< draft-ietf-6lo-rfc6775-update-17.txt		draft-ietf-6lo-rfc6775-update-18.txt >
	6lo P. Thubert, Ed.		6lo P. Thubert, Ed.
	Internet-Draft Cisco		Internet-Draft Cisco
	Updates: 6775 (if approved) E. Nordmark		Updates: 6775 (if approved) E. Nordmark
	Intended status: Standards Track Zededa		Intended status: Standards Track Zededa
	Expires: October 5, 2018 S. Chakrabarti		Expires: October 8, 2018 S. Chakrabarti
	Verizon		Verizon
	C. Perkins		C. Perkins
	Futurewei		Futurewei
	April 3, 2018		April 6, 2018
	Registration Extensions for 6LoWPAN Neighbor Discovery		Registration Extensions for 6LoWPAN Neighbor Discovery
	draft-ietf-6lo-rfc6775-update-17		draft-ietf-6lo-rfc6775-update-18
	Abstract		Abstract
	This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to		This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
	clarify the role of the protocol as a registration technique,		clarify the role of the protocol as a registration technique,
	simplify the registration operation in 6LoWPAN routers, as well as to		simplify the registration operation in 6LoWPAN routers, as well as to
	provide enhancements to the registration capabilities and mobility		provide enhancements to the registration capabilities and mobility
	detection for different network topologies including the backbone		detection for different network topologies including the backbone
	routers performing proxy Neighbor Discovery in a low power network.		routers performing proxy Neighbor Discovery in a low power network.
	skipping to change at page 1, line 40 ¶		skipping to change at page 1, line 40 ¶
	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 https://datatracker.ietf.org/drafts/current/.		Drafts is at https://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 5, 2018.		This Internet-Draft will expire on October 8, 2018.
	Copyright Notice		Copyright Notice
	Copyright (c) 2018 IETF Trust and the persons identified as the		Copyright (c) 2018 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
	(https://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 . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3		2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
	2.1. BCP 14 . . . . . . . . . . . . . . . . . . . . . . . . . 3		2.1. BCP 14 . . . . . . . . . . . . . . . . . . . . . . . . . 4
	2.2. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . . . 3		2.2. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . . . 4
	2.3. References . . . . . . . . . . . . . . . . . . . . . . . 4		2.3. References . . . . . . . . . . . . . . . . . . . . . . . 5
	2.4. New Terms . . . . . . . . . . . . . . . . . . . . . . . . 4		2.4. New Terms . . . . . . . . . . . . . . . . . . . . . . . . 5
	3. Applicability of Address Registration Options . . . . . . . . 5		3. Applicability of Address Registration Options . . . . . . . . 7
	4. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 6		4. Extended ND Options and Messages . . . . . . . . . . . . . . 8
	4.1. Extended Address Registration Option (EARO) . . . . . . . 7		4.1. Extended Address Registration Option (EARO) . . . . . . . 8
	4.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 8		4.2. Extended Duplicate Address Message Formats . . . . . . . 11
	4.2.1. Comparing TID values . . . . . . . . . . . . . . . . 9		4.3. New 6LoWPAN Capability Bits in the Capability Indication
	4.3. Registration Ownership Verifier . . . . . . . . . . . . . 10		Option . . . . . . . . . . . . . . . . . . . . . . . . . 12
	4.4. Extended Duplicate Address Messages . . . . . . . . . . . 11		5. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 13
	4.5. Registering the Target Address . . . . . . . . . . . . . 12		5.1. Extending the Address Registration Option . . . . . . . . 15
	4.6. Link-Local Addresses and Registration . . . . . . . . . . 12		5.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 16
	4.7. Maintaining the Registration States . . . . . . . . . . . 14		5.2.1. Comparing TID values . . . . . . . . . . . . . . . . 16
	5. Detecting Enhanced ARO Capability Support . . . . . . . . . . 15		5.3. Registration Ownership Verifier . . . . . . . . . . . . . 18
	6. Extended ND Options and Messages . . . . . . . . . . . . . . 16		5.4. Extended Duplicate Address Messages . . . . . . . . . . . 19
	6.1. Extended Address Registration Option (EARO) . . . . . . . 16		5.5. Registering the Target Address . . . . . . . . . . . . . 19
	6.2. Extended Duplicate Address Message Formats . . . . . . . 19		5.6. Link-Local Addresses and Registration . . . . . . . . . . 20
	6.3. New 6LoWPAN Capability Bits in the Capability Indication		5.7. Maintaining the Registration States . . . . . . . . . . . 21
	Option . . . . . . . . . . . . . . . . . . . . . . . . . 20		6. Backward Compatibility . . . . . . . . . . . . . . . . . . . 23
	7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 21		6.1. Signaling EARO Capability Support . . . . . . . . . . . . 23
	7.1. Discovering the Capabilities of Router . . . . . . . . . 21		6.2. First Exchanges . . . . . . . . . . . . . . . . . . . . . 24
	7.2. RFC6775-only 6LoWPAN Node . . . . . . . . . . . . . . . . 21		6.3. RFC6775-only 6LoWPAN Node . . . . . . . . . . . . . . . . 24
	7.3. RFC6775-only 6LoWPAN Router . . . . . . . . . . . . . . . 22		6.4. RFC6775-only 6LoWPAN Router . . . . . . . . . . . . . . . 24
	7.4. RFC6775-only 6LoWPAN Border Router . . . . . . . . . . . 22		6.5. RFC6775-only 6LoWPAN Border Router . . . . . . . . . . . 25
	8. Security Considerations . . . . . . . . . . . . . . . . . . . 22		7. Security Considerations . . . . . . . . . . . . . . . . . . . 25
	9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 24		8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27
	10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25		9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
	10.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . 25		9.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . . 28
	10.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 25		9.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 28
	10.3. New ARO Status values . . . . . . . . . . . . . . . . . 26		9.3. New ARO Status values . . . . . . . . . . . . . . . . . . 29
	10.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . 27		9.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . . 30
	11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28		10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 31
	12. References . . . . . . . . . . . . . . . . . . . . . . . . . 28		11. References . . . . . . . . . . . . . . . . . . . . . . . . . 31
	12.1. Normative References . . . . . . . . . . . . . . . . . . 28		11.1. Normative References . . . . . . . . . . . . . . . . . . 31
	12.2. Informative References . . . . . . . . . . . . . . . . . 29		11.2. Terminology Related References . . . . . . . . . . . . . 32
	12.3. External Informative References . . . . . . . . . . . . 33		11.3. Informative References . . . . . . . . . . . . . . . . . 32
			11.4. External Informative References . . . . . . . . . . . . 36
	Appendix A. Applicability and Requirements Served (Not		Appendix A. Applicability and Requirements Served (Not
	Normative) . . . . . . . . . . . . . . . . . . . . . 33		Normative) . . . . . . . . . . . . . . . . . . . . . 36
	Appendix B. Requirements (Not Normative) . . . . . . . . . . . . 34		Appendix B. Requirements (Not Normative) . . . . . . . . . . . . 37
	B.1. Requirements Related to Mobility . . . . . . . . . . . . 34		B.1. Requirements Related to Mobility . . . . . . . . . . . . 37
	B.2. Requirements Related to Routing Protocols . . . . . . . . 35		B.2. Requirements Related to Routing Protocols . . . . . . . . 38
	B.3. Requirements Related to the Variety of Low-Power Link		B.3. Requirements Related to the Variety of Low-Power Link
	types . . . . . . . . . . . . . . . . . . . . . . . . . . 36		types . . . . . . . . . . . . . . . . . . . . . . . . . . 39
	B.4. Requirements Related to Proxy Operations . . . . . . . . 36		B.4. Requirements Related to Proxy Operations . . . . . . . . 39
	B.5. Requirements Related to Security . . . . . . . . . . . . 37		B.5. Requirements Related to Security . . . . . . . . . . . . 40
	B.6. Requirements Related to Scalability . . . . . . . . . . . 38		B.6. Requirements Related to Scalability . . . . . . . . . . . 41
	B.7. Requirements Related to Operations and Management . . . . 38		B.7. Requirements Related to Operations and Management . . . . 42
	B.8. Matching Requirements with Specifications . . . . . . . . 39		B.8. Matching Requirements with Specifications . . . . . . . . 42
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 44
	1. Introduction		1. Introduction
	The scope of this draft is an IPv6 Low-Power Network including star		The scope of this draft is an IPv6 Low-Power Network including star
	and mesh topologies. This specification modifies and extends the		and mesh topologies. In that context, "Neighbor Discovery
	behavior and protocol elements of "Neighbor Discovery Optimization		Optimization for IPv6 over Low-Power Wireless Personal Area Networks"
	for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND)		(6LoWPAN ND) [RFC6775] defines a registration mechanism that
	[RFC6775] to enable additional capabilities and enhancements		leverages a central registrar for the main purpose of Duplicate
	including:		Address Detection (DAD), with the intention to reduce the dependency
			of the IPv6 Neighbor Discovery Protocol (IPv6 ND) [RFC4861][RFC4862]
			on network-layer multicast and link-layer broadcast operations.
			This specification updates 6LoWPAN ND to simplify the registration
			operation in 6LoWPAN routers and to extend the protocol as a more
			generic registration technique. The specified updates enable other
			specifications to define new services such as Source Address
			Validation (SAVI) with [I-D.ietf-6lo-ap-nd], participation as an
			unaware leaf to an abstract routing protocol such as the "Routing
			Protocol for Low Power and Lossy Networks" [RFC6550] (RPL) with
			[I-D.thubert-roll-unaware-leaves], and registration to a backbone
			routers performing proxy Neighbor Discovery in a Low-Power and Lossy
			Network (LLN) with [I-D.ietf-6lo-backbone-router].
			In more details, this specification modifies and extends the behavior
			and protocol elements of 6LoWPAN ND to enable the following new
			capabilities:
	o determining the freshest location in case of mobility (TID)		o determining the freshest location in case of mobility (TID)
	o Simplifying the registration flow for Link-Local Addresses		o Simplifying the registration flow for Link-Local Addresses
	o Support of a Leaf Node in a Route-Over network		o Support of a Leaf Node in a Route-Over network
	o Proxy registration in a Route-Over network		o Proxy registration in a Route-Over network
			o Associating the registration with a variable-length Registration
			Ownership Verifier (ROVR)
	o Registration to a IPv6 ND proxy over a Backbone Link (6BBR)		o Registration to a IPv6 ND proxy over a Backbone Link (6BBR)
	o Clarification of support for privacy and temporary addresses		o Clarification of support for privacy and temporary addresses
			A more comprehensive set of requirements is provided in Appendix B.
	2. Terminology		2. Terminology
	2.1. BCP 14		2.1. BCP 14
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and		"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
	"OPTIONAL" in this document are to be interpreted as described in BCP		"OPTIONAL" in this document are to be interpreted as described in BCP
	14 [RFC2119][RFC8174] when, and only when, they appear in all		14 [RFC2119][RFC8174] when, and only when, they appear in all
	capitals, as shown here.		capitals, as shown here.
	skipping to change at page 5, line 6 ¶		skipping to change at page 6, line 10 ¶
	2.4. New Terms		2.4. New Terms
	This specification introduces the following terminology:		This specification introduces the following terminology:
	Backbone Link: An IPv6 transit link that interconnects two or more		Backbone Link: An IPv6 transit link that interconnects two or more
	Backbone Routers. It is expected to be of high speed compared		Backbone Routers. It is expected to be of high speed compared
	to the LLN in order to carry the traffic that is required to		to the LLN in order to carry the traffic that is required to
	federate multiple segments of the potentially large LLN into a		federate multiple segments of the potentially large LLN into a
	single IPv6 subnet.		single IPv6 subnet.
	Backbone Router: A logical network function in an IPv6 router that		Backbone Router: A logical network function in an IPv6 router that
	federates an LLN over a Backbone Link. In order to do so, the		federates an LLN over a Backbone Link. In order to do so, the
	Backbone Router (6BBR) proxies the 6LoWPAN ND operations		Backbone Router (6BBR) proxies the 6LoWPAN ND operations
	detailed in this document onto the matching operations that run		detailed in this document onto the matching operations that run
	over the backbone, typically IPv6 ND. Note that 6BBR is a		over the backbone, typically IPv6 ND. Note that 6BBR is a
	logical function, just like 6LR and 6LBR, and that the same		logical function, just like 6LR and 6LBR, and that the same
	physical router may operate all three.		physical router may operate all three.
