< draft-ietf-roll-enrollment-priority-02.txt		draft-ietf-roll-enrollment-priority-03.txt >
	ROLL Working Group M. Richardson		ROLL Working Group M. Richardson
	Internet-Draft Sandelman Software Works		Internet-Draft Sandelman Software Works
	Intended status: Informational April 25, 2020		Intended status: Standards Track R. Jadhav
	Expires: October 27, 2020		Expires: March 29, 2021 Huawei Tech
			September 25, 2020
	Enabling secure network enrollment in RPL networks		Controlling Secure Network Enrollment in RPL networks
	draft-ietf-roll-enrollment-priority-02		draft-ietf-roll-enrollment-priority-03
	Abstract		Abstract
	[I-D.ietf-6tisch-enrollment-enhanced-beacon] defines a method by		[I-D.ietf-6tisch-enrollment-enhanced-beacon] defines a method by
	which a potential [I-D.ietf-6tisch-minimal-security] join proxy can		which a potential [I-D.ietf-6tisch-minimal-security] enrollment proxy
	announce itself as a available for new Pledges to enroll on a		can announce itself as a available for new Pledges to enroll on a
	network. The announcement includes a priority for enrollment. This		network. The announcement includes a priority for enrollment. This
	document provides a mechanism by which a RPL DODAG root can disable		document provides a mechanism by which