< draft-ietf-roll-useofrplinfo-17.txt		draft-ietf-roll-useofrplinfo-18.txt >
	ROLL Working Group M. Robles		ROLL Working Group M. Robles
	Internet-Draft Ericsson		Internet-Draft Ericsson
	Updates: 6553, 6550, 8138 (if approved) M. Richardson		Updates: 6553, 6550, 8138 (if approved) M. Richardson
	Intended status: Standards Track SSW		Intended status: Standards Track SSW
	Expires: April 30, 2018 P. Thubert		Expires: May 2, 2018 P. Thubert
	Cisco		Cisco
	October 27, 2017		October 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-17		draft-ietf-roll-useofrplinfo-18
	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. Additionally, this		to design efficient compression of these headers. Additionally, this
	document updates the RFC 6553 adding a change to the RPL Option Type		document updates the RFC 6553 adding a change to the RPL Option Type
	skipping to change at page 1, line 40 ¶		skipping to change at page 1, line 40 ¶
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on April 30, 2018.		This Internet-Draft will expire on May 2, 2018.
	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
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	skipping to change at page 2, line 31 ¶		skipping to change at page 2, line 31 ¶
	4. Sample/reference topology . . . . . . . . . . . . . . . . . . 8		4. Sample/reference topology . . . . . . . . . . . . . . . . . . 8
	5. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 10		5. Use cases . . . . . . . . . . . . . . . . . . . . . . . . . . 10
	6. Storing mode . . . . . . . . . . . . . . . . . . . . . . . . 12		6. Storing mode . . . . . . . . . . . . . . . . . . . . . . . . 12
	6.1. Storing Mode: Interaction between Leaf and Root . . . . . 13		6.1. Storing Mode: Interaction between Leaf and Root . . . . . 13
	6.1.1. SM: Example of Flow from RPL-aware-leaf to root . . . 14		6.1.1. SM: Example of Flow from RPL-aware-leaf to root . . . 14
	6.1.2. SM: Example of Flow from root to RPL-aware-leaf . . . 15		6.1.2. SM: Example of Flow from root to RPL-aware-leaf . . . 15
	6.1.3. SM: Example of Flow from root to not-RPL-aware-leaf . 15		6.1.3. SM: Example of Flow from root to not-RPL-aware-leaf . 15
	6.1.4. SM: Example of Flow from not-RPL-aware-leaf to root . 16		6.1.4. SM: Example of Flow from not-RPL-aware-leaf to root . 16
	6.2. Storing Mode: Interaction between Leaf and Internet . . . 17		6.2. Storing Mode: Interaction between Leaf and Internet . . . 17
	6.2.1. SM: Example of Flow from RPL-aware-leaf to Internet . 17		6.2.1. SM: Example of Flow from RPL-aware-leaf to Internet . 17
	6.2.2. SM: Example of Flow from Internet to RPL-aware-leaf . 18		6.2.2. SM: Example of Flow from Internet to RPL-aware-leaf . 17
	6.2.3. SM: Example of Flow from not-RPL-aware-leaf to		6.2.3. SM: Example of Flow from not-RPL-aware-leaf to
	Internet . . . . . . . . . . . . . . . . . . . . . . 19		Internet . . . . . . . . . . . . . . . . . . . . . . 18
	6.2.4. SM: Example of Flow from Internet to non-RPL-aware-		6.2.4. SM: Example of Flow from Internet to non-RPL-aware-
	leaf . . . . . . . . . . . . . . . . . . . . . . . . 20		leaf . . . . . . . . . . . . . . . . . . . . . . . . 19
	6.3. Storing Mode: Interaction between Leaf and Leaf . . . . . 21		6.3. Storing Mode: Interaction between Leaf and Leaf . . . . . 20
	6.3.1. SM: Example of Flow from RPL-aware-leaf to RPL-aware-		6.3.1. SM: Example of Flow from RPL-aware-leaf to RPL-aware-
	leaf . . . . . . . . . . . . . . . . . . . . . . . . 21		leaf . . . . . . . . . . . . . . . . . . . . . . . . 20
	6.3.2. SM: Example of Flow from RPL-aware-leaf to non-RPL-		6.3.2. SM: Example of Flow from RPL-aware-leaf to non-RPL-
	aware-leaf . . . . . . . . . . . . . . . . . . . . . 22		aware-leaf . . . . . . . . . . . . . . . . . . . . . 21
	6.3.3. SM: Example of Flow from not-RPL-aware-leaf to RPL-		6.3.3. SM: Example of Flow from not-RPL-aware-leaf to RPL-
	aware-leaf . . . . . . . . . . . . . . . . . . . . . 23		aware-leaf . . . . . . . . . . . . . . . . . . . . . 22
	6.3.4. SM: Example of Flow from not-RPL-aware-leaf to not-		6.3.4. SM: Example of Flow from not-RPL-aware-leaf to not-
	RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 24		RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 23
	7. Non Storing mode . . . . . . . . . . . . . . . . . . . . . . 26		7. Non Storing mode . . . . . . . . . . . . . . . . . . . . . . 24
	7.1. Non-Storing Mode: Interaction between Leaf and Root . . . 27		7.1. Non-Storing Mode: Interaction between Leaf and Root . . . 25
	7.1.1. Non-SM: Example of Flow from RPL-aware-leaf to root . 28		7.1.1. Non-SM: Example of Flow from RPL-aware-leaf to root . 26
	7.1.2. on-SM: Example of Flow from root to RPL-aware-leaf . 28		7.1.2. on-SM: Example of Flow from root to RPL-aware-leaf . 26
	7.1.3. Non-SM: Example of Flow from root to not-RPL-aware-		7.1.3. Non-SM: Example of Flow from root to not-RPL-aware-
	leaf . . . . . . . . . . . . . . . . . . . . . . . . 29		leaf . . . . . . . . . . . . . . . . . . . . . . . . 27
	7.1.4. Non-SM: Example of Flow from not-RPL-aware-leaf to		7.1.4. Non-SM: Example of Flow from not-RPL-aware-leaf to
	root . . . . . . . . . . . . . . . . . . . . . . . . 30		root . . . . . . . . . . . . . . . . . . . . . . . . 28
	7.2. Non-Storing Mode: Interaction between Leaf and Internet . 31		7.2. Non-Storing Mode: Interaction between Leaf and Internet . 29
	7.2.1. Non-SM: Example of Flow from RPL-aware-leaf to		7.2.1. Non-SM: Example of Flow from RPL-aware-leaf to
	Internet . . . . . . . . . . . . . . . . . . . . . . 31		Internet . . . . . . . . . . . . . . . . . . . . . . 29
	7.2.2. Non-SM: Example of Flow from Internet to RPL-aware-		7.2.2. Non-SM: Example of Flow from Internet to RPL-aware-
	leaf . . . . . . . . . . . . . . . . . . . . . . . . 32		leaf . . . . . . . . . . . . . . . . . . . . . . . . 30
	7.2.3. Non-SM: Example of Flow from not-RPL-aware-leaf to		7.2.3. Non-SM: Example of Flow from not-RPL-aware-leaf to
	Internet . . . . . . . . . . . . . . . . . . . . . . 33		Internet . . . . . . . . . . . . . . . . . . . . . . 31
	7.2.4. Non-SM: Example of Flow from Internet to not-RPL-		7.2.4. Non-SM: Example of Flow from Internet to not-RPL-
	aware-leaf . . . . . . . . . . . . . . . . . . . . . 34		aware-leaf . . . . . . . . . . . . . . . . . . . . . 32
	7.3. Non-Storing Mode: Interaction between Leafs . . . . . . . 35		7.3. Non-Storing Mode: Interaction between Leafs . . . . . . . 33
	7.3.1. Non-SM: Example of Flow from RPL-aware-leaf to RPL-		7.3.1. Non-SM: Example of Flow from RPL-aware-leaf to RPL-
	aware-leaf . . . . . . . . . . . . . . . . . . . . . 35		aware-leaf . . . . . . . . . . . . . . . . . . . . . 33
	7.3.2. Non-SM: Example of Flow from RPL-aware-leaf to not-		7.3.2. Non-SM: Example of Flow from RPL-aware-leaf to not-
	RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 37		RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 35
	7.3.3. Non-SM: Example of Flow from not-RPL-aware-leaf to		7.3.3. Non-SM: Example of Flow from not-RPL-aware-leaf to
	RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 38		RPL-aware-leaf . . . . . . . . . . . . . . . . . . . 36
	7.3.4. Non-SM: Example of Flow from not-RPL-aware-leaf to		7.3.4. Non-SM: Example of Flow from not-RPL-aware-leaf to
	not-RPL-aware-leaf . . . . . . . . . . . . . . . . . 39		not-RPL-aware-leaf . . . . . . . . . . . . . . . . . 37
	8. Observations about the cases . . . . . . . . . . . . . . . . 40		8. Observations about the cases . . . . . . . . . . . . . . . . 37
	8.1. Storing mode . . . . . . . . . . . . . . . . . . . . . . 40		8.1. Storing mode . . . . . . . . . . . . . . . . . . . . . . 37
	8.2. Non-Storing mode . . . . . . . . . . . . . . . . . . . . 41		8.2. Non-Storing mode . . . . . . . . . . . . . . . . . . . . 38
	9. 6LoRH Compression cases . . . . . . . . . . . . . . . . . . . 41		9. 6LoRH Compression cases . . . . . . . . . . . . . . . . . . . 38
	10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 41		10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 39
	11. Security Considerations . . . . . . . . . . . . . . . . . . . 42		11. Security Considerations . . . . . . . . . . . . . . . . . . . 39
	12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 45		12. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 42
	13. References . . . . . . . . . . . . . . . . . . . . . . . . . 45		13. References . . . . . . . . . . . . . . . . . . . . . . . . . 42
	13.1. Normative References . . . . . . . . . . . . . . . . . . 45		13.1. Normative References . . . . . . . . . . . . . . . . . . 42
	13.2. Informative References . . . . . . . . . . . . . . . . . 46		13.2. Informative References . . . . . . . . . . . . . . . . . 43
	Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 48		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 45
	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 4, line 16 ¶		skipping to change at page 4, line 16 ¶
	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 clarifies what is the correct and the		discussion. This document clarifies what is the correct and the
	incorrect behaviour.		incorrect 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		[RFC8138] defines a method to compress RPL Option information and
	Option information and Routing Header type 3 [RFC6554], an efficient		Routing Header type 3 [RFC6554], an efficient IP-in-IP technique, and
	IP-in-IP technique, and use cases proposed for the		use cases proposed for the [Second6TischPlugtest] involving 6loRH.
	[Second6TischPlugtest] involving 6loRH.