	Extended LLN: Multiple LLNs as defined in [RFC6550], interconnected		Extended LLN: Multiple LLNs as defined in [RFC6550], interconnected
	by a Backbone Link via Backbone Routers, and forming a single		by a Backbone Link via Backbone Routers, and forming a single
	IPv6 Multi-Link Subnet.		IPv6 Multi-Link Subnet.
	Registration: The process during which a 6LN registers an IPv6		Registration: The process during which a 6LN registers an IPv6
	Address with a 6LR in order to obtain services such as DAD and		Address with a 6LR in order to obtain services such as DAD and
	routing back. In a Route-Over network, a router that provides		routing back. In a Route-Over network, a router that provides
	connectivity to the LLN (typically a 6LBR, e.g., collocated		connectivity to the LLN (typically a 6LBR, e.g., collocated
	with a RPL Root) may serve as proxy for the registration of the		with a RPL Root) may serve as proxy for the registration of the
	6LN to the 6BBR so the 6BBR can provide IPv6 ND proxy services		6LN to the 6BBR so the 6BBR can provide IPv6 ND proxy services
	over the Backbone.		over the Backbone.
	Binding: The association between an IP address, a MAC address, a		Binding: The association between an IP address, a MAC address, a
	port, and other information about the node that owns the IP		physical port on a switch, and other information about the node
	Address.		that owns the IP Address.
	Registered Node: The 6LN for which the registration is performed,		Registered Node: The 6LN for which the registration is performed,
	and which owns the fields in the Extended ARO option.		and which owns the fields in the Extended ARO option.
	Registering Node: The node that performs the registration; this may		Registering Node: The node that performs the registration; this may
	be the Registered Node, or a proxy such as a 6LBR performing a		be the Registered Node, or a proxy such as a 6LBR performing a
	registration to a 6BBR, on behalf of the Registered Node.		registration to a 6BBR, on behalf of the Registered Node.
	Registered Address: An address owned by the Registered Node that was		Registered Address: An address owned by the Registered Node that was
	or is being registered.		or is being registered.
	RFC6775-only: Applied to an implementation, a type of node, or a		RFC6775-only: Applied to an implementation, a type of node, or a
	type of message, this adjective indicates a behavior that is		type of message, this adjective indicates a behavior that is
	strictly as specified by [RFC6775] as opposed to updated with		strictly as specified by [RFC6775] as opposed to updated with
	this specification.		this specification.
	updated: Qualifies a 6LN, a 6LR, or a 6LBR that supports this		updated: Qualifies a 6LN, a 6LR, or a 6LBR that supports this
	specification.		specification.
	3. Applicability of Address Registration Options		3. Applicability of Address Registration Options
	The purpose of the Address Registration Option (ARO) in [RFC6775] is		The purpose of the Address Registration Option (ARO) in [RFC6775] is
	to facilitate duplicate address detection (DAD) for hosts as well as		to facilitate duplicate address detection (DAD) for hosts as well as
	to populate Neighbor Cache Entries (NCEs) [RFC4861] in the routers.		to populate Neighbor Cache Entries (NCEs) [RFC4861] in the routers.
	This reduces the reliance on multicast operations, which are often as		This reduces the reliance on multicast operations, which are often as
	intrusive as broadcast, in IPv6 ND operations.		intrusive as broadcast, in IPv6 ND operations.
	skipping to change at page 6, line 34 ¶		skipping to change at page 7, line 47 ¶
	packets (entries that do not appear to be in use may be flushed). In		packets (entries that do not appear to be in use may be flushed). In
	contrast, a router serving the Address Registration mechanism needs		contrast, a router serving the Address Registration mechanism needs
	enough storage to hold NCEs for all the addresses that may be		enough storage to hold NCEs for all the addresses that may be
	registered to it, regardless of whether or not they are actively		registered to it, regardless of whether or not they are actively
	communicating. The number of registrations supported by a 6LoWPAN		communicating. The number of registrations supported by a 6LoWPAN
	Router (6LR) or 6LoWPAN Border Router (6LBR) MUST be clearly		Router (6LR) or 6LoWPAN Border Router (6LBR) MUST be clearly
	documented by the vendor and the dynamic use of associated resources		documented by the vendor and the dynamic use of associated resources
	SHOULD be made available to the network operator, e.g., to a		SHOULD be made available to the network operator, e.g., to a
	management console.		management console.
	In order to deploy this, network administrators MUST ensure that		In order to deploy this, network administrators need to ensure that
	6LR/6LBRs in their network support the number and type of devices		6LR/6LBRs in their network support the number and type of devices
	that can register to them, based on the number of IPv6 addresses that		that can register to them, based on the number of IPv6 addresses that
	those devices require and their address renewal rate and behavior.		those devices require and their address renewal rate and behavior.
	4. Updating RFC 6775		4. Extended ND Options and Messages
	This specification introduces the Extended Address Registration		This specification does not introduce new options, but it modifies
	Option (EARO) based on the ARO as defined [RFC6775]. A 'T' flag is		existing ones and updates the associated behaviors as specified in
	added to indicate that a new field, the Transaction ID (TID) is		the following subsections.
	populated. The 'T' flag MUST be set in NS messages when this
	specification is used, and echoed in NA messages to confirm that the		4.1. Extended Address Registration Option (EARO)
	protocol is supported. The EUI-64 field is overloaded to carry
	different types of information and its size may be increased when		The Address Registration Option (ARO) is defined in section 4.1 of
	backward compatibility is not an issue.		[RFC6775]. This specification introduces the Extended Address
			Registration Option (EARO) based on the ARO for use in NS and NA
			messages. The EARO conveys additional information such as a sequence
			counter called Transaction ID (TID) that is used to determine the
			latest location of a registering mobile device. A 'T' flag is added
			to indicate that the TID field is populated.
			The EARO also signals whether the 6LN expects routing or proxy
			services from the 6LR using a new 'R' flag.
			The EUI-64 field is overloaded and renamed ROVR in order to carry
			different types of information, e.g., cryptographic information of
			variable size. A larger ROVR size may be used if and only if
			backward compatibility is not an issue in the particular deployment.
			Section 5.1 discusses those changes in depth.
			An NS message with an EARO is a registration if and only if it also
			carries an SLLA Option [RFC6775]. The EARO is also used in NS and NA
			messages between Backbone Routers [I-D.ietf-6lo-backbone-router] over
			the Backbone Link to sort out the distributed registration state; in
			that case, it does not carry the SLLA Option and is not confused with
			a registration.
			When using the EARO, the address being registered is found in the
			Target Address field of the NS and NA messages.
			The EARO extends the ARO and is indicated by the 'T' flag being set.
			The format of the EARO is as follows:
			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
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Type | Length | Status | Reserved |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Reserved |R|T| TID | Registration Lifetime |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| |
			... Registration Ownership Verifier ...
			| |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			Figure 1: EARO
			Option Fields
			Type: 33
			Length: 8-bit unsigned integer. The length of the whole
			option in units of 8 bytes. It MUST be 2 when
			operating in a backward-compatible mode with a ROVR
			size of 64 bits. It MAY be 3, 4 or 5, denoting a
			ROVR size of 128, 192 and 256 bits respectively.
			Status: 8-bit unsigned integer. Indicates the status of a
			registration in the NA response. MUST be set to 0 in
			NS messages. See Table 1 below.
			+-------+-----------------------------------------------------------+
			| Value | Description |
			+-------+-----------------------------------------------------------+
			| 0..2 | See [RFC6775]. Note: a Status of 1 ("Duplicate Address") |
			| | applies to the Registered Address. If the Source Address |
			| | conflicts with an existing registration, "Duplicate |
			| | Source Address" MUST be used. |
			| | |
			| 3 | Moved: The registration failed because it is not the |
			| | freshest. This Status indicates that the registration is |
			| | rejected because another more recent registration was |
			| | done, as indicated by a same ROVR and a more recent TID. |
			| | One possible cause is a stale registration that has |
			| | progressed slowly in the network and was passed by a more |
			| | recent one. It could also indicate a ROVR collision. |
			| | |
			| 4 | Removed: The binding state was removed. This status may |
			| | be placed in an NA(EARO) message that is sent as the |
			| | rejection of a proxy registration to a Backbone Router, |
			| | or in an asynchronous NA(EARO) at any time. |
			| | |
			| 5 | Validation Requested: The Registering Node is challenged |
			| | for owning the Registered Address or for being an |
			| | acceptable proxy for the registration. This Status is |
			| | expected in asynchronous messages from a registrar (6LR, |
			| | 6LBR, 6BBR) to indicate that the registration state is |
			| | removed, for instance, due to a movement of the device. |
			| | |
			| 6 | Duplicate Source Address: The address used as source of |
			| | the NS(ARO) conflicts with an existing registration. |
			| | |
			| 7 | Invalid Source Address: The address used as source of the |
			| | NS(ARO) is not a Link-Local Address as prescribed by this |
			| | document. |
			| | |
			| 8 | Registered Address topologically incorrect: The address |
			| | being registered is not usable on this link, e.g., it is |
			| | not topologically correct |
			| | |
			| 9 | 6LBR Registry saturated: A new registration cannot be |
			| | accepted because the 6LBR Registry is saturated. Note: |
			| | this code is used by 6LBRs instead of Status 2 when |
			| | responding to a Duplicate Address message exchange and is |
			| | passed on to the Registering Node by the 6LR. |
			| | |
			| 10 | Validation Failed: The proof of ownership of the |
			| | registered address is not correct. |
			+-------+-----------------------------------------------------------+
			Table 1: EARO Status
			Reserved: This field is unused. It MUST be initialized to zero
			by the sender and MUST be ignored by the receiver.
			R: One-bit flag. If the 'R' flag is set, the
			Registering Node expects that the 6LR ensures
			reachability for the registered address, e.g., by
			injecting the address in a Route-Over routing
			protocol or proxying ND over a Backbone Link.
			T: One-bit flag. Set if the next octet is used as a
			TID.
			TID: One-byte integer; a Transaction ID that is maintained
			by the node and incremented with each transaction of
			one or more registrations performed at the same time
			to one or more respective 6LRs. This field MUST be
			ignored if the 'T' flag is not set.
			Registration Lifetime: 16-bit integer; expressed in minutes. 0
			means that the registration has ended and the
			associated state MUST be removed.
			Registration Ownership Verifier (ROVR): Enables the correlation
			between multiple attempts to register a same IPv6
			Address. The ROVR is stored in the 6LR and the 6LBR
			in the state associated to the registration. This
			can be a unique ID of the Registering Node, such as
			the EUI-64 address of an interface. This can also be
			a token obtained with cryptographic methods which can
			be used in additional protocol exchanges to associate
			a cryptographic identity (key) with this registration
			to ensure that only the owner can modify it later.
			The scope of a ROVR is the registration of a
			particular IPv6 Address and it must not be used to
			correlate registrations of different addresses.
			4.2. Extended Duplicate Address Message Formats
			The DAR and DAC messages are defined in section 4.4 of [RFC6775].
			Those messages follow a common base format, which enables information
			from the ARO to be transported over multiple hops.
			Those messages are extended to adapt to the new EARO format, as
			follows:
			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
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Type | Code | Checksum |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Status | TID | Registration Lifetime |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| |
			... Registration Ownership Verifier ...
			| |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| |
			+ +
			| |
			+ Registered Address +
			| |
			+ +
			| |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			Figure 2: Duplicate Address Messages Format
			Modified Message Fields
			Code: The ICMP Code as defined in [RFC4443]. The ICMP Code
			MUST be set to 1 with this specification. An non-
			null value of the ICMP Code indicates support for
			this specification.
			TID: 1-byte integer; same definition and processing as the
			TID in the EARO as defined in Section 4.1. This
			field MUST be ignored if the ICMP Code is null.
			Registration Ownership Verifier (ROVR): The size of the ROVR is
			computed from the overall size of the IPv6 packet.
			It MUST be 64bits long when operating in backward-
			compatible mode. This field has the same definition
			and processing as the ROVR in the EARO option as
			defined in Section 4.1.
			4.3. New 6LoWPAN Capability Bits in the Capability Indication Option
			This specification defines 5 new capability bits for use in the 6CIO,
			which was introduced by [RFC7400] for use in IPv6 ND RA messages.
			This specification introduces the "E" flag to indicate that extended
			ARO can be used in a registration. A 6LR that supports this
			specification MUST set the "E" flag.
