< draft-korhonen-dmm-prefix-properties-00.txt		draft-korhonen-dmm-prefix-properties-01.txt >
	Distributed Mobility Management (DMM) J. Korhonen		Distributed Mobility Management (DMM) J. Korhonen
	Internet-Draft Nokia Siemens Networks		Internet-Draft Nokia Siemens Networks
	Updates: 4861 (if approved) B. Patil		Updates: 4861,3484 (if approved) B. Patil
	Intended status: Standards Track Nokia		Intended status: Standards Track Nokia
	Expires: August 26, 2012 S. Gundavelli		Expires: September 12, 2012 S. Gundavelli
	Cisco		Cisco
	February 23, 2012		March 11, 2012
	IPv6 Prefix Mobility Management Properties		IPv6 Prefix Mobility Management Properties
	draft-korhonen-dmm-prefix-properties-00.txt		draft-korhonen-dmm-prefix-properties-01.txt
	Abstract		Abstract
	This specification defines an extension to the IPv6 Neighbor		This specification defines an extension to the IPv6 Neighbor
	Discovery protocol and its Prefix Information Option. The Prefix		Discovery protocol and its Prefix Information Option. The Prefix
	Information Option is extended with flag bits that describe the		Information Option is extended with flag bits that describe the
	mobility management properties associated to the prefix. This		mobility management properties associated to the prefix. This
	specification updates RFC4861.		specification updates RFC4861 and also updates RFC3484 Source Address
			Selection algorithm.
	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 43 ¶		skipping to change at page 1, line 44 ¶
	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 August 26, 2012.		This Internet-Draft will expire on September 12, 2012.
	Copyright Notice		Copyright Notice
	Copyright (c) 2012 IETF Trust and the persons identified as the		Copyright (c) 2012 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Background and Motivation . . . . . . . . . . . . . . . . . . . 3		2. Background and Motivation . . . . . . . . . . . . . . . . . . . 3
	3. Option Formats . . . . . . . . . . . . . . . . . . . . . . . . 3		3. Option Formats . . . . . . . . . . . . . . . . . . . . . . . . 4
	4. Host Considerations . . . . . . . . . . . . . . . . . . . . . . 5		4. Host Considerations . . . . . . . . . . . . . . . . . . . . . . 6
	4.1. Internal Data Structures . . . . . . . . . . . . . . . . . 5		4.1. Internal Data Structures . . . . . . . . . . . . . . . . . 6
	4.2. Default Address Selection . . . . . . . . . . . . . . . . . 5		4.2. Default Address Selection . . . . . . . . . . . . . . . . . 6
	5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5		5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6
	6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5		6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6
	7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6		7. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
	7.1. Normative References . . . . . . . . . . . . . . . . . . . 6		7.1. Normative References . . . . . . . . . . . . . . . . . . . 7
	7.2. Informative References . . . . . . . . . . . . . . . . . . 6		7.2. Informative References . . . . . . . . . . . . . . . . . . 7
	Appendix A. Additions to the Socket Interface and the		Appendix A. Additions to the Socket Interface and the
	Protocol-Independent Nodename Translation . . . . . . 6		Protocol-Independent Nodename Translation . . . . . . 8
	A.1. Socket Interface . . . . . . . . . . . . . . . . . . . . . 7		A.1. Socket Interface . . . . . . . . . . . . . . . . . . . . . 8
	A.2. Protocol-Independent Nodename Translation . . . . . . . . . 7		A.2. Protocol-Independent Nodename Translation . . . . . . . . . 8
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 7		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 9
	1. Introduction		1. Introduction
	This specification defines an extension to the IPv6 Neighbor		This specification defines an extension to the IPv6 Neighbor
	Discovery protocol and its Prefix Information Option (PIO) [RFC4861].		Discovery protocol and its Prefix Information Option (PIO) [RFC4861].
	The Prefix Information Option is extended with flag bits that		The Prefix Information Option is extended with flag bits that
	describe the mobility management properties associated to the prefix,		describe the mobility management properties associated to the prefix,
	and at the same time defines corresponding source address selection		and at the same time defines corresponding source address selection
	hint flags to the IPv6 Socket API for Source Address Selection		hint flags to the IPv6 Socket API for Source Address Selection
	[RFC5014].		[RFC5014].
	skipping to change at page 3, line 41 ¶		skipping to change at page 3, line 41 ¶
	The underlying assumption is that a MN has multiple prefixes to		The underlying assumption is that a MN has multiple prefixes to
	choose from. Typically this means either the MN has multiple		choose from. Typically this means either the MN has multiple
	interfaces or an interface has been configured with multiple		interfaces or an interface has been configured with multiple
	prefixes. This specification does not make a distinction between		prefixes. This specification does not make a distinction between
	these alternatives and does not either make any assumptions how the		these alternatives and does not either make any assumptions how the
	possible transfer of a prefix is done between interfaces in the case		possible transfer of a prefix is done between interfaces in the case
	a network based mobility solution is used.		a network based mobility solution is used.