	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: A 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 does not implement RPL, thus we		RPL-not-capable: A device which does not implement RPL, thus we can
	can say that the device is not-RPL-aware. Please note that the		say that the device is not-RPL-aware. Please note that the device
	device can be found inside the LLN. In this document a not-RPL-aware		can be found inside the LLN. In this document a not-RPL-aware node
	node which 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		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		of it, is changed during a planned outage, or suddenly, causing an
	skipping to change at page 5, line 32 ¶		skipping to change at page 5, line 32 ¶
	option type, and the third bit indicates that the Option Data may		option type, and the third bit indicates that the Option Data may
	change en route. The remaining bits serve as the option type.		change en route. The remaining bits serve as the option type.
	Hex Value Binary Value		Hex Value Binary Value
	act chg rest Description Reference		act chg rest Description Reference
	--------- --- --- ------- ----------------- ----------		--------- --- --- ------- ----------------- ----------
	0x63 01 1 00011 RPL Option [RFC6553]		0x63 01 1 00011 RPL Option [RFC6553]
	Figure 1: Option Type in RPL Option.		Figure 1: Option Type in RPL Option.
	Recent changes in [I-D.ietf-6man-rfc2460bis], state: "it is now		Recent changes in [RFC8200] (section 4, page 8), states: "it is now
	expected that nodes along a packet's delivery path only examine and		expected that nodes along a packet's delivery path only examine and
	process the Hop-by-Hop Options header if explicitly configured to do		process the Hop-by-Hop Options header if explicitly configured to do
	so". Processing of the Hop-by-Hop Options header (by IPv6		so". Processing of the Hop-by-Hop Options header (by IPv6
	intermediate nodes) is now optional, but if they are configured to		intermediate nodes) is now optional, but if they are configured to
	process the header, and if such nodes encounter an option with the		process the header, and if such nodes encounter an option with the
	first two bits set to 01, they will drop the packet (if they conform		first two bits set to 01, they will drop the packet (if they conform
	[I-D.ietf-6man-rfc2460bis]). The hosts should do the same,		to [RFC8200]). Host systems should do the same, irrespective of the
	irrespective of the configuration.		configuration.
	Based on That, if an IPv6 (intermediate) node (RPL-not-capable)		Based on That, if an IPv6 (intermediate) node (RPL-not-capable)
	receives a packet with an RPL Option, it should ignore the HBH RPL		receives a packet with an RPL Option, it should ignore the HBH RPL
	option (skip over this option and continue processing the header).		option (skip over this option and continue processing the header).
	Thus, this document updates the Option Type field to: the two high		Thus, 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'.		order bits MUST be set to '00' and the third bit is equal to '1'.
	The first two bits indicate that the IPv6 node MUST skip over this		The first two bits indicate that the IPv6 node MUST skip over this
	option and continue processing the header		option and continue processing the header ([RFC8200] Section 4.2) if
	(Section 4.2.[I-D.ietf-6man-rfc2460bis] ) if it doesn't recognize the		it doesn't recognize the option type, and the third bit continues to
	option type, and the third bit continues to be set to indicate that		be set to indicate that the Option Data may change en route. The
	the Option Data may change en route. The remaining bits serve as the		remaining bits serve as the option type and remain as 0x3. This
	option type and remain as 0x3. This ensures that a packet that		ensures that a packet that leaves the RPL domain of an LLN (or that
	leaves the RPL domain of an LLN (or that leaves the LLN entirely)		leaves the LLN entirely) will not be discarded when it contains the
	will not be discarded when it contains the [RFC6553] RPL Hop-by-Hop		[RFC6553] RPL Hop-by-Hop option known as RPI.
	option known as RPI. This is an update to [RFC6553].
			This is a significant update to [RFC6553].
	Hex Value Binary Value		Hex Value Binary Value
	act chg rest Description Reference		act chg rest Description Reference
	--------- --- --- ------- ----------------- ----------		--------- --- --- ------- ----------------- ----------
	0x23 00 1 00011 RPL Option [RFCXXXX]		0x23 00 1 00011 RPL Option [RFCXXXX]
	Figure 2: Proposed change to the Option Type in RPL Option.		Figure 2: Revised Option Type in RPL Option.
	This change creates a flag day for existing networks which are		This change creates a flag day for existing networks which are
	currently using 0x63 as the RPI value. A move to 0x23 will not be		currently using 0x63 as the RPI value. A move to 0x23 will not be
	understood by those networks. It is suggested that implementations		understood by those networks. It is suggested that implementations
	accept both 0x63 and 0x23 when processing. When forwarding packets,		accept both 0x63 and 0x23 when processing. When forwarding packets,
	implementations SHOULD use the same value as it was received. When		implementations SHOULD use the same value as it was received. When
	originating new packets, implementations SHOULD have an option to		originating new packets, implementations SHOULD have an option to
	determine which value to originate with, this option is controlled by		determine which value to originate with, this option is controlled by
	the DIO option described below.		the DIO option described below.
	A network which is switching from straight 6lowpan compression		A network which is switching from straight 6lowpan compression
	mechanism to those described in [I-D.ietf-roll-routing-dispatch] will		mechanism to those described in [RFC8183] will experience a flag day
	experience a flag day in the data compression anyway, and if possible		in the data compression anyway, and if possible this change can be
	this change can be deployed at the same time.		deployed at the same time.
	3.2. Updates to RFC 8138		3.2. Updates to RFC 8138
	RPI-6LoRH header provides a compressed form for the RPL RPI		RPI-6LoRH header provides a compressed form for the RPL RPI
	[RFC8138]. It should be considered when the Option Type in RPL		[RFC8138]. It should be considered when the Option Type in RPL
	Option is decompressed, should take the value of 0x23 instead of		Option is decompressed, should take the value of 0x23 instead of
	0x63.		0x63.
	3.3. Updates to RFC 6550: Indicating the new RPI in the DODAG		3.3. Updates to RFC 6550: Indicating the new RPI in the DODAG
	Configuration Option Flag.		Configuration Option Flag.
	In order to avoid a flag day caused by lack of interoperation between		In order to avoid a flag day caused by lack of interoperation between
	new RPI (0x23) and old RPI (0x63) nodes, the new nodes need to be		new RPI (0x23) and old RPI (0x63) nodes, when there is a mix of new
	told that there are old RPI nodes present. This can be done via the		nodes and old nodes, the new nodes may be put into a compatibilit
	DODAG Configuration Option flag which will propogate through the		mode until all of the old nodes are replaced or upgraded.
	network. Failure to receive this information will cause dual mode
	nodes to originate traffic with the old-RPI (0x63) value.
	As states in [RFC6550] the DODAG Configuration option is present in		This can be done via a DODAG Configuration Option flag which will
	DIO messages. the DODAG Configuration option distribute		propogate through the network. Failure to receive this information
	configuration information which is generally static and unchanging		will cause new nodes to remain in compatibility mode, and originate
	within the DODAG. This information is configured at the DODAG root		traffic with the old-RPI (0x63) value.
	and distributed throughout the DODAG with the DODAG Configuration
	option. Nodes other than the DODAG root must not modify this
	information when propagating the DODAG Configuration option.
	The DODAG Configuration Option is as follow. We are interested in		As stated in [RFC6550] the DODAG Configuration option is present in
	the Flag field. The remaining fields states as defined in [RFC6550].		DIO messages. The DODAG Configuration option distributes
			configuration information. It is generally static, and does not
			change within the DODAG. This information is configured at the DODAG
			root and distributed throughout the DODAG with the DODAG
			Configuration option. Nodes other than the DODAG root do not modify
			this information when propagating the DODAG Configuration option.
			The DODAG Configuration Option is as follows. The Flag field is the
			interesting field. The remaining fields states as defined in
			[RFC6550].
	Flags: The 4-bits remaining unused in the Flags field are reserved		Flags: The 4-bits remaining unused in the Flags field are reserved
	for flags. The field MUST be initialized to zero by the sender and		for flags. The field MUST be initialized to zero by the sender and
	MUST be ignored by the receiver.		MUST be ignored by the receiver.
	0 1 2 3		0 1 2 3
	+-----------------+---------------------------------------------------+		+-----------------+---------------------------------------------------+
	| Type = 0x04 | Opt Length = 14| Flags | A | PCS| DIOIntDoubl. |		| Type = 0x04 | Opt Length = 14| Flags | A | PCS| DIOIntDoubl. |
	+---------------------------------------------------------------------+		+---------------------------------------------------------------------+
	| DIOIntMin. | DIORedund. | MaxRankIncrease |		| DIOIntMin. | DIORedund. | MaxRankIncrease |
	+-----------------+---------------------------------------------------+		+-----------------+---------------------------------------------------+
	| MinHopRankIncrease | OCP |		| MinHopRankIncrease | OCP |
	+-----------------+---------------------------------------------------+		+-----------------+---------------------------------------------------+
	|Reserved | Def. Lifetime | Lifetime Unit |		|Reserved | Def. Lifetime | Lifetime Unit |
	+-----------------+-----------------+---------------------------------+		+-----------------+-----------------+---------------------------------+
	Figure 3: DODAG Configuration Option.		Figure 3: DODAG Configuration Option.
	We propose to use the flag in the DODAG Configuration option as		Bit number three of flag field in the DODAG Configuration option is
	follows:		to be used as follows:
	+------------+-----------------+---------------+		+------------+-----------------+---------------+
	| Bit number | Description | Reference |		| Bit number | Description | Reference |
	+------------+-----------------+---------------+		+------------+-----------------+---------------+
	| 3 | RPI 0x23 enable | This document |		| 3 | RPI 0x23 enable | This document |
	+------------+-----------------+---------------+		+------------+-----------------+---------------+
	Figure 4: DODAG Configuration Option Flag to indicate the RPI-flag-		Figure 4: DODAG Configuration Option Flag to indicate the RPI-flag-
	day.		day.
	skipping to change at page 8, line 19 ¶		skipping to change at page 8, line 22 ¶
	(6LoWPAN Node) as leaf logically organized in a DODAG structure.		(6LoWPAN Node) as leaf logically organized in a DODAG structure.
	(Destination Oriented Directed Acyclic Graph).		(Destination Oriented 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; in non-storing (RPL-NSM), it is fully source
	source routed. A RPL Instance is either fully storing or fully non-		routed. A RPL Instance is either fully storing or fully non-storing,
	storing, i.e. a RPL Instance with a combination of storing and non-		i.e. a RPL Instance with a combination of storing and non-storing
	storing nodes is not supported with the current specifications at the		nodes is not supported with the current specifications at the time of
	time of writing this document.		writing this document.