			A similar flag "D" indicates the support of Extended Duplicate
			Address Messages by the 6LBR; A 6LBR that supports this specification
			MUST set the "D" flag. The "D" flag is learned from advertisements
			by a 6LBR, and is propagated down a graph of 6LRs as a node acting as
			6LN registers to a 6LR (which could be the 6LBR), and in turn becomes
			a 6LR to which other 6LNs will register.
			The new "L", "B", and "P" flags, indicate whether a router is capable
			of acting as 6LR, 6LBR, and 6BBR, respectively. These flags are not
			mutually exclusive and a node MUST set all the flags that are
			relevant to it.
			As an example, a 6LBR sets the "B" and "D" flags. If it acts as a
			6LR, then it sets the "L" and "E" flags. If it is collocated with a
			6BBR, then it also sets the "P" flag.
			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
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Type | Length = 1 | Reserved |D|L|B|P|E|G|
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			| Reserved |
			+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
			Figure 3: New capability Bits L, B, P, E in the 6CIO
			Option Fields
			Type: 36
			L: Node is a 6LR.
			B: Node is a 6LBR.
			P: Node is a 6BBR.
			E: Node supports registrations based on EARO.
			D: 6LBR supports EDA messages.
			5. Updating RFC 6775
			The Extended Address Registration Option (EARO) (see Section 4.1)
			replaces the ARO used within Neighbor Discovery NS and NA messages
			between a 6LN and its 6LR. Similarly, the EDA messages, EDAR and
			EDAC, replace the DAR and DAC messages so as to transport the new
			information between 6LRs and 6LBRs across an LLN mesh such as a
			6TiSCH network.
	The extensions to the ARO option are used in the Duplicate Address		The extensions to the ARO option are used in the Duplicate Address
	messages, the Duplicate Address Request (DAR) and Duplicate Address		messages, the Duplicate Address Request (DAR) and Duplicate Address
	Confirmation (DAC), so as to convey the additional information all		Confirmation (DAC), so as to convey the additional information all
	the way to the 6LBR. In turn the 6LBR may proxy the registration		the way to the 6LBR. In turn the 6LBR may proxy the registration
	using IPv6 ND over a Backbone Link as illustrated in Figure 1. Note		using IPv6 ND over a Backbone Link as illustrated in Figure 4. Note
	that this specification avoids the Duplicate Address message flow for		that this specification avoids the Duplicate Address message flow for
	Link-Local Addresses in a Route-Over [RFC6606] topology.		Link-Local Addresses in a Route-Over [RFC6606] topology (see
			Section 5.6).
	6LN 6LR 6LBR 6BBR		6LN 6LR 6LBR 6BBR
	| | | |		| | | |
	| NS(EARO) | | |		| NS(EARO) | | |
	|--------------->| | |		|--------------->| | |
	| | Extended DAR | |		| | Extended DAR | |
	| |-------------->| |		| |-------------->| |
	| | | |		| | | |
	| | | proxy NS(EARO) |		| | | proxy NS(EARO) |
	| | |--------------->|		| | |--------------->|
	skipping to change at page 7, line 31 ¶		skipping to change at page 14, line 37 ¶
	| | | | <wait>		| | | | <wait>
	| | | |		| | | |
	| | | proxy NA(EARO) |		| | | proxy NA(EARO) |
	| | |<---------------|		| | |<---------------|
	| | Extended DAC | |		| | Extended DAC | |
	| |<--------------| |		| |<--------------| |
	| NA(EARO) | | |		| NA(EARO) | | |
	|<---------------| | |		|<---------------| | |
	| | | |		| | | |
	Figure 1: (Re-)Registration Flow		Figure 4: (Re-)Registration Flow
	In order to support various types of link layers, this specification		In order to support various types of link layers, this specification
	allows multiple registrations, including for privacy / temporary		allows multiple registrations, including for privacy / temporary
	addresses and provides new mechanisms to help clean up stale		addresses and provides new mechanisms to help clean up stale
	registration state as soon as possible, e.g., after a movement (see		registration state as soon as possible, e.g., after a movement (see
	Section 8).		Section 7).
	Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface		Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface
	and locates available 6LRs. A Registering Node prefers registering		and locates available 6LRs. A Registering Node prefers registering
	to a 6LR that is found to support this specification, as discussed in		to a 6LR that is found to support this specification, as discussed in
	Section 5, over an RFC6775-only one, and operates in a backward-		Section 6.1, over an RFC6775-only one, and operates in a backward-
	compatible fashion when attaching to an RFC6775-only 6LR.		compatible fashion when attaching to an RFC6775-only 6LR.
	4.1. Extended Address Registration Option (EARO)		5.1. Extending the Address Registration Option
	The Extended ARO (EARO) replaces the ARO and is backward compatible		The Extended ARO (EARO) replaces the ARO and is backward compatible
	with the ARO if and only if the Length of the option is set to 2.		with the ARO if and only if the Length of the option is set to 2.
	Its format is presented in Section 6.1. More details on backward		Its format is presented in Section 4.1. More details on backward
	compatibility can be found in Section 7.		compatibility can be found in Section 6.
	The semantics of the Neighbor Solicitation (NS) and the ARO are		The semantics of the Neighbor Solicitation (NS) and the ARO are
	modified as follows:		modified as follows:
	o The address that is being registered with an NS with an EARO is		o The Target Address in the NS containing the EARO is now the field
	now the Target Address, as opposed to the Source Address as		that indicates the address that is being registered, as opposed to
	specified in [RFC6775] (see Section 4.5). This change enables a		the Source Address field as specified in [RFC6775] (see
	6LBR to use one of its addresses as source of the proxy-		Section 5.5). This change enables a 6LBR to use one of its
	registration of an address that belongs to a LLN Node to a 6BBR.		addresses as source of the proxy-registration of an address that
	This also limits the use of an address as source address before it		belongs to a LLN Node to a 6BBR. This also limits the use of an
	is registered and the associated DAD process is complete.		address as source address before it is registered and the
			associated DAD process is complete.
	o The EUI-64 field in the ARO Option is renamed Registration		o The EUI-64 field in the ARO Option is renamed Registration
	Ownership Verifier (ROVR) and is not required to be derived from a		Ownership Verifier (ROVR) and is not required to be derived from a
	MAC address (see Section 4.3).		MAC address (see Section 5.3).
	o The option Length MAY be different than 2 and take a value between		o The option Length MAY be different than 2 and take a value between
	3 and 5, in which case the EARO is not backward compatible with an		3 and 5, in which case the EARO is not backward compatible with an
	ARO. The increase of size corresponds to a larger ROVR field, so		ARO. The increase of size corresponds to a larger ROVR field, so
	the size of the ROVR is inferred from the option Length.		the size of the ROVR is inferred from the option Length.
	o This document specifies a new flag in the EARO, the 'R' flag. If		o This document specifies a new flag in the EARO, the 'R' flag. If
	the 'R' flag is set, the Registering Node expects that the 6LR		the 'R' flag is set, the Registering Node expects that the 6LR
	ensures reachability for the Registered Address, e.g., by means of		ensures reachability for the Registered Address, e.g., by means of
	routing or proxying ND. Conversely, when it is not set, the 'R'		routing or proxying ND. Conversely, when it is not set, the 'R'
	flag indicates that the Registering Node is a router, which for		flag indicates that the Registering Node is a router, which for
	instance participates to a Route-Over routing protocol such as the		instance participates to a Route-Over routing protocol such as RPL
	IPv6 Routing Protocol for Low-Power and Lossy Networks [RFC6550]		[RFC6550] and that it will take care of injecting its Address over
	(RPL) and that it will take care of injecting its Address over the		the routing protocol by itself. A 6LN that acts only as a host,
	routing protocol by itself. A 6LN that acts only as a host, when		when registering, MUST set the 'R' flag to indicate that it is not
	registering, MUST set the 'R' flag to indicate that it is not a		a router and that it will not handle its own reachability. A 6LR
	router and that it will not handle its own reachability. A 6LR
	that manages its reachability SHOULD NOT set the 'R' flag; if it		that manages its reachability SHOULD NOT set the 'R' flag; if it
	does, routes towards this router may be installed on its behalf		does, routes towards this router may be installed on its behalf
	and may interfere with those it injects.		and may interfere with those it injects.
	o The specification introduces a Transaction ID (TID) field in the		o The specification introduces a Transaction ID (TID) field in the
	EARO (see Section 4.2). The TID MUST be provided by a node that		EARO (see Section 5.2). The TID MUST be provided by a node that
	supports this specification and another new flag, the 'T' flag,		supports this specification and another new flag, the 'T' flag,
	MUST be set to indicate so.		MUST be set to indicate so.
	o Finally, this specification introduces new status codes to help		o Finally, this specification introduces new status codes to help
	diagnose the cause of a registration failure (see Table 1).		diagnose the cause of a registration failure (see Table 1).
	4.2. Transaction ID		5.2. Transaction ID
	The TID is a sequence number that is incremented by the 6LN with each		The TID is a sequence number that is incremented by the 6LN with each
	re-registration to a 6LR. The TID is used to detect the freshness of		re-registration to a 6LR. The TID is used to detect the freshness of
	the registration request and to detect one single registration by		the registration request and to detect one single registration by
	multiple 6LoWPAN border routers (e.g., 6LBRs and 6BBRs) supporting		multiple 6LoWPAN border routers (e.g., 6LBRs and 6BBRs) supporting
	the same 6LoWPAN. The TID may also be used by the network to route		the same 6LoWPAN. The TID may also be used by the network to route
	to the current (freshest known) location of a moving node by spotting		to the current (freshest known) location of a moving node by spotting
	the most recent TID.		the most recent TID.
	When a Registered Node is registered with multiple 6BBRs in parallel,		When a Registered Node is registered with multiple 6BBRs in parallel,
	the same TID MUST be used. This enables the 6BBRs to determine that		the same TID MUST be used. This enables the 6BBRs to determine that
	the registrations are the same, and distinguish that situation from a		the registrations are the same, and distinguish that situation from a
	movement (see section 4 of [I-D.ietf-6lo-backbone-router] and		movement (see section 4 of [I-D.ietf-6lo-backbone-router] and
	Section 4.7 below).		Section 5.7 below).
	4.2.1. Comparing TID values		5.2.1. Comparing TID values
	As a note to the implementer, the operation of the TID is fully		As a note to the implementer, the operation of the TID is fully
	compatible with that of the RPL Path Sequence counter as described in		compatible with that of the RPL Path Sequence counter as described in
	the "Sequence Counter Operation" section of the "IPv6 Routing		the "Sequence Counter Operation" section of the "IPv6 Routing
	Protocol for Low-Power and Lossy Networks" [RFC6550] specification.		Protocol for Low-Power and Lossy Networks" [RFC6550] specification.
	A TID is deemed to be fresher than another when its value is greater		A TID is deemed to be fresher than another when its value is greater
	per the operations detailed in this section.		per the operations detailed in this section.
	The TID range is subdivided in a 'lollipop' fashion ([Perlman83]),		The TID range is subdivided in a 'lollipop' fashion ([Perlman83]),
	skipping to change at page 10, line 27 ¶		skipping to change at page 17, line 42 ¶
	2. In the case where both sequence counters to be compared are		2. In the case where both sequence counters to be compared are
	less than or equal to 127, and in the case where both		less than or equal to 127, and in the case where both
	sequence counters to be compared are greater than or equal to		sequence counters to be compared are greater than or equal to
	128:		128:
	1. If the absolute magnitude of difference between the two		1. If the absolute magnitude of difference between the two
	sequence counters is less than or equal to		sequence counters is less than or equal to
	SEQUENCE_WINDOW, then a comparison as described in		SEQUENCE_WINDOW, then a comparison as described in
	[RFC1982] is used to determine the relationships greater		[RFC1982] is used to determine the relationships greater
	than, less than, and equal.		than, less than, and equal.
	2. If the absolute magnitude of difference of the two		2. If the absolute magnitude of difference of the two
	sequence counters is greater than SEQUENCE_WINDOW, then a		sequence counters is greater than SEQUENCE_WINDOW, then a
	desynchronization has occurred and the two sequence		desynchronization has occurred and the two sequence
	numbers are not comparable.		numbers are not comparable.
	4. If two sequence numbers are determined to be not comparable,		4. If two sequence numbers are determined to be not comparable,
	i.e., the results of the comparison are not defined, then a node		i.e., the results of the comparison are not defined, then a node
	should give precedence to the sequence number that was most		should give precedence to the sequence number that was most
	recently incremented. Failing this, the node should select the		recently incremented. Failing this, the node should select the
	sequence number in order to minimize the resulting changes to its		sequence number in order to minimize the resulting changes to its
	own state.		own state.