	2. Background and Motivation		2. Background and Motivation
	[Discussion: explain the background and subsequently the motivation,		IP mobility and its centralized topological anchoring of IP addresses
	which lead to "coloring" prefixes, and what we expect to gain from		has known issues. For instance, non-optimal routing is a classical
	this extension to IPv6 addressing & neighbor discovery protocol. To		example. Another concerns include excessive tunneling, increased
	be written later.]		signaling due the maintenance of mobility related bindings,
			aggregation of traffic to centralized mobility anchor gateways and
			unnecessary IP mobility related state management for IP traffic that
			does not as such benefit from mobility. In general, it is observed
			that most applications do not need IP level mobility, and work just
			fine with "temporary" IP addresses that come and go. However, IP
			mobility still has its virtues making the applications unaware of
			mobility, and certain wireless mobile networking architecture make
			extensive use of network based IP mobility.
			In order to overcome some of the above issues, use of local resources
			and topologically local addressing could be enhanced. In many cases
			this would lead to use of multiple addresses of which some provide
			mobility and some do not. However, an end host has to have means to
			distinguish between addresses that provide mobility, and those that
			are short lived and usable only within a limited topological area.
			This specification provides extensions to IPv6 address management and
			source address selection so that end hosts (and their applications)
			can select a proper address for their needs.
			[to be enhanced]
	3. Option Formats		3. Option Formats
	Neighbor Discovery messages include zero or more options, some of		Neighbor Discovery messages include zero or more options, some of
	which may appear multiple times in the same message. Options should		which may appear multiple times in the same message. Options should
	be padded when necessary to ensure that they end on their natural 64-		be padded when necessary to ensure that they end on their natural 64-
	bit boundaries. Figure 1 illustrates a Prefix Information Option		bit boundaries. Figure 1 illustrates a Prefix Information Option
	[RFC4861] that is extended with flag bits describing the mobility		[RFC4861] that is extended with flag bits describing the mobility
	properties of the prefix:		properties of the prefix:
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| 3 | 4 | Prefix Length |L|A| C | Rsvd1 |		| 3 | 4 | Prefix Length |L|A| Rsvd1 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Valid Lifetime |		| Valid Lifetime |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Preferred Lifetime |		| Preferred Lifetime |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Reserved2 |		| C | Reserved2 |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |		| |
	+ +		+ +
	| |		| |
	+ Prefix +		+ Prefix +
	| |		| |
	+ +		+ +
	| |		| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 1: Extended Prefix Information Option		Figure 1: Extended Prefix Information Option
	'C' 2-bit flag field describing the mobility properties of the		'C' 2-bit flag field describing the mobility properties of the
	prefix. The following properties are defined:		prefix. The following properties are defined:
	00 No specific property associated to the prefix. The prefix is		00 No specific property associated to the prefix. The prefix is
	treated according to RFC4861.		treated according to RFC4861.
	01 The prefix provides network based mobility and will remain		01 The prefix may or may not provide network based mobility, and
	unchanged at the valid lifetime of the prefix.		if mobility is provided that is only within a limited area.
			Therefore, the end host must be prepared that the prefix may
	10 The prefix provides network based mobility but only within a		become invalid abruptly before the valid or even the
	limited area, thus the end host must be prepared that the
	prefix may become invalid before the valid or even the
	preferred lifetime expire.		preferred lifetime expire.
			10 The prefix provides network based mobility and should remain
			unchanged the valid lifetime of the prefix.
