< draft-ietf-roll-useofrplinfo-14.txt		draft-ietf-roll-useofrplinfo-15.txt >
	ROLL Working Group M. Robles		ROLL Working Group M. Robles
	Internet-Draft Ericsson		Internet-Draft Ericsson
	Updates: 6550 (if approved) M. Richardson		Updates: 6553, 6550 (if approved) M. Richardson
	Intended status: Standards Track SSW		Intended status: Standards Track SSW
	Expires: October 7, 2017 P. Thubert		Expires: December 31, 2017 P. Thubert
	Cisco		Cisco
	April 5, 2017		June 29, 2017
	When to use RFC 6553, 6554 and IPv6-in-IPv6		When to use RFC 6553, 6554 and IPv6-in-IPv6
	draft-ietf-roll-useofrplinfo-14		draft-ietf-roll-useofrplinfo-15
	Abstract		Abstract
	This document looks at different data flows through LLN (Low-Power		This document looks at different data flows through LLN (Low-Power
	and Lossy Networks) where RPL (IPv6 Routing Protocol for Low-Power		and Lossy Networks) where RPL (IPv6 Routing Protocol for Low-Power
	and Lossy Networks) is used to establish routing. The document		and Lossy Networks) is used to establish routing. The document
	enumerates the cases where RFC 6553, RFC 6554 and IPv6-in-IPv6		enumerates the cases where RFC 6553, RFC 6554 and IPv6-in-IPv6
	encapsulation is required. This analysis provides the basis on which		encapsulation is required. This analysis provides the basis on which
	to design efficient compression of these headers.		to design efficient compression of these headers.
	skipping to change at page 1, line 38 ¶		skipping to change at page 1, line 38 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at http://datatracker.ietf.org/drafts/current/.		Drafts is at http://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on October 7, 2017.		This Internet-Draft will expire on December 31, 2017.
	Copyright Notice		Copyright Notice
	Copyright (c) 2017 IETF Trust and the persons identified as the		Copyright (c) 2017 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(http://trustee.ietf.org/license-info) in effect on the date of		(http://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Terminology and Requirements Language . . . . . . . . . . . . 3		2. Terminology and Requirements Language . . . . . . . . . . . . 4
	2.1. hop-by-hop IPv6-in-IPv6 headers . . . . . . . . . . . . . 4		2.1. hop-by-hop IPv6-in-IPv6 headers . . . . . . . . . . . . . 4
	3. Sample/reference topology . . . . . . . . . . . . . . . . . . 4		3. Updates to RFC6553 and RFC 6550 . . . . . . . . . . . . . . . 5
	4. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 7		3.1. Updates to RFC 6553 . . . . . . . . . . . . . . . . . . . 5
	5. Storing mode . . . . . . . . . . . . . . . . . . . . . . . . 9		3.2. Updates to RFC 6550 . . . . . . . . . . . . . . . . . . . 6
	5.1. Example of Flow from RPL-aware-leaf to root . . . . . . . 10		4. Sample/reference topology . . . . . . . . . . . . . . . . . . 6
	5.2. Example of Flow from root to RPL-aware-leaf . . . . . . . 11		5. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 9
	5.3. Example of Flow from root to not-RPL-aware-leaf . . . . . 12		6. Storing mode . . . . . . . . . . . . . . . . . . . . . . . . 11
	5.4. Example of Flow from not-RPL-aware-leaf to root . . . . . 12		6.1. Storing Mode: Interaction between Leaf and Root . . . . . 12
	5.5. Example of Flow from RPL-aware-leaf to Internet . . . . . 13		6.1.1. SM: Example of Flow from RPL-aware-leaf to root . . . 13
	5.6. Example of Flow from Internet to RPL-aware-leaf . . . . . 14		6.1.2. SM: Example of Flow from root to RPL-aware-leaf . . . 14
	5.7. Example of Flow from not-RPL-aware-leaf to Internet . . . 14		6.1.3. SM: Example of Flow from root to not-RPL-aware-leaf . 14
	5.8. Example of Flow from Internet to non-RPL-aware-leaf . . . 15		6.1.4. SM: Example of Flow from not-RPL-aware-leaf to root . 15
	5.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf . . 16		6.2. Storing Mode: Interaction between Leaf and Internet . . . 16
	5.10. Example of Flow from RPL-aware-leaf to non-RPL-aware-leaf 17		6.2.1. SM: Example of Flow from RPL-aware-leaf to Internet . 16
	5.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf 18		6.2.2. SM: Example of Flow from Internet to RPL-aware-leaf . 17
	5.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-		6.2.3. SM: Example of Flow from not-RPL-aware-leaf to
	leaf . . . . . . . . . . . . . . . . . . . . . . . . . . 19		Internet . . . . . . . . . . . . . . . . . . . . . . 18
	6. Non Storing mode . . . . . . . . . . . . . . . . . . . . . . 20		6.2.4. SM: Example of Flow from Internet to non-RPL-aware-
	6.1. Example of Flow from RPL-aware-leaf to root . . . . . . . 21		leaf . . . . . . . . . . . . . . . . . . . . . . . . 19
	6.2. Example of Flow from root to RPL-aware-leaf . . . . . . . 22		6.3. Storing Mode: Interaction between Leaf and Leaf . . . . . 20
	6.3. Example of Flow from root to not-RPL-aware-leaf . . . . . 22		6.3.1. SM: Example of Flow from RPL-aware-leaf to RPL-aware-
	6.4. Example of Flow from not-RPL-aware-leaf to root . . . . . 23		leaf . . . . . . . . . . . . . . . . . . . . . . . . 20
	6.5. Example of Flow from RPL-aware-leaf to Internet . . . . . 24		6.3.2. SM: Example of Flow from RPL-aware-leaf to non-RPL-
	6.6. Example of Flow from Internet to RPL-aware-leaf . . . . . 25		aware-leaf . . . . . . . . . . . . . . . . . . . . . 21
	6.7. Example of Flow from not-RPL-aware-leaf to Internet . . . 25		6.3.3. SM: Example of Flow from not-RPL-aware-leaf to RPL-
	6.8. Example of Flow from Internet to not-RPL-aware-leaf . . . 26		aware-leaf . . . . . . . . . . . . . . . . . . . . . 22
	6.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf . . 27		6.3.4. SM: Example of Flow from not-RPL-aware-leaf to not-
	6.10. Example of Flow from RPL-aware-leaf to not-RPL-aware-leaf 28		RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 23
	6.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf 29		7. Non Storing mode . . . . . . . . . . . . . . . . . . . . . . 25
	6.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-		7.1. Non-Storing Mode: Interaction between Leaf and Root . . . 26
	leaf . . . . . . . . . . . . . . . . . . . . . . . . . . 30		7.1.1. Non-SM: Example of Flow from RPL-aware-leaf to root . 27
	7. Observations about the cases . . . . . . . . . . . . . . . . 31		7.1.2. on-SM: Example of Flow from root to RPL-aware-leaf . 27
	7.1. Storing mode . . . . . . . . . . . . . . . . . . . . . . 31		7.1.3. Non-SM: Example of Flow from root to not-RPL-aware-
	7.2. Non-Storing mode . . . . . . . . . . . . . . . . . . . . 32		leaf . . . . . . . . . . . . . . . . . . . . . . . . 28
	8. 6LoRH Compression cases . . . . . . . . . . . . . . . . . . . 32		7.1.4. Non-SM: Example of Flow from not-RPL-aware-leaf to
	9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 32		root . . . . . . . . . . . . . . . . . . . . . . . . 29
	10. Security Considerations . . . . . . . . . . . . . . . . . . . 32		7.2. Non-Storing Mode: Interaction between Leaf and Internet . 30
	11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 35		7.2.1. Non-SM: Example of Flow from RPL-aware-leaf to
	12. References . . . . . . . . . . . . . . . . . . . . . . . . . 35		Internet . . . . . . . . . . . . . . . . . . . . . . 30
	12.1. Normative References . . . . . . . . . . . . . . . . . . 35
	12.2. Informative References . . . . . . . . . . . . . . . . . 36		7.2.2. Non-SM: Example of Flow from Internet to RPL-aware-
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 38		leaf . . . . . . . . . . . . . . . . . . . . . . . . 31
			7.2.3. Non-SM: Example of Flow from not-RPL-aware-leaf to
			Internet . . . . . . . . . . . . . . . . . . . . . . 32
			7.2.4. Non-SM: Example of Flow from Internet to not-RPL-
			aware-leaf . . . . . . . . . . . . . . . . . . . . . 33
			7.3. Non-Storing Mode: Interaction between Leafs . . . . . . . 34
			7.3.1. Non-SM: Example of Flow from RPL-aware-leaf to RPL-
			aware-leaf . . . . . . . . . . . . . . . . . . . . . 34
			7.3.2. Non-SM: Example of Flow from RPL-aware-leaf to not-
			RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 36
			7.3.3. Non-SM: Example of Flow from not-RPL-aware-leaf to
			RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 37
			7.3.4. Non-SM: Example of Flow from not-RPL-aware-leaf to
			not-RPL-aware-leaf . . . . . . . . . . . . . . . . . 38
			8. Observations about the cases . . . . . . . . . . . . . . . . 39
			8.1. Storing mode . . . . . . . . . . . . . . . . . . . . . . 39
			8.2. Non-Storing mode . . . . . . . . . . . . . . . . . . . . 40
			9. 6LoRH Compression cases . . . . . . . . . . . . . . . . . . . 40
			10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 40
			11. Security Considerations . . . . . . . . . . . . . . . . . . . 40
			12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 43
			13. References . . . . . . . . . . . . . . . . . . . . . . . . . 43
			13.1. Normative References . . . . . . . . . . . . . . . . . . 43
			13.2. Informative References . . . . . . . . . . . . . . . . . 44
			Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 46
	1. Introduction		1. Introduction
	RPL (IPv6 Routing Protocol for Low-Power and Lossy Networks)		RPL (IPv6 Routing Protocol for Low-Power and Lossy Networks)
	[RFC6550] is a routing protocol for constrained networks. RFC 6553		[RFC6550] is a routing protocol for constrained networks. RFC 6553
	[RFC6553] defines the "RPL option" (RPI), carried within the IPv6		[RFC6553] defines the "RPL option" (RPI), carried within the IPv6
	Hop-by-Hop header to quickly identify inconsistencies (loops) in the		Hop-by-Hop header to quickly identify inconsistencies (loops) in the
	routing topology. RFC 6554 [RFC6554] defines the "RPL Source Route		routing topology. RFC 6554 [RFC6554] defines the "RPL Source Route
	Header" (RH3), an IPv6 Extension Header to deliver datagrams within a		Header" (RH3), an IPv6 Extension Header to deliver datagrams within a
	RPL routing domain, particularly in non-storing mode.		RPL routing domain, particularly in non-storing mode.
	skipping to change at page 3, line 31 ¶		skipping to change at page 4, line 7 ¶
	traffic at all which is mostly hop-by-hop traffic (one exception		traffic at all which is mostly hop-by-hop traffic (one exception
	being DAO messages in non-storing mode).		being DAO messages in non-storing mode).
	It has become clear from attempts to do multi-vendor		It has become clear from attempts to do multi-vendor
	interoperability, and from a desire to compress as many of the above		interoperability, and from a desire to compress as many of the above
	artifacts as possible that not all implementors agree when artifacts		artifacts as possible that not all implementors agree when artifacts
	are necessary, or when they can be safely omitted, or removed.		are necessary, or when they can be safely omitted, or removed.
	An interim meeting went through the 24 cases defined here to discover		An interim meeting went through the 24 cases defined here to discover
	if there were any shortcuts, and this document is the result of that		if there were any shortcuts, and this document is the result of that
	discussion. This document should not be defining anything new, but		discussion. This document clarify what is correct and incorrect
	it may clarify what is correct and incorrect behaviour.		behaviour.
	The related document A Routing Header Dispatch for 6LoWPAN (6LoRH)		The related document A Routing Header Dispatch for 6LoWPAN (6LoRH)
	[I-D.ietf-roll-routing-dispatch] defines a method to compress RPL		[I-D.ietf-roll-routing-dispatch] defines a method to compress RPL
	Option information and Routing Header type 3 [RFC6554], an efficient		Option information and Routing Header type 3 [RFC6554], an efficient
	IP-in-IP technique, and use cases proposed for the		IP-in-IP technique, and use cases proposed for the
	[Second6TischPlugtest] involving 6loRH.		[Second6TischPlugtest] involving 6loRH.
	The related document updates [RFC6550]. In general, any packet that
	leaves the RPL domain of an LLN (or leaves the LLN entirely) will NOT
	be discarded, when it has the [RFC6553] RPL Option Header known as
	the RPI or [RFC6554] SRH3 Extension Header (S)RH3. Due to changes to
	[I-D.ietf-6man-rfc2460bis] the RPI Hop-by-Hop option MAY be left in
	place even if the end host does not understand it.
	2. Terminology and Requirements Language		2. Terminology and Requirements Language
	The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",		The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
	"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this		"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
	document are to be interpreted as described in RFC 2119 [RFC2119].		document are to be interpreted as described in RFC 2119 [RFC2119].
	Terminology defined in [RFC7102] applies to this document: LBR, LLN,		Terminology defined in [RFC7102] applies to this document: LBR, LLN,
	RPL, RPL Domain and ROLL.		RPL, RPL Domain and ROLL.
	RPL-node: It is device which implements RPL, thus we can say that the		RPL-node: It is device which implements RPL, thus we can say that the
	device is RPL-capable or RPL-aware. Please note that the device can		device is RPL-capable or RPL-aware. Please note that the device can
	be found inside the LLN or outside LLN. In this document a RPL-node		be found inside the LLN or outside LLN. In this document a RPL-node
	which is a leaf of a DODAG is called RPL-aware-leaf.		which is a leaf of a DODAG is called RPL-aware-leaf.