	4.3. Registration Ownership Verifier		5.3. Registration Ownership Verifier
	The ROVR field generalizes the EUI-64 field of the ARO defined in		The ROVR field generalizes the EUI-64 field of the ARO defined in
	[RFC6775]. It is scoped to a registration and enables recognizing		[RFC6775]. It is scoped to a registration and enables recognizing
	and blocking an attempt to register a duplicate address, which is		and blocking an attempt to register a duplicate address, which is
	characterized by a different ROVR in the conflicting registrations.		characterized by a different ROVR in the conflicting registrations.
	It can also be used to protect the ownership of a Registered Address,		It can also be used to protect the ownership of a Registered Address,
	if the proof-of-ownership of the ROVR can be obtained (more in		if the proof-of-ownership of the ROVR can be obtained (more in
	Section 4.6).		Section 5.6).
	The ROVR can be of different types, as long as the type is signaled		The ROVR can be of different types, as long as the type is signaled
	in the message that carries the new type. For instance, the type can		in the message that carries the new type. For instance, the type can
	be a cryptographic string and used to prove the ownership of the		be a cryptographic string and used to prove the ownership of the
	registration as specified in "Address Protected Neighbor Discovery		registration as specified in "Address Protected Neighbor Discovery
	for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd]. In order to		for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd]. In order to
	support the flows related to the proof-of-ownership, this		support the flows related to the proof-of-ownership, this
	specification introduces new status codes "Validation Requested" and		specification introduces new status codes "Validation Requested" and
	"Validation Failed" in the EARO.		"Validation Failed" in the EARO.
	skipping to change at page 11, line 39 ¶		skipping to change at page 19, line 9 ¶
	will not collision with that of an IPv6 Address derived from EUI-64		will not collision with that of an IPv6 Address derived from EUI-64
	and using the EUI-64 as ROVR per [RFC6775].		and using the EUI-64 as ROVR per [RFC6775].
	The Registering Node SHOULD store the ROVR, or enough information to		The Registering Node SHOULD store the ROVR, or enough information to
	regenerate it, in persistent memory. If this is not done and an		regenerate it, in persistent memory. If this is not done and an
	event such as a reboot causes a loss of state, re-registering the		event such as a reboot causes a loss of state, re-registering the
	same address could be impossible until the 6LRs and the 6LBR time out		same address could be impossible until the 6LRs and the 6LBR time out
	the previous registration, or a management action is taken to clear		the previous registration, or a management action is taken to clear
	the relevant state in the network.		the relevant state in the network.
	4.4. Extended Duplicate Address Messages		5.4. Extended Duplicate Address Messages
	In order to map the new EARO content in the Extended Duplicate		In order to map the new EARO content in the Extended Duplicate
	Address (EDA) messages, a new TID field is added to the Extended DAR		Address (EDA) messages, a new TID field is added to the Extended DAR
	(EDAR) and the Extended DAC (EDAC) messages as a replacement of the		(EDAR) and the Extended DAC (EDAC) messages as a replacement of the
	Reserved field, and a non-null value of the ICMP Code indicates		Reserved field, and a non-null value of the ICMP Code indicates
	support for this specification. The format of the EDA messages is		support for this specification. The format of the EDA messages is
	presented in Section 6.2.		presented in Section 4.2.
	As with the EARO, the Extended Duplicate Address messages are		As with the EARO, the Extended Duplicate Address messages are
	backward compatible with the RFC6775-only versions as long as the		backward compatible with the RFC6775-only versions as long as the
	ROVR field is 64 bits long. Remarks concerning backwards		ROVR field is 64 bits long. Remarks concerning backwards
	compatibility for the protocol between the 6LN and the 6LR apply		compatibility for the protocol between the 6LN and the 6LR apply
	similarly between a 6LR and a 6LBR.		similarly between a 6LR and a 6LBR.
	4.5. Registering the Target Address		5.5. Registering the Target Address
	The Registering Node is the node that performs the registration to		The Registering Node is the node that performs the registration to
	the 6BBR. As in [RFC6775], it may be the Registered Node as well, in		the 6BBR. As in [RFC6775], it may be the Registered Node as well, in
	which case it registers one of its own addresses and indicates its		which case it registers one of its own addresses and indicates its
	own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO).		own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO).
	This specification adds the capability to proxy the registration		This specification adds the capability to proxy the registration
	operation on behalf of a Registered Node that is reachable over an		operation on behalf of a Registered Node that is reachable over an
	LLN mesh. In that case, if the Registered Node is reachable from the		LLN mesh. In that case, if the Registered Node is reachable from the
	6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC		6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC
	skipping to change at page 12, line 36 ¶		skipping to change at page 20, line 5 ¶
	found in the Target Address field of the NS and NA messages as		found in the Target Address field of the NS and NA messages as
	opposed to the Source Address. With this convention, a TLLA option		opposed to the Source Address. With this convention, a TLLA option
	indicates the link-layer address of the 6LN that owns the address.		indicates the link-layer address of the 6LN that owns the address.
	If Registering Node expects packets for the 6LN, e.g., a 6LBR also		If Registering Node expects packets for the 6LN, e.g., a 6LBR also
	acting as RPL Root, then it MUST place its own Link Layer Address in		acting as RPL Root, then it MUST place its own Link Layer Address in
	the SLLA Option that MUST always be placed in a registration NS(EARO)		the SLLA Option that MUST always be placed in a registration NS(EARO)
	message. This maintains compatibility with RFC6775-only 6LoWPAN ND		message. This maintains compatibility with RFC6775-only 6LoWPAN ND
	[RFC6775].		[RFC6775].
	4.6. Link-Local Addresses and Registration		5.6. Link-Local Addresses and Registration
	Considering that LLN nodes are often not wired and may move, there is		Considering that LLN nodes are often not wired and may move, there is
	no guarantee that a Link-Local Address stays unique between a		no guarantee that a Link-Local Address stays unique between a
	potentially variable and unbounded set of neighboring nodes.		potentially variable and unbounded set of neighboring nodes.
	Compared to [RFC6775], this specification only requires that a Link-		Compared to [RFC6775], this specification only requires that a Link-
	Local Address be unique from the perspective of the two nodes that		Local Address be unique from the perspective of the two nodes that
	use it to communicate (e.g., the 6LN and the 6LR in an NS/NA		use it to communicate (e.g., the 6LN and the 6LR in an NS/NA
	exchange). This simplifies the DAD process in a Route-Over topology		exchange). This simplifies the DAD process in a Route-Over topology
	for Link-Local Addresses by avoiding an exchange of EDA messages		for Link-Local Addresses by avoiding an exchange of EDA messages
	skipping to change at page 13, line 24 ¶		skipping to change at page 20, line 39 ¶
	the standpoint of this 6LR and the registration is not a duplicate.		the standpoint of this 6LR and the registration is not a duplicate.
	Alternatively, two different 6LRs might expose the same Link-Local		Alternatively, two different 6LRs might expose the same Link-Local
	Address but different link-layer addresses. In that case, a 6LN MUST		Address but different link-layer addresses. In that case, a 6LN MUST
	only interact with at most one of the 6LRs.		only interact with at most one of the 6LRs.
	The DAD process between the 6LR and a 6LBR, which is based on an		The DAD process between the 6LR and a 6LBR, which is based on an
	exchange of EDA messages, does not need to take place for Link-Local		exchange of EDA messages, does not need to take place for Link-Local
	Addresses.		Addresses.
	When registering to a 6LR that conforms to this specification (see		When registering to a 6LR that conforms to this specification (see
	Section 7.1, a node MUST use a Link-Local Address as the source		Section 6.2, a node MUST use a Link-Local Address as the source
	address of the registration, whatever the type of IPv6 address that		address of the registration, whatever the type of IPv6 address that
	is being registered. That Link-Local Address MUST be either an		is being registered. That Link-Local Address MUST be either an
	address that is already registered to the 6LR, or the address that is		address that is already registered to the 6LR, or the address that is
	being registered.		being registered.
	When a Registering Node does not have an already-registered Address,		When a Registering Node does not have an already-registered Address,
	it MUST register a Link-Local Address, using it as both the Source		it MUST register a Link-Local Address, using it as both the Source
	and the Target Address of an NS(EARO) message. In that case, it is		and the Target Address of an NS(EARO) message. In that case, it is
	RECOMMENDED to use a Link-Local Address that is (expected to be)		RECOMMENDED to use a Link-Local Address that is (expected to be)
	globally unique, e.g., derived from a globally unique EUI-64 address.		globally unique, e.g., derived from a globally unique EUI-64 address.
	skipping to change at page 14, line 5 ¶		skipping to change at page 21, line 20 ¶
	A node needs to register its IPv6 Global Unicast Addresses (GUAs) to		A node needs to register its IPv6 Global Unicast Addresses (GUAs) to
	a 6LR in order to establish global reachability for these addresses		a 6LR in order to establish global reachability for these addresses
	via that 6LR. When registering with an updated 6LR, a Registering		via that 6LR. When registering with an updated 6LR, a Registering
	Node does not use a GUA as Source Address, in contrast to a node that		Node does not use a GUA as Source Address, in contrast to a node that
	complies to [RFC6775]. For non-Link-Local Addresses, the exchange of		complies to [RFC6775]. For non-Link-Local Addresses, the exchange of
	EDA messages MUST conform to [RFC6775], but the extended formats		EDA messages MUST conform to [RFC6775], but the extended formats
	described in this specification for the DAR and the DAC are used to		described in this specification for the DAR and the DAC are used to
	relay the extended information in the case of an EARO.		relay the extended information in the case of an EARO.
	4.7. Maintaining the Registration States		5.7. Maintaining the Registration States
	This section discusses protocol actions that involve the Registering		This section discusses protocol actions that involve the Registering
	Node, the 6LR, and the 6LBR. It must be noted that the portion that		Node, the 6LR, and the 6LBR. It must be noted that the portion that
	deals with a 6LBR only applies to those addresses that are registered		deals with a 6LBR only applies to those addresses that are registered
	to it; as discussed in Section 4.6, this is not the case for Link-		to it; as discussed in Section 5.6, this is not the case for Link-
	Local Addresses. The registration state includes all data that is		Local Addresses. The registration state includes all data that is
	stored in the router relative to that registration, in particular,		stored in the router relative to that registration, in particular,
	but not limited to, an NCE. 6LBRs and 6BBRs may store additional		but not limited to, an NCE. 6LBRs and 6BBRs may store additional
	registration information in more complex abstract data structures and		registration information in more complex abstract data structures and
	use protocols that are out of scope of this document to keep them		use protocols that are out of scope of this document to keep them
	synchronized when they are distributed.		synchronized when they are distributed.
	When its resource available to store registration states are		When its resource available to store registration states are
	exhausted, a 6LR cannot accept a new registration. In that		exhausted, a 6LR cannot accept a new registration. In that
	situation, the EARO is returned in an NA message with a Status Code		situation, the EARO is returned in an NA message with a Status Code
	skipping to change at page 14, line 50 ¶		skipping to change at page 22, line 16 ¶
	A node that ceases to use an address SHOULD attempt to de-register		A node that ceases to use an address SHOULD attempt to de-register
	that address from all the 6LRs to which it has registered the		that address from all the 6LRs to which it has registered the
	address. This is achieved using an NS(EARO) message with a		address. This is achieved using an NS(EARO) message with a
	Registration Lifetime of 0. If this is not done, the associated		Registration Lifetime of 0. If this is not done, the associated
	state will remain in the network till the current Registration		state will remain in the network till the current Registration
	Lifetime expires and this may lead to a situation where the 6LR		Lifetime expires and this may lead to a situation where the 6LR
	resources become saturated, even if they are correctly planned to		resources become saturated, even if they are correctly planned to
	start with. The 6LR may then take defensive measures that may		start with. The 6LR may then take defensive measures that may
	prevent this node or some other nodes from owning as many addresses		prevent this node or some other nodes from owning as many addresses
	as they would expect (see Section 8).		as they would expect (see Section 7).