	+--------------+		+--------------+
	| Upper Layers |		| Upper Layers |
	| |		| |
	+--------------+		+--------------+
	| RPL |		| RPL |
	| |		| |
	+--------------+		+--------------+
	| ICMPv6 |		| ICMPv6 |
	| |		| |
	skipping to change at page 9, line 50 ¶		skipping to change at page 10, line 4 ¶
	F | | G | H | |		F | | G | H | |
	+-----+-+ +-|-----+ +---|--+ +---|---+ +---|---+		+-----+-+ +-|-----+ +---|--+ +---|---+ +---|---+
	| Raf | | ~Raf | | Raf | | Raf | | ~Raf |		| Raf | | ~Raf | | Raf | | Raf | | ~Raf |
	| 6LN | | 6LN | | 6LN | | 6LN | | 6LN |		| 6LN | | 6LN | | 6LN | | 6LN | | 6LN |
	+-------+ +-------+ +------+ +-------+ +-------+		+-------+ +-------+ +------+ +-------+ +-------+
	Figure 6: A reference RPL Topology.		Figure 6: 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
	letters above the nodes are there so that they may be referenced in		letters above the nodes are there so that they may be referenced in
	subsequent sections. In the figure, a 6LR is a router. A 6LN can be		subsequent sections. In the figure, 6LR represents a full router
	a router or a host. The 6LN leaves (Raf - "RPL aware leaf"-) marked		node. The 6LN is a RPL aware router, or host.
	as (F and I) are RPL hosts that does not have forwarding capability.
	The 6LN leaf (H) is a RPL router. The leafs marked as ~Raf "not-RPL		But, the 6LN leaves (Raf - "RPL aware leaf"-) marked as (F, H and I)
	aware leaf" (G and J) are devices which do not speak RPL at all (not-		are RPL nodes with no children hosts.
	RPL-aware), but uses Router-Advertisements, 6LowPAN DAR/DAC and
	efficient-ND only to participate in the network [RFC6775]. In the		The leafs marked as ~Raf "not-RPL aware leaf" (G and J) are devices
	document these leafs (G and J) are often named IPv6 node. The 6LBR		which do not speak RPL at all (not-RPL-aware), but uses Router-
	in the figure is the root of the Global DODAG.		Advertisements, 6LowPAN DAR/DAC and efficient-ND only to participate
			in the network [RFC6775]. In the document these leafs (G and J) are
			also refered to as an IPv6 node.
			The 6LBR ("A") in the figure is the root of the Global DODAG.
	5. Use cases		5. Use cases
	In the data plane a combination of RFC6553, RFC6554 and IPv6-in-IPv6		In the data plane a combination of RFC6553, RFC6554 and IPv6-in-IPv6
	encapsulation is going to be analyzed for a number of representative		encapsulation are going to be analyzed for a number of representative
	traffic flows.		traffic flows.
	This document assumes that the LLN is using the no-drop RPI option		This document assumes that the LLN is using the no-drop RPI option
	(0x23).		(0x23).
	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 leaves that do not
	understand RPL and they are part of hte LLN. We name these nodes as		understand RPL, but are part of the LLN. We name these nodes as not-
	not-RPL-aware-leaf.(e.g. section 5.4- Flow from not-RPL-aware-leaf to		RPL-aware-leaf. (e.g. Section 6.1.4 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 6.2.3 Flow from not-
	aware-leaf to Internet)		RPL-aware-leaf to Internet)
	The uses cases comprise as follow:		The uses cases comprise as follow:
	Interaction between Leaf and Root:		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
	skipping to change at page 10, line 47 ¶		skipping to change at page 11, line 4 ¶
	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:		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:		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 is consistent with the rule that a Header cannot be
	removed on the fly inside an IPv6 packet that is being routed. This		inserted or removed on the fly inside an IPv6 packet that is being
	is a fundamental precept of the IPv6 architecture as outlined in		routed. This is a fundamental precept of the IPv6 architecture as
	[RFC2460]. Extensions may not be added or removed except by the		outlined in [RFC2460]. Extensions may not be added or removed except
	sender or the receiver.		by the sender or the receiver.
	But, options in the Hop-by-Hop Option Header whose option type has		However, unlike [RFC6553], the Hop-by-Hop Option Header used for the
	the first two bits set to '00' MUST ignored when received by a host		RPI artifact has the first two bits set to '00'. This means that the
	or router that does not understand that option ( Section 4.2		RPI artifact will be ignored when received by a host or router that
	[I-D.ietf-6man-rfc2460bis]).		does not understand that option ( Section 4.2 [RFC8200]).
	This means that when the no-drop RPI option code 0x23 is used, a		This means that when the no-drop RPI option code 0x23 is used, a
	packet that leaves the RPL domain of an LLN (or that leaves the LLN		packet that leaves the RPL domain of an LLN (or that leaves the LLN
	entirely) will not be discarded when it contains the [RFC6553] RPL		entirely) will not be discarded when it contains the [RFC6553] RPL
	Hop-by-Hop option known as RPI. Thus, the RPI Hop-by-Hop option MAY		Hop-by-Hop option known as RPI. Thus, the RPI Hop-by-Hop option MAY
	be left in place even if the end host does not understand it.		be left in place even if the end host does not understand it.
	NOTE: There is some possible security risk when the RPI information		NOTE: There is some possible security risk when the RPI information
	is released to the Internet. At this point this is a theoretical		is released to the Internet. At this point this is a theoretical
	situation. It is clear that the RPI option would waste some network		situation; no clear attack has been described. At worst, it is clear
	bandwidth when it escapes.		that the RPI option would waste some network bandwidth when it
			escapes. This is traded off against the savings in the LLN by not
			having to encapsulate the packet in order to remove the artifact.
	An intermediate router that needs to add an extension header (SHR3 or		Despite being legal to leave the RPI artifact in place, an
	RPI Option) must encapsulate the packet in an (additional) outer IP		intermediate router that needs to add an extension header (SHR3 or
	header. The new header can be placed is placed after this new outer		RPI Option) MUST still encapsulate the packet in an (additional)
	IP header.		outer IP header. The new header is placed after this new outer IP
			header.
	A corollory is that an SHR3 or RPI Option can only be removed by an		A corollory is that an SHR3 or RPI Option can only be removed by an
	intermediate router if it is placed in an encapsulating IPv6 Header,		intermediate router if it is placed in an encapsulating IPv6 Header,
	which is addressed to the intermediate router. When it does so, the		which is addressed TO the intermediate router. When it does so, the
	whole encapsulating header must be removed. (A replacement may be		whole encapsulating header must be removed. (A replacement may be
	added). This sometimes can result in outer IP headers being		added). This sometimes can result in outer IP headers being
	addressed to the next hop router using link-local addresses.		addressed to the next hop router using link-local addresses.
	Both RPI and RH3 headers may be modified in very specific ways by		Both RPI and RH3 headers may be modified in very specific ways by
	routers on the path of the packet without the need to add to remove		routers on the path of the packet without the need to add to remove
	an encapsulating header. Both headers were designed with this		an encapsulating header. Both headers were designed with this
	modification in mind, and both the RPL RH and the RPL option are		modification in mind, and both the RPL RH and the RPL option are
	marked mutable but recoverable: so an IPsec AH security header can be		marked mutable but recoverable: so an IPsec AH security header can be
	applied across these headers, but it can not secure the values which		applied across these headers, but it can not secure the values which
	mutate.		mutate.
	RPI should be present in every single RPL data packet. There is one		RPI should be present in every single RPL data packet. There is one
	exception in non-storing mode: when a packet is going down from the		exception in non-storing mode: when a packet is going down from the
	root. In a downward non-storing mode, the entire route is written,		root. In a downward non-storing mode, the entire route is written,
	so there can be no loops by construction, nor any confusion about		so there can be no loops by construction, nor any confusion about
	which forwarding table to use (as the root has already made all		which forwarding table to use (as the root has already made all
	routing decisions). There still may be cases (such as in 6tisch)		routing decisions). However, there are still cases, such as in
	where the instanceID portion of the RPI header may still be needed to		6tisch, where the instanceID portion of the RPI header may still be
	pick an appropriate priority or channel at each hop.		needed to 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.
	6. Storing mode		6. Storing mode
	In storing mode (fully stateful), the sender can determine if the		In storing mode (fully stateful), the sender can determine if the
	destination is inside the LLN by looking if the destination address		destination is inside the LLN by looking if the destination address
	is matched by the DIO's PIO option.		is matched by the DIO's PIO option.
	The following table summarizes what headers are needed in the		The following table itemizes which headers are needed in the
	following scenarios, and indicates when the IP-in-IP header must be		following scenarios, and indicates if 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, or when it can target the destination
	destination node directly. There are these possible situations: hop-		node directly. There are these possible situations: hop-by-hop
	by-hop necessary (indicated by "hop"), or destination address		necessary (indicated by "hop"), or destination address possible
	possible (indicated by "dst"). In all cases hop by hop can be used.		(indicated by "dst"). In all cases hop by hop MAY 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 storing 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		In each case, 6LR_i are the intermediate routers from source to
	(Figure 2).		destination. "1 <= i >= n", n is the number of routers (6LR) that
			the packet go through from source (6LN) to destination.
	+---------------------+--------------+----------+--------------+		The leaf can be a router 6LR or a host, both indicated as 6LN (see
	| Interaction between | Use Case | IP-in-IP | IP-in-IP dst |		Figure 6).
	+---------------------+--------------+----------+--------------+
	| | Raf to root | No | -- |		+---------------------+--------------+----------+--------------+
	+ +--------------+----------+--------------+		| Interaction between | Use Case | IP-in-IP | IP-in-IP dst |
	| Leaf - Root | root to Raf | No | -- |		+---------------------+--------------+----------+--------------+
	+ +--------------+----------+--------------+		| | Raf to root | No | -- |
	| | root to ~Raf | No | -- |		+ +--------------+----------+--------------+
	+ +--------------+----------+--------------+		| Leaf - Root | root to Raf | No | -- |
	| | ~Raf to root | Yes | root |		+ +--------------+----------+--------------+
	+---------------------+--------------+----------+--------------+		| | root to ~Raf | No | -- |
	| | Raf to Int | No | -- |		+ +--------------+----------+--------------+
	+ +--------------+----------+--------------+		| | ~Raf to root | Yes | root |
	| Leaf - Internet | Int to Raf | Yes | Raf |		+---------------------+--------------+----------+--------------+
	+ +--------------+----------+--------------+		| | Raf to Int | No | -- |
	| | ~Raf to Int | Yes | root |		+ +--------------+----------+--------------+
	+ +--------------+----------+--------------+		| Leaf - Internet | Int to Raf | Yes | Raf |
	| | Int to ~Raf | Yes | hop |		+ +--------------+----------+--------------+
	+---------------------+--------------+----------+--------------+		| | ~Raf to Int | Yes | root |
	| | Raf to Raf | No | -- |		+ +--------------+----------+--------------+
	+ +--------------+----------+--------------+		| | Int to ~Raf | Yes | hop |
	| | Raf to ~Raf | No | -- |		+---------------------+--------------+----------+--------------+
	+ Leaf - Leaf +--------------+----------+--------------+		| | Raf to Raf | No | -- |
	| | ~Raf to Raf | Yes | dst |		+ +--------------+----------+--------------+
	+ +--------------+----------+--------------+		| | Raf to ~Raf | No | -- |
	| | ~Raf to ~Raf | Yes | hop |		+ Leaf - Leaf +--------------+----------+--------------+
	+---------------------+--------------+----------+--------------+		| | ~Raf to Raf | Yes | dst |
			+ +--------------+----------+--------------+
			| | ~Raf to ~Raf | Yes | hop |
			+---------------------+--------------+----------+--------------+
	Figure 7: IP-in-IP encapsulation in Storing mode.		Figure 7: IP-in-IP encapsulation in Storing mode.