	RPL-not-capable: It is device which do not implement RPL, thus we can		RPL-not-capable: It is device which do not implement RPL, thus we can
	say that the device is not-RPL-aware. Please note that the device		say that the device is not-RPL-aware. Please note that the device
	can be found inside the LLN. In this document a not-RPL-node which		can be found inside the LLN. In this document a not-RPL-aware node
	is a leaf of a DODAG is called not-RPL-aware-leaf.		which is a leaf of a DODAG is called not-RPL-aware-leaf.
	pledge: a new device which seeks admission to a network. (from		pledge: a new device which seeks admission to a network. (from
	[I-D.ietf-anima-bootstrapping-keyinfra])		[I-D.ietf-anima-bootstrapping-keyinfra])
	Join Registrar and Coordinator (JRC): a device which brings new nodes		Join Registrar and Coordinator (JRC): a device which brings new nodes
	(pledges) into a network. (from		(pledges) into a network. (from
	[I-D.ietf-anima-bootstrapping-keyinfra])		[I-D.ietf-anima-bootstrapping-keyinfra])
			Flag day: A "flag day" is a procedure in which the network, or a part
			of it, is changed during a planned outage, or suddenly, causing an
			outage while the network recovers [RFC4192]
	2.1. hop-by-hop IPv6-in-IPv6 headers		2.1. hop-by-hop IPv6-in-IPv6 headers
	The term "hop-by-hop IPv6-in-IPv6" header refers to: adding a header		The term "hop-by-hop IPv6-in-IPv6" header refers to: adding a header
	that originates from a node to an adjacent node, using the addresses		that originates from a node to an adjacent node, using the addresses
	(usually the GUA or ULA, but could use the link-local addresses) of		(usually the GUA or ULA, but could use the link-local addresses) of
	each node. If the packet must traverse multiple hops, then it must		each node. If the packet must traverse multiple hops, then it must
	be decapsulated at each hop, and then re-encapsulated again in a		be decapsulated at each hop, and then re-encapsulated again in a
	similar fashion.		similar fashion.
	3. Sample/reference topology		3. Updates to RFC6553 and RFC 6550
			3.1. Updates to RFC 6553
			[RFC6553] states that in the Option Type field of the RPL Option
			header, the two high order bits MUST be set to '01' and the third bit
			is equal to '1'. The first two bits indicate that the IPv6 node MUST
			discard the packet if it doesn't recognize the option type, and the
			third bit indicates that the Option Data may change en route. The
			remaining bits serve as the option type.
			Recent changes in [I-D.ietf-6man-rfc2460bis], state: "it is now
			expected that nodes along a packet's delivery path only examine and
			process the Hop-by-Hop Options header if explicitly configured to do
			so". That means that nodes that do not understand a particular Hop-
			by-Hop Option in a received packet are unlikely to be configured to
			process it.
			Thus, if an IPv6 node (RPL-not-capable) receives a packet with an RPL
			Option, it should ignore the HBH option. To further solidify the
			desire for the RPL options to be ignored, this document updates the
			Option Type field to: the two high order bits MUST be set to '00' and
			the third bit is equal to '1'.
			These two high order bits indicate that the IPv6 node MUST skip over
			this option and continue processing the header if it doesn't
			recognize the option type.
			The third bit continues to be set to indicate that the Option Data
			may change en route. The remaining bits serve as the option type and
			remain as 0x3. This an update to [RFC6553].
			This change creates a flag day for existing networks which are
			currently using 0x63 as the RPI value. A move to 0x43 will not be
			understood by those networks. It is suggested that implementations
			accept both 0x63 and 0x43 when processing. When forwarding packets,
			implementations SHOULD use the same value as we received. When
			originating new packets, implementations SHOULD have an option to
			determine which value to originate with, this option is controlled by
			the DAO option described below.
			A network which is switching from straight 6lowpan compression
			mechanism to those described in [I-D.ietf-roll-routing-dispatch] will
			experience a flag day in the data compression anyway, and if possible
			this change can be deployed at the same time.
			In general, any packet that leaves the RPL domain of an LLN (or
			leaves the LLN entirely) will NOT be discarded, when it has the
			[RFC6553] RPL Option Header known as the RPI or [RFC6554] SRH3
			Extension Header (S)RH3. Because of [I-D.ietf-6man-rfc2460bis] the
			RPI Hop-by-Hop option MAY be left in place even if the end host does
			not understand it.
			3.2. Updates to RFC 6550
			In order to avoid a flag day caused by lack of interoperation between
			new RPI (0x43) and old RPI (0x63) nodes, the new nodes need to be
			told that there are old RPI nodes present. This can be done via a
			new DIO Option which will propogate through the network. Failure to
			receive this flag will cause dual mode nodes to originate traffic
			with the old-RPI (0x63) value.
			DIO Option: 0x05 RPI 0x43 enable MCRXXX
			Flags: 8-bit unused field reserved for flags. The field MUST be
			initialized to zero by the sender and MUST be ignored by the
			receiver.
			We propose to use a bit flag as follows:
			+----+----+----+----+----+----+----+----+
			| | | | | | | | |
			| | | | | | | | FR |
			| | | | | | | | |
			+----+----+----+----+----+----+----+----+
			Figure 1: A DIO Flag to indicate the RPI-flag-day.
			FR(RPI-flag-day): the flag with values of 1 indicates that RPL Option
			field is set to "00", values of 0 indicates that RPL Option field is
			set to "01"
			4. Sample/reference topology
	A RPL network is composed of a 6LBR (6LoWPAN Border Router), Backbone		A RPL network is composed of a 6LBR (6LoWPAN Border Router), Backbone
	Router (6BBR), 6LR (6LoWPAN Router) and 6LN (6LoWPAN Node) as leaf		Router (6BBR), 6LR (6LoWPAN Router) and 6LN (6LoWPAN Node) as leaf
	logically organized in a DODAG structure (Destination Oriented		logically organized in a DODAG structure. (Destination Oriented
	Directed Acyclic Graph).		Directed Acyclic Graph).
	RPL defines the RPL Control messages (control plane), a new ICMPv6		RPL defines the RPL Control messages (control plane), a new ICMPv6
	[RFC4443] message with Type 155. DIS (DODAG Information		[RFC4443] message with Type 155. DIS (DODAG Information
	Solicitation), DIO (DODAG Information Object) and DAO (Destination		Solicitation), DIO (DODAG Information Object) and DAO (Destination
	Advertisement Object) messages are all RPL Control messages but with		Advertisement Object) messages are all RPL Control messages but with
	different Code values. A RPL Stack is showed in Figure 1.		different Code values. A RPL Stack is showed in Figure 1.
	RPL supports two modes of Downward traffic: in storing mode (RPL-SM),		RPL supports two modes of Downward traffic: in storing mode (RPL-SM),
	it is fully stateful or an in non-storing (RPL-NSM), it is fully		it is fully stateful or an in non-storing (RPL-NSM), it is fully
	skipping to change at page 5, line 25 ¶		skipping to change at page 7, line 38 ¶
	| IPv6 |		| IPv6 |
	| |		| |
	+--------------+		+--------------+
	| 6LoWPAN |		| 6LoWPAN |
	| |		| |
	+--------------+		+--------------+
	| PHY-MAC |		| PHY-MAC |
	| |		| |
	+--------------+		+--------------+
	Figure 1: RPL Stack.		Figure 2: RPL Stack.
	+---------+		+------------+
	+---+Internet |		| INTERNET ----------+
	| +---------+		| | |
	|		+------------+ |
	+----+--+		|
	| DODAG | node:01		|
	+---------+ Root +----------+		|
	| | 6LBR | |		A |
	| +----+--+ |		+-------+
	| | |		|6LBR |
	| | |		+-----------|(root) |-------+
	... ... ...		| +-------+ |
	| | |		| |
	+-----+-+ +--+---+ +--+---+		| |
	|6LR | | | | |		| |
	+-----+ | | | | |		| |
	| | 11 | | 12 | | 13 +------+		| B |C
	| +-----+-+ +-+----+ +-+----+ |		+---|---+ +---|---+
	| | | | |		| 6LR | | 6LR |
	| | | | |		+-------->| |--+ +--- ---+
	| 21 | 22 | 23 | 24 | 25		| +-------+ | | +-------+ |
	+-+---+ +-+---+ +--+--+ +- --+ +---+-+		| | | |
	|Leaf | | | | | |Leaf| |Leaf |		| | | |
	| 6LN | | | | | | 6LN| | 6LN |		| | | |
	+-----+ +-----+ +-----+ +----+ +-----+		| | | |
			| D | E | |
			+-|-----+ +---|---+ | |
			| 6LR | | 6LR | | |
			| | +------ | | |
			+---|---+ | +---|---+ | |
			| | | | |
			| | +--+ | |
			| | | | |
			| | | | |
			| | | I | J |
			F | | G | H | |
			+-----+-+ +-|-----+ +---|--+ +---|---+ +---|---+
			| Raf | | ~Raf | | Raf | | Raf | | ~Raf |
			| 6LN | | 6LN | | 6LN | | 6LN | | 6LN |
			+-------+ +-------+ +------+ +-------+ +-------+
	Figure 2: A reference RPL Topology.		Figure 3: A reference RPL Topology.
	Figure 2 shows the reference RPL Topology for this document. The		Figure 2 shows the reference RPL Topology for this document. The
	numbers in or above the nodes are there so that they may be		letters above the nodes are there so that they may be referenced in
	referenced in subsequent sections. In the figure, a 6LN can be a		subsequent sections. In the figure, a 6LR is a router. A 6LN can be
	router or a host. The 6LN leafs marked as (21) is a RPL host that		a router or a host. The 6LN leaves (Raf - "RPL aware leaf"-) marked
	does not have forwarding capability and (25) is a RPL router. The		as (F and I) are RPL hosts that does not have forwarding capability.
	leaf marked 6LN (24) is a device which does not speak RPL at all		The 6LN leaf (H) is a RPL router. The leafs marked as ~Raf "not-RPL
	(not-RPL-aware), but uses Router-Advertisements, 6LowPAN DAR/DAC and		aware leaf" (G and J) are devices which do not speak RPL at all (not-
			RPL-aware), but uses Router-Advertisements, 6LowPAN DAR/DAC and
	efficient-ND only to participate in the network [RFC6775]. In the		efficient-ND only to participate in the network [RFC6775]. In the
	document this leaf (24) is often named IPv6 node. The 6LBR in the		document these leafs (G and J) are often named IPv6 node. The 6LBR
	figure is the root of the Global DODAG.		in the figure is the root of the Global DODAG.
	This document is in part motivated by the work that is ongoing at the
	6TiSCH working group. The 6TiSCH architecture
	[I-D.ietf-6tisch-architecture] draft explains the network
	architecture of a 6TiSCH network.
	4. Use cases		5. Use cases
	In data plane context a combination of RFC6553, RFC6554 and IPv6-in-		In the data plane a combination of RFC6553, RFC6554 and IPv6-in-IPv6
	IPv6 encapsulation is going to be analyzed for the following traffic		encapsulation is going to be analyzed for a number of representative
	flows.		traffic flows.
	This version of the document assumes the changes in		While this document assumes the HbH changes in
	[I-D.ietf-6man-rfc2460bis] are passed (at the time to write this		[I-D.ietf-6man-rfc2460bis] proceed, and/or that the LLN is using the
	specification, the draft is on version 05).		no-drop RPI option (0x43).
	The uses cases describe the communication between RPL-aware-nodes,		The uses cases describe the communication between RPL-aware-nodes,
	with the root (6LBR), and with Internet. This document also describe		with the root (6LBR), and with Internet. This document also describe
	the communication between nodes acting as leaf that does not		the communication between nodes acting as leaf that does not
	understand RPL and they are part of hte LLN. We name these nodes as		understand RPL and they are part of hte LLN. We name these nodes as
	not-RPL-aware-leaf.(e.g. section 5.4- Flow from not-RPL-aware-leaf to		not-RPL-aware-leaf.(e.g. section 5.4- Flow from not-RPL-aware-leaf to
	root) We describe also how is the communication inside of the LLN		root) We describe also how is the communication inside of the LLN
	when it has the final destination addressed outside of the LLN e.g.		when it has the final destination addressed outside of the LLN e.g.
	with destination to Internet. (e.g. section 5.7- Flow from not-RPL-		with destination to Internet. (e.g. section 5.7- Flow from not-RPL-
	aware-leaf to Internet)		aware-leaf to Internet)
	The uses cases comprise as follow:		The uses cases comprise as follow:
			Interaction between Leaf and Root:
	RPL-aware-leaf to root		RPL-aware-leaf to root
	root to RPL-aware-leaf		root to RPL-aware-leaf
	not-RPL-aware-leaf to root		not-RPL-aware-leaf to root
	root to not-RPL-aware-leaf		root to not-RPL-aware-leaf
			Interaction between Leaf and Internet:
	RPL-aware-leaf to Internet		RPL-aware-leaf to Internet
	Internet to RPL-aware-leaf		Internet to RPL-aware-leaf
	not-RPL-aware-leaf to Internet		not-RPL-aware-leaf to Internet
	Internet to not-RPL-aware-leaf		Internet to not-RPL-aware-leaf
			Interaction between Leafs:
	RPL-aware-leaf to RPL-aware-leaf (storing and non-storing)		RPL-aware-leaf to RPL-aware-leaf (storing and non-storing)
	RPL-aware-leaf to not-RPL-aware-leaf (non-storing)		RPL-aware-leaf to not-RPL-aware-leaf (non-storing)
	not-RPL-aware-leaf to RPL-aware-leaf (storing and non-storing)		not-RPL-aware-leaf to RPL-aware-leaf (storing and non-storing)
	not-RPL-aware-leaf to not-RPL-aware-leaf (non-storing)		not-RPL-aware-leaf to not-RPL-aware-leaf (non-storing)
	This document assumes the rule that a Header cannot be inserted or		This document assumes the rule that a Header cannot be inserted or
	removed on the fly inside an IPv6 packet that is being routed. This		removed on the fly inside an IPv6 packet that is being routed. This
	skipping to change at page 9, line 15 ¶		skipping to change at page 11, line 29 ¶
	where the instanceID portion of the RPI header may still be needed to		where the instanceID portion of the RPI header may still be needed to
	pick an appropriate priority or channel at each hop.		pick an appropriate priority or channel at each hop.
	In the tables present in this document, the term "RPL aware leaf" is		In the tables present in this document, the term "RPL aware leaf" is
	has been shortened to "Raf", and "not-RPL aware leaf" has been		has been shortened to "Raf", and "not-RPL aware leaf" has been
	shortened to "~Raf" to make the table fit in available space.		shortened to "~Raf" to make the table fit in available space.