	A node that moves away from a particular 6LR SHOULD attempt to de-		A node that moves away from a particular 6LR SHOULD attempt to de-
	register all of its addresses registered to that 6LR and register to		register all of its addresses registered to that 6LR and register to
	a new 6LR with an incremented TID. When/if the node shows up		a new 6LR with an incremented TID. When/if the node shows up
	elsewhere, an asynchronous NA(EARO) or EDAC message with a Status		elsewhere, an asynchronous NA(EARO) or EDAC message with a Status
	Code of "Moved" SHOULD be used to clean up the state in the previous		Code of "Moved" SHOULD be used to clean up the state in the previous
	location. For instance, as described in		location. For instance, as described in
	[I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a		[I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a
	6BBR in an NA(EARO) message to indicate that the ownership of the		6BBR in an NA(EARO) message to indicate that the ownership of the
	proxy state on the Backbone Link was transferred to another 6BBR as		proxy state on the Backbone Link was transferred to another 6BBR as
	the consequence of a movement of the device. If the receiver of the		the consequence of a movement of the device. If the receiver of the
	message has a state corresponding to the related address, it SHOULD		message has a state corresponding to the related address, it SHOULD
	propagate the status down the forwarding path to the Registered node		propagate the status down the forwarding path to the Registered node
	(e.g., reversing an existing RPL [RFC6550] path as prescribed in		(e.g., reversing an existing RPL [RFC6550] path as prescribed in
	[I-D.ietf-roll-efficient-npdao]). Whether it could do so or not, the		[I-D.ietf-roll-efficient-npdao]). Whether it could do so or not, the
	receiver MUST clean up said state.		receiver MUST clean up said state.
	Upon receiving an NS(EARO) message with a Registration Lifetime of 0		Upon receiving an NS(EARO) message with a Registration Lifetime of 0
	and determining that this EARO is the freshest for a given NCE (see		and determining that this EARO is the freshest for a given NCE (see
	Section 4.2), a 6LR cleans up its NCE. If the address was registered		Section 5.2), a 6LR cleans up its NCE. If the address was registered
	to the 6LBR, then the 6LR MUST report to the 6LBR, through a		to the 6LBR, then the 6LR MUST report to the 6LBR, through a
	Duplicate Address exchange with the 6LBR, indicating the null		Duplicate Address exchange with the 6LBR, indicating the null
	Registration Lifetime and the latest TID that this 6LR is aware of.		Registration Lifetime and the latest TID that this 6LR is aware of.
	Upon receiving the EDAR message, the 6LBR evaluates if this is the		Upon receiving the EDAR message, the 6LBR evaluates if this is the
	most recent TID it has received for that particular registry entry.		most recent TID it has received for that particular registry entry.
	If so, then the EDAR is answered with an EDAC message bearing a		If so, then the EDAR is answered with an EDAC message bearing a
	Status of "Success" and the entry is scheduled to be removed.		Status of "Success" and the entry is scheduled to be removed.
	Otherwise, a Status Code of "Moved" is returned instead, and the		Otherwise, a Status Code of "Moved" is returned instead, and the
	existing entry is maintained.		existing entry is maintained.
	When an address is scheduled to be removed, the 6LBR SHOULD keep its		When an address is scheduled to be removed, the 6LBR SHOULD keep its
	entry in a DELAY state for a configurable period of time, so as to		entry in a DELAY state for a configurable period of time, so as to
	protect a mobile node that de-registered from one 6LR and did not		protect a mobile node that de-registered from one 6LR and did not
	register yet to a new one, or the new registration did not yet reach		register yet to a new one, or the new registration did not yet reach
	the 6LBR due to propagation delays in the network. Once the DELAY		the 6LBR due to propagation delays in the network. Once the DELAY
	time is passed, the 6LBR silently removes its entry.		time is passed, the 6LBR silently removes its entry.
	5. Detecting Enhanced ARO Capability Support		6. Backward Compatibility
			This specification changes the behavior of the peers in a
			registration flow. To enable backward compatibility, a 6LN that
			registers to a 6LR that is not known to support this specification
			MUST behave in a manner that is backward-compatible with [RFC6775].
			On the contrary, if the 6LR is found to support this specification,
			then the 6LN MUST conform to this specification when communicating
			with that 6LR.
			A 6LN that supports this specification MUST always use an EARO as a
			replacement for an ARO in its registration to a router. This is
			backward-compatible since the 'T' flag and TID field are reserved in
			[RFC6775], and are ignored by an RFC6775-only router. A router that
			supports this specification MUST answer an NS(ARO) and an NS(EARO)
			with an NA(EARO). A router that does not support this specification
			will consider the ROVR as an EUI-64 address and treat it the same,
			which has no consequence if the Registered Addresses are different.
			6.1. Signaling EARO Capability Support
	"Generic Header Compression for IPv6 over 6LoWPANs" [RFC7400]		"Generic Header Compression for IPv6 over 6LoWPANs" [RFC7400]
	introduces the 6LoWPAN Capability Indication Option (6CIO) to		introduces the 6LoWPAN Capability Indication Option (6CIO) to
	indicate a node's capabilities to its peers. The 6CIO MUST be		indicate a node's capabilities to its peers. The 6CIO MUST be
	present in both Router Solicitation (RS) and Router Advertisement		present in both Router Solicitation (RS) and Router Advertisement
	(RA) messages, unless the information therein was already shared.		(RA) messages, unless the information therein was already shared.
	This can have happened in recent exchanges. The information can also		This can have happened in recent exchanges. The information can also
	be implicit, or pre-configured in all nodes in a network. In any		be implicit, or pre-configured in all nodes in a network. In any
	case, a 6CIO MUST be placed in an RA message that is sent in response		case, a 6CIO MUST be placed in an RA message that is sent in response
	to an RS with a 6CIO.		to an RS with a 6CIO.
	Section 6.3 defines a new flag for the 6CIO to signal support for		Section 4.3 defines a new flag for the 6CIO to signal support for
	EARO by the issuer of the message and Section 7.1 specifies how the		EARO by the issuer of the message and Section 6.2 specifies how the
	flag is to be used. New flags are also added to the 6CIO to signal		flag is to be used. New flags are also added to the 6CIO to signal
	the sender's capability to act as a 6LR, 6LBR, and 6BBR (see		the sender's capability to act as a 6LR, 6LBR, and 6BBR (see
	Section 6.3).		Section 4.3).
	Section 6.3 also defines a new flag that indicates the support of EDA		Section 4.3 also defines a new flag that indicates the support of EDA
	messages by the 6LBR. This flag is valid in RA messages but not in		messages by the 6LBR. This flag is valid in RA messages but not in
	RS messages. More information on the 6LBR is found in a separate		RS messages. More information on the 6LBR is found in a separate
	Authoritative Border Router Option (ABRO). The ABRO is placed in RA		Authoritative Border Router Option (ABRO). The ABRO is placed in RA
	messages as prescribed by [RFC6775]; in particular, it MUST be placed		messages as prescribed by [RFC6775]; in particular, it MUST be placed
	in an RA message that is sent in response to an RS with a 6CIO		in an RA message that is sent in response to an RS with a 6CIO
	indicating the capability to act as a 6LR, since the RA propagates		indicating the capability to act as a 6LR, since the RA propagates
	information between routers.		information between routers.
	6. Extended ND Options and Messages		6.2. First Exchanges
	This specification does not introduce new options, but it modifies
	existing ones and updates the associated behaviors as specified in
	the following subsections.
	6.1. Extended Address Registration Option (EARO)
	The Address Registration Option (ARO) is defined in section 4.1 of
	[RFC6775].
	The Extended Address Registration Option (EARO) replaces the ARO used
	within Neighbor Discovery NS and NA messages between a 6LN and its
	6LR. Similarly, the EDA messages, EDAR and EDAC, replace the DAR and
	DAC messages so as to transport the new information between 6LRs and
	6LBRs across LLN meshes such as 6TiSCH networks.
	An NS message with an EARO is a registration if and only if it also
	carries an SLLA Option. The EARO is also used in NS and NA messages
	between Backbone Routers [I-D.ietf-6lo-backbone-router] over the
	Backbone Link to sort out the distributed registration state; in that
	case, it does not carry the SLLA Option and is not confused with a
	registration.
	When using the EARO, the address being registered is found in the
	Target Address field of the NS and NA messages.
	The EARO extends the ARO and is indicated by the 'T' flag being set.
	The format of the EARO is as follows:
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Length | Status | Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Reserved |R|T| TID | Registration Lifetime |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |
	... Registration Ownership Verifier ...
	| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 2: EARO
	Option Fields
	Type: 33
	Length: 8-bit unsigned integer. The length of the option in
	units of 8 bytes. It MUST be 2 when operating in
	backward-compatible mode. It MAY be 3, 4 or 5,
	denoting a ROVR size of 128, 192 and 256 bits
	respectively.
	Status: 8-bit unsigned integer. Indicates the status of a
	registration in the NA response. MUST be set to 0 in
	NS messages. See Table 1 below.
	+-------+-----------------------------------------------------------+
	| Value | Description |
	+-------+-----------------------------------------------------------+
	| 0..2 | See [RFC6775]. Note: a Status of 1 ("Duplicate Address") |
	| | applies to the Registered Address. If the Source Address |
	| | conflicts with an existing registration, "Duplicate |
	| | Source Address" MUST be used. |
	| | |
	| 3 | Moved: The registration failed because it is not the |
	| | freshest. This Status indicates that the registration is |
	| | rejected because another more recent registration was |
	| | done, as indicated by a same ROVR and a more recent TID. |
	| | One possible cause is a stale registration that has |
	| | progressed slowly in the network and was passed by a more |
	| | recent one. It could also indicate a ROVR collision. |
	| | |
	| 4 | Removed: The binding state was removed. This status may |
	| | be placed in an NA(EARO) message that is sent as the |
	| | rejection of a proxy registration to a Backbone Router, |
	| | or in an asynchronous NA(EARO) at any time. |
	| | |
	| 5 | Validation Requested: The Registering Node is challenged |
	| | for owning the Registered Address or for being an |
	| | acceptable proxy for the registration. This Status is |
	| | expected in asynchronous messages from a registrar (6LR, |
	| | 6LBR, 6BBR) to indicate that the registration state is |
	| | removed, for instance, due to a movement of the device. |
	| | |
	| 6 | Duplicate Source Address: The address used as source of |
	| | the NS(ARO) conflicts with an existing registration. |
	| | |
	| 7 | Invalid Source Address: The address used as source of the |
	| | NS(ARO) is not a Link-Local Address as prescribed by this |
	| | document. |
	| | |
	| 8 | Registered Address topologically incorrect: The address |
	| | being registered is not usable on this link, e.g., it is |
	| | not topologically correct |
	| | |
	| 9 | 6LBR Registry saturated: A new registration cannot be |
	| | accepted because the 6LBR Registry is saturated. Note: |
	| | this code is used by 6LBRs instead of Status 2 when |
	| | responding to a Duplicate Address message exchange and is |
	| | passed on to the Registering Node by the 6LR. |
	| | |
	| 10 | Validation Failed: The proof of ownership of the |
	| | registered address is not correct. |
	+-------+-----------------------------------------------------------+
	Table 1: EARO Status
	Reserved: This field is unused. It MUST be initialized to zero
	by the sender and MUST be ignored by the receiver.
	R: One-bit flag. If the 'R' flag is set, the
	Registering Node expects that the 6LR ensures
	reachability for the registered address, e.g., by
	injecting the address in a Route-Over routing
	protocol or proxying ND over a Backbone Link.
	T: One-bit flag. Set if the next octet is used as a
	TID.
	TID: One-byte integer; a Transaction ID that is maintained
	by the node and incremented with each transaction.
	Registration Lifetime: 16-bit integer; expressed in minutes. 0
	means that the registration has ended and the
	associated state MUST be removed.
	Registration Ownership Verifier (ROVR): Enables the correlation
	between multiple attempts to register a same IPv6
	Address. This can be a unique ID of the Registering
	Node, such as the EUI-64 address of an interface.
	This can also be a token obtained with cryptographic
	methods and used as proof of ownership of the
	registration. The scope of a ROVR is the
	registration of a particular IPv6 Address and it
	cannot be used to correlate registrations of
	different addresses.
	6.2. Extended Duplicate Address Message Formats
	The DAR and DAC messages are defined in section 4.4 of [RFC6775].
	Those messages follow a common base format, which enables information
	from the ARO to be transported over multiple hops.
	Those messages are extended to adapt to the new EARO format, as
	follows:
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Code | Checksum |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Status | TID | Registration Lifetime |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |
	... Registration Ownership Verifier ...
	| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| |
	+ +
	| |
	+ Registered Address +
	| |
	+ +
	| |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 3: Duplicate Address Messages Format
	Modified Message Fields
	Code: The ICMP Code as defined in [RFC4443]. The ICMP Code
	MUST be set to 1 with this specification. An non-
	null value of the ICMP Code indicates support for
	this specification.