	6.1. Storing Mode: Interaction between Leaf and Root		6.1. Storing Mode: Interaction between Leaf and Root
	In this section we are going to describe the communication flow in		In this section we are going to describe the communication flow in
	storing mode (SM) between,		storing mode (SM) between,
	RPL-aware-leaf to root		RPL-aware-leaf to root
	skipping to change at page 13, line 43 ¶		skipping to change at page 14, line 4 ¶
	Figure 7: IP-in-IP encapsulation in Storing mode.		Figure 7: IP-in-IP encapsulation in Storing mode.
	6.1. Storing Mode: Interaction between Leaf and Root		6.1. Storing Mode: Interaction between Leaf and Root
	In this section we are going to describe the communication flow in		In this section we are going to describe the communication flow in
	storing mode (SM) between,		storing mode (SM) between,
	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
	6.1.1. SM: Example of Flow from RPL-aware-leaf to root		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] an 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)
	For example, the communication flow would be: Node F --> Node E -->		For example, a communication flow could be: Node F --> Node E -->
	Node B --> Node A root(6LBR)		Node B --> Node A root(6LBR)
	6LR_i (Node E and Node B) are the intermediate routers from source to		As it was mentioned in this document 6LRs, 6LBR are always full-
	destination. In this case, "1 <= i >= n", n is the number of routers		fledged RPL 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-
	fledge RPL routers.
	The 6LN (Node F) inserts the RPI header, and sends the packet to 6LR		The 6LN (Node F) inserts the RPI header, and sends the packet to 6LR
	(Node E) which decrements the rank in RPI and sends the packet up.		(Node E) which decrements the rank in RPI and sends the packet up.
	When the packet arrives at 6LBR (Node A), the RPI is removed and the		When the packet arrives at 6LBR (Node A), the RPI is removed and the
	packet is processed.		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
	skipping to change at page 15, line 23 ¶		skipping to change at page 15, line 23 ¶
	+-------------------+-----+-------+------+		+-------------------+-----+-------+------+
	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
	6.1.2. SM: 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) -->		For example, a communication flow could be: Node A root(6LBR) -->
	Node B --> Node D --> Node F		Node B --> Node D --> Node F
	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
	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 (it examines the
	for multiple tables), the packet is processed in 6LN and RPI removed.		instanceID to identify the right forwarding table), the packet is
			processed in the 6LN and the RPI removed.
	No IP-in-IP header is required.		No IP-in-IP header is required.
	+-------------------+------+-------+------+		+-------------------+------+-------+------+
	| Header | 6LBR | 6LR_i | 6LN |		| Header | 6LBR | 6LR_i | 6LN |
	+-------------------+------+-------+------+		+-------------------+------+-------+------+
	| 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
	6.1.3. SM: 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
	this case, "1 <= i >= n", n is the number of routers (6LR) that the
	packet go through from source (6LBR) to destination (IPv6).
			For example, a communication flow could be: Node A root(6LBR) -->
			Node B --> Node E --> Node G
	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 |
	+-------------------+------+-------+----------------+		+-------------------+------+-------+----------------+
	| Inserted headers | RPI | -- | -- |		| Inserted headers | RPI | -- | -- |
	| Removed headers | -- | -- | -- |		| Removed headers | -- | -- | -- |
	| Re-added headers | -- | -- | -- |		| Re-added headers | -- | -- | -- |
	| Modified headers | -- | RPI | -- |		| Modified headers | -- | RPI | -- |
	skipping to change at page 16, line 33 ¶		skipping to change at page 16, line 26 ¶
	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
	6.1.4. SM: 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 -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A root(6LBR)		Node B --> Node A root(6LBR)
	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
	packet go through from source (IPv6) to destination (6LBR). For
	example, 6LR_1 (i=1) is the router that receives the packets from the
	IPv6 node (Node G).
	When the packet arrives from IPv6 node (Node G) to 6LR_1 (Node E),		When the packet arrives from IPv6 node (Node G) to 6LR_1 (Node E),
	the 6LR_1 will insert a RPI header, encapsuladed in a IPv6-in-IPv6		the 6LR_1 will insert a RPI header, encapsuladed in a IPv6-in-IPv6
	header. The IPv6-in-IPv6 header can be addressed to the next hop		header. The IPv6-in-IPv6 header can be addressed to the next hop
	(Node B), or to the root (Node A). The root removes the header and		(Node B), or to the root (Node A). The root removes the header and
	processes the packet.		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) | -- | -- |
	skipping to change at page 17, line 48 ¶		skipping to change at page 17, line 30 ¶
	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 -->		For example, the communication flow could be: Node F --> Node D -->
	Node B --> Node A root(6LBR) --> Internet		Node B --> Node A root(6LBR) --> Internet
	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
	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)
	+-------------------+------+-------+------+----------------+		+-------------------+------+-------+------+----------------+
	| Header | 6LN | 6LR_i | 6LBR | Internet |		| Header | 6LN | 6LR_i | 6LBR | Internet |
	+-------------------+------+-------+------+----------------+		+-------------------+------+-------+------+----------------+
	| Inserted headers | RPI | -- | -- | -- |		| Inserted headers | RPI | -- | -- | -- |
	| Removed headers | -- | -- | -- | -- |		| Removed headers | -- | -- | -- | -- |
	skipping to change at page 18, line 26 ¶		skipping to change at page 18, line 4 ¶
	+-------------------+------+-------+------+----------------+		+-------------------+------+-------+------+----------------+
	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
	6.2.2. SM: 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, a communication flow could be: Internet --> Node A
	For example, the communication flow could be: Internet --> Node A
	root(6LBR) --> Node B --> Node D --> Node F		root(6LBR) --> Node B --> Node D --> Node F
	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
	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.
	+----------+---------+--------------+---------------+---------------+		+----------+---------+--------------+---------------+---------------+
	| Header | Interne | 6LBR | 6LR_i | 6LN |		| Header | Interne | 6LBR | 6LR_i | 6LN |
	| | t | | | |		| | t | | | |
	+----------+---------+--------------+---------------+---------------+		+----------+---------+--------------+---------------+---------------+
	| Inserted | -- | IP-in- | -- | -- |		| Inserted | -- | IP-in- | -- | -- |
	skipping to change at page 19, line 32 ¶		skipping to change at page 18, line 39 ¶
	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
	6.2.3. SM: 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 -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A root(6LBR) --> Internet		Node B --> Node A root(6LBR) --> Internet
	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
	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. (EDNOTE: we SHOULD recommend one
			or the other)
	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
	6LBR will set the flow label of the packet to a non-zero value when		6LBR will set the flow label of the packet to a non-zero value when
	sending to the Internet.		sending to the Internet.
	+---------+-----+-------------+-------------+-------------+---------+		+---------+-----+-------------+-------------+-------------+---------+
	| Header | IPv | 6LR_1 | 6LR_i | 6LBR | Interne |		| Header | IPv | 6LR_1 | 6LR_i | 6LBR | Interne |
	| | 6 | | [i=2,..,n]_ | | t |		| | 6 | | [i=2,..,n]_ | | t |
	+---------+-----+-------------+-------------+-------------+---------+		+---------+-----+-------------+-------------+-------------+---------+
	skipping to change at page 20, line 34 ¶		skipping to change at page 19, line 34 ¶
	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
	6.2.4. SM: 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		For example, a communication flow could be: Internet --> Node A
	root(6LBR) --> Node B --> Node E --> Node G		root(6LBR) --> Node B --> Node E --> Node G
	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
	packet go through from 6LBR to not-RPL-aware-leaf (IPv6). 6LR_i
	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 is addressed to the not-RPL-aware-leaf, leaving the RPI
	RPI inside.		inside.
			Note that there is a requirement that the final node be able to
			remove one or more IPIP headers which are all addressed to it.
			(EDNOTE: this should go into [I-D.ietf-6man-rfc6434-bis])
	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
	in order to aid in compression.		in order to aid in compression.
	+-----------+----------+---------------+---------------+------------+		+-----------+----------+---------------+---------------+------------+
	| Header | Internet | 6LBR | 6LR_i | IPv6 |		| Header | Internet | 6LBR | 6LR_i | IPv6 |
	+-----------+----------+---------------+---------------+------------+		+-----------+----------+---------------+---------------+------------+
	| Inserted | -- | IP-in-IP(RPI) | -- | -- |		| Inserted | -- | IP-in-IP(RPI) | -- | -- |
	| headers | | | | |		| headers | | | | |
	| Removed | -- | -- | -- | -- |		| Removed | -- | -- | -- | -- |
	skipping to change at page 21, line 40 ¶		skipping to change at page 20, line 40 ¶
	RPL-aware-leaf to not-RPL-aware-leaf		RPL-aware-leaf to not-RPL-aware-leaf
	not-RPL-aware-leaf to RPL-aware-leaf		not-RPL-aware-leaf to RPL-aware-leaf
	not-RPL-aware-leaf to not-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		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. See section 9 in
			[RFC6550].
	In this case the flow comprises:		When the nodes are not directly connected, then in storing mode, the
			flow comprises:
	6LN --> 6LR_ia --> common parent (6LR_x) --> 6LR_id --> 6LN		6LN --> 6LR_ia --> common parent (6LR_x) --> 6LR_id --> 6LN
	For example, the communication flow could be: Node F --> Node D -->		For example, a communication flow could be: Node F --> Node D -->
	Node B --> Node E --> Node H		Node B --> Node E --> Node H
	6LR_ia (Node D) are the intermediate routers from source to the		6LR_ia (Node D) are the intermediate routers from source to the
	common parent (6LR_x) (Node B) In this case, "1 <= ia >= n", n is the		common parent (6LR_x) (Node B) In this case, "1 <= ia >= n", n is the
	number of routers (6LR) that the packet go through from 6LN (Node F)		number of routers (6LR) that the packet go through from 6LN (Node F)
	to the common parent (6LR_x).		to the common parent (6LR_x).