	11 Reserved. Treated as '00' by the receiver.		11 Reserved. Treated as '00' by the receiver.
	A common use case is to define 'C' flags when the 'A'=1 i.e. when		A common use case is to define 'C' flags when the 'A'=1 i.e. when
	Stateless Address AutoConfiguration (SLAAC) is used. However, it is		Stateless Address AutoConfiguration (SLAAC) is used. However, it is
	possible to associate 'C' flags also to prefixes when 'A'=0. In		possible to associate 'C' flags also to prefixes when 'A'=0. In
	cases when there are multiple learned prefixes with 'C' flags set to		cases when there are multiple learned prefixes with 'C' flags set to
	a non-zero value that can also be aggregated, then the longest prefix		a non-zero value that can also be aggregated, then the longest prefix
	takes precedence.		takes precedence.
			If the prefix lifetime(s) is set to infinity that does not override
			the prefix mobility properties indicated in 'C' flags. For instance,
			a prefix with an infinite lifetime but 'C' flags set to '01' indicate
			that the prefix is bound to change abruptly due a handover at some
			point of time.
			'C' flags also define the prefix preference for an IP stack that
			understands the extensions defined in this specification. The IP
			stack SHOULD use the following preferences to supersede
			[I-D.ietf-6man-rfc3484bis] Source Address Selection Rule 8 when
			selecting a default source address among multiple choices and an
			application has not explicitly indicate what kind of source address
			it prefers:
			00 Medium (default) preference.
			01 High preference.
			10 Low preference.
			11 Reserved - MUST NOT be used.
	4. Host Considerations		4. Host Considerations
	4.1. Internal Data Structures		4.1. Internal Data Structures
	The host internal data structures need to be extended with 'mobility		The host internal data structures need to be extended with 'mobility
	property' flag information associated to the learned prefix and		property' flag information associated to the learned prefix and
	configured addresses. How this is accomplished is host		configured addresses. How this is accomplished is host
	implementation specific. It is also a host implementation issue how		implementation specific. It is also a host implementation issue how
	an application can learn or query mobility properties of an address		an application can learn or query mobility properties of an address
	or a prefix. One possibility is to provide such information through		or a prefix. One possibility is to provide such information through
	the socket API extensions (see discussion in Appendix A). Other		the socket API extensions (see discussion in Appendix A). Other
	possibilities include the use of e.g., ioctl() or NetLink [RFC3549]		possibilities include the use of e.g., ioctl() or NetLink [RFC3549]
	extensions.		extensions.
	4.2. Default Address Selection		4.2. Default Address Selection
	The 'mobility property' flags are only used as a hint. They do not		The 'mobility property' flags are only used as a hint. They do not
	affect the existing [RFC3484] automatically. A specific rule to		affect the existing [I-D.ietf-6man-rfc3484bis] automatically. A
	host's policy table has to be inserted by an application or some		specific rule to host's policy table has to be inserted by an
	daemon process. Alternatively, an application can express its		application or some daemon process. Alternatively, an application
	address mobility property preferences through the socket API		can express its address mobility property preferences through the
	extensions (see discussion in Appendix A), which means the socket		socket API extensions (see discussion in Appendix A), which means the
	library or middleware has to modify [RFC3484] policy table or		socket library or middleware has to modify [I-D.ietf-6man-rfc3484bis]
	algorithm.		policy table or algorithm.
	5. Security Considerations		5. Security Considerations
	Existing Prefix Information Option related security considerations		Existing Prefix Information Option related security considerations
	apply as described in [RFC4861] and [RFC4191]. A malicious node on		apply as described in [RFC4861] and [RFC4191]. A malicious node on
	the shared link could include such 'mobility property' flags in a		the shared link could include such 'mobility property' flags in a
	Prefix Information Option causing the host to learn wrong information		Prefix Information Option causing the host to learn wrong information
	regarding the prefix and thus make misguided selection of prefixes on		regarding the prefix and thus make misguided selection of prefixes on
	the link. Similarly a malicious middleman on the link could modify		the link. Similarly a malicious middleman on the link could modify
	'mobility property' flags in a Prefix Information Option causing		'mobility property' flags in a Prefix Information Option causing
	skipping to change at page 6, line 6 ¶		skipping to change at page 7, line 6 ¶
	Router Advertisements.		Router Advertisements.
	6. IANA Considerations		6. IANA Considerations
	Section 3 defines a new flag bits (2 bit 'C' flag) to the IPv6		Section 3 defines a new flag bits (2 bit 'C' flag) to the IPv6
	Neighbor Discovery protocol's Prefix Information Option [RFC4861].		Neighbor Discovery protocol's Prefix Information Option [RFC4861].