	TID: 1-byte integer; same definition and processing as the
	TID in the EARO as defined in Section 6.1.
	Registration Ownership Verifier (ROVR): The size of the ROVR is
	computed from the overall size of the IPv6 packet.
	It MUST be 64bits long when operating in backward-
	compatible mode. This field has the same definition
	and processing as the ROVR in the EARO option as
	defined in Section 6.1.
	6.3. New 6LoWPAN Capability Bits in the Capability Indication Option
	This specification defines 5 new capability bits for use in the 6CIO,
	which was introduced by [RFC7400] for use in IPv6 ND RA messages.
	This specification introduces the "E" flag to indicate that extended
	ARO can be used in a registration. A 6LR that supports this
	specification MUST set the "E" flag.
	A similar flag "D" indicates the support of Extended Duplicate
	Address Messages by the 6LBR; A 6LBR that supports this specification
	MUST set the "D" flag. The "D" flag is learned from advertisements
	by a 6LBR, and is propagated down a graph of 6LRs as a node acting as
	6LN registers to a 6LR (which could be the 6LBR), and in turn becomes
	a 6LR to which other 6LNs will register.
	The new "L", "B", and "P" flags, indicate whether a router is capable
	of acting as 6LR, 6LBR, and 6BBR, respectively. These flags are not
	mutually exclusive and a node MUST set all the flags that are
	relevant to it.
	As an example, a 6LBR sets the "B" and "D" flags. If it acts as a
	6LR, then it sets the "L" and "E" flags. If it is collocated with a
	6BBR, then it also sets the "P" flag.
	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
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type | Length = 1 | Reserved |D|L|B|P|E|G|
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Reserved |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	Figure 4: New capability Bits L, B, P, E in the 6CIO
	Option Fields
	Type: 36
	L: Node is a 6LR.
	B: Node is a 6LBR.
	P: Node is a 6BBR.
	E: Node supports registrations based on EARO.
	D: 6LBR supports EDA messages.
	7. Backward Compatibility
	7.1. Discovering the Capabilities of Router
	A 6LR that supports this specification MUST place a 6CIO in its RA
	messages. A typical flow when a node starts up is that it sends a
	multicast RS and receives one or more unicast RA messages. If the
	6LR can process Extended ARO, then the "E" Flag is set in the RA.
	This specification changes the behavior of the peers in a		A typical flow when a node starts up is that it sends a multicast RS
	registration flow. To enable backward compatibility, a 6LN that		and receives one or more unicast RA messages. If the 6LR can process
	registers to a 6LR that is not known to support this specification		Extended ARO, then it places a 6CIO in its RA message back with the
	MUST behave in a manner that is backward-compatible with [RFC6775].		"E" Flag set as required in Section 6.1.
	On the contrary, if the 6LR is known to support this specification,
	then the 6LN MUST conform to this specification when communicating
	with that 6LR.
	In order to ensure that it registers a first address successfully a		In order to ensure that it registers a first address successfully a
	6LN MAY register a Link Local Address that is derived from an EUI-64,		6LN MAY register a Link Local Address that is derived from an EUI-64,
	placing the same address in the Source and Target Address fields of		placing the same address in the Source and Target Address fields of
	the NS(EARO) message. For such an address, DAD is not required (see		the NS(EARO) message. For such an address, DAD is not required (see
	[RFC6775]) and using the SLLA Option in the NS is actually more		[RFC6775]) and using the SLLA Option in the NS is actually more
	consistent with existing ND specifications such as the "Optimistic		consistent with existing ND specifications such as the "Optimistic
	Duplicate Address Detection (ODAD) for IPv6" [RFC4429]. The 6LN MAY		Duplicate Address Detection (ODAD) for IPv6" [RFC4429]. The 6LN MAY
	then use that address to register one or more other addresses.		then use that address to register one or more other addresses.
	A 6LN that supports this specification MUST always use an EARO as a		6.3. RFC6775-only 6LoWPAN Node
	replacement for an ARO in its registration to a router. This is
	harmless since the 'T' flag and TID field are reserved in [RFC6775],
	and are ignored by an RFC6775-only router. A router that supports
	this specification MUST answer an NS(ARO) and an NS(EARO) with an
	NA(EARO). A router that does not support this specification will
	consider the ROVR as an EUI-64 address and treat it the same, which
	has no consequence if the Registered Addresses are different.
	7.2. RFC6775-only 6LoWPAN Node
	An RFC6775-only 6LN will use the Registered Address as the source		An RFC6775-only 6LN will use the Registered Address as the source
	address of the NS message and will not use an EARO. An updated 6LR		address of the NS message and will not use an EARO. An updated 6LR
	MUST accept that registration if it is valid per [RFC6775], and it		MUST accept that registration if it is valid per [RFC6775], and it
	MUST manage the binding cache accordingly. The updated 6LR MUST then		MUST manage the binding cache accordingly. The updated 6LR MUST then
	use the RFC6775-only EDA messages as specified in [RFC6775] to		use the RFC6775-only EDA messages as specified in [RFC6775] to
	indicate to the 6LBR that the TID is not present in the messages.		indicate to the 6LBR that the TID is not present in the messages.
	The main difference from [RFC6775] is that the exchange of EDA		The main difference from [RFC6775] is that the exchange of EDA
	messages for the purpose of DAD is avoided for Link-Local Addresses.		messages for the purpose of DAD is avoided for Link-Local Addresses.
	skipping to change at page 22, line 4 ¶		skipping to change at page 24, line 32 ¶
	An RFC6775-only 6LN will use the Registered Address as the source		An RFC6775-only 6LN will use the Registered Address as the source
	address of the NS message and will not use an EARO. An updated 6LR		address of the NS message and will not use an EARO. An updated 6LR
	MUST accept that registration if it is valid per [RFC6775], and it		MUST accept that registration if it is valid per [RFC6775], and it
	MUST manage the binding cache accordingly. The updated 6LR MUST then		MUST manage the binding cache accordingly. The updated 6LR MUST then
	use the RFC6775-only EDA messages as specified in [RFC6775] to		use the RFC6775-only EDA messages as specified in [RFC6775] to
	indicate to the 6LBR that the TID is not present in the messages.		indicate to the 6LBR that the TID is not present in the messages.
	The main difference from [RFC6775] is that the exchange of EDA		The main difference from [RFC6775] is that the exchange of EDA
	messages for the purpose of DAD is avoided for Link-Local Addresses.		messages for the purpose of DAD is avoided for Link-Local Addresses.
	In any case, the 6LR MUST use an EARO in the reply, and can use any		In any case, the 6LR MUST use an EARO in the reply, and can use any
	of the Status codes defined in this specification.		of the Status codes defined in this specification.
	7.3. RFC6775-only 6LoWPAN Router		6.4. RFC6775-only 6LoWPAN Router
	An updated 6LN discovers the capabilities of the 6LR in the 6CIO in		An updated 6LN discovers the capabilities of the 6LR in the 6CIO in
	RA messages from that 6LR; if the 6CIO was not present in the RA,		RA messages from that 6LR; if the 6CIO was not present in the RA,
	then the 6LR is assumed to be a RFC6775-only 6LoWPAN Router.		then the 6LR is assumed to be a RFC6775-only 6LoWPAN Router.
	An updated 6LN MUST use an EARO in the request regardless of the type		An updated 6LN MUST use an EARO in the request regardless of the type
	of 6LR, RFC6775-only or updated, which implies that the 'T' flag is		of 6LR, RFC6775-only or updated, which implies that the 'T' flag is
	set. It MUST use a ROVR of 64 bits if the 6LR is an RFC6775-only		set. It MUST use a ROVR of 64 bits if the 6LR is an RFC6775-only
	6LoWPAN Router.		6LoWPAN Router.
	skipping to change at page 22, line 30 ¶		skipping to change at page 25, line 8 ¶
	the RFC6775-only 6LR will send an RFC6775-only DAR message, which		the RFC6775-only 6LR will send an RFC6775-only DAR message, which
	cannot be compared with an updated one for freshness. Allowing		cannot be compared with an updated one for freshness. Allowing
	RFC6775-only DAR messages to replace a state established by the		RFC6775-only DAR messages to replace a state established by the
	updated protocol in the 6LBR would be an attack vector and that		updated protocol in the 6LBR would be an attack vector and that
	cannot be the default behavior. But if RFC6775-only and updated 6LRs		cannot be the default behavior. But if RFC6775-only and updated 6LRs
	coexist temporarily in a network, then it makes sense for an		coexist temporarily in a network, then it makes sense for an
	administrator to install a policy that allows this, and the		administrator to install a policy that allows this, and the
	capability to install such a policy should be configurable in a 6LBR		capability to install such a policy should be configurable in a 6LBR
	though it is out of scope for this document.		though it is out of scope for this document.
	7.4. RFC6775-only 6LoWPAN Border Router		6.5. RFC6775-only 6LoWPAN Border Router
	With this specification, the Duplicate Address messages are extended		With this specification, the Duplicate Address messages are extended
	to transport the EARO information. Similarly to the NS/NA exchange,		to transport the EARO information. Similarly to the NS/NA exchange,
	an updated 6LBR MUST always use the EDA messages.		an updated 6LBR MUST always use the EDA messages.
	Note that an RFC6775-only 6LBR will accept and process an EDAR		Note that an RFC6775-only 6LBR will accept and process an EDAR
	message as if it were an RFC6775-only DAR, as long as the ROVR is 64		message as if it were an RFC6775-only DAR, as long as the ROVR is 64
	bits long. An updated 6LR discovers the capabilities of the 6LBR in		bits long. An updated 6LR discovers the capabilities of the 6LBR in
	the 6CIO in RA messages from the 6LR; if the 6CIO was not present in		the 6CIO in RA messages from the 6LR; if the 6CIO was not present in
	any RA, then the 6LBR si assumed to be a RFC6775-only 6LoWPAN Border		any RA, then the 6LBR si assumed to be a RFC6775-only 6LoWPAN Border
	Router.		Router.
	If the 6LBR is RFC6775-only, and the ROVR in the NS(EARO) was more		If the 6LBR is RFC6775-only, and the ROVR in the NS(EARO) was more
	than 64 bits long, then the 6LR MUST truncate the ROVR to the 64		than 64 bits long, then the 6LR MUST truncate the ROVR to the 64
	rightmost bit and place the result in the EDAR message to maintain		rightmost bit and place the result in the EDAR message to maintain
	compatibility. This way, the support of DAD is preserved.		compatibility. This way, the support of DAD is preserved.
	8. Security Considerations		7. Security Considerations
	This specification extends [RFC6775], and the security section of		This specification extends [RFC6775], and the security section of
	that document also applies to this as well. In particular, it is		that document also applies to this as well. In particular, it is
	expected that the link layer is sufficiently protected to prevent		expected that the link layer is sufficiently protected to prevent
	rogue access, either by means of physical or IP security on the		rogue access, either by means of physical or IP security on the
	Backbone Link and link-layer cryptography on the LLN.		Backbone Link and link-layer cryptography on the LLN.
	[RFC6775] does not protect the content of its messages and expects a		[RFC6775] does not protect the content of its messages and expects a
	lower layer encryption to defeat potential attacks. This		lower layer encryption to defeat potential attacks. This
	specification also expects that the LLN MAC provides secure unicast		specification also expects that the LLN MAC provides secure unicast
	to/from the Backbone Router and secure Broadcast or Multicast from		to/from the Backbone Router and secure Broadcast or Multicast from
	the Backbone Router in a way that prevents tampering with or		the Backbone Router in a way that prevents tampering with or
	replaying the Neighbor Discovery messages.		replaying the Neighbor Discovery messages.
	This specification recommends using privacy techniques (see		This specification recommends using privacy techniques (see
	Section 9) and protecting against address theft such as provided by		Section 8) and protecting against address theft such as provided by
	"Address Protected Neighbor Discovery for Low-power and Lossy		"Address Protected Neighbor Discovery for Low-power and Lossy
	Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the		Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the
	Registered Address using a cryptographic ROVR.		Registered Address using a cryptographic ROVR.
	The registration mechanism may be used by a rogue node to attack the		The registration mechanism may be used by a rogue node to attack the
	6LR or the 6LBR with a Denial-of-Service attack against the registry.		6LR or the 6LBR with a Denial-of-Service attack against the registry.