	6LR_id (Node E) are the intermediate routers from the common parent		6LR_id (Node E) are the intermediate routers from the common parent
	(6LR_x) (Node B) to destination 6LN (Node H). In this case, "1 <= id		(6LR_x) (Node B) to destination 6LN (Node H). In this case, "1 <= id
	>= m", m is the number of routers (6LR) that the packet go through		>= m", m is the number of routers (6LR) that the packet go through
	from the common parent (6LR_x) to destination 6LN.		from the common parent (6LR_x) to destination 6LN.
	This case is assumed in the same RPL Domain. In the common parent		It is assume that the two nodes are in the same RPL Domain (that they
	(Node B), the direction of RPI is changed (from increasing to		share the same DODAG root). At the common parent (Node B), the
	decreasing the rank).		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 22, line 45 ¶		skipping to change at page 21, line 47 ¶
	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
	6.3.2. SM: 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 -->		For example, a communication flow could be: Node F --> Node D -->
	Node B --> Node E --> Node G		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 (Node E) are the intermediate routers from the common parent		6LR_id (Node E) are the intermediate routers from the common parent
	(6LR_x) (Node B) to destination not-RPL-aware 6LN (IPv6) (Node G).		(6LR_x) (Node B) to destination not-RPL-aware 6LN (IPv6) (Node G).
	In this case, "1 <= id >= m", m is the number of routers (6LR) that		In this case, "1 <= id >= m", m is the number of routers (6LR) that
	skipping to change at page 23, line 39 ¶		skipping to change at page 22, line 41 ¶
	Storing: Summary of the use of headers for RPL-aware-leaf to non-RPL-		Storing: Summary of the use of headers for RPL-aware-leaf to non-RPL-
	aware-leaf		aware-leaf
	6.3.3. SM: 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
	For example, the communication flow could be: Node G --> Node E -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node D --> Node F		Node B --> Node D --> Node F
	6LR_ia (Node E) are the intermediate routers from source (not-RPL-		6LR_ia (Node E) are the intermediate routers from source (not-RPL-
	aware 6LN (IPv6)) (Node G) to the common parent (6LR_x) (Node B) In		aware 6LN (IPv6)) (Node G) to the common parent (6LR_x) (Node B). In
	this case, "1 <= ia >= n", n is the number of routers (6LR) that the		this case, "1 <= ia >= n", n is the number of routers (6LR) that the
	packet go through from source to the common parent.		packet go through from source to the common parent.
	6LR_id (Node D) are the intermediate routers from the common parent		6LR_id (Node D) are the intermediate routers from the common parent
	(6LR_x) (Node B) to destination 6LN (Node F). In this case, "1 <= id		(6LR_x) (Node B) to destination 6LN (Node F). In this case, "1 <= id
	>= m", m is the number of routers (6LR) that the packet go through		>= m", m is the number of routers (6LR) that the packet go through
	from the common parent (6LR_x) to destination 6LN.		from the common parent (6LR_x) to destination 6LN.
	The 6LR_ia (ia=1) (Node E) receives the packet from the the IPv6 node		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		(Node G) and inserts and the RPI header encapsulated in IPv6-in-IPv6
	skipping to change at page 24, line 41 ¶		skipping to change at page 23, line 43 ¶
	+--------+------+------------+------------+------------+------------+		+--------+------+------------+------------+------------+------------+
	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
	6.3.4. SM: Example of Flow from not-RPL-aware-leaf to not-RPL-aware-		6.3.4. SM: Example of Flow from not-RPL-aware-leaf to not-RPL-aware-
	leaf		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 --> 6LR_id --> not-
	6LR_id --> not-RPL-aware 6LN (IPv6 dst)		RPL-aware 6LN (IPv6 dst)
	For example, the communication flow could be: Node G --> Node E -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A (root) --> Node C --> Node J		Node B --> Node A (root) --> Node C --> Node J
	Internet 6LR_ia (Node E and Node B) are the intermediate routers from		Internal nodes 6LR_ia (e.g: Node E or Node B) are the intermediate
	source (not-RPL-aware 6LN (IPv6 src))(Node G) to the root (6LBR)		routers from the not-RPL-aware source (Node G) to the root (6LBR)
	(Node A) In this case, "1 < ia >= n", n is the number of routers		(Node A). In this case, "1 < ia >= n", n is the number of routers
	(6LR) that the packet go through from IPv6 src to the root.		(6LR) that the packet go through from IPv6 src to the root.
	6LR_id (C) are the intermediate routers from the root (Node A) to		6LR_id (C) are the intermediate routers from the root (Node A) to the
	destination (IPv6 dst) (Node J). In this case, "1 <= id >= m", m is		destination Node J. In this case, "1 <= id >= m", m is the number of
	the number of routers (6LR) that the packet go through from the root		routers (6LR) that the packet go through from the root to destination
	to destination (IPv6 dst).		(IPv6 dst).
	This flow is identical to Section 6.3.3		Note that this flow is identical to Section 6.3.3, except for where
			the IPIP header is inserted.
	The 6LR_1 (Node E) receives the packet from the the IPv6 node (Node		The 6LR_1 (Node E) receives the packet from the the IPv6 node (Node
	G) and inserts the RPI header (RPIa) encapsulated in IPv6-in-IPv6		G) and inserts the RPI header (RPIa), encapsulated in an IPv6-in-IPv6
	header. The IPv6-in-IPv6 header is addressed to the 6LBR. The 6LBR		header. The IPv6-in-IPv6 header is addressed to the final
	remove the IPv6-in-IPv6 header and insert another one (RPIb) with		destination.
	destination to 6LR_m (Node C) node.
	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
	exists a shorter P2P path to the destination 6LN in storing mode.
	One possible solution is given by the work in
	[I-D.ietf-roll-dao-projection]. Once we have route projection, the
	root can find that this traffic deserves optimization (based on
	volume and path length, or additional knowledge on that particular
	flow) and project a DAO into 6LR_1.
	+-------+-----+-----------+-----------+-----------+-----------+-----+		+----------+-----+-------------+--------------+--------------+------+
	| Heade | IPv | 6LR_1 | 6LR_ia | 6LBR | 6LR_m | IPv |		| Header | IPv | 6LR_1 | 6LR_ia | 6LR_m | IPv6 |
	| r | 6 | | | | | 6 |		| | 6 | | | | dst |
	| | src | | | | | dst |		| | src | | | | |
	+-------+-----+-----------+-----------+-----------+-----------+-----+		+----------+-----+-------------+--------------+--------------+------+
	| Inser | -- | IP-in- | -- | IP-in- | -- | -- |		| Inserted | -- | IP-in- | -- | -- | -- |
	| ted h | | IP(RPI_a) | | IP(RPI_b) | | |		| headers | | IP(RPI) | | | |
	| eader | | | | | | |		| Removed | -- | -- | -- | -- | -- |
	| s | | | | | | |		| headers | | | | | |
	| Remov | -- | -- | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- | -- |
	| ed he | | | | | | |		| headers | | | | | |
	| aders | | | | | | |		| Modified | -- | -- | IP-in- | IP-in- | -- |
	| Re- | -- | -- | -- | -- | IP-in- | -- |		| headers | | | IP(RPI) | IP(RPI) | |
	| added | | | | | IP(RPI_b) | |		| Untouche | -- | -- | -- | -- | -- |
	| heade | | | | | | |		| d | | | | | |
	| rs | | | | | | |		| headers | | | | | |
	| Modif | -- | -- | IP-in- | -- | IP-in- | -- |		+----------+-----+-------------+--------------+--------------+------+
	| ied h | | | IP(RPI_a) | | IP(RPI_b) | |
	| eader | | | | | | |
	| s | | | | | | |
	| Untou | -- | -- | -- | -- | -- | -- |
	| ched | | | | | | |
	| heade | | | | | | |
	| 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
	7. Non Storing mode		7. Non Storing mode
	In Non Storing Mode (Non SM) (fully source routed), the 6LBR (DODAG		In Non Storing Mode (Non SM) (fully source routed), the 6LBR (DODAG
	root) has complete knowledge about the connectivity of all DODAG		root) has complete knowledge about the connectivity of all DODAG
	nodes, and all traffic flows through the root node. Thus, there is		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		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. Only the 6LBR needs to act if compensation is necessary for
	nodes.		non-RPL aware receivers.
	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 RPI, RH3 and IP-in-IP		following scenarios, and indicates when the RPI, RH3 and IP-in-IP
	header must be inserted. There are these possible situations:		header must be inserted. There are these possible situations:
	destination address possible (indicated by "dst"), to a 6LR, to a 6LN		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		or to the root. In cases where no IP-in-IP header is needed, the
	column is left blank.		column is left blank.
	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 3).		(Figure 3).
	+-----------------+--------------+-----+-----+----------+----------+		+-----------------+--------------+-----+-----+----------+----------+
	| Interaction | Use Case | RPI | RH3 | IP-in-IP | IP-in-IP |		| Interaction | Use Case | RPI | RH3 | IP-in-IP | IP-in-IP |
	| between | | | | | dst |		| between | | | | | dst |
	+-----------------+--------------+-----+-----+----------+----------+		+-----------------+--------------+-----+-----+----------+----------+
	| | Raf to root | Yes | No | No | -- |		| | Raf to root | Yes | No | No | -- |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| Leaf - Root | root to Raf | Opt | Yes | No | -- |		| Leaf - Root | root to Raf | Opt | Yes | No | -- |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| | root to ~Raf | No | Yes | Yes | 6LR |		| | root to ~Raf |no(1)| Yes | Yes | 6LR |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| | ~Raf to root | Yes | No | Yes | root |		| | ~Raf to root | Yes | No | Yes | root |
	+-----------------+--------------+-----+-----+----------+----------+		+-----------------+--------------+-----+-----+----------+----------+
	| | Raf to Int | Yes | No | Yes | root |		| | Raf to Int | Yes | No | Yes | root |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| Leaf - Internet | Int to Raf | Opt | Yes | Yes | dst |		| Leaf - Internet | Int to Raf |no(1)| Yes | Yes | dst |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| | ~Raf to Int | Yes | No | Yes | root |		| | ~Raf to Int | Yes | No | Yes | root |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| | Int to ~Raf | Opt | Yes | Yes | 6LR |		| | Int to ~Raf |no(1)| Yes | Yes | 6LR |
	+-----------------+--------------+-----+-----+----------+----------+		+-----------------+--------------+-----+-----+----------+----------+
	| | Raf to Raf | Yes | Yes | Yes | root/dst |		| | Raf to Raf | Yes | Yes | Yes | root/dst |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| | Raf to ~Raf | Yes | Yes | Yes | root/6LR |		| | Raf to ~Raf | Yes | Yes | Yes | root/6LR |
	+ Leaf - Leaf +--------------+-----+-----+----------+----------+		+ Leaf - Leaf +--------------+-----+-----+----------+----------+
	| | ~Raf to Raf | Yes | Yes | Yes | root/6LN |		| | ~Raf to Raf | Yes | Yes | Yes | root/6LN |
	+ +--------------+-----+-----+----------+----------+		+ +--------------+-----+-----+----------+----------+
	| | ~Raf to ~Raf | Yes | Yes | Yes | root/6LR |		| | ~Raf to ~Raf | Yes | Yes | Yes | root/6LR |
	+-----------------+--------------+-----+-----+----------+----------+		+-----------------+--------------+-----+-----+----------+----------+
			(1)-6tisch networks may need the RPI information.