	7. References		7. References
	7.1. Normative References		7.1. Normative References
			[I-D.ietf-6man-rfc3484bis]
			Thaler, D., Draves, R., Matsumoto, A., and T. Chown,
			"Default Address Selection for Internet Protocol version 6
			(IPv6)", draft-ietf-6man-rfc3484bis-01 (work in progress),
			March 2012.
	[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.
	[RFC3484] Draves, R., "Default Address Selection for Internet
	Protocol version 6 (IPv6)", RFC 3484, February 2003.
	[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,		[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
	"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,		"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
	September 2007.		September 2007.
	7.2. Informative References		7.2. Informative References
	[RFC3493] Gilligan, R., Thomson, S., Bound, J., McCann, J., and W.		[RFC3493] Gilligan, R., Thomson, S., Bound, J., McCann, J., and W.
	Stevens, "Basic Socket Interface Extensions for IPv6",		Stevens, "Basic Socket Interface Extensions for IPv6",
	RFC 3493, February 2003.		RFC 3493, February 2003.
	skipping to change at page 7, line 19 ¶		skipping to change at page 8, line 22 ¶
	Socket Interface [RFC3493][RFC5014] and the Protocol-Independent		Socket Interface [RFC3493][RFC5014] and the Protocol-Independent
	Nodename Translation [RFC5014]. These socket APIs and DNS resolver		Nodename Translation [RFC5014]. These socket APIs and DNS resolver
	APIs extension correspond to the Prefix Information option mobility		APIs extension correspond to the Prefix Information option mobility
	properties flag bit settings.		properties flag bit settings.
	A.1. Socket Interface		A.1. Socket Interface
	This specification extends the socket option IPV6_ADDR_PREFERENCES at		This specification extends the socket option IPV6_ADDR_PREFERENCES at
	the IPPROTO_IPV6 level. The following new flags are defined to		the IPPROTO_IPV6 level. The following new flags are defined to
	query, alter or set the default rule of source address selection		query, alter or set the default rule of source address selection
	rules [RFC3484]. They are also defined as a result of including the		rules [I-D.ietf-6man-rfc3484bis]. They are also defined as a result
	<netinet/in.h> header:		of including the <netinet/in.h> header:
	IPV6_PREFER_SRC_HNP /* Prefer Home Network Prefix derived IPv6		IPV6_PREFER_SRC_HNP /* Prefer Home Network Prefix derived IPv6
	address as source */		address as source */
	IPV6_PREFER_SRC_HNP_TMP /* Prefer temoporary Home Network Prefix		IPV6_PREFER_SRC_HNP_TMP /* Prefer temoporary Home Network Prefix
	derived IPv6 address as source */		derived IPv6 address as source */
	A.2. Protocol-Independent Nodename Translation		A.2. Protocol-Independent Nodename Translation
	the Default Address Selection [RFC3484] document indicates possible		the Default Address Selection [I-D.ietf-6man-rfc3484bis] document
	implementation strategies for getaddrinfo(). The address selection		indicates possible implementation strategies for getaddrinfo(). The
	hint flags for the getaddrinfo() specificed in this document extend		address selection hint flags for the getaddrinfo() specificed in this
	the 'int ai_eflags' field in the struct addrinfo [RFC5014][RFC3493].		document extend the 'int ai_eflags' field in the struct addrinfo
			[RFC5014][RFC3493].
	The IPV6 source address preference values (IPV6_PREFER_SRC_HNP and		The IPV6 source address preference values (IPV6_PREFER_SRC_HNP and
	IPV6_PREFER_SRC_HNP_TMP) defined for the IPV6_ADDR_PREFERENCES socket		IPV6_PREFER_SRC_HNP_TMP) defined for the IPV6_ADDR_PREFERENCES socket
	option are also defined as address selection preference flags in		option are also defined as address selection preference flags in
	<netdb.h> header for the "ai_eflags" extended flag-set field of the		<netdb.h> header for the "ai_eflags" extended flag-set field of the
	addrinfo data structure.		addrinfo data structure.
	Similarly to [RFC5014], if contradictory flags, such as		Similarly to [RFC5014], if contradictory flags, such as
	IPV6_PREFER_SRC_HOME and IPV6_PREFER_SRC_HNP*, are set in ai_eflags,		IPV6_PREFER_SRC_HOME and IPV6_PREFER_SRC_HNP*, are set in ai_eflags,
	the getaddrinfo() fails and returns the value EAI_BADEXTFLAGS. This		the getaddrinfo() fails and returns the value EAI_BADEXTFLAGS. This
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