	It may also happen that the registry of a 6LR or a 6LBR is saturated		It may also happen that the registry of a 6LR or a 6LBR is saturated
	and cannot take any more registrations, which effectively denies the		and cannot take any more registrations, which effectively denies the
	requesting node the capability to use a new address. In order to		requesting node the capability to use a new address. In order to
	alleviate those concerns, Section 4.7 provides a number of		alleviate those concerns, Section 5.7 provides a number of
	recommendations that ensure that a stale registration is removed as		recommendations that ensure that a stale registration is removed as
	soon as possible from the 6LR and 6LBR. In particular, this		soon as possible from the 6LR and 6LBR. In particular, this
	specification recommends that:		specification recommends that:
	o A node that ceases to use an address SHOULD attempt to de-register		o A node that ceases to use an address SHOULD attempt to de-register
	that address from all the 6LRs to which it is registered. See		that address from all the 6LRs to which it is registered. See
	Section 4.2 for the mechanism to avoid replay attacks and avoiding		Section 5.2 for the mechanism to avoid replay attacks and avoiding
	the use of stale registration information.		the use of stale registration information.
	o The Registration lifetimes SHOULD be individually configurable for		o The Registration lifetimes SHOULD be individually configurable for
	each address or group of addresses. The nodes SHOULD be		each address or group of addresses. The nodes SHOULD be
	configured with a Registration Lifetime that reflects their		configured with a Registration Lifetime that reflects their
	expectation of how long they will use the address with the 6LR to		expectation of how long they will use the address with the 6LR to
	which it is registered. In particular, use cases that involve		which it is registered. In particular, use cases that involve
	mobility or rapid address changes SHOULD use lifetimes that are		mobility or rapid address changes SHOULD use lifetimes that are
	larger yet of a same order as the duration of the expectation of		larger yet of a same order as the duration of the expectation of
	presence.		presence.
	o The router (6LR or 6LBR) SHOULD be configurable so as to limit the		o The router (6LR or 6LBR) SHOULD be configurable so as to limit the
	number of addresses that can be registered by a single node, but		number of addresses that can be registered by a single node, but
	as a protective measure only. In any case, a router MUST be able		as a protective measure only. In any case, a router MUST be able
	to keep a minimum number of addresses per node. That minimum		to keep a minimum number of addresses per node. That minimum
	depends on the type of device and ranges between 3 for a very		depends on the type of device and ranges between 3 for a very
	constrained LLN and 10 for a larger device. A node may be		constrained LLN and 10 for a larger device. A node may be
	identified by its MAC address, as long as it is not obfuscated by		identified by its MAC address, as long as it is not obfuscated by
	privacy measures. A stronger identification (e.g., by security		privacy measures. A stronger identification (e.g., by security
	credentials) is RECOMMENDED. When the maximum is reached, the		credentials) is RECOMMENDED. When the maximum is reached, the
	router should use a Least-Recently-Used (LRU) algorithm to clean		router should use a Least-Recently-Used (LRU) algorithm to clean
	skipping to change at page 24, line 9 ¶		skipping to change at page 26, line 38 ¶
	constrained LLN and 10 for a larger device. A node may be		constrained LLN and 10 for a larger device. A node may be
	identified by its MAC address, as long as it is not obfuscated by		identified by its MAC address, as long as it is not obfuscated by
	privacy measures. A stronger identification (e.g., by security		privacy measures. A stronger identification (e.g., by security
	credentials) is RECOMMENDED. When the maximum is reached, the		credentials) is RECOMMENDED. When the maximum is reached, the
	router should use a Least-Recently-Used (LRU) algorithm to clean		router should use a Least-Recently-Used (LRU) algorithm to clean
	up the addresses, keeping at least one Link-Local Address. The		up the addresses, keeping at least one Link-Local Address. The
	router SHOULD attempt to keep one or more stable addresses if		router SHOULD attempt to keep one or more stable addresses if
	stability can be determined, e.g., because they are used over a		stability can be determined, e.g., because they are used over a
	much longer time span than other (privacy, shorter-lived)		much longer time span than other (privacy, shorter-lived)
	addresses.		addresses.
	o In order to avoid denial of registration for the lack of		o In order to avoid denial of registration for the lack of
	resources, administrators should take great care to deploy		resources, administrators should take great care to deploy
	adequate numbers of 6LRs to cover the needs of the nodes in their		adequate numbers of 6LRs to cover the needs of the nodes in their
	range, so as to avoid a situation of starving nodes. It is		range, so as to avoid a situation of starving nodes. It is
	expected that the 6LBR that serves an LLN is a more capable node		expected that the 6LBR that serves an LLN is a more capable node
	than the average 6LR, but in a network condition where it may		than the average 6LR, but in a network condition where it may
	become saturated, a particular deployment should distribute the		become saturated, a particular deployment should distribute the
	6LBR functionality, for instance by leveraging a high speed		6LBR functionality, for instance by leveraging a high speed
	Backbone Link and Backbone Routers to aggregate multiple LLNs into		Backbone Link and Backbone Routers to aggregate multiple LLNs into
	a larger subnet.		a larger subnet.
	The LLN nodes depend on the 6LBR and the 6BBR for their operation. A		The LLN nodes depend on the 6LBR and the 6BBR for their operation. A
	trust model must be put in place to ensure that the right devices are		trust model must be put in place to ensure that the right devices are
	acting in these roles so as to avoid threats such as black-holing or		acting in these roles so as to avoid threats such as black-holing or
	bombing attack whereby an impersonated 6LBR would destroy state in		bombing attack whereby an impersonated 6LBR would destroy state in
	the network by using the "Removed" Status code. This trust model		the network by using the "Removed" Status code. This trust model
	could be at a minimum based on a Layer-2 access control, or could		could be at a minimum based on a Layer-2 access control, or could
	provide role validation as well (see Req5.1 in Appendix B.5).		provide role validation as well (see Req5.1 in Appendix B.5).
	9. Privacy Considerations		8. Privacy Considerations
	As indicated in Section 3, this protocol does not inherently limit		As indicated in Section 3, this protocol does not inherently limit
	the number of IPv6 addresses that each device can form. However, to		the number of IPv6 addresses that each device can form. However, to
	mitigate denial-of-service attacks, it can be useful as a protective		mitigate denial-of-service attacks, it can be useful as a protective
	measure to have a limit that is high enough not to interfere with the		measure to have a limit that is high enough not to interfere with the
	normal behavior of devices in the network. A host should be able to		normal behavior of devices in the network. A host should be able to
	form and register any address that is topologically correct in the		form and register any address that is topologically correct in the
	subnet(s) advertised by the 6LR/6LBR.		subnet(s) advertised by the 6LR/6LBR.
	This specification does not mandate any particular way for forming		This specification does not mandate any particular way for forming
	skipping to change at page 25, line 14 ¶		skipping to change at page 27, line 44 ¶
	derived from the Lower Layer address. When it is not critical to		derived from the Lower Layer address. When it is not critical to
	benefit from that compression, e.g., the address can be compressed		benefit from that compression, e.g., the address can be compressed
	statefully, or it is rarely used and/or it is used only over one hop,		statefully, or it is rarely used and/or it is used only over one hop,
	then privacy concerns should be considered. In particular, new		then privacy concerns should be considered. In particular, new
	implementations should follow the IETF "Recommendation on Stable IPv6		implementations should follow the IETF "Recommendation on Stable IPv6
	Interface Identifiers" [RFC8064]. [RFC8064] recommends the use of "A		Interface Identifiers" [RFC8064]. [RFC8064] recommends the use of "A
	Method for Generating Semantically Opaque Interface Identifiers with		Method for Generating Semantically Opaque Interface Identifiers with
	IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for		IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for
	generating Interface Identifiers to be used in SLAAC.		generating Interface Identifiers to be used in SLAAC.
	10. IANA Considerations		9. IANA Considerations
	Note to RFC Editor, to be removed: please replace "This RFC"		Note to RFC Editor, to be removed: please replace "This RFC"
	throughout this document by the RFC number for this specification		throughout this document by the RFC number for this specification
	once it is allocated.		once it is allocated.
	IANA is requested to make a number of changes under the "Internet		IANA is requested to make a number of changes under the "Internet
	Control Message Protocol version 6 (ICMPv6) Parameters" registry, as		Control Message Protocol version 6 (ICMPv6) Parameters" registry, as
	follows.		follows.
	10.1. ARO Flags		9.1. ARO Flags
	IANA is requested to create a new subregistry for "ARO Flags". This		IANA is requested to create a new subregistry for "ARO Flags". This
	specification defines 8 positions, bit 0 to bit 7, and assigns bit 6		specification defines 8 positions, bit 0 to bit 7, and assigns bit 6
	for the 'R' flag and bit 7 for the 'T' flag (see Section 6.1). The		for the 'R' flag and bit 7 for the 'T' flag (see Section 4.1). The
	policy is "IETF Review" or "IESG Approval" [RFC8126]. The initial		policy is "IETF Review" or "IESG Approval" [RFC8126]. The initial
	content of the registry is as shown in Table 2.		content of the registry is as shown in Table 2.
	New subregistry for ARO Flags under the "Internet Control Message		New subregistry for ARO Flags under the "Internet Control Message
	Protocol version 6 (ICMPv6) [RFC4443] Parameters"		Protocol version 6 (ICMPv6) [RFC4443] Parameters"
	+-------------+--------------+-----------+		+-------------+--------------+-----------+
	| ARO Status | Description | Document |		| ARO Status | Description | Document |
	+-------------+--------------+-----------+		+-------------+--------------+-----------+
	| 0..5 | Unassigned | |		| 0..5 | Unassigned | |
	| | | |		| | | |
	| 6 | 'R' Flag | This RFC |		| 6 | 'R' Flag | This RFC |
	| | | |		| | | |
	| 7 | 'T' Flag | This RFC |		| 7 | 'T' Flag | This RFC |
	+-------------+--------------+-----------+		+-------------+--------------+-----------+
	Table 2: new ARO Flags		Table 2: new ARO Flags
	10.2. ICMP Codes		9.2. ICMP Codes
	IANA is requested to create 2 new subregistries of the ICMPv6 "Code"		IANA is requested to create 2 new subregistries of the ICMPv6 "Code"
	Fields registry, which itself is a subregistry of the Internet		Fields registry, which itself is a subregistry of the Internet
	Control Message Protocol version 6 (ICMPv6) Parameters for the ICMP		Control Message Protocol version 6 (ICMPv6) Parameters for the ICMP
	codes. The new subregistries relate to the ICMP type 157, Duplicate		codes. The new subregistries relate to the ICMP type 157, Duplicate
	Address Request (shown in Table 3), and 158, Duplicate Address		Address Request (shown in Table 3), and 158, Duplicate Address
	Confirmation (shown in Table 4), respectively. The range of an		Confirmation (shown in Table 4), respectively. The range of an
	ICMPv6 "Code" Field is 0..255 in all cases. The policy is "IETF		ICMPv6 "Code" Field is 0..255 in all cases. The policy is "IETF
	Review" or "IESG Approval" [RFC8126] for both subregistries. The new		Review" or "IESG Approval" [RFC8126] for both subregistries. The new
	subregistries are initialized as follows:		subregistries are initialized as follows:
	skipping to change at page 26, line 39 ¶		skipping to change at page 29, line 33 ¶
	+---------+----------------------+------------+		+---------+----------------------+------------+
	| 0 | Original DAC message | RFC 6775 |		| 0 | Original DAC message | RFC 6775 |
	| | | |		| | | |
	| 1 | Extended DAC message | This RFC |		| 1 | Extended DAC message | This RFC |
	| | | |		| | | |
	| 2...255 | Unassigned | |		| 2...255 | Unassigned | |
	+---------+----------------------+------------+		+---------+----------------------+------------+
	Table 4: new ICMPv6 Code Fields		Table 4: new ICMPv6 Code Fields
	10.3. New ARO Status values		9.3. New ARO Status values
	IANA is requested to make additions to the Address Registration		IANA is requested to make additions to the Address Registration
	Option Status Values Registry as follows:		Option Status Values Registry as follows:
	Address Registration Option Status Values Registry		Address Registration Option Status Values Registry
	+-------------+-----------------------------------------+-----------+		+-------------+-----------------------------------------+-----------+
	| ARO Status | Description | Document |		| ARO Status | Description | Document |
	+-------------+-----------------------------------------+-----------+		+-------------+-----------------------------------------+-----------+
	| 3 | Moved | This RFC |		| 3 | Moved | This RFC |
	skipping to change at page 27, line 30 ¶		skipping to change at page 30, line 30 ¶
	| 8 | Registered Address topologically | This RFC |		| 8 | Registered Address topologically | This RFC |
	| | incorrect | |		| | incorrect | |
	| | | |		| | | |
	| 9 | 6LBR Registry saturated | This RFC |		| 9 | 6LBR Registry saturated | This RFC |
	| | | |		| | | |
	| 10 | Validation Failed | This RFC |		| 10 | Validation Failed | This RFC |
	+-------------+-----------------------------------------+-----------+		+-------------+-----------------------------------------+-----------+
	Table 5: New ARO Status values		Table 5: New ARO Status values
	10.4. New 6LoWPAN capability Bits		9.4. New 6LoWPAN capability Bits
	IANA is requested to make additions to the Subregistry for "6LoWPAN		IANA is requested to make additions to the Subregistry for "6LoWPAN
	capability Bits" as follows:		capability Bits" as follows:
	Subregistry for "6LoWPAN capability Bits" under the "Internet Control		Subregistry for "6LoWPAN capability Bits" under the "Internet Control
	Message Protocol version 6 (ICMPv6) Parameters"		Message Protocol version 6 (ICMPv6) Parameters"
	+-----------------+----------------------+-----------+		+-----------------+----------------------+-----------+
	| Capability Bit | Description | Document |		| Capability Bit | Description | Document |
	+-----------------+----------------------+-----------+		+-----------------+----------------------+-----------+
	skipping to change at page 28, line 5 ¶		skipping to change at page 31, line 5 ¶
	| | | |		| | | |
	| 12 | 6LBR capable (B bit) | This RFC |		| 12 | 6LBR capable (B bit) | This RFC |
	| | | |		| | | |
	| 13 | 6BBR capable (P bit) | This RFC |		| 13 | 6BBR capable (P bit) | This RFC |
	| | | |		| | | |
	| 14 | EARO support (E bit) | This RFC |		| 14 | EARO support (E bit) | This RFC |
	+-----------------+----------------------+-----------+		+-----------------+----------------------+-----------+
	Table 6: New 6LoWPAN capability Bits		Table 6: New 6LoWPAN capability Bits
	11. Acknowledgments		10. Acknowledgments
	Kudos to Eric Levy-Abegnoli who designed the First Hop Security		Kudos to Eric Levy-Abegnoli who designed the First Hop Security
	infrastructure upon which the first backbone router was implemented.		infrastructure upon which the first backbone router was implemented.