	Figure 8: Headers needed in Non-Storing mode: RPI, RH3, IP-in-IP		Figure 8: Headers needed in Non-Storing mode: RPI, RH3, IP-in-IP
	encapsulation.		encapsulation.
	7.1. Non-Storing Mode: Interaction between Leaf and Root		7.1. Non-Storing Mode: Interaction between Leaf and Root
	In this section we are going to describe the communication flow in		In this section we are going to describe the communication flow in
	Non Storing Mode (Non-SM) between,		Non Storing Mode (Non-SM) between,
	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
	7.1.1. Non-SM: Example of Flow from RPL-aware-leaf to root		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 -->		For example, a communication flow could be: Node F --> Node D -->
	Node B --> Node A (root)		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 |
	skipping to change at page 28, line 41 ¶		skipping to change at page 26, line 48 ¶
	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
	7.1.2. on-SM: 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		For example, a communication flow could be: Node A (root) --> Node B
	B --> Node D --> Node F		--> 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 29, line 24 ¶		skipping to change at page 27, line 32 ¶
	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
	7.1.3. Non-SM: 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		For example, a communication flow could be: Node A (root) --> Node B
	B --> Node E --> Node G		--> 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, it is modified at each intermediate 6LR
	and so on) and it is fully consumed in the last 6LR (6LR_n), but left		(6LR_1 and so on) and it is fully consumed in the last 6LR (6LR_n),
	there. If RPI is left present, the IPv6 node which does not		but left 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 may optionally address the IP-in-IP header to the last
	6LR.		6LR, such that it is removed prior to the IPv6 node.
	+---------------+-------------+---------------+--------------+------+		+---------------+-------------+---------------+--------------+------+
	| Header | 6LBR | 6LR_i(i=1) | 6LR_n(i=n) | IPv6 |		| Header | 6LBR | 6LR_i(i=1) | 6LR_n(i=n) | IPv6 |
	+---------------+-------------+---------------+--------------+------+		+---------------+-------------+---------------+--------------+------+
	| Inserted | (opt: RPI), | -- | -- | -- |		| Inserted | (opt: RPI), | -- | -- | -- |
	| headers | RH3 | | | |		| headers | RH3 | | | |
	| Removed | -- | RH3 | -- | -- |		| Removed | -- | RH3 | -- | -- |
	| headers | | | | |		| headers | | | | |
	| Re-added | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- |
	| headers | | | | |		| headers | | | | |
	skipping to change at page 30, line 29 ¶		skipping to change at page 28, line 29 ¶
	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
	7.1.4. Non-SM: 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 -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A (root)		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) (Node E),		In this case the RPI is added by the first 6LR (6LR1) (Node E),
	encapsulated in an IP-in-IP header, and is modified in the followings		encapsulated in an IP-in-IP header, and is modified in the following
	6LRs. The 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 | -- | -- | -- | -- |
	skipping to change at page 31, line 25 ¶		skipping to change at page 29, line 25 ¶
	| 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
	7.2. Non-Storing Mode: Interaction between Leaf and Internet		7.2. Non-Storing Mode: Interaction between Leaf and Internet
	In this section we are going to describe the communication flow in		This section will describe the communication flow in Non Storing Mode
	Non Storing Mode (Non-SM) between,		(Non-SM) between:
	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
	7.2.1. Non-SM: Example of Flow from RPL-aware-leaf to Internet		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 -->		For example, a communication flow could be: Node F --> Node D -->
	Node B --> Node A --> Internet		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
	skipping to change at page 32, line 28 ¶		skipping to change at page 30, line 28 ¶
	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
	7.2.2. Non-SM: 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		For example, a communication flow could be: Internet --> Node A
	(root) --> Node B --> Node D --> Node F		(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 as required by networks such as 6tisch.
			The RPI is unnecessary for loop detection.
	+--------+-------+----------------+----------------+----------------+		+----------+---------+--------------+---------------+---------------+
	| Header | Inter | 6LBR | 6LR_i | 6LN |		| Header | Interne | 6LBR | 6LR_i | 6LN |
	| | net | | | |		| | t | | | |
	+--------+-------+----------------+----------------+----------------+		+----------+---------+--------------+---------------+---------------+
	| Insert | -- | IP-in-IP(RH3,o | -- | -- |		| Inserted | -- | IP-in-IP (RH | -- | -- |
	| ed hea | | pt:RPI) | | |		| headers | | 3,opt:RPI) | | |
	| ders | | | | |		| Removed | -- | -- | -- | IP-in-IP |
	| Remove | -- | -- | -- | IP-in-IP(RH3,o |		| headers | | | | (RH3,opt:RPI) |
	| d head | | | | pt:RPI) |		| Re-added | -- | -- | -- | -- |
	| ers | | | | |		| headers | | | | |
	| Re- | -- | -- | -- | -- |		| Modified | -- | -- | IP-in-IP | -- |
	| added | | | | |		| headers | | | (RH3,opt:RPI) | |
	| header | | | | |		| Untouche | -- | -- | -- | -- |
	| s | | | | |		| d | | | | |
	| Modifi | -- | -- | IP-in-IP(RH3,o | -- |		| headers | | | | |
	| ed hea | | | pt:RPI) | |		+----------+---------+--------------+---------------+---------------+
	| ders | | | | |
	| Untouc | -- | -- | -- | -- |
	| hed he | | | | |
	| 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
	7.2.3. Non-SM: 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 -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A --> Internet		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 (see Section 6.2.3).
	+---------+-----+-------------+-------------+-------------+---------+		+-----------+------+-----------+-------------+-----------+----------+
	| Header | IPv | 6LR_1 | 6LR_i | 6LBR | Interne |		| Header | IPv6 | 6LR_1 | 6LR_i | 6LBR | Internet |
	| | 6 | | [i=2,..,n]_ | | t |		| | | | [i=2,..,n]_ | | |
	+---------+-----+-------------+-------------+-------------+---------+		+-----------+------+-----------+-------------+-----------+----------+
	| Inserte | -- | IP-in- | -- | -- | -- |		| Inserted | -- | IP-in-IP | -- | -- | -- |
	| d | | IP(RPI) | | | |		| headers | | (RPI) | | | |
	| headers | | | | | |		| Removed | -- | -- | -- | IP-in-IP | -- |
	| Removed | -- | -- | -- | IP-in- | -- |		| headers | | | | (RPI) | |
	| headers | | | | IP(RPI) | |		| Re-added | -- | -- | -- | -- | -- |
	| Re- | -- | -- | -- | -- | -- |		| headers | | | | | |
	| added | | | | | |		| Modified | -- | -- | IP-in-IP | -- | -- |
	| headers | | | | | |		| headers | | | (RPI) | | |
	| Modifie | -- | -- | IP-in- | -- | -- |		| Untouched | -- | -- | -- | -- | -- |
	| d | | | IP(RPI) | | |		| headers | | | | | |
	| headers | | | | | |		+-----------+------+-----------+-------------+-----------+----------+
	| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |
	| 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
	7.2.4. Non-SM: 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		For example, a communication flow could be: Internet --> Node A
	(root) --> Node B --> Node E --> Node G		(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.
	+--------+-------+----------------+------------+-------------+------+		+----------+---------+---------+-----------+-----------------+------+
	| Header | Inter | 6LBR | 6LR_1 | 6LR_i(i=2,. | IPv6 |		| Header | Interne | 6LBR | 6LR_1 | 6LR_i(i=2,..,n) | IPv6 |
	| | net | | | .,n) | |		| | t | | | | |
	+--------+-------+----------------+------------+-------------+------+		+----------+---------+---------+-----------+-----------------+------+
	| Insert | -- | IP-in-IP(RH3,o | -- | -- | -- |		| Inserted | -- | IP-in- | -- | -- | -- |
	| ed hea | | pt:RPI) | | | |		| headers | | IP | | | |
	| ders | | | | | |		| | | (RH3, o | | | |
	| Remove | -- | -- | -- | IP-in- | -- |		| | | pt:RPI) | | | |
	| d head | | | | IP(RH3, | |		| Removed | -- | -- | -- | IP-in-IP | -- |
	| ers | | | | RPI) | |		| headers | | | | (RH3,RPI) | |
	| Re- | -- | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- | -- |
	| added | | | | | |		| headers | | | | | |
	| header | | | | | |		| Modified | -- | -- | IP-in-IP | IP-in-IP | -- |
	| s | | | | | |		| headers | | | (RH3,RPI) | (RH3,RPI) | |
	| Modifi | -- | -- | IP-in- | IP-in- | -- |		| Untouche | -- | -- | -- | -- | RPI |
	| ed hea | | | IP(RH3, | IP(RH3, | |		| d | | | | | |
	| ders | | | RPI) | RPI) | |		| headers | | | | | |
	| Untouc | -- | -- | -- | -- | RPI |		+----------+---------+---------+-----------+-----------------+------+
	| hed he | | | | | |
	| 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
	7.3. Non-Storing Mode: Interaction between Leafs		7.3. Non-Storing Mode: Interaction between Leafs
	In this section we are going to describe the communication flow in		In this section we are going to describe the communication flow in
	Non Storing Mode (Non-SM) between,		Non Storing Mode (Non-SM) between,
	RPL-aware-leaf to RPL-aware-leaf		RPL-aware-leaf to RPL-aware-leaf
	skipping to change at page 35, line 49 ¶		skipping to change at page 33, line 46 ¶
	not-RPL-aware-leaf to RPL-aware-leaf		not-RPL-aware-leaf to RPL-aware-leaf
	not-RPL-aware-leaf to not-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		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 -->		For example, a communication flow could be: Node F --> Node D -->
	Node B --> Node A (root) --> Node B --> Node E --> Node H		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 37, line 5 ¶		skipping to change at page 34, line 28 ¶
	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 7.1.2, 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_ia | 6LBR | 6LR_id | 6LN dst |
	| | | ia | | d | |		+-----------+----------+--------+-------------+--------+------------+
	+---------+-------------+------+--------------+-------+-------------+		| Inserted | IP-in-IP | -- | IP-in-IP | -- | -- |
	| Inserte | IP-in- | -- | IP-in-IP(RH3 | -- | -- |		| headers | (RPI1) | | (RH3->6LN, | | |
	| d | IP(RPI1) | | to 6LN, opt | | |		| | | | opt RPI2) | | |
	| headers | | | RPI2) | | |		| Removed | -- | -- | IP-in-IP | -- | IP-in-IP |
	| Removed | -- | -- | IP-in- | -- | IP-in- |		| headers | | | (RPI1) | | (RH3, opt |
	| headers | | | IP(RPI1) | | IP(RH3, opt |		| | | | | | RPI2) |
	| | | | | | RPI2) |		| Re-added | -- | -- | -- | -- | -- |
	| Re- | -- | -- | -- | -- | -- |		| headers | | | | | |
	| added | | | | | |		| Modified | -- | RPI1 | -- | RPI2 | -- |
	| headers | | | | | |		| headers | | | | | |
	| Modifie | -- | RPI1 | -- | RPI2 | -- |		| Untouched | -- | -- | -- | -- | -- |
	| d | | | | | |		| headers | | | | | |
	| headers | | | | | |		+-----------+----------+--------+-------------+--------+------------+
	| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |
	| 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
	7.3.2. Non-SM: Example of Flow from RPL-aware-leaf to not-RPL-aware-		7.3.2. Non-SM: Example of Flow from RPL-aware-leaf to not-RPL-aware-
	leaf		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 -->		For example, a communication flow could be: Node F --> Node D -->
	Node B --> Node A (root) --> Node B --> Node E --> Node G		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).