	The earlier examples are more extensive to make sure that the process		The earlier examples are more extensive to make sure that the process
	is clear, while later examples are more concise.		is clear, while later examples are more concise.
	5. Storing mode		6. Storing mode
	In storing mode (fully stateful), the sender cannot determine whether		In storing mode (fully stateful), the sender cannot determine whether
	the destination is RPL-capable and thus would need an IP-in-IP		the destination is RPL-capable and thus would need an IP-in-IP
	header. The IP-in-IP header needs to be addressed on a hop-by-hop		header. The IP-in-IP header needs to be addressed on a hop-by-hop
	basis so that the last 6LR can remove the RPI header. Additionally,		basis so that the last 6LR can remove the RPI header. Additionally,
	The sender can determine if the destination is inside the LLN by		The sender can determine if the destination is inside the LLN by
	looking if the destination address is matched by the DIO's PIO		looking if the destination address is matched by the DIO's PIO
	option.		option.
	The following table summarizes what headers are needed in the		The following table summarizes what headers are needed in the
	following scenarios, and indicates when the IP-in-IP header must be		following scenarios, and indicates when the IP-in-IP header must be
	inserted on a hop-by-hop basis, and when it can target the		inserted on a hop-by-hop basis, and when it can target the
	destination node directly. There are these possible situations: hop-		destination node directly. There are these possible situations: hop-
	by-hop necessary (indicated by "hop"), or destination address		by-hop necessary (indicated by "hop"), or destination address
	possible (indicated by "dst"). In all cases hop by hop can be used.		possible (indicated by "dst"). In all cases hop by hop can be used.
	In cases where no IP-in-IP header is needed, the column is left		In cases where no IP-in-IP header is needed, the column is left
	blank.		blank.
	In all cases the RPI headers are needed, since it identifies		In all cases the RPI headers are needed, since it identifies
	inconsistencies (loops) in the routing topology. In all cases the		inconsistencies (loops) in the routing topology. In all cases the
	RH3 is not need because we do not indicate the route in stroing mode.		RH3 is not need because we do not indicate the route in storing mode.
	The leaf can be a router 6LR or a host, both indicated as 6LN		The leaf can be a router 6LR or a host, both indicated as 6LN
	(Figure 2).		(Figure 2).
	+--------------+-----------+---------------+		+---------------------+--------------+----------+--------------+
	| Use Case | IP-in-IP | IP-in-IP dst |		| Interaction between | Use Case | IP-in-IP | IP-in-IP dst |
	+--------------+-----------+---------------+		+---------------------+--------------+----------+--------------+
	| Raf to root | No | -- |		| | Raf to root | No | -- |
	| root to Raf | No | -- |		+ +--------------+----------+--------------+
	| root to ~Raf | No | -- |		| Leaf - Root | root to Raf | No | -- |
	| ~Raf to root | Yes | root |		+ +--------------+----------+--------------+
	| Raf to Int | No | -- |		| | root to ~Raf | No | -- |
	| Int to Raf | Yes | raf |		+ +--------------+----------+--------------+
	| ~Raf to Int | root | raf |		| | ~Raf to root | Yes | root |
	| ~Raf to Int | Yes | root |		+---------------------+--------------+----------+--------------+
	| Int to ~Raf | Yes | hop |		| | Raf to Int | No | -- |
	| Raf to Raf | No | -- |		+ +--------------+----------+--------------+
	| Raf to ~Raf | No | -- |		| Leaf - Internet | Int to Raf | Yes | Raf |
	| ~Raf to Raf | Yes | dst |		+ +--------------+----------+--------------+
	| ~Raf to ~Raf | Yes | hop |		| | ~Raf to Int | Yes | root |
	+--------------+-----------+---------------+		+ +--------------+----------+--------------+
			| | Int to ~Raf | Yes | hop |
			+---------------------+--------------+----------+--------------+
			| | Raf to Raf | No | -- |
			+ +--------------+----------+--------------+
			| | Raf to ~Raf | No | -- |
			+ Leaf - Leaf +--------------+----------+--------------+
			| | ~Raf to Raf | Yes | dst |
			+ +--------------+----------+--------------+
			| | ~Raf to ~Raf | Yes | hop |
			+---------------------+--------------+----------+--------------+
	Table 1: IP-in-IP encapsulation in Storing mode		Figure 4: IP-in-IP encapsulation in Storing mode.
	5.1. Example of Flow from RPL-aware-leaf to root		6.1. Storing Mode: Interaction between Leaf and Root
			In this section we are going to describe the communication flow in
			storing mode (SM) between,
			RPL-aware-leaf to root
			root to RPL-aware-leaf
			not-RPL-aware-leaf to root
			root to not-RPL-aware-leaf
			6.1.1. SM: Example of Flow from RPL-aware-leaf to root
	In storing mode, RFC 6553 (RPI) is used to send RPL Information		In storing mode, RFC 6553 (RPI) is used to send RPL Information
	instanceID and rank information.		instanceID and rank information.
	As stated in Section 16.2 of [RFC6550] a RPL-aware-leaf node does		As stated in Section 16.2 of [RFC6550] a RPL-aware-leaf node does
	not generally issue DIO messages; a leaf node accepts DIO messages		not generally issue DIO messages; a leaf node accepts DIO messages
	from upstream. (When the inconsistency in routing occurs, a leaf		from upstream. (When the inconsistency in routing occurs, a leaf
	node will generate a DIO with an infinite rank, to fix it). It may		node will generate a DIO with an infinite rank, to fix it). It may
	issue DAO and DIS messages though it generally ignores DAO and DIS		issue DAO and DIS messages though it generally ignores DAO and DIS
	messages.		messages.
	In this case the flow comprises:		In this case the flow comprises:
	RPL-aware-leaf (6LN) --> 6LR_i --> root(6LBR)		RPL-aware-leaf (6LN) --> 6LR_i --> root(6LBR)
	6LR_i are the intermediate routers from source to destination. In		For example, the communication flow would be: Node F --> Node E -->
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		Node B --> Node A root(6LBR)
	packet go through from source (6LN) to destination (6LBR).
			6LR_i (Node E and Node B) are the intermediate routers from source to
			destination. In this case, "1 <= i >= n", n is the number of routers
			(6LR) that the packet go through from source (6LN) to destination
			(6LBR).
	As it was mentioned In this document 6LRs, 6LBR are always full-		As it was mentioned In this document 6LRs, 6LBR are always full-
	fledge RPL routers.		fledge RPL routers.
	The 6LN inserts the RPI header, and sends the packet to 6LR which		The 6LN (Node F) inserts the RPI header, and sends the packet to 6LR
	decrements the rank in RPI and sends the packet up. When the packet		(Node E) which decrements the rank in RPI and sends the packet up.
	arrives at 6LBR, the RPI is removed and the packet is processed.		When the packet arrives at 6LBR (Node A), the RPI is removed and the
			packet is processed.
	No IP-in-IP header is required.		No IP-in-IP header is required.
	The RPI header can be removed by the 6LBR because the packet is		The RPI header can be removed by the 6LBR because the packet is
	addressed to the 6LBR. The 6LN must know that it is communicating		addressed to the 6LBR. The 6LN must know that it is communicating
	with the 6LBR to make use of this scenario. The 6LN can know the		with the 6LBR to make use of this scenario. The 6LN can know the
	address of the 6LBR because it knows the address of the root via the		address of the 6LBR because it knows the address of the root via the
	DODAGID in the DIO messages.		DODAGID in the DIO messages.
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	skipping to change at page 11, line 23 ¶		skipping to change at page 14, line 17 ¶
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	| Inserted headers | RPI | -- | -- |		| Inserted headers | RPI | -- | -- |
	| Removed headers | -- | -- | RPI |		| Removed headers | -- | -- | RPI |
	| Re-added headers | -- | -- | -- |		| Re-added headers | -- | -- | -- |
	| Modified headers | -- | RPI | -- |		| Modified headers | -- | RPI | -- |
	| Untouched headers | -- | -- | -- |		| Untouched headers | -- | -- | -- |
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	Storing: Summary of the use of headers from RPL-aware-leaf to root		Storing: Summary of the use of headers from RPL-aware-leaf to root
	5.2. Example of Flow from root to RPL-aware-leaf		6.1.2. SM: Example of Flow from root to RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)		root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)
			For example, the communication flow would be: Node A root(6LBR) -->
			Node B --> Node D --> Node F
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LBR) to destination (6LN).		packet go through from source (6LBR) to destination (6LN).
	In this case the 6LBR inserts RPI header and sends the packet down,		In this case the 6LBR inserts RPI header and sends the packet down,
	the 6LR is going to increment the rank in RPI (examines instanceID		the 6LR is going to increment the rank in RPI (examines instanceID
	for multiple tables), the packet is processed in 6LN and RPI removed.		for multiple tables), the packet is processed in 6LN and RPI removed.
	No IP-in-IP header is required.		No IP-in-IP header is required.
	skipping to change at page 12, line 5 ¶		skipping to change at page 14, line 48 ¶
	+-------------------+------+-------+------+		+-------------------+------+-------+------+
	| Inserted headers | RPI | -- | -- |		| Inserted headers | RPI | -- | -- |
	| Removed headers | -- | -- | RPI |		| Removed headers | -- | -- | RPI |
	| Re-added headers | -- | -- | -- |		| Re-added headers | -- | -- | -- |
	| Modified headers | -- | RPI | -- |		| Modified headers | -- | RPI | -- |
	| Untouched headers | -- | -- | -- |		| Untouched headers | -- | -- | -- |
	+-------------------+------+-------+------+		+-------------------+------+-------+------+
	Storing: Summary of the use of headers from root to RPL-aware-leaf		Storing: Summary of the use of headers from root to RPL-aware-leaf
	5.3. Example of Flow from root to not-RPL-aware-leaf		6.1.3. SM: Example of Flow from root to not-RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)		root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)
			For example, the communication flow would be: Node A root(6LBR) -->
			Node B --> Node E --> Node G
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LBR) to destination (IPv6).		packet go through from source (6LBR) to destination (IPv6).
	As the RPI extension can be ignored by the not-RPL-aware leaf, this		As the RPI extension can be ignored by the not-RPL-aware leaf, this
	situation is identical to the previous scenario.		situation is identical to the previous scenario.
	+-------------------+------+-------+----------------+		+-------------------+------+-------+----------------+
	| Header | 6LBR | 6LR_i | IPv6 |		| Header | 6LBR | 6LR_i | IPv6 |
	skipping to change at page 12, line 31 ¶		skipping to change at page 15, line 27 ¶
	| Inserted headers | RPI | -- | -- |		| Inserted headers | RPI | -- | -- |
	| Removed headers | -- | -- | -- |		| Removed headers | -- | -- | -- |
	| Re-added headers | -- | -- | -- |		| Re-added headers | -- | -- | -- |
	| Modified headers | -- | RPI | -- |		| Modified headers | -- | RPI | -- |
	| Untouched headers | -- | -- | RPI (Ignored) |		| Untouched headers | -- | -- | RPI (Ignored) |
	+-------------------+------+-------+----------------+		+-------------------+------+-------+----------------+
	Storing: Summary of the use of headers from root to not-RPL-aware-		Storing: Summary of the use of headers from root to not-RPL-aware-
	leaf		leaf
	5.4. Example of Flow from not-RPL-aware-leaf to root		6.1.4. SM: Example of Flow from not-RPL-aware-leaf to root
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i --> root (6LBR)		not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i --> root (6LBR)
			For example, the communication flow would be: Node G --> Node E -->
			Node B --> Node A root(6LBR)
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 < i >= n", n is the number of routers (6LR) that the		this case, "1 < i >= n", n is the number of routers (6LR) that the
	packet go through from source (IPv6) to destination (6LBR). For		packet go through from source (IPv6) to destination (6LBR). For
	example, 6LR_1 (i=1) is the router that receives the packets from the		example, 6LR_1 (i=1) is the router that receives the packets from the
	IPv6 node.		IPv6 node (Node G).
	When the packet arrives from IPv6 node to 6LR_1, the 6LR_1 will		When the packet arrives from IPv6 node (Node G) to 6LR_1 (Node E),
	insert a RPI header, encapsuladed in a IPv6-in-IPv6 header. The		the 6LR_1 will insert a RPI header, encapsuladed in a IPv6-in-IPv6
	IPv6-in-IPv6 header can be addressed to the next hop, or to the root.		header. The IPv6-in-IPv6 header can be addressed to the next hop
	The root removes the header and processes the packet.		(Node B), or to the root (Node A). The root removes the header and
			processes the packet.
	+------------+------+---------------+---------------+---------------+		+------------+------+---------------+---------------+---------------+
	| Header | IPv6 | 6LR_1 | 6LR_i | 6LBR |		| Header | IPv6 | 6LR_1 | 6LR_i | 6LBR |
	+------------+------+---------------+---------------+---------------+		+------------+------+---------------+---------------+---------------+
	| Inserted | -- | IP-in-IP(RPI) | -- | -- |		| Inserted | -- | IP-in-IP(RPI) | -- | -- |
	| headers | | | | |		| headers | | | | |
	| Removed | -- | -- | -- | IP-in-IP(RPI) |		| Removed | -- | -- | -- | IP-in-IP(RPI) |
	| headers | | | | |		| headers | | | | |
	| Re-added | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- |
	| headers | | | | |		| headers | | | | |
	| Modified | -- | -- | IP-in-IP(RPI) | -- |		| Modified | -- | -- | IP-in-IP(RPI) | -- |
	| headers | | | | |		| headers | | | | |
	| Untouched | -- | -- | -- | -- |		| Untouched | -- | -- | -- | -- |
	| headers | | | | |		| headers | | | | |
	+------------+------+---------------+---------------+---------------+		+------------+------+---------------+---------------+---------------+
	Storing: Summary of the use of headers from not-RPL-aware-leaf to		Storing: Summary of the use of headers from not-RPL-aware-leaf to
	root		root
	5.5. Example of Flow from RPL-aware-leaf to Internet		6.2. Storing Mode: Interaction between Leaf and Internet
			In this section we are going to describe the communication flow in
			storing mode (SM) between,
			RPL-aware-leaf to Internet
			Internet to RPL-aware-leaf
			not-RPL-aware-leaf to Internet
			Internet to not-RPL-aware-leaf
			6.2.1. SM: Example of Flow from RPL-aware-leaf to Internet
	RPL information from RFC 6553 MAY go out to Internet as it will be		RPL information from RFC 6553 MAY go out to Internet as it will be
	ignored by nodes which have not been configured to be RPI aware.		ignored by nodes which have not been configured to be RPI aware.