	Many thanks to Sedat Gormus, Rahul Jadhav, Tim Chown, Juergen		Many thanks to Sedat Gormus, Rahul Jadhav, Tim Chown, Juergen
	Schoenwaelder, Chris Lonvick, Dave Thaler, Adrian Farrel, Peter Yee,		Schoenwaelder, Chris Lonvick, Dave Thaler, Adrian Farrel, Peter Yee,
	Warren Kumari, and Lorenzo Colitti for their various contributions		Warren Kumari, Benjamin Kaduk, Mirja Kuhlewind, and Lorenzo Colitti
	and reviews. Also, many thanks to Thomas Watteyne for the world		for their various contributions and reviews. Also, many thanks to
	first implementation of a 6LN that was instrumental to the early		Thomas Watteyne for the world first implementation of a 6LN that was
	tests of the 6LR, 6LBR and Backbone Router.		instrumental to the early tests of the 6LR, 6LBR and Backbone Router.
	12. References		11. References
	12.1. Normative References		11.1. 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,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://www.rfc-editor.org/info/rfc2119>.
	[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing		[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
	Architecture", RFC 4291, DOI 10.17487/RFC4291, February		Architecture", RFC 4291, DOI 10.17487/RFC4291, February
	2006, <https://www.rfc-editor.org/info/rfc4291>.		2006, <https://www.rfc-editor.org/info/rfc4291>.
	skipping to change at page 28, line 45 ¶		skipping to change at page 31, line 45 ¶
	[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,
	DOI 10.17487/RFC4861, September 2007,		DOI 10.17487/RFC4861, September 2007,
	<https://www.rfc-editor.org/info/rfc4861>.		<https://www.rfc-editor.org/info/rfc4861>.
	[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless		[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
	Address Autoconfiguration", RFC 4862,		Address Autoconfiguration", RFC 4862,
	DOI 10.17487/RFC4862, September 2007,		DOI 10.17487/RFC4862, September 2007,
	<https://www.rfc-editor.org/info/rfc4862>.		<https://www.rfc-editor.org/info/rfc4862>.
	[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
	over Low-Power Wireless Personal Area Networks (6LoWPANs):
	Overview, Assumptions, Problem Statement, and Goals",
	RFC 4919, DOI 10.17487/RFC4919, August 2007,
	<https://www.rfc-editor.org/info/rfc4919>.
	[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6		[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
	Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,		Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
	DOI 10.17487/RFC6282, September 2011,		DOI 10.17487/RFC6282, September 2011,
	<https://www.rfc-editor.org/info/rfc6282>.		<https://www.rfc-editor.org/info/rfc6282>.
	[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem
	Statement and Requirements for IPv6 over Low-Power
	Wireless Personal Area Network (6LoWPAN) Routing",
	RFC 6606, DOI 10.17487/RFC6606, May 2012,
	<https://www.rfc-editor.org/info/rfc6606>.
	[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.		[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
	Bormann, "Neighbor Discovery Optimization for IPv6 over		Bormann, "Neighbor Discovery Optimization for IPv6 over
	Low-Power Wireless Personal Area Networks (6LoWPANs)",		Low-Power Wireless Personal Area Networks (6LoWPANs)",
	RFC 6775, DOI 10.17487/RFC6775, November 2012,		RFC 6775, DOI 10.17487/RFC6775, November 2012,
	<https://www.rfc-editor.org/info/rfc6775>.		<https://www.rfc-editor.org/info/rfc6775>.
	[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
	Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
	2014, <https://www.rfc-editor.org/info/rfc7102>.
	[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
	Constrained-Node Networks", RFC 7228,
	DOI 10.17487/RFC7228, May 2014,
	<https://www.rfc-editor.org/info/rfc7228>.
	[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for		[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
	IPv6 over Low-Power Wireless Personal Area Networks		IPv6 over Low-Power Wireless Personal Area Networks
	(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November		(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
	2014, <https://www.rfc-editor.org/info/rfc7400>.		2014, <https://www.rfc-editor.org/info/rfc7400>.
	[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for		[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
	Writing an IANA Considerations Section in RFCs", BCP 26,		Writing an IANA Considerations Section in RFCs", BCP 26,
	RFC 8126, DOI 10.17487/RFC8126, June 2017,		RFC 8126, DOI 10.17487/RFC8126, June 2017,
	<https://www.rfc-editor.org/info/rfc8126>.		<https://www.rfc-editor.org/info/rfc8126>.
	[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, <https://www.rfc-editor.org/info/rfc8174>.		May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	12.2. Informative References		11.2. Terminology Related References
			[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
			over Low-Power Wireless Personal Area Networks (6LoWPANs):
			Overview, Assumptions, Problem Statement, and Goals",
			RFC 4919, DOI 10.17487/RFC4919, August 2007,
			<https://www.rfc-editor.org/info/rfc4919>.
			[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem
			Statement and Requirements for IPv6 over Low-Power
			Wireless Personal Area Network (6LoWPAN) Routing",
			RFC 6606, DOI 10.17487/RFC6606, May 2012,
			<https://www.rfc-editor.org/info/rfc6606>.
			[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
			Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
			2014, <https://www.rfc-editor.org/info/rfc7102>.
			[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
			Constrained-Node Networks", RFC 7228,
			DOI 10.17487/RFC7228, May 2014,
			<https://www.rfc-editor.org/info/rfc7228>.
			11.3. Informative References
	[I-D.chakrabarti-nordmark-6man-efficient-nd]		[I-D.chakrabarti-nordmark-6man-efficient-nd]
	Chakrabarti, S., Nordmark, E., Thubert, P., and M.		Chakrabarti, S., Nordmark, E., Thubert, P., and M.
	Wasserman, "IPv6 Neighbor Discovery Optimizations for		Wasserman, "IPv6 Neighbor Discovery Optimizations for
	Wired and Wireless Networks", draft-chakrabarti-nordmark-		Wired and Wireless Networks", draft-chakrabarti-nordmark-
	6man-efficient-nd-07 (work in progress), February 2015.		6man-efficient-nd-07 (work in progress), February 2015.
	[I-D.delcarpio-6lo-wlanah]		[I-D.delcarpio-6lo-wlanah]
	Vega, L., Robles, I., and R. Morabito, "IPv6 over		Vega, L., Robles, I., and R. Morabito, "IPv6 over
	802.11ah", draft-delcarpio-6lo-wlanah-01 (work in		802.11ah", draft-delcarpio-6lo-wlanah-01 (work in
	skipping to change at page 31, line 10 ¶		skipping to change at page 34, line 16 ¶
	Perkins, C., Stanley, D., Kumari, W., and J. Zuniga,		Perkins, C., Stanley, D., Kumari, W., and J. Zuniga,
	"Multicast Considerations over IEEE 802 Wireless Media",		"Multicast Considerations over IEEE 802 Wireless Media",
	draft-perkins-intarea-multicast-ieee802-03 (work in		draft-perkins-intarea-multicast-ieee802-03 (work in
	progress), July 2017.		progress), July 2017.
	[I-D.struik-lwip-curve-representations]		[I-D.struik-lwip-curve-representations]
	Struik, R., "Alternative Elliptic Curve Representations",		Struik, R., "Alternative Elliptic Curve Representations",
	draft-struik-lwip-curve-representations-00 (work in		draft-struik-lwip-curve-representations-00 (work in
	progress), October 2017.		progress), October 2017.
			[I-D.thubert-roll-unaware-leaves]
			Thubert, P., "Routing for RPL Leaves", draft-thubert-roll-
			unaware-leaves-04 (work in progress), March 2018.
	[RFC1958] Carpenter, B., Ed., "Architectural Principles of the		[RFC1958] Carpenter, B., Ed., "Architectural Principles of the
	Internet", RFC 1958, DOI 10.17487/RFC1958, June 1996,		Internet", RFC 1958, DOI 10.17487/RFC1958, June 1996,
	<https://www.rfc-editor.org/info/rfc1958>.		<https://www.rfc-editor.org/info/rfc1958>.
	[RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,		[RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,
	DOI 10.17487/RFC1982, August 1996,		DOI 10.17487/RFC1982, August 1996,
	<https://www.rfc-editor.org/info/rfc1982>.		<https://www.rfc-editor.org/info/rfc1982>.
	[RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with		[RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with
	CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September		CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September
	skipping to change at page 33, line 5 ¶		skipping to change at page 36, line 16 ¶
	Donaldson, "Transmission of IPv6 over Master-Slave/Token-		Donaldson, "Transmission of IPv6 over Master-Slave/Token-
	Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163,		Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163,
	May 2017, <https://www.rfc-editor.org/info/rfc8163>.		May 2017, <https://www.rfc-editor.org/info/rfc8163>.
	[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,		[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
	Przygienda, T., and S. Aldrin, "Multicast Using Bit Index		Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
	Explicit Replication (BIER)", RFC 8279,		Explicit Replication (BIER)", RFC 8279,
	DOI 10.17487/RFC8279, November 2017,		DOI 10.17487/RFC8279, November 2017,
	<https://www.rfc-editor.org/info/rfc8279>.		<https://www.rfc-editor.org/info/rfc8279>.
	12.3. External Informative References		11.4. External Informative References
	[IEEEstd802154]		[IEEEstd802154]
	IEEE, "IEEE Standard for Low-Rate Wireless Networks",		IEEE, "IEEE Standard for Low-Rate Wireless Networks",
	IEEE Standard 802.15.4, DOI 10.1109/IEEE		IEEE Standard 802.15.4, DOI 10.1109/IEEE
	P802.15.4-REVd/D01, June 2017,		P802.15.4-REVd/D01, June 2017,
	<http://ieeexplore.ieee.org/document/7460875/>.		<http://ieeexplore.ieee.org/document/7460875/>.
	[Perlman83]		[Perlman83]
	Perlman, R., "Fault-Tolerant Broadcast of Routing		Perlman, R., "Fault-Tolerant Broadcast of Routing
	Information", North-Holland Computer Networks 7: 395-405,		Information", North-Holland Computer Networks 7: 395-405,
End of changes. 90 change blocks.
	406 lines changed or deleted		484 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/