	+--------+-----------+------------+-------------+------------+------+		+-----------+----------+----------+------------+------------+-------+
	| Header | 6LN | 6LR_1 | 6LBR | 6LR_id | IPv6 |		| Header | 6LN | 6LR_1 | 6LBR | 6LR_id | IPv6 |
	+--------+-----------+------------+-------------+------------+------+		+-----------+----------+----------+------------+------------+-------+
	| Insert | IP-in- | -- | IP-in- | -- | -- |		| Inserted | IP-in-IP | -- | IP-in-IP | -- | -- |
	| ed hea | IP(RPI1) | | IP(RH3, opt | | |		| headers | (RPI1) | | (RH3, opt | | |
	| ders | | | RPI_2) | | |		| | | | RPI_2) | | |
	| Remove | -- | -- | IP-in- | IP-in- | -- |		| Removed | -- | -- | IP-in-IP | IP-in-IP | -- |
	| d head | | | IP(RPI_1) | IP(RH3, | |		| headers | | | (RPI_1) | (RH3, opt | |
	| ers | | | | opt RPI_2) | |		| | | | | RPI_2) | |
	| Re- | -- | -- | -- | -- | -- |		| Re-added | -- | -- | -- | -- | -- |
	| added | | | | | |		| headers | | | | | |
	| header | | | | | |		| Modified | -- | IP-in-IP | -- | IP-in-IP | -- |
	| s | | | | | |		| headers | | (RPI_1) | | (RH3, opt | |
	| Modifi | -- | IP-in- | -- | IP-in- | -- |		| | | | | RPI_2) | |
	| ed hea | | IP(RPI_1) | | IP(RH3, | |		| Untouched | -- | -- | -- | -- | opt |
	| ders | | | | opt RPI_2) | |		| headers | | | | | RPI_2 |
	| Untouc | -- | -- | -- | -- | opt |		+-----------+----------+----------+------------+------------+-------+
	| hed he | | | | | RPI_ |
	| 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
	7.3.3. Non-SM: Example of Flow from not-RPL-aware-leaf to RPL-aware-		7.3.3. Non-SM: Example of Flow from not-RPL-aware-leaf to RPL-aware-
	leaf		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 -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A (root) --> Node B --> Node E --> Node H		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
	header containing an RH3 header and optional RPI (RPI_2).		header containing an RH3 header and optional RPI (RPI_2).
	+--------+-----+------------+-------------+------------+------------+		+-----------+------+----------+-----------+------------+------------+
	| Header | IPv | 6LR_1 | 6LBR | 6LR_id | 6LN |		| Header | IPv6 | 6LR_1 | 6LBR | 6LR_id | 6LN |
	| | 6 | | | | |		+-----------+------+----------+-----------+------------+------------+
	+--------+-----+------------+-------------+------------+------------+		| Inserted | -- | IP-in-IP | IP-in-IP | -- | -- |
	| Insert | -- | IP-in- | IP-in- | -- | -- |		| headers | | (RPI_1) | (RH3, opt | | |
	| ed hea | | IP(RPI_1) | IP(RH3, opt | | |		| | | | RPI_2) | | |
	| ders | | | RPI_2) | | |		| Removed | -- | -- | IP-in-IP | -- | IP-in-IP |
	| Remove | -- | -- | IP-in- | -- | IP-in- |		| headers | | | (RPI_1) | | (RH3, opt |
	| d head | | | IP(RPI_1) | | IP(RH3, |		| | | | | | RPI_2) |
	| ers | | | | | opt RPI_2) |		| Re-added | -- | -- | -- | -- | -- |
	| Re- | -- | -- | -- | -- | -- |		| headers | | | | | |
	| added | | | | | |		| Modified | -- | -- | -- | IP-in-IP | -- |
	| header | | | | | |		| headers | | | | (RH3, opt | |
	| s | | | | | |		| | | | | RPI_2) | |
	| Modifi | -- | -- | -- | IP-in- | -- |		| Untouched | -- | -- | -- | -- | -- |
	| ed hea | | | | IP(RH3, | |		| headers | | | | | |
	| ders | | | | opt RPI_2) | |		+-----------+------+----------+-----------+------------+------------+
	| Untouc | -- | -- | -- | -- | -- |
	| hed he | | | | | |
	| 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
	7.3.4. Non-SM: Example of Flow from not-RPL-aware-leaf to not-RPL-		7.3.4. Non-SM: Example of Flow from not-RPL-aware-leaf to not-RPL-
	aware-leaf		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 -->		For example, a communication flow could be: Node G --> Node E -->
	Node B --> Node A (root) --> Node C --> Node J		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.
	+---------+-----+--------------+---------------+-------------+------+		+------------+-------+-----------+------------+-------------+-------+
	| Header | IPv | 6LR_1 | 6LBR | 6LR_id | IPv6 |		| Header | IPv6 | 6LR_1 | 6LBR | 6LR_id | IPv6 |
	| | 6 | | | | dst |		| | src | | | | dst |
	| | src | | | | |		+------------+-------+-----------+------------+-------------+-------+
	+---------+-----+--------------+---------------+-------------+------+		| Inserted | -- | IP-in-IP | IP-in-IP | -- | -- |
	| Inserte | -- | IP-in- | IP-in-IP(RH3) | -- | -- |		| headers | | (RPI_1) | (RH3) | | |
	| d | | IP(RPI_1) | | | |		| Removed | -- | -- | IP-in-IP | IP-in-IP | -- |
	| headers | | | | | |		| headers | | | (RPI_1) | (RH3, opt | |
	| Removed | -- | -- | IP-in- | IP-in- | -- |		| | | | | RPI_2) | |
	| headers | | | IP(RPI_1) | IP(RH3, opt | |		| Re-added | -- | -- | -- | -- | -- |
	| | | | | RPI_2) | |		| headers | | | | | |
	| Re- | -- | -- | -- | -- | -- |		| Modified | -- | -- | -- | -- | -- |
	| added | | | | | |		| headers | | | | | |
	| headers | | | | | |		| Untouched | -- | -- | -- | -- | -- |
	| Modifie | -- | -- | -- | -- | -- |		| headers | | | | | |
	| d | | | | | |		+------------+-------+-----------+------------+-------------+-------+
	| headers | | | | | |
	| Untouch | -- | -- | -- | -- | -- |
	| ed | | | | | |
	| 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
	8. Observations about the cases		8. Observations about the cases
	8.1. Storing mode		8.1. Storing mode
	[I-D.ietf-roll-routing-dispatch] shows that the hop-by-hop IP-in-IP		[RFC8183] shows that the hop-by-hop IP-in-IP header can be compressed
	header can be compressed using IP-in-IP 6LoRH (IP-in-IP-6LoRH) header		using IP-in-IP 6LoRH (IP-in-IP-6LoRH) header as described in
	as described in Section 7 of the document.		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 change of the RPI option type from 0x63 to 0x23, there		Thanks to the change of the RPI option type from 0x63 to 0x23, there
	is no longer any uncertainty about when to use an IP-in-IP header in		is no longer any uncertainty about when to use an IP-in-IP header in
	the storing mode. A Hop-by-Hop Options Header containing the RPI		the storing mode. A Hop-by-Hop Options Header containing the RPI
	option SHOULD always be added when 6LRs originate packets (without		option SHOULD always be added when 6LRs originate packets (without
	IP-in-IP headers), and IP-in-IP headers should always be added		IP-in-IP headers), and IP-in-IP headers should always be added
	(addressed to the root when on the way up, to the end-host when on		(addressed to the root when on the way up, to the end-host when on
	the way down) when a 6LR find that it needs to insert a Hop-by-Hop		the way down) when a 6LR find that it needs to insert a Hop-by-Hop
	Options Header containing the RPI option.		Options Header containing the RPI option.
	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)
	should be signaled in the RPL protocol itself.
	8.2. 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 for traffic originating from the root to
			leafs.
	Unlike in the storing mode case, there is no need for all nodes to		The non-storing mode case does not require the type change from 0x63
	know about the existence of non-RPL aware nodes. Only the 6LBR needs		to 0x23, as the root can always create the right packet. The type
	to change when there are non-RPL aware nodes. Further, in the non-		change does not adversely affect the non-storing case.
	storing case, the 6LBR is informed by the DAOs when there are non-RPL
	aware nodes.
	9. 6LoRH Compression cases		9. 6LoRH Compression cases
	The [I-D.ietf-roll-routing-dispatch] proposes a compression method		The [RFC8183] proposes a compression method for RPI, RH3 and IPv6-in-
	for RPI, RH3 and IPv6-in-IPv6.		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 |
	+--+-----+---+--------------+-----------+-------------+-------------+		+--+-----+---+--------------+-----------+-------------+-------------+
	skipping to change at page 42, line 13 ¶		skipping to change at page 39, line 18 ¶
	Options and Hop-by-Hop Options registry from 0x63 to 0x23.		Options and Hop-by-Hop Options registry from 0x63 to 0x23.