	In this case the flow comprises:		In this case the flow comprises:
	RPL-aware-leaf (6LN) --> 6LR_i --> root (6LBR) --> Internet		RPL-aware-leaf (6LN) --> 6LR_i --> root (6LBR) --> Internet
			For example, the communication flow could be: Node F --> Node D -->
			Node B --> Node A root(6LBR) --> Internet
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LN) to 6LBR.		packet go through from source (6LN) to 6LBR.
	No IP-in-IP header is required.		No IP-in-IP header is required.
	Note: In this use case we use a node as leaf, but this use case can		Note: In this use case we use a node as leaf, but this use case can
	be also applicable to any RPL-node type (e.g. 6LR)		be also applicable to any RPL-node type (e.g. 6LR)
	+-------------------+------+-------+------+----------------+		+-------------------+------+-------+------+----------------+
	skipping to change at page 14, line 5 ¶		skipping to change at page 17, line 21 ¶
	| Inserted headers | RPI | -- | -- | -- |		| Inserted headers | RPI | -- | -- | -- |
	| Removed headers | -- | -- | -- | -- |		| Removed headers | -- | -- | -- | -- |
	| Re-added headers | -- | -- | -- | -- |		| Re-added headers | -- | -- | -- | -- |
	| Modified headers | -- | RPI | -- | -- |		| Modified headers | -- | RPI | -- | -- |
	| Untouched headers | -- | -- | RPI | RPI (Ignored) |		| Untouched headers | -- | -- | RPI | RPI (Ignored) |
	+-------------------+------+-------+------+----------------+		+-------------------+------+-------+------+----------------+
	Storing: Summary of the use of headers from RPL-aware-leaf to		Storing: Summary of the use of headers from RPL-aware-leaf to
	Internet		Internet
	5.6. Example of Flow from Internet to RPL-aware-leaf		6.2.2. SM: Example of Flow from Internet to RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	Internet --> root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)		Internet --> root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)
			For example, the communication flow could be: Internet --> Node A
			root(6LBR) --> Node B --> Node D --> Node F
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from 6LBR to destination(6LN).		packet go through from 6LBR to destination(6LN).
	When the packet arrives from Internet to 6LBR the RPI header is added		When the packet arrives from Internet to 6LBR the RPI header is added
	in a outer IPv6-in-IPv6 header and sent to 6LR, which modifies the		in a outer IPv6-in-IPv6 header and sent to 6LR, which modifies the
	rank in the RPI. When the packet arrives at 6LN the RPI header is		rank in the RPI. When the packet arrives at 6LN the RPI header is
	removed and the packet processed.		removed and the packet processed.
	+----------+---------+--------------+---------------+---------------+		+----------+---------+--------------+---------------+---------------+
	skipping to change at page 14, line 40 ¶		skipping to change at page 18, line 25 ¶
	| Modified | -- | -- | IP-in-IP(RPI) | -- |		| Modified | -- | -- | IP-in-IP(RPI) | -- |
	| headers | | | | |		| headers | | | | |
	| Untouche | -- | -- | -- | -- |		| Untouche | -- | -- | -- | -- |
	| d | | | | |		| d | | | | |
	| headers | | | | |		| headers | | | | |
	+----------+---------+--------------+---------------+---------------+		+----------+---------+--------------+---------------+---------------+
	Storing: Summary of the use of headers from Internet to RPL-aware-		Storing: Summary of the use of headers from Internet to RPL-aware-
	leaf		leaf
	5.7. Example of Flow from not-RPL-aware-leaf to Internet		6.2.3. SM: Example of Flow from not-RPL-aware-leaf to Internet
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i -->root (6LBR) -->		not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i -->root (6LBR) -->
	Internet		Internet
			For example, the communication flow could be: Node G --> Node E -->
			Node B --> Node A root(6LBR) --> Internet
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 < i >= n", n is the number of routers (6LR) that the		this case, "1 < i >= n", n is the number of routers (6LR) that the
	packet go through from source(IPv6) to 6LBR.		packet go through from source(IPv6) to 6LBR.
	The 6LR_1 (i=1) node will add an IP-in-IP(RPI) header addressed		The 6LR_1 (i=1) node will add an IP-in-IP(RPI) header addressed
	either to the root, or hop-by-hop such that the root can remove the		either to the root, or hop-by-hop such that the root can remove the
	RPI header before passing upwards.		RPI header before passing upwards.
	The originating node will ideally leave the IPv6 flow label as zero		The originating node will ideally leave the IPv6 flow label as zero
	so that the packet can be better compressed through the LLN. The		so that the packet can be better compressed through the LLN. The
	skipping to change at page 15, line 37 ¶		skipping to change at page 19, line 28 ¶
	| d | | | IP(RPI) | | |		| d | | | IP(RPI) | | |
	| headers | | | | | |		| headers | | | | | |
	| Untouch | -- | -- | -- | -- | -- |		| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |		| ed | | | | | |
	| headers | | | | | |		| headers | | | | | |
	+---------+-----+-------------+-------------+-------------+---------+		+---------+-----+-------------+-------------+-------------+---------+
	Storing: Summary of the use of headers from not-RPL-aware-leaf to		Storing: Summary of the use of headers from not-RPL-aware-leaf to
	Internet		Internet
	5.8. Example of Flow from Internet to non-RPL-aware-leaf		6.2.4. SM: Example of Flow from Internet to non-RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	Internet --> root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)		Internet --> root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)
			For example, the communication flow could be: Internet --> Node A
			root(6LBR) --> Node B --> Node E --> Node G
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 < i >= n", n is the number of routers (6LR) that the		this case, "1 < i >= n", n is the number of routers (6LR) that the
	packet go through from 6LBR to not-RPL-aware-leaf (IPv6). 6LR_i		packet go through from 6LBR to not-RPL-aware-leaf (IPv6). 6LR_i
	updates the rank in the RPI.		updates the rank in the RPI.
	The 6LBR will have to add an RPI header within an IP-in-IP header.		The 6LBR will have to add an RPI header within an IP-in-IP header.
	The IP-in-IP can be addressed to the not-RPL-aware-leaf, leaving the		The IP-in-IP can be addressed to the not-RPL-aware-leaf, leaving the
	RPI inside.		RPI inside.
	The 6LBR MAY set the flow label on the inner IP-in-IP header to zero		The 6LBR MAY set the flow label on the inner IP-in-IP header to zero
	skipping to change at page 16, line 26 ¶		skipping to change at page 20, line 23 ¶
	| headers | | | | |		| headers | | | | |
	| Modified | -- | -- | IP-in-IP(RPI) | -- |		| Modified | -- | -- | IP-in-IP(RPI) | -- |
	| headers | | | | |		| headers | | | | |
	| Untouched | -- | -- | -- | RPI |		| Untouched | -- | -- | -- | RPI |
	| headers | | | | (Ignored) |		| headers | | | | (Ignored) |
	+-----------+----------+---------------+---------------+------------+		+-----------+----------+---------------+---------------+------------+
	Storing: Summary of the use of headers from Internet to non-RPL-		Storing: Summary of the use of headers from Internet to non-RPL-
	aware-leaf		aware-leaf
	5.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf		6.3. Storing Mode: Interaction between Leaf and Leaf
			In this section we are going to describe the communication flow in
			storing mode (SM) between,
			RPL-aware-leaf to RPL-aware-leaf
			RPL-aware-leaf to not-RPL-aware-leaf
			not-RPL-aware-leaf to RPL-aware-leaf
			not-RPL-aware-leaf to not-RPL-aware-leaf
			6.3.1. SM: Example of Flow from RPL-aware-leaf to RPL-aware-leaf
	In [RFC6550] RPL allows a simple one-hop optimization for both		In [RFC6550] RPL allows a simple one-hop optimization for both
	storing and non-storing networks. A node may send a packet destined		storing and non-storing networks. A node may send a packet destined
	to a one-hop neighbor directly to that node. Section 9 in [RFC6550].		to a one-hop neighbor directly to that node. Section 9 in [RFC6550].
	In this case the flow comprises:		In this case the flow comprises:
	6LN --> 6LR_ia --> common parent (6LR_x) --> 6LR_id --> 6LN		6LN --> 6LR_ia --> common parent (6LR_x) --> 6LR_id --> 6LN
	6LR_ia are the intermediate routers from source to the common parent		For example, the communication flow could be: Node F --> Node D -->
	(6LR_x) In this case, "1 <= ia >= n", n is the number of routers		Node B --> Node E --> Node H
	(6LR) that the packet go through from 6LN to the common parent
	(6LR_x).
	6LR_id are the intermediate routers from the common parent (6LR_x) to		6LR_ia (Node D) are the intermediate routers from source to the
	destination 6LN. In this case, "1 <= id >= m", m is the number of		common parent (6LR_x) (Node B) In this case, "1 <= ia >= n", n is the
	routers (6LR) that the packet go through from the common parent		number of routers (6LR) that the packet go through from 6LN (Node F)
	(6LR_x) to destination 6LN.		to the common parent (6LR_x).
	This case is assumed in the same RPL Domain. In the common parent,		6LR_id (Node E) are the intermediate routers from the common parent
	the direction of RPI is changed (from increasing to decreasing the		(6LR_x) (Node B) to destination 6LN (Node H). In this case, "1 <= id
	rank).		>= m", m is the number of routers (6LR) that the packet go through
			from the common parent (6LR_x) to destination 6LN.
			This case is assumed in the same RPL Domain. In the common parent
			(Node B), the direction of RPI is changed (from increasing to
			decreasing the rank).
	While the 6LR nodes will update the RPI, no node needs to add or		While the 6LR nodes will update the RPI, no node needs to add or
	remove the RPI, so no IP-in-IP headers are necessary. This may be		remove the RPI, so no IP-in-IP headers are necessary. This may be
	done regardless of where the destination is, as the included RPI will		done regardless of where the destination is, as the included RPI will
	be ignored by the receiver.		be ignored by the receiver.
	+---------------+--------+--------+---------------+--------+--------+		+---------------+--------+--------+---------------+--------+--------+
	| Header | 6LN | 6LR_ia | 6LR_x (common | 6LR_id | 6LN |		| Header | 6LN | 6LR_ia | 6LR_x (common | 6LR_id | 6LN |
	| | src | | parent) | | dst |		| | src | | parent) | | dst |
	+---------------+--------+--------+---------------+--------+--------+		+---------------+--------+--------+---------------+--------+--------+
	skipping to change at page 17, line 26 ¶		skipping to change at page 21, line 38 ¶
	| headers | | | | | |		| headers | | | | | |
	| Modified | -- | RPI | RPI | RPI | -- |		| Modified | -- | RPI | RPI | RPI | -- |
	| headers | | | | | |		| headers | | | | | |
	| Untouched | -- | -- | -- | -- | -- |		| Untouched | -- | -- | -- | -- | -- |
	| headers | | | | | |		| headers | | | | | |
	+---------------+--------+--------+---------------+--------+--------+		+---------------+--------+--------+---------------+--------+--------+
	Storing: Summary of the use of headers for RPL-aware-leaf to RPL-		Storing: Summary of the use of headers for RPL-aware-leaf to RPL-
	aware-leaf		aware-leaf
	5.10. Example of Flow from RPL-aware-leaf to non-RPL-aware-leaf		6.3.2. SM: Example of Flow from RPL-aware-leaf to non-RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	6LN --> 6LR_ia --> common parent (6LR_x) --> 6LR_id --> not-RPL-aware		6LN --> 6LR_ia --> common parent (6LR_x) --> 6LR_id --> not-RPL-aware
	6LN (IPv6)		6LN (IPv6)
			For example, the communication flow could be: Node F --> Node D -->
			Node B --> Node E --> Node G
	6LR_ia are the intermediate routers from source (6LN) to the common		6LR_ia are the intermediate routers from source (6LN) to the common
	parent (6LR_x) In this case, "1 <= ia >= n", n is the number of		parent (6LR_x) In this case, "1 <= ia >= n", n is the number of
	routers (6LR) that the packet go through from 6LN to the common		routers (6LR) that the packet go through from 6LN to the common
	parent (6LR_x).		parent (6LR_x).
	6LR_id are the intermediate routers from the common parent (6LR_x) to		6LR_id (Node E) are the intermediate routers from the common parent
	destination not-RPL-aware 6LN (IPv6). In this case, "1 <= id >= m",		(6LR_x) (Node B) to destination not-RPL-aware 6LN (IPv6) (Node G).
	m is the number of routers (6LR) that the packet go through from the		In this case, "1 <= id >= m", m is the number of routers (6LR) that
	common parent (6LR_x) to destination 6LN.		the packet go through from the common parent (6LR_x) to destination
			6LN.
			This situation is identical to the previous situation Section 6.3.1
	This situation is identical to the previous situation Section 5.9
	+-----------+------+--------+---------------+--------+--------------+		+-----------+------+--------+---------------+--------+--------------+
	| Header | 6LN | 6LR_ia | 6LR_x(common | 6LR_id | IPv6 |		| Header | 6LN | 6LR_ia | 6LR_x(common | 6LR_id | IPv6 |
	| | src | | parent) | | |		| | src | | parent) | | |
	+-----------+------+--------+---------------+--------+--------------+		+-----------+------+--------+---------------+--------+--------------+
	| Inserted | RPI | -- | -- | -- | -- |		| Inserted | RPI | -- | -- | -- | -- |
	| headers | | | | | |		| headers | | | | | |
	| Removed | -- | -- | -- | -- | RPI |		| Removed | -- | -- | -- | -- | RPI |
	| headers | | | | | |		| headers | | | | | |
	| Re-added | -- | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- | -- |
	| headers | | | | | |		| headers | | | | | |
	| Modified | -- | RPI | RPI | RPI | -- |		| Modified | -- | RPI | RPI | RPI | -- |
	| headers | | | | | |		| headers | | | | | |
	| Untouched | -- | -- | -- | -- | RPI(Ignored) |		| Untouched | -- | -- | -- | -- | RPI(Ignored) |
	| headers | | | | | |		| headers | | | | | |
	+-----------+------+--------+---------------+--------+--------------+		+-----------+------+--------+---------------+--------+--------------+
	Storing: Summary of the use of headers for RPL-aware-leaf to RPL-		Storing: Summary of the use of headers for RPL-aware-leaf to non-RPL-
	aware-leaf		aware-leaf
	5.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf		6.3.3. SM: Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware 6LN (IPv6) --> 6LR_ia --> common parent (6LR_x) -->		not-RPL-aware 6LN (IPv6) --> 6LR_ia --> common parent (6LR_x) -->
	6LR_id --> 6LN		6LR_id --> 6LN
	6LR_ia are the intermediate routers from source (not-RPL-aware 6LN		For example, the communication flow could be: Node G --> Node E -->
	(IPv6)) to the common parent (6LR_x) In this case, "1 <= ia >= n", n		Node B --> Node D --> Node F
	is the number of routers (6LR) that the packet go through from source
	to the common parent.
