgs is a set of 4 flags: |X|Y|P|T|
			+-+-+-+-+
			X and Y may each be set to 0 or 1.
			o P = 0 indicates a multicast address that is not assigned
			based on the network prefix. This indicates a multicast
			address as defined in [ADDRARCH].
			o P = 1 indicates a multicast address that is assigned based
			on the network prefix.
			o T is set according to the definition in Section 2.7
			of [ADDRARCH]. Unicast-Prefix-based addresses would
			typically not be IANA assigned, so in most cases T would
			be set to 1.
			This document changes Section 6 of [RFC3306] as follows:
			OLD:
			These settings create an SSM range of FF3x::/32 (where 'x' is any
			valid scope value). The source address field in the IPv6 header
			identifies the owner of the multicast address.
			NEW:
			T flag is set according to whether the addresses are assigned by
			IANA.
			If the flag bits are to 0011, these settings create an SSM range
			of ff3x::/32 (where 'x' is any valid scope value). The source
			address field in the IPv6 header identifies the owner of the
			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
			This document changes Section 2 of [RFC3956] as follows:
			OLD:
			As described in [RFC3306], the multicast address format is as
			follows:
			| 8 | 4 | 4 | 8 | 8 | 64 | 32 |
			+--------+----+----+--------+----+----------------+----------+
			|11111111|flgs|scop|reserved|plen| network prefix | group ID |
			+--------+----+----+--------+----+----------------+----------+
			Where flgs are "0011". (The first two bits are as yet undefined,
			sent as zero and ignored on receipt.)
			NEW:
			As described in [RFC3306], the multicast address format is as
			follows:
			| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
			+--------+----+----+---------+----+----------------+----------+
			|11111111|flgs|scop|flgs|rsvd|plen| network prefix | group ID |
			+--------+----+----+---------+----+----------------+----------+
			+-+-+-+-+
			flgs is a set of four flags: |X|R|P|T|
			+-+-+-+-+
			X may be set to 0 or 1.
			This document changes Section 3 of [RFC3956] as follows:
			OLD:
			| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
			+--------+----+----+----+----+----+----------------+----------+
			|11111111|flgs|scop|rsvd|RIID|plen| network prefix | group ID |
			+--------+----+----+----+----+----+----------------+----------+
			+-+-+-+-+
			flgs is a set of four flags: |0|R|P|T|
			+-+-+-+-+
			When the highest-order bit is 0, R = 1 indicates a multicast address
			that embeds the address on the RP. Then P MUST be set to 1, and
			consequently T MUST be set to 1, as specified in [RFC3306]. In
			effect, this implies the prefix FF70::/12. In this case, the last 4
			bits of the previously reserved field are interpreted as embedding
			the RP interface ID, as specified in this memo.
			The behavior is unspecified if P or T is not set to 1, as then the
			prefix would not be FF70::/12. Likewise, the encoding and the
			protocol mode used when the two high-order bits in "flgs" are set to
			11 ("FFF0::/12") is intentionally unspecified until such time that
			the highest-order bit is defined. Without further IETF
			specification, implementations SHOULD NOT treat the FFF0::/12 range
			as Embedded-RP.
			NEW:
			| 8 | 4 | 4 | 4 | 4 | 8 | 64 | 32 |
			+--------+----+----+----+----+----+----------------+----------+
			|11111111|flgs|scop|flgs|RIID|plen| network prefix | group ID |
			+--------+----+----+----+----+----+----------------+----------+
			+-+-+-+-+
			flgs is a set of four flags: |X|R|P|T|
			+-+-+-+-+
			X may be set to 0 or 1.
			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
			unicast-prefix based addresses. This implies that for instance prefixes
			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. The behavior is unspecified if P is not set to 1. When the
			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.
			This document changes Section 4 of [RFC3956] as follows:
			OLD:
			It MUST be a multicast address with "flgs" set to 0111, that is,
			to be of the prefix FF70::/12,
			NEW:
			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
			document as it is a prefix-based address.
			This document changes Section 7.1 of [RFC3956] as follows:
			OLD:
			To avoid loops and inconsistencies, for addresses in the range
			FF70::/12, the Embedded-RP mapping MUST be considered the longest
			possible match and higher priority than any other mechanism.
			NEW:
			To avoid loops and inconsistencies, for addresses with R-bit set
			to 1, the Embedded-RP mapping MUST be considered the longest
			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
	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.
	5. Security Considerations		6. Security Considerations
	Security considerations discussed in [RFC3956], [RFC3306], [RFC4607]		Security considerations discussed in [RFC3956], [RFC3306], [RFC4607]
	and [RFC4291] MUST be taken into account.		and [RFC4291] MUST be taken into account.
	6. 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.
	7. 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.
End of changes. 9 change blocks.
	12 lines changed or deleted		254 lines changed or added
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