	Hex Value Binary Value		Hex Value Binary Value
	act chg rest Description Reference		act chg rest Description Reference
	--------- --- --- ------- ----------------- ----------		--------- --- --- ------- ----------------- ----------
	0x23 00 1 00011 RPL Option [RFCXXXX]		0x23 00 1 00011 RPL Option [RFCXXXX]
	0x63 01 1 00011 RPL Option(DEPRECATED) [RFC6553][RFCXXXX]		0x63 01 1 00011 RPL Option(DEPRECATED) [RFC6553][RFCXXXX]
	Figure 10: Option Type in RPL Option.		Figure 10: Option Type in RPL Option.
	We propose to use DODAG Configuration Option Flags in the DODAG		The DODAG Configuration Option Flags in the DODAG Configuration
	Configuration option as follows:		option is updated as follows:
	+------------+-----------------+---------------+		+------------+-----------------+---------------+
	| Bit number | Description | Reference |		| Bit number | Description | Reference |
	+------------+-----------------+---------------+		+------------+-----------------+---------------+
	| 3 | RPI 0x23 enable | This document |		| 3 | RPI 0x23 enable | This document |
	+------------+-----------------+---------------+		+------------+-----------------+---------------+
	Figure 11: DODAG Configuration Option Flag to indicate the RPI-flag-		Figure 11: DODAG Configuration Option Flag to indicate the RPI-flag-
	day.		day.
	skipping to change at page 44, line 16 ¶		skipping to change at page 41, line 22 ¶
	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
	with an IPIP header to add the needed RH3 header. As such, the		with an IPIP header to add the needed RH3 header. As such, the
	attacker's RH3 header will not be seen by the network until it		attacker's RH3 header will not be seen by the network until it
	reaches the end host, which will decapsulate it. An end-host SHOULD		reaches the end host, which will decapsulate it. An end-host SHOULD
	be suspicious about a RH3 header which has additional hops which have		be suspicious about a RH3 header which has additional hops which have
	not yet been processed, and SHOULD ignore such a second RH3 header.		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 [RFC8183] to compress the IPIP
	to compress the IPIP and RH3 headers. As such, the compressor at the		and RH3 headers. As such, the compressor at the RPL-root will see
	RPL-root will see the second RH3 header and MAY choose to discard the		the second RH3 header and MAY choose to discard the packet if the RH3
	packet if the RH3 header has not been completely consumed. A		header has not been completely consumed. A consumed (inert) RH3
	consumed (inert) RH3 header could be present in a packet that flows		header could be present in a packet that flows from one LLN, crosses
	from one LLN, crosses the Internet, and enters another LLN. As per		the Internet, and enters another LLN. As per the discussion in this
	the discussion in this document, such headers do not need to be		document, such headers do not need to be removed. However, there is
	removed. However, there is no case described in this document where		no case described in this document where an RH3 is inserted in a non-
	an RH3 is inserted in a non-storing network on traffic that is		storing network on traffic that is leaving the LLN, but this document
	leaving the LLN, but this document SHOULD NOT preclude such a future		SHOULD NOT preclude such a future innovation. It should just be
	innovation. It should just be noted that an incoming RH3 must be		noted that an incoming RH3 must be fully consumed, or very carefully
	fully consumed, or very carefully inspected.		inspected.
	The RPI header, if permitted to enter the LLN, could be used by an		The RPI header, if permitted to enter the LLN, could be used by an
	attacker to change the priority of a packet by selecting a different		attacker to change the priority of a packet by selecting a different
	RPL instanceID, perhaps one with a higher energy cost, for instance.		RPL instanceID, perhaps one with a higher energy cost, for instance.
	It could also be that not all nodes are reachable in an LLN using the		It could also be that not all nodes are reachable in an LLN using the
	default instanceID, but a change of instanceID would permit an		default instanceID, but a change of instanceID would permit an
	attacker to bypass such filtering. Like the RH3, an RPI header is to		attacker to bypass such filtering. Like the RH3, an RPI header is to
	be inserted by the RPL root on traffic entering the LLN by first		be inserted by the RPL root on traffic entering the LLN by first
	inserting an IPIP header. The attacker's RPI header therefore will		inserting an IPIP header. The attacker's RPI header therefore will
	not be seen by the network. Upon reaching the destination node the		not be seen by the network. Upon reaching the destination node the
	skipping to change at page 45, line 19 ¶		skipping to change at page 42, line 23 ¶
	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,
	Ralph Droms, Cenk Guendogan, C. M. Heard, Rahul Jadhav, Matthias		Ralph Droms, Cenk Guendogan, C. M. Heard, Rahul Jadhav, Matthias
	Kovatsch, Peter van der Stok, Xavier Vilajosana and Thomas Watteyne.		Kovatsch, Peter van der Stok, Xavier Vilajosana and Thomas Watteyne.
	13. References		13. References
	13.1. Normative References		13.1. Normative References
	[I-D.ietf-6man-rfc2460bis]
	Deering, S. and R. Hinden, "Internet Protocol, Version 6
	(IPv6) Specification", draft-ietf-6man-rfc2460bis-13 (work
	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,
	<https://www.rfc-editor.org/info/rfc2119>.		<https://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, DOI 10.17487/RFC2460,		(IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460,
	December 1998, <https://www.rfc-editor.org/info/rfc2460>.		December 1998, <https://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
	skipping to change at page 46, line 33 ¶		skipping to change at page 43, line 33 ¶
	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,
	<https://www.rfc-editor.org/info/rfc7416>.		<https://www.rfc-editor.org/info/rfc7416>.
	[RFC8138] Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie,		[RFC8138] Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie,
	"IPv6 over Low-Power Wireless Personal Area Network		"IPv6 over Low-Power Wireless Personal Area Network
	(6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138,		(6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138,
	April 2017, <https://www.rfc-editor.org/info/rfc8138>.		April 2017, <https://www.rfc-editor.org/info/rfc8138>.
			[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
			(IPv6) Specification", STD 86, RFC 8200,
			DOI 10.17487/RFC8200, July 2017,
			<https://www.rfc-editor.org/info/rfc8200>.
	13.2. 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-04 (work in progress), July 2017.		backbone-router-04 (work in progress), July 2017.
			[I-D.ietf-6man-rfc6434-bis]
			Chown, T., Loughney, J., and T. Winters, "IPv6 Node
			Requirements", draft-ietf-6man-rfc6434-bis-02 (work in
			progress), October 2017.
	[I-D.ietf-6tisch-architecture]		[I-D.ietf-6tisch-architecture]
	Thubert, P., "An Architecture for IPv6 over the TSCH mode		Thubert, P., "An Architecture for IPv6 over the TSCH mode
	of IEEE 802.15.4", draft-ietf-6tisch-architecture-12 (work		of IEEE 802.15.4", draft-ietf-6tisch-architecture-12 (work
	in progress), August 2017.		in progress), August 2017.
	[I-D.ietf-6tisch-dtsecurity-secure-join]		[I-D.ietf-6tisch-dtsecurity-secure-join]
	Richardson, M., "6tisch Secure Join protocol", draft-ietf-		Richardson, M., "6tisch Secure Join protocol", draft-ietf-
	6tisch-dtsecurity-secure-join-01 (work in progress),		6tisch-dtsecurity-secure-join-01 (work in progress),
	February 2017.		February 2017.
	skipping to change at page 47, line 26 ¶		skipping to change at page 44, line 36 ¶
	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-08 (work in progress), October 2017.		keyinfra-08 (work in progress), October 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-02 (work in		state in RPL", draft-ietf-roll-dao-projection-02 (work in
	progress), September 2017.		progress), September 2017.
	[I-D.ietf-roll-routing-dispatch]
	Thubert, P., Bormann, C., Toutain, L., and R. Cragie,
	"6LoWPAN Routing Header", draft-ietf-roll-routing-
	dispatch-05 (work in progress), October 2016.
	[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for		[RFC4192] Baker, F., Lear, E., and R. Droms, "Procedures for
	Renumbering an IPv6 Network without a Flag Day", RFC 4192,		Renumbering an IPv6 Network without a Flag Day", RFC 4192,
	DOI 10.17487/RFC4192, September 2005,		DOI 10.17487/RFC4192, September 2005,
	<https://www.rfc-editor.org/info/rfc4192>.		<https://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", STD 89,		Protocol Version 6 (IPv6) Specification", STD 89,
	RFC 4443, DOI 10.17487/RFC4443, March 2006,		RFC 4443, DOI 10.17487/RFC4443, March 2006,
	<https://www.rfc-editor.org/info/rfc4443>.		<https://www.rfc-editor.org/info/rfc4443>.
	skipping to change at page 48, line 9 ¶		skipping to change at page 45, line 15 ¶
	[RFC6997] Goyal, M., Ed., Baccelli, E., Philipp, M., Brandt, A., and		[RFC6997] Goyal, M., Ed., Baccelli, E., Philipp, M., Brandt, A., and
	J. Martocci, "Reactive Discovery of Point-to-Point Routes		J. Martocci, "Reactive Discovery of Point-to-Point Routes
	in Low-Power and Lossy Networks", RFC 6997,		in Low-Power and Lossy Networks", RFC 6997,
	DOI 10.17487/RFC6997, August 2013,		DOI 10.17487/RFC6997, August 2013,
	<https://www.rfc-editor.org/info/rfc6997>.		<https://www.rfc-editor.org/info/rfc6997>.
	[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and		[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
	Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January		Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
	2014, <https://www.rfc-editor.org/info/rfc7102>.		2014, <https://www.rfc-editor.org/info/rfc7102>.
			[RFC8183] Austein, R., "An Out-of-Band Setup Protocol for Resource
			Public Key Infrastructure (RPKI) Production Services",
			RFC 8183, DOI 10.17487/RFC8183, July 2017,
			<https://www.rfc-editor.org/info/rfc8183>.
	[Second6TischPlugtest]		[Second6TischPlugtest]
	"2nd 6Tisch Plugtest", <http://www.ietf.org/mail-		"2nd 6Tisch Plugtest", <http://www.ietf.org/mail-
	archive/web/6tisch/current/pdfgDMQcdCkRz.pdf>.		archive/web/6tisch/current/pdfgDMQcdCkRz.pdf>.
	Authors' Addresses		Authors' Addresses
	Maria Ines Robles		Maria Ines Robles
	Ericsson		Ericsson
	Hirsalantie 11		Hirsalantie 11
	Jorvas 02420		Jorvas 02420
End of changes. 130 change blocks.
	491 lines changed or deleted		434 lines changed or added
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