	6LR_id are the intermediate routers from the common parent (6LR_x) to		6LR_ia (Node E) are the intermediate routers from source (not-RPL-
	destination 6LN. In this case, "1 <= id >= m", m is the number of		aware 6LN (IPv6)) (Node G) to the common parent (6LR_x) (Node B) In
	routers (6LR) that the packet go through from the common parent		this case, "1 <= ia >= n", n is the number of routers (6LR) that the
	(6LR_x) to destination 6LN.		packet go through from source to the common parent.
	The 6LR_ia (ia=1) receives the packet from the the IPv6 node and		6LR_id (Node D) are the intermediate routers from the common parent
	inserts and the RPI header encapsulated in IPv6-in-IPv6 header. The		(6LR_x) (Node B) to destination 6LN (Node F). In this case, "1 <= id
	IP-in-IP header is addressed to the destination 6LN.		>= m", m is the number of routers (6LR) that the packet go through
			from the common parent (6LR_x) to destination 6LN.
			The 6LR_ia (ia=1) (Node E) receives the packet from the the IPv6 node
			(Node G) and inserts and the RPI header encapsulated in IPv6-in-IPv6
			header. The IP-in-IP header is addressed to the destination 6LN
			(Node F).
	+--------+------+------------+------------+------------+------------+		+--------+------+------------+------------+------------+------------+
	| Header | IPv6 | 6LR_ia | common | 6LR_id | 6LN |		| Header | IPv6 | 6LR_ia | common | 6LR_id | 6LN |
	| | | | parent | | |		| | | | parent | | |
	| | | | (6LRx) | | |		| | | | (6LRx) | | |
	+--------+------+------------+------------+------------+------------+		+--------+------+------------+------------+------------+------------+
	| Insert | -- | IP-in- | -- | -- | -- |		| Insert | -- | IP-in- | -- | -- | -- |
	| ed hea | | IP(RPI) | | | |		| ed hea | | IP(RPI) | | | |
	| ders | | | | | |		| ders | | | | | |
	| Remove | -- | -- | -- | -- | IP-in- |		| Remove | -- | -- | -- | -- | IP-in- |
	skipping to change at page 19, line 31 ¶		skipping to change at page 23, line 36 ¶
	| ed hea | | | IP(RPI) | IP(RPI) | |		| ed hea | | | IP(RPI) | IP(RPI) | |
	| ders | | | | | |		| ders | | | | | |
	| Untouc | -- | -- | -- | -- | -- |		| Untouc | -- | -- | -- | -- | -- |
	| hed he | | | | | |		| hed he | | | | | |
	| aders | | | | | |		| aders | | | | | |
	+--------+------+------------+------------+------------+------------+		+--------+------+------------+------------+------------+------------+
	Storing: Summary of the use of headers from not-RPL-aware-leaf to		Storing: Summary of the use of headers from not-RPL-aware-leaf to
	RPL-aware-leaf		RPL-aware-leaf
	5.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-leaf		6.3.4. SM: Example of Flow from not-RPL-aware-leaf to not-RPL-aware-
			leaf
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware 6LN (IPv6 src)--> 6LR_1--> 6LR_ia --> root (6LBR) -->		not-RPL-aware 6LN (IPv6 src)--> 6LR_1--> 6LR_ia --> root (6LBR) -->
	6LR_id --> not-RPL-aware 6LN (IPv6 dst)		6LR_id --> not-RPL-aware 6LN (IPv6 dst)
	6LR_ia are the intermediate routers from source (not-RPL-aware 6LN		For example, the communication flow could be: Node G --> Node E -->
	(IPv6 src)) to the root (6LBR) In this case, "1 < ia >= n", n is the		Node B --> Node A (root) --> Node C --> Node J
	number of routers (6LR) that the packet go through from IPv6 src to
	the root.
	6LR_id are the intermediate routers from the root to destination		Internet 6LR_ia (Node E and Node B) are the intermediate routers from
	(IPv6 dst). In this case, "1 <= id >= m", m is the number of routers		source (not-RPL-aware 6LN (IPv6 src))(Node G) to the root (6LBR)
	(6LR) that the packet go through from the root to destination (IPv6		(Node A) In this case, "1 < ia >= n", n is the number of routers
	dst).		(6LR) that the packet go through from IPv6 src to the root.
	This flow is identical to Section 5.11		6LR_id (C) are the intermediate routers from the root (Node A) to
			destination (IPv6 dst) (Node J). In this case, "1 <= id >= m", m is
			the number of routers (6LR) that the packet go through from the root
			to destination (IPv6 dst).
	The 6LR_1 receives the packet from the the IPv6 node and inserts the		This flow is identical to Section 6.3.3
	RPI header (RPIa) encapsulated in IPv6-in-IPv6 header. The IPv6-in-
	IPv6 header is addressed to the 6LBR. The 6LBR remove the IPv6-in-		The 6LR_1 (Node E) receives the packet from the the IPv6 node (Node
	IPv6 header and insert another one (RPIb) with destination to 6LR_m		G) and inserts the RPI header (RPIa) encapsulated in IPv6-in-IPv6
	node.		header. The IPv6-in-IPv6 header is addressed to the 6LBR. The 6LBR
			remove the IPv6-in-IPv6 header and insert another one (RPIb) with
			destination to 6LR_m (Node C) node.
	One of the side-effects of inserting IP-in-IP RPI header at 6LR_1, is		One of the side-effects of inserting IP-in-IP RPI header at 6LR_1, is
	that now all the packets will go through the 6LBR, even though there		that now all the packets will go through the 6LBR, even though there
	exists a shorter P2P path to the destination 6LN in storing mode.		exists a shorter P2P path to the destination 6LN in storing mode.
	One possible solution is given by the work in		One possible solution is given by the work in
	[I-D.ietf-roll-dao-projection]. Once we have route projection, the		[I-D.ietf-roll-dao-projection]. Once we have route projection, the
	root can find that this traffic deserves optimization (based on		root can find that this traffic deserves optimization (based on
	volume and path length, or additional knowledge on that particular		volume and path length, or additional knowledge on that particular
	flow) and project a DAO into 6LR_1.		flow) and project a DAO into 6LR_1.
	skipping to change at page 20, line 45 ¶		skipping to change at page 25, line 34 ¶
	| s | | | | | | |		| s | | | | | | |
	| Untou | -- | -- | -- | -- | -- | -- |		| Untou | -- | -- | -- | -- | -- | -- |
	| ched | | | | | | |		| ched | | | | | | |
	| heade | | | | | | |		| heade | | | | | | |
	| rs | | | | | | |		| rs | | | | | | |
	+-------+-----+-----------+-----------+-----------+-----------+-----+		+-------+-----+-----------+-----------+-----------+-----------+-----+
	Storing: Summary of the use of headers from not-RPL-aware-leaf to		Storing: Summary of the use of headers from not-RPL-aware-leaf to
	non-RPL-aware-leaf		non-RPL-aware-leaf
	6. Non Storing mode		7. Non Storing mode
	+--------------+------+------+-----------+---------------+
	| Use Case | RPI | RH3 | IP-in-IP | IP-in-IP dst |
	+--------------+------+------+-----------+---------------+
	| Raf to root | Yes | No | No | -- |
	| root to Raf | Opt | Yes | No | -- |
	| root to ~Raf | No | Yes | Yes | 6LR |
	| ~Raf to root | Yes | No | Yes | root |
	| Raf to Int | Yes | No | Yes | root |
	| Int to Raf | Opt | Yes | Yes | dst |
	| ~Raf to Int | Yes | No | Yes | root |
	| Int to ~Raf | Opt | Yes | Yes | 6LR |
	| Raf to Raf | Yes | Yes | Yes | root/dst |
	| Raf to ~Raf | Yes | Yes | Yes | root/6LR |
	| ~Raf to Raf | Yes | Yes | Yes | root/6LN |
	| ~Raf to ~Raf | Yes | Yes | Yes | root/6LR |
	+--------------+------+------+-----------+---------------+
	Table 2: Headers needed in Non-Storing mode: RPI, RH3, IP-in-IP		In Non Storing Mode (Non SM) (fully source routed), the 6LBR (DODAG
	encapsulation		root) has complete knowledge about the connectivity of all DODAG
			nodes, and all traffic flows through the root node. Thus, there is
			no need for all nodes to know about the existence of non-RPL aware
			nodes. Only the 6LBR needs to change when there are non-RPL aware
			nodes.
	6.1. Example of Flow from RPL-aware-leaf to root		The following table summarizes what headers are needed in the
			following scenarios, and indicates when the RPI, RH3 and IP-in-IP
			header must be inserted. There are these possible situations:
			destination address possible (indicated by "dst"), to a 6LR, to a 6LN
			or to the root. In cases where no IP-in-IP header is needed, the
			column is left blank.
			The leaf can be a router 6LR or a host, both indicated as 6LN
			(Figure 3).
			+-----------------+--------------+-----+-----+----------+----------+
			| Interaction | Use Case | RPI | RH3 | IP-in-IP | IP-in-IP |
			| between | | | | | dst |
			+-----------------+--------------+-----+-----+----------+----------+
			| | Raf to root | Yes | No | No | -- |
			+ +--------------+-----+-----+----------+----------+
			| Leaf - Root | root to Raf | Opt | Yes | No | -- |
			+ +--------------+-----+-----+----------+----------+
			| | root to ~Raf | No | Yes | Yes | 6LR |
			+ +--------------+-----+-----+----------+----------+
			| | ~Raf to root | Yes | No | Yes | root |
			+-----------------+--------------+-----+-----+----------+----------+
			| | Raf to Int | Yes | No | Yes | root |
			+ +--------------+-----+-----+----------+----------+
			| Leaf - Internet | Int to Raf | Opt | Yes | Yes | dst |
			+ +--------------+-----+-----+----------+----------+
			| | ~Raf to Int | Yes | No | Yes | root |
			+ +--------------+-----+-----+----------+----------+
			| | Int to ~Raf | Opt | Yes | Yes | 6LR |
			+-----------------+--------------+-----+-----+----------+----------+
			| | Raf to Raf | Yes | Yes | Yes | root/dst |
			+ +--------------+-----+-----+----------+----------+
			| | Raf to ~Raf | Yes | Yes | Yes | root/6LR |
			+ Leaf - Leaf +--------------+-----+-----+----------+----------+
			| | ~Raf to Raf | Yes | Yes | Yes | root/6LN |
			+ +--------------+-----+-----+----------+----------+
			| | ~Raf to ~Raf | Yes | Yes | Yes | root/6LR |
			+-----------------+--------------+-----+-----+----------+----------+
			Figure 5: Headers needed in Non-Storing mode: RPI, RH3, IP-in-IP
			encapsulation.
			7.1. Non-Storing Mode: Interaction between Leaf and Root
			In this section we are going to describe the communication flow in
			Non Storing Mode (Non-SM) between,
			RPL-aware-leaf to root
			root to RPL-aware-leaf
			not-RPL-aware-leaf to root
			root to not-RPL-aware-leaf
			7.1.1. Non-SM: Example of Flow from RPL-aware-leaf to root
	In non-storing mode the leaf node uses default routing to send		In non-storing mode the leaf node uses default routing to send
	traffic to the root. The RPI header must be included to avoid/detect		traffic to the root. The RPI header must be included to avoid/detect
	loops.		loops.
	RPL-aware-leaf (6LN) --> 6LR_i --> root(6LBR)		RPL-aware-leaf (6LN) --> 6LR_i --> root(6LBR)
			For example, the communication flow could be: Node F --> Node D -->
			Node B --> Node A (root)
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LN) to destination (6LBR).		packet go through from source (6LN) to destination (6LBR).
	This situation is the same case as storing mode.		This situation is the same case as storing mode.
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	| Header | 6LN | 6LR_i | 6LBR |		| Header | 6LN | 6LR_i | 6LBR |
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	| Inserted headers | RPI | -- | -- |		| Inserted headers | RPI | -- | -- |
	| Removed headers | -- | -- | RPI |		| Removed headers | -- | -- | RPI |
	| Re-added headers | -- | -- | -- |		| Re-added headers | -- | -- | -- |
	| Modified headers | -- | RPI | -- |		| Modified headers | -- | RPI | -- |
	| Untouched headers | -- | -- | -- |		| Untouched headers | -- | -- | -- |
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	Non Storing: Summary of the use of headers from RPL-aware-leaf to		Non Storing: Summary of the use of headers from RPL-aware-leaf to
	root		root
	6.2. Example of Flow from root to RPL-aware-leaf		7.1.2. on-SM: Example of Flow from root to RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)		root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)
			For example, the communication flow could be: Node A (root) --> Node
			B --> Node D --> Node F
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LBR) to destination (6LN).		packet go through from source (6LBR) to destination (6LN).
	The 6LBR will insert an RH3, and may optionally insert an RPI header.		The 6LBR will insert an RH3, and may optionally insert an RPI header.
	No IP-in-IP header is necessary as the traffic originates with an RPL		No IP-in-IP header is necessary as the traffic originates with an RPL
	aware node, the 6LBR. The destination is known to RPL-aware because,		aware node, the 6LBR. The destination is known to RPL-aware because,
	the root knows the whole topology in non-storing mode.		the root knows the whole topology in non-storing mode.
	+-------------------+-----------------+-------+----------+		+-------------------+-----------------+-------+----------+
	skipping to change at page 22, line 33 ¶		skipping to change at page 28, line 18 ¶
	| Inserted headers | (opt: RPI), RH3 | -- | -- |		| Inserted headers | (opt: RPI), RH3 | -- | -- |
	| Removed headers | -- | -- | RH3,RPI |		| Removed headers | -- | -- | RH3,RPI |
	| Re-added headers | -- | -- | -- |		| Re-added headers | -- | -- | -- |
	| Modified headers | -- | RH3 | -- |		| Modified headers | -- | RH3 | -- |
	| Untouched headers | -- | -- | -- |		| Untouched headers | -- | -- | -- |
	+-------------------+-----------------+-------+----------+		+-------------------+-----------------+-------+----------+
	Non Storing: Summary of the use of headers from root to RPL-aware-		Non Storing: Summary of the use of headers from root to RPL-aware-
	leaf		leaf
	6.3. Example of Flow from root to not-RPL-aware-leaf		7.1.3. Non-SM: Example of Flow from root to not-RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)		root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)
			For example, the communication flow could be: Node A (root) --> Node
			B --> Node E --> Node G
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LBR) to destination (IPv6).		packet go through from source (6LBR) to destination (IPv6).
	In 6LBR the RH3 is added, modified in each intermediate 6LR (6LR_1		In 6LBR the RH3 is added, modified in each intermediate 6LR (6LR_1
	and so on) and it is fully consumed in the last 6LR (6LR_n), but left		and so on) and it is fully consumed in the last 6LR (6LR_n), but left
	there. If RPI is left present, the IPv6 node which does not		there. If RPI is left present, the IPv6 node which does not
	understand it will ignore it (following 2460bis), thus encapsulation		understand it will ignore it (following 2460bis), thus encapsulation
	is not necesary. Due the complete knowledge of the topology at the		is not necesary. Due the complete knowledge of the topology at the
	root, the 6LBR is able to address the IP-in-IP header to the last		root, the 6LBR is able to address the IP-in-IP header to the last
	skipping to change at page 23, line 23 ¶		skipping to change at page 29, line 23 ¶
	| headers | | | | |		| headers | | | | |
	| Modified | -- | (opt: RPI), | (opt: RPI), | -- |		| Modified | -- | (opt: RPI), | (opt: RPI), | -- |
	| headers | | RH3 | RH3 | |		| headers | | RH3 | RH3 | |
	| Untouched | -- | -- | -- | RPI |		| Untouched | -- | -- | -- | RPI |
	| headers | | | | |		| headers | | | | |
	+---------------+-------------+---------------+--------------+------+		+---------------+-------------+---------------+--------------+------+
	Non Storing: Summary of the use of headers from root to not-RPL-		Non Storing: Summary of the use of headers from root to not-RPL-
	aware-leaf		aware-leaf
	6.4. Example of Flow from not-RPL-aware-leaf to root		7.1.4. Non-SM: Example of Flow from not-RPL-aware-leaf to root
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i --> root (6LBR)		not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i --> root (6LBR)
			For example, the communication flow could be: Node G --> Node E -->
			Node B --> Node A (root)
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 < i >= n", n is the number of routers (6LR) that the		this case, "1 < i >= n", n is the number of routers (6LR) that the
	packet go through from source (IPv6) to destination (6LBR). For		packet go through from source (IPv6) to destination (6LBR). For
	example, 6LR_1 (i=1) is the router that receives the packets from the		example, 6LR_1 (i=1) is the router that receives the packets from the
	IPv6 node.		IPv6 node.
	In this case the RPI is added by the first 6LR (6LR1), encapsulated		In this case the RPI is added by the first 6LR (6LR1) (Node E),
	in an IP-in-IP header, and is modified in the followings 6LRs. The		encapsulated in an IP-in-IP header, and is modified in the followings
	RPI and entire packet is consumed by the root.		6LRs. The RPI and entire packet is consumed by the root.
	+------------+------+---------------+---------------+---------------+		+------------+------+---------------+---------------+---------------+
	| Header | IPv6 | 6LR_1 | 6LR_i | 6LBR |		| Header | IPv6 | 6LR_1 | 6LR_i | 6LBR |
	+------------+------+---------------+---------------+---------------+		+------------+------+---------------+---------------+---------------+
	| Inserted | -- | IP-in-IP(RPI) | -- | -- |		| Inserted | -- | IP-in-IP(RPI) | -- | -- |
	| headers | | | | |		| headers | | | | |
	| Removed | -- | -- | -- | IP-in-IP(RPI) |		| Removed | -- | -- | -- | IP-in-IP(RPI) |
	| headers | | | | |		| headers | | | | |
	| Re-added | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- |
	| headers | | | | |		| headers | | | | |
	| Modified | -- | -- | IP-in-IP(RPI) | -- |		| Modified | -- | -- | IP-in-IP(RPI) | -- |
	| headers | | | | |		| headers | | | | |
	| Untouched | -- | -- | -- | -- |		| Untouched | -- | -- | -- | -- |
	| headers | | | | |		| headers | | | | |
	+------------+------+---------------+---------------+---------------+		+------------+------+---------------+---------------+---------------+
	Non Storing: Summary of the use of headers from not-RPL-aware-leaf to		Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
	root		root
	6.5. Example of Flow from RPL-aware-leaf to Internet		7.2. Non-Storing Mode: Interaction between Leaf and Internet
			In this section we are going to describe the communication flow in
			Non Storing Mode (Non-SM) between,
			RPL-aware-leaf to Internet
			Internet to RPL-aware-leaf
			not-RPL-aware-leaf to Internet
			Internet to not-RPL-aware-leaf
			7.2.1. Non-SM: Example of Flow from RPL-aware-leaf to Internet
	In this case the flow comprises:		In this case the flow comprises:
	RPL-aware-leaf (6LN) --> 6LR_i --> root (6LBR) --> Internet		RPL-aware-leaf (6LN) --> 6LR_i --> root (6LBR) --> Internet
			For example, the communication flow could be: Node F --> Node D -->
			Node B --> Node A --> Internet
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LN) to 6LBR.		packet go through from source (6LN) to 6LBR.
	This case is identical to storing-mode case.		This case is identical to storing-mode case.
	The IPv6 flow label should be set to zero to aid in compression, and		The IPv6 flow label should be set to zero to aid in compression, and
	the 6LBR will set it to a non-zero value when sending towards the		the 6LBR will set it to a non-zero value when sending towards the
	Internet.		Internet.
	skipping to change at page 25, line 5 ¶		skipping to change at page 31, line 22 ¶
	| Inserted headers | RPI | -- | -- | -- |		| Inserted headers | RPI | -- | -- | -- |
	| Removed headers | -- | -- | -- | -- |		| Removed headers | -- | -- | -- | -- |
	| Re-added headers | -- | -- | -- | -- |		| Re-added headers | -- | -- | -- | -- |
	| Modified headers | -- | RPI | -- | -- |		| Modified headers | -- | RPI | -- | -- |
	| Untouched headers | -- | -- | RPI | RPI (Ignored) |		| Untouched headers | -- | -- | RPI | RPI (Ignored) |
	+-------------------+------+-------+------+----------------+		+-------------------+------+-------+------+----------------+
	Non Storing: Summary of the use of headers from RPL-aware-leaf to		Non Storing: Summary of the use of headers from RPL-aware-leaf to
	Internet		Internet
	6.6. Example of Flow from Internet to RPL-aware-leaf		7.2.2. Non-SM: Example of Flow from Internet to RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	Internet --> root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)		Internet --> root (6LBR) --> 6LR_i --> RPL-aware-leaf (6LN)
			For example, the communication flow could be: Internet --> Node A
			(root) --> Node B --> Node D --> Node F
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 <= i >= n", n is the number of routers (6LR) that the		this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from 6LBR to destination(6LN).		packet go through from 6LBR to destination(6LN).
	The 6LBR must add an RH3 header. As the 6LBR will know the path and		The 6LBR must add an RH3 header. As the 6LBR will know the path and
	address of the target node, it can address the IP-in-IP header to		address of the target node, it can address the IP-in-IP header to
	that node. The 6LBR will zero the flow label upon entry in order to		that node. The 6LBR will zero the flow label upon entry in order to
	aid compression.		aid compression.
	The RPI may be added or not, it is optional.		The RPI may be added or not, it is optional.
	skipping to change at page 25, line 47 ¶		skipping to change at page 32, line 30 ¶
	| ed hea | | | pt:RPI) | |		| ed hea | | | pt:RPI) | |
	| ders | | | | |		| ders | | | | |
	| Untouc | -- | -- | -- | -- |		| Untouc | -- | -- | -- | -- |
	| hed he | | | | |		| hed he | | | | |
	| aders | | | | |		| aders | | | | |
	+--------+-------+----------------+----------------+----------------+		+--------+-------+----------------+----------------+----------------+
	Non Storing: Summary of the use of headers from Internet to RPL-		Non Storing: Summary of the use of headers from Internet to RPL-
	aware-leaf		aware-leaf
	6.7. Example of Flow from not-RPL-aware-leaf to Internet		7.2.3. Non-SM: Example of Flow from not-RPL-aware-leaf to Internet
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i -->root (6LBR) -->		not-RPL-aware-leaf (IPv6) --> 6LR_1 --> 6LR_i -->root (6LBR) -->
	Internet		Internet
			For example, the communication flow could be: Node G --> Node E -->
			Node B --> Node A --> Internet
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 < i >= n", n is the number of routers (6LR) that the		this case, "1 < i >= n", n is the number of routers (6LR) that the
	packet go through from source(IPv6) to 6LBR. e.g 6LR_1 (i=1).		packet go through from source(IPv6) to 6LBR. e.g 6LR_1 (i=1).
	In this case the flow label is recommended to be zero in the IPv6		In this case the flow label is recommended to be zero in the IPv6
	node. As RPL headers are added in the IPv6 node, the first 6LR		node. As RPL headers are added in the IPv6 node, the first 6LR
	(6LR_1) will add an RPI header inside a new IP-in-IP header. The IP-		(6LR_1) will add an RPI header inside a new IP-in-IP header. The IP-
	in-IP header will be addressed to the root. This case is identical		in-IP header will be addressed to the root. This case is identical
	to the storing-mode case (Section 5.7).		to the storing-mode case (Section 5.7).
	skipping to change at page 26, line 37 ¶		skipping to change at page 33, line 28 ¶
	| d | | | IP(RPI) | | |		| d | | | IP(RPI) | | |
	| headers | | | | | |		| headers | | | | | |
	| Untouch | -- | -- | -- | -- | -- |		| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |		| ed | | | | | |
	| headers | | | | | |		| headers | | | | | |
	+---------+-----+-------------+-------------+-------------+---------+		+---------+-----+-------------+-------------+-------------+---------+
	Non Storing: Summary of the use of headers from not-RPL-aware-leaf to		Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
	Internet		Internet
	6.8. Example of Flow from Internet to not-RPL-aware-leaf		7.2.4. Non-SM: Example of Flow from Internet to not-RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	Internet --> root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)		Internet --> root (6LBR) --> 6LR_i --> not-RPL-aware-leaf (IPv6)
			For example, the communication flow could be: Internet --> Node A
			(root) --> Node B --> Node E --> Node G
	6LR_i are the intermediate routers from source to destination. In		6LR_i are the intermediate routers from source to destination. In
	this case, "1 < i >= n", n is the number of routers (6LR) that the		this case, "1 < i >= n", n is the number of routers (6LR) that the
	packet go through from 6LBR to not-RPL-aware-leaf (IPv6).		packet go through from 6LBR to not-RPL-aware-leaf (IPv6).
	The 6LBR must add an RH3 header inside an IP-in-IP header. The 6LBR		The 6LBR must add an RH3 header inside an IP-in-IP header. The 6LBR
	will know the path, and will recognize that the final node is not an		will know the path, and will recognize that the final node is not an
	RPL capable node as it will have received the connectivity DAO from		RPL capable node as it will have received the connectivity DAO from
	the nearest 6LR. The 6LBR can therefore make the IP-in-IP header		the nearest 6LR. The 6LBR can therefore make the IP-in-IP header
	destination be the last 6LR. The 6LBR will set to zero the flow		destination be the last 6LR. The 6LBR will set to zero the flow
	label upon entry in order to aid compression.		label upon entry in order to aid compression.
	skipping to change at page 27, line 32 ¶		skipping to change at page 34, line 30 ¶
	| ed hea | | | IP(RH3, | IP(RH3, | |		| ed hea | | | IP(RH3, | IP(RH3, | |
	| ders | | | RPI) | RPI) | |		| ders | | | RPI) | RPI) | |
	| Untouc | -- | -- | -- | -- | RPI |		| Untouc | -- | -- | -- | -- | RPI |
	| hed he | | | | | |		| hed he | | | | | |
	| aders | | | | | |		| aders | | | | | |
	+--------+-------+----------------+------------+-------------+------+		+--------+-------+----------------+------------+-------------+------+
	NonStoring: Summary of the use of headers from Internet to non-RPL-		NonStoring: Summary of the use of headers from Internet to non-RPL-
	aware-leaf		aware-leaf
	6.9. Example of Flow from RPL-aware-leaf to RPL-aware-leaf		7.3. Non-Storing Mode: Interaction between Leafs
			In this section we are going to describe the communication flow in
			Non Storing Mode (Non-SM) between,
			RPL-aware-leaf to RPL-aware-leaf
			RPL-aware-leaf to not-RPL-aware-leaf
			not-RPL-aware-leaf to RPL-aware-leaf
			not-RPL-aware-leaf to not-RPL-aware-leaf
			7.3.1. Non-SM: Example of Flow from RPL-aware-leaf to RPL-aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	6LN src --> 6LR_ia --> root (6LBR) --> 6LR_id --> 6LN dst		6LN src --> 6LR_ia --> root (6LBR) --> 6LR_id --> 6LN dst
			For example, the communication flow could be: Node F --> Node D -->
			Node B --> Node A (root) --> Node B --> Node E --> Node H
	6LR_ia are the intermediate routers from source to the root In this		6LR_ia are the intermediate routers from source to the root In this
	case, "1 <= ia >= n", n is the number of routers (6LR) that the		case, "1 <= ia >= n", n is the number of routers (6LR) that the
	packet go through from 6LN to the root.		packet go through from 6LN to the root.
	6LR_id are the intermediate routers from the root to the destination.		6LR_id are the intermediate routers from the root to the destination.
	In this case, "1 <= ia >= m", m is the number of the intermediate		In this case, "1 <= ia >= m", m is the number of the intermediate
	routers (6LR).		routers (6LR).
	This case involves only nodes in same RPL Domain. The originating		This case involves only nodes in same RPL Domain. The originating
	node will add an RPI header to the original packet, and send the		node will add an RPI header to the original packet, and send the
	skipping to change at page 28, line 15 ¶		skipping to change at page 35, line 29 ¶
	carry the useless RPI option.		carry the useless RPI option.
	The 6LBR will need to insert an RH3 header, which requires that it		The 6LBR will need to insert an RH3 header, which requires that it
	add an IP-in-IP header. It SHOULD be able to remove the RPI, as it		add an IP-in-IP header. It SHOULD be able to remove the RPI, as it
	was contained in an IP-in-IP header addressed to it. Otherwise,		was contained in an IP-in-IP header addressed to it. Otherwise,
	there MAY be an RPI header buried inside the inner IP header, which		there MAY be an RPI header buried inside the inner IP header, which
	should get ignored.		should get ignored.
	Networks that use the RPL P2P extension [RFC6997] are essentially		Networks that use the RPL P2P extension [RFC6997] are essentially
	non-storing DODAGs and fall into this scenario or scenario		non-storing DODAGs and fall into this scenario or scenario
	Section 6.2, with the originating node acting as 6LBR.		Section 7.1.2, with the originating node acting as 6LBR.
	+---------+-------------+------+--------------+-------+-------------+		+---------+-------------+------+--------------+-------+-------------+
	| Header | 6LN src | 6LR_ | 6LBR | 6LR_i | 6LN dst |		| Header | 6LN src | 6LR_ | 6LBR | 6LR_i | 6LN dst |
	| | | ia | | d | |		| | | ia | | d | |
	+---------+-------------+------+--------------+-------+-------------+		+---------+-------------+------+--------------+-------+-------------+
	| Inserte | IP-in- | -- | IP-in-IP(RH3 | -- | -- |		| Inserte | IP-in- | -- | IP-in-IP(RH3 | -- | -- |
	| d | IP(RPI1) | | to 6LN, opt | | |		| d | IP(RPI1) | | to 6LN, opt | | |
	| headers | | | RPI2) | | |		| headers | | | RPI2) | | |
	| Removed | -- | -- | IP-in- | -- | IP-in- |		| Removed | -- | -- | IP-in- | -- | IP-in- |
	| headers | | | IP(RPI1) | | IP(RH3, opt |		| headers | | | IP(RPI1) | | IP(RH3, opt |
	skipping to change at page 28, line 41 ¶		skipping to change at page 36, line 29 ¶
	| d | | | | | |		| d | | | | | |
	| headers | | | | | |		| headers | | | | | |
	| Untouch | -- | -- | -- | -- | -- |		| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |		| ed | | | | | |
	| headers | | | | | |		| headers | | | | | |
	+---------+-------------+------+--------------+-------+-------------+		+---------+-------------+------+--------------+-------+-------------+
	Non Storing: Summary of the use of headers for RPL-aware-leaf to RPL-		Non Storing: Summary of the use of headers for RPL-aware-leaf to RPL-
	aware-leaf		aware-leaf
	6.10. Example of Flow from RPL-aware-leaf to not-RPL-aware-leaf		7.3.2. Non-SM: Example of Flow from RPL-aware-leaf to not-RPL-aware-
			leaf
	In this case the flow comprises:		In this case the flow comprises:
	6LN --> 6LR_ia --> root (6LBR) --> 6LR_id --> not-RPL-aware (IPv6)		6LN --> 6LR_ia --> root (6LBR) --> 6LR_id --> not-RPL-aware (IPv6)
			For example, the communication flow could be: Node F --> Node D -->
			Node B --> Node A (root) --> Node B --> Node E --> Node G
	6LR_ia are the intermediate routers from source to the root In this		6LR_ia are the intermediate routers from source to the root In this
	case, "1 <= ia >= n", n is the number of intermediate routers (6LR)		case, "1 <= ia >= n", n is the number of intermediate routers (6LR)
	6LR_id are the intermediate routers from the root to the destination.		6LR_id are the intermediate routers from the root to the destination.
	In this case, "1 <= ia >= m", m is the number of the intermediate		In this case, "1 <= ia >= m", m is the number of the intermediate
	routers (6LR).		routers (6LR).
	As in the previous case, the 6LN will insert an RPI (RPI_1) header		As in the previous case, the 6LN will insert an RPI (RPI_1) header
	which MUST be in an IP-in-IP header addressed to the root so that the		which MUST be in an IP-in-IP header addressed to the root so that the
	6LBR can remove this RPI. The 6LBR will then insert an RH3 inside a		6LBR can remove this RPI. The 6LBR will then insert an RH3 inside a
	new IP-in-IP header addressed to the 6LN destination node. The RPI		new IP-in-IP header addressed to the 6LN destination node. The RPI
	is optional from 6LBR to 6LR_id (RPI_2).		is optional from 6LBR to 6LR_id (RPI_2).
	skipping to change at page 29, line 38 ¶		skipping to change at page 37, line 29 ¶
	| ed hea | | IP(RPI_1) | | IP(RH3, | |		| ed hea | | IP(RPI_1) | | IP(RH3, | |
	| ders | | | | opt RPI_2) | |		| ders | | | | opt RPI_2) | |
	| Untouc | -- | -- | -- | -- | opt |		| Untouc | -- | -- | -- | -- | opt |
	| hed he | | | | | RPI_ |		| hed he | | | | | RPI_ |
	| aders | | | | | 2 |		| aders | | | | | 2 |
	+--------+-----------+------------+-------------+------------+------+		+--------+-----------+------------+-------------+------------+------+
	Non Storing: Summary of the use of headers from RPL-aware-leaf to		Non Storing: Summary of the use of headers from RPL-aware-leaf to
	not-RPL-aware-leaf		not-RPL-aware-leaf
	6.11. Example of Flow from not-RPL-aware-leaf to RPL-aware-leaf		7.3.3. Non-SM: Example of Flow from not-RPL-aware-leaf to RPL-aware-
			leaf
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware 6LN (IPv6) --> 6LR_ia --> root (6LBR) --> 6LR_id -->		not-RPL-aware 6LN (IPv6) --> 6LR_ia --> root (6LBR) --> 6LR_id -->
	6LN		6LN
			For example, the communication flow could be: Node G --> Node E -->
			Node B --> Node A (root) --> Node B --> Node E --> Node H
	6LR_ia are the intermediate routers from source to the root In this		6LR_ia are the intermediate routers from source to the root In this
	case, "1 <= ia >= n", n is the number of intermediate routers (6LR)		case, "1 <= ia >= n", n is the number of intermediate routers (6LR)
	6LR_id are the intermediate routers from the root to the destination.		6LR_id are the intermediate routers from the root to the destination.
	In this case, "1 <= ia >= m", m is the number of the intermediate		In this case, "1 <= ia >= m", m is the number of the intermediate
	routers (6LR).		routers (6LR).
	This scenario is mostly identical to the previous one. The RPI is		This scenario is mostly identical to the previous one. The RPI is
	added by the first 6LR (6LR_1) inside an IP-in-IP header addressed to		added by the first 6LR (6LR_1) inside an IP-in-IP header addressed to
	the root. The 6LBR will remove this RPI, and add it's own IP-in-IP		the root. The 6LBR will remove this RPI, and add it's own IP-in-IP
	skipping to change at page 30, line 35 ¶		skipping to change at page 38, line 30 ¶
	| ed hea | | | | IP(RH3, | |		| ed hea | | | | IP(RH3, | |
	| ders | | | | opt RPI_2) | |		| ders | | | | opt RPI_2) | |
	| Untouc | -- | -- | -- | -- | -- |		| Untouc | -- | -- | -- | -- | -- |
	| hed he | | | | | |		| hed he | | | | | |
	| aders | | | | | |		| aders | | | | | |
	+--------+-----+------------+-------------+------------+------------+		+--------+-----+------------+-------------+------------+------------+
	Non Storing: Summary of the use of headers from not-RPL-aware-leaf to		Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
	RPL-aware-leaf		RPL-aware-leaf
	6.12. Example of Flow from not-RPL-aware-leaf to not-RPL-aware-leaf		7.3.4. Non-SM: Example of Flow from not-RPL-aware-leaf to not-RPL-
			aware-leaf
	In this case the flow comprises:		In this case the flow comprises:
	not-RPL-aware 6LN (IPv6 src)--> 6LR_ia --> root (6LBR) --> 6LR_id -->		not-RPL-aware 6LN (IPv6 src)--> 6LR_ia --> root (6LBR) --> 6LR_id -->
	not-RPL-aware (IPv6 dst)		not-RPL-aware (IPv6 dst)
			For example, the communication flow could be: Node G --> Node E -->
			Node B --> Node A (root) --> Node C --> Node J
	6LR_ia are the intermediate routers from source to the root In this		6LR_ia are the intermediate routers from source to the root In this
	case, "1 <= ia >= n", n is the number of intermediate routers (6LR)		case, "1 <= ia >= n", n is the number of intermediate routers (6LR)
	6LR_id are the intermediate routers from the root to the destination.		6LR_id are the intermediate routers from the root to the destination.
	In this case, "1 <= ia >= m", m is the number of the intermediate		In this case, "1 <= ia >= m", m is the number of the intermediate
	routers (6LR).		routers (6LR).
	This scenario is the combination of the previous two cases.		This scenario is the combination of the previous two cases.
	+---------+-----+--------------+---------------+-------------+------+		+---------+-----+--------------+---------------+-------------+------+
	skipping to change at page 31, line 30 ¶		skipping to change at page 39, line 30 ¶
	| d | | | | | |		| d | | | | | |
	| headers | | | | | |		| headers | | | | | |
	| Untouch | -- | -- | -- | -- | -- |		| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |		| ed | | | | | |
	| headers | | | | | |		| headers | | | | | |
	+---------+-----+--------------+---------------+-------------+------+		+---------+-----+--------------+---------------+-------------+------+
	Non Storing: Summary of the use of headers from not-RPL-aware-leaf to		Non Storing: Summary of the use of headers from not-RPL-aware-leaf to
	not-RPL-aware-leaf		not-RPL-aware-leaf
	7. Observations about the cases		8. Observations about the cases
	7.1. Storing mode		8.1. Storing mode
	[I-D.ietf-roll-routing-dispatch] shows that the hop-by-hop IP-in-IP		[I-D.ietf-roll-routing-dispatch] shows that the hop-by-hop IP-in-IP
	header can be compressed using IP-in-IP 6LoRH (IP-in-IP-6LoRH) header		header can be compressed using IP-in-IP 6LoRH (IP-in-IP-6LoRH) header
	as described in Section 7 of the document.		as described in Section 7 of the document.
	There are potential significant advantages to having a single code		There are potential significant advantages to having a single code
	path that always processes IP-in-IP headers with no options.		path that always processes IP-in-IP headers with no options.
	Thanks to the relaxation of the RFC2460 rule about discarding unknown		Thanks to the relaxation of the RFC2460 rule about discarding unknown
	Hop-by-Hop options, there is no longer any uncertainty about when to		Hop-by-Hop options, there is no longer any uncertainty about when to
	use an IPIP header in the storing mode case. The RPI header SHOULD		use an IPIP header in the storing mode case. The RPI header SHOULD
	always be added when 6LRs originate packets (without IPIP headers),		always be added when 6LRs originate packets (without IPIP headers),
	and IPIP headers should always be added (addressed to the root when		and IPIP headers should always be added (addressed to the root when
	on the way up, to the end-host when on the way down) when a 6LR finds		on the way up, to the end-host when on the way down) when a 6LR finds
	it needs to insert an RPI header.		it needs to insert an RPI header.
	In order to support the above two cases with full generality, the		In order to support the above two cases with full generality, the
	different situations (always do IP-in-IP vs never use IP-in-IP)		different situations (always do IP-in-IP vs never use IP-in-IP)
	should be signaled in the RPL protocol itself.		should be signaled in the RPL protocol itself.
	7.2. Non-Storing mode		8.2. Non-Storing mode
	In the non-storing case, dealing with non-RPL aware leaf nodes is		In the non-storing case, dealing with non-RPL aware leaf nodes is
	much easier as the 6LBR (DODAG root) has complete knowledge about the		much easier as the 6LBR (DODAG root) has complete knowledge about the
	connectivity of all DODAG nodes, and all traffic flows through the		connectivity of all DODAG nodes, and all traffic flows through the
	root node.		root node.
	The 6LBR can recognize non-RPL aware leaf nodes because it will		The 6LBR can recognize non-RPL aware leaf nodes because it will
	receive a DAO about that node from the 6LN immediately above that		receive a DAO about that node from the 6LN immediately above that
	node. This means that the non-storing mode case can avoid ever using		node. This means that the non-storing mode case can avoid ever using
	hop-by-hop IP-in-IP headers.		hop-by-hop IP-in-IP headers.
	Unlike in the storing mode case, there is no need for all nodes to		Unlike in the storing mode case, there is no need for all nodes to
	know about the existence of non-RPL aware nodes. Only the 6LBR needs		know about the existence of non-RPL aware nodes. Only the 6LBR needs
	to change when there are non-RPL aware nodes. Further, in the non-		to change when there are non-RPL aware nodes. Further, in the non-
	storing case, the 6LBR is informed by the DAOs when there are non-RPL		storing case, the 6LBR is informed by the DAOs when there are non-RPL
	aware nodes.		aware nodes.
	8. 6LoRH Compression cases		9. 6LoRH Compression cases
	The [I-D.ietf-roll-routing-dispatch] proposes a compression method		The [I-D.ietf-roll-routing-dispatch] proposes a compression method
	for RPI, RH3 and IPv6-in-IPv6.		for RPI, RH3 and IPv6-in-IPv6.
	In Storing Mode, for the examples of Flow from RPL-aware-leaf to non-		In Storing Mode, for the examples of Flow from RPL-aware-leaf to non-
	RPL-aware-leaf and non-RPL-aware-leaf to non-RPL-aware-leaf comprise		RPL-aware-leaf and non-RPL-aware-leaf to non-RPL-aware-leaf comprise
	an IP-in-IP and RPI compression headers. The type of this case is		an IP-in-IP and RPI compression headers. The type of this case is
	critical since IP-in-IP is encapsulating a RPI header.		critical since IP-in-IP is encapsulating a RPI header.
	+--+-----+---+--------------+-----------+-------------+-------------+		+--+-----+---+--------------+-----------+-------------+-------------+
	|1 | 0|0 |TSE| 6LoRH Type 6 | Hop Limit | RPI - 6LoRH | LOWPAN IPHC |		|1 | 0|0 |TSE| 6LoRH Type 6 | Hop Limit | RPI - 6LoRH | LOWPAN IPHC |
	+--+-----+---+--------------+-----------+-------------+-------------+		+--+-----+---+--------------+-----------+-------------+-------------+
	Figure 3: Critical IP-in-IP (RPI).		Figure 6: Critical IP-in-IP (RPI).
	9. IANA Considerations		10. IANA Considerations
	There are no IANA considerations related to this document.		This document updates the registration made in [RFC6553] to the IPv6
			Hop-by-Hop Registry from 0x43 to 0x63.
	10. Security Considerations		11. Security Considerations
	The security considerations covering of [RFC6553] and [RFC6554] apply		The security considerations covering of [RFC6553] and [RFC6554] apply
	when the packets get into RPL Domain.		when the packets get into RPL Domain.
	The IPIP mechanism described in this document is much more limited		The IPIP mechanism described in this document is much more limited
	than the general mechanism described in [RFC2473]. The willingness		than the general mechanism described in [RFC2473]. The willingness
	of each node in the LLN to decapsulate packets and forward them could		of each node in the LLN to decapsulate packets and forward them could
	be exploited by nodes to disguise the origin of an attack.		be exploited by nodes to disguise the origin of an attack.
	Nodes outside of the LLN will need to pass IPIP traffic through the		Nodes outside of the LLN will need to pass IPIP traffic through the
	skipping to change at page 34, line 27 ¶		skipping to change at page 42, line 27 ¶
	via the "Use IPsec". This solution has all the problems that		via the "Use IPsec". This solution has all the problems that
	[RFC5406] goes into. In an LLN such a solution would degenerate into		[RFC5406] goes into. In an LLN such a solution would degenerate into
	every node having a tunnel with every other node. It would provide a		every node having a tunnel with every other node. It would provide a
	small amount of origin address authentication at a very high cost;		small amount of origin address authentication at a very high cost;
	doing BCP38 at every node (linking layer-3 addresses to layer-2		doing BCP38 at every node (linking layer-3 addresses to layer-2
	addresses, and to already present layer-2 cryptographic mechanisms)		addresses, and to already present layer-2 cryptographic mechanisms)
	would be cheaper should RPL be run in an environment where hostile		would be cheaper should RPL be run in an environment where hostile
	nodes are likely to be a part of the LLN.		nodes are likely to be a part of the LLN.
	The RH3 header usage described here can be abused in equivalent ways		The RH3 header usage described here can be abused in equivalent ways
	to the IPIP header. In non-storing networks where an RH3 may be		with an IPIP header to add the needed RH3 header. As such, the
	acted upon, packets arriving into the LLN will be encapsulated with		attacker's RH3 header will not be seen by the network until it
	an IPIP header to add the needed RH3 header. As such, the attacker's		reaches the end host, which will decapsulate it. An end-host SHOULD
	RH3 header will not be seen by the network until it reaches the end		be suspicious about a RH3 header which has additional hops which have
	host, which will decapsulate it. An end-host SHOULD be suspicious		not yet been processed, and SHOULD ignore such a second RH3 header.
	about a RH3 header which has additional hops which have not yet been
	processed, and SHOULD ignore such a second RH3 header.
	In addition, the LLN will likely use [I-D.ietf-roll-routing-dispatch]		In addition, the LLN will likely use [I-D.ietf-roll-routing-dispatch]
	to compress the IPIP and RH3 headers. As such, the compressor at the		to compress the IPIP and RH3 headers. As such, the compressor at the
	RPL-root will see the second RH3 header and MAY choose to discard the		RPL-root will see the second RH3 header and MAY choose to discard the
	packet if the RH3 header has not been completely consumed. A		packet if the RH3 header has not been completely consumed. A
	consumed (inert) RH3 header could be present in a packet that flows		consumed (inert) RH3 header could be present in a packet that flows
	from one LLN, crosses the Internet, and enters another LLN. As per		from one LLN, crosses the Internet, and enters another LLN. As per
	the discussion in this document, such headers do not need to be		the discussion in this document, such headers do not need to be
	removed. However, there is no case described in this document where		removed. However, there is no case described in this document where
	an RH3 is inserted in a non-storing network on traffic that is		an RH3 is inserted in a non-storing network on traffic that is
	skipping to change at page 35, line 23 ¶		skipping to change at page 43, line 21 ¶
	The RH3 and RPI headers could be abused by an attacker inside of the		The RH3 and RPI headers could be abused by an attacker inside of the
	network to route packets on non-obvious ways, perhaps eluding		network to route packets on non-obvious ways, perhaps eluding
	observation. This usage is in fact part of [RFC6997] and can not be		observation. This usage is in fact part of [RFC6997] and can not be
	restricted at all. This is a feature, not a bug.		restricted at all. This is a feature, not a bug.
	[RFC7416] deals with many other threats to LLNs not directly related		[RFC7416] deals with many other threats to LLNs not directly related
	to the use of IPIP headers, and this document does not change that		to the use of IPIP headers, and this document does not change that
	analysis.		analysis.
	11. Acknowledgments		12. Acknowledgments
	This work is partially funded by the FP7 Marie Curie Initial Training		This work is partially funded by the FP7 Marie Curie Initial Training
	Network (ITN) METRICS project (grant agreement No. 607728).		Network (ITN) METRICS project (grant agreement No. 607728).
	The authors would like to acknowledge the review, feedback, and		The authors would like to acknowledge the review, feedback, and
	comments of (alphabetical order): Robert Cragie, Simon Duquennoy,		comments of (alphabetical order): Robert Cragie, Simon Duquennoy,
	Cenk Guendogan, Rahul Jadhav, Peter van der Stok, Xavier Vilajosana		Cenk Guendogan, C. M. Heard, Rahul Jadhav, Peter van der Stok,
	and Thomas Watteyne.		Xavier Vilajosana and Thomas Watteyne.
	12. References		13. References
	12.1. Normative References		13.1. Normative References
	[I-D.ietf-6man-rfc2460bis]		[I-D.ietf-6man-rfc2460bis]
	<>, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6)		Deering, S. and R. Hinden, "Internet Protocol, Version 6
	Specification", draft-ietf-6man-rfc2460bis-09 (work in		(IPv6) Specification", draft-ietf-6man-rfc2460bis-13 (work
	progress), March 2017.		in progress), May 2017.
	[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,
	<http://www.rfc-editor.org/info/rfc2119>.		<http://www.rfc-editor.org/info/rfc2119>.
	[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6		[RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6
	(IPv6) Specification", RFC 2460, December 1998.		(IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
			December 1998, <http://www.rfc-editor.org/info/rfc2460>.
	[RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in		[RFC2473] Conta, A. and S. Deering, "Generic Packet Tunneling in
	IPv6 Specification", RFC 2473, DOI 10.17487/RFC2473,		IPv6 Specification", RFC 2473, DOI 10.17487/RFC2473,
	December 1998, <http://www.rfc-editor.org/info/rfc2473>.		December 1998, <http://www.rfc-editor.org/info/rfc2473>.
	[RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering:		[RFC2827] Ferguson, P. and D. Senie, "Network Ingress Filtering:
	Defeating Denial of Service Attacks which employ IP Source		Defeating Denial of Service Attacks which employ IP Source
	Address Spoofing", BCP 38, RFC 2827, May 2000.		Address Spoofing", BCP 38, RFC 2827, DOI 10.17487/RFC2827,
			May 2000, <http://www.rfc-editor.org/info/rfc2827>.
	[RFC5406] Bellovin, S., "Guidelines for Specifying the Use of IPsec		[RFC5406] Bellovin, S., "Guidelines for Specifying the Use of IPsec
	Version 2", BCP 146, RFC 5406, February 2009.		Version 2", BCP 146, RFC 5406, DOI 10.17487/RFC5406,
			February 2009, <http://www.rfc-editor.org/info/rfc5406>.
	[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,		[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
	Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,		Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
	JP., and R. Alexander, "RPL: IPv6 Routing Protocol for		JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
	Low-Power and Lossy Networks", RFC 6550,		Low-Power and Lossy Networks", RFC 6550,
	DOI 10.17487/RFC6550, March 2012,		DOI 10.17487/RFC6550, March 2012,
	<http://www.rfc-editor.org/info/rfc6550>.		<http://www.rfc-editor.org/info/rfc6550>.
	[RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low-		[RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low-
	Power and Lossy Networks (RPL) Option for Carrying RPL		Power and Lossy Networks (RPL) Option for Carrying RPL
	skipping to change at page 36, line 46 ¶		skipping to change at page 44, line 44 ¶
	of IPv6 Extension Headers", RFC 7045,		of IPv6 Extension Headers", RFC 7045,
	DOI 10.17487/RFC7045, December 2013,		DOI 10.17487/RFC7045, December 2013,
	<http://www.rfc-editor.org/info/rfc7045>.		<http://www.rfc-editor.org/info/rfc7045>.
	[RFC7416] Tsao, T., Alexander, R., Dohler, M., Daza, V., Lozano, A.,		[RFC7416] Tsao, T., Alexander, R., Dohler, M., Daza, V., Lozano, A.,
	and M. Richardson, Ed., "A Security Threat Analysis for		and M. Richardson, Ed., "A Security Threat Analysis for
	the Routing Protocol for Low-Power and Lossy Networks		the Routing Protocol for Low-Power and Lossy Networks
	(RPLs)", RFC 7416, DOI 10.17487/RFC7416, January 2015,		(RPLs)", RFC 7416, DOI 10.17487/RFC7416, January 2015,
	<http://www.rfc-editor.org/info/rfc7416>.		<http://www.rfc-editor.org/info/rfc7416>.
	12.2. Informative References		13.2. Informative References
	[DDOS-KREBS]		[DDOS-KREBS]
	Goodin, D., "Record-breaking DDoS reportedly delivered by		Goodin, D., "Record-breaking DDoS reportedly delivered by
	>145k hacked cameras", September 2016,		>145k hacked cameras", September 2016,
	<http://arstechnica.com/security/2016/09/botnet-of-145k-		<http://arstechnica.com/security/2016/09/botnet-of-145k-
	cameras-reportedly-deliver-internets-biggest-ddos-ever/>.		cameras-reportedly-deliver-internets-biggest-ddos-ever/>.
	[I-D.ietf-6lo-backbone-router]		[I-D.ietf-6lo-backbone-router]
	Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo-		Thubert, P., "IPv6 Backbone Router", draft-ietf-6lo-
	backbone-router-03 (work in progress), January 2017.		backbone-router-03 (work in progress), January 2017.
	skipping to change at page 37, line 28 ¶		skipping to change at page 45, line 28 ¶
	[I-D.ietf-anima-autonomic-control-plane]		[I-D.ietf-anima-autonomic-control-plane]
	Behringer, M., Eckert, T., and S. Bjarnason, "An Autonomic		Behringer, M., Eckert, T., and S. Bjarnason, "An Autonomic
	Control Plane", draft-ietf-anima-autonomic-control-		Control Plane", draft-ietf-anima-autonomic-control-
	plane-06 (work in progress), March 2017.		plane-06 (work in progress), March 2017.
	[I-D.ietf-anima-bootstrapping-keyinfra]		[I-D.ietf-anima-bootstrapping-keyinfra]
	Pritikin, M., Richardson, M., Behringer, M., Bjarnason,		Pritikin, M., Richardson, M., Behringer, M., Bjarnason,
	S., and K. Watsen, "Bootstrapping Remote Secure Key		S., and K. Watsen, "Bootstrapping Remote Secure Key
	Infrastructures (BRSKI)", draft-ietf-anima-bootstrapping-		Infrastructures (BRSKI)", draft-ietf-anima-bootstrapping-
	keyinfra-05 (work in progress), March 2017.		keyinfra-06 (work in progress), May 2017.
	[I-D.ietf-roll-dao-projection]		[I-D.ietf-roll-dao-projection]
	Thubert, P. and J. Pylakutty, "Root initiated routing		Thubert, P. and J. Pylakutty, "Root initiated routing
	state in RPL", draft-ietf-roll-dao-projection-01 (work in		state in RPL", draft-ietf-roll-dao-projection-01 (work in
	progress), March 2017.		progress), March 2017.
	[I-D.ietf-roll-routing-dispatch]		[I-D.ietf-roll-routing-dispatch]
	Thubert, P., Bormann, C., Toutain, L., and R. Cragie,		Thubert, P., Bormann, C., Toutain, L., and R. Cragie,
	"6LoWPAN Routing Header", draft-ietf-roll-routing-		"6LoWPAN Routing Header", draft-ietf-roll-routing-
	dispatch-05 (work in progress), October 2016.		dispatch-05 (work in progress), October 2016.
			[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for
			Renumbering an IPv6 Network without a Flag Day", RFC 4192,
			DOI 10.17487/RFC4192, September 2005,
			<http://www.rfc-editor.org/info/rfc4192>.
	[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet		[RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet
	Control Message Protocol (ICMPv6) for the Internet		Control Message Protocol (ICMPv6) for the Internet
	Protocol Version 6 (IPv6) Specification", RFC 4443,		Protocol Version 6 (IPv6) Specification", RFC 4443,
	DOI 10.17487/RFC4443, March 2006,		DOI 10.17487/RFC4443, March 2006,
	<http://www.rfc-editor.org/info/rfc4443>.		<http://www.rfc-editor.org/info/rfc4443>.
	[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,
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	256 lines changed or deleted		582 lines changed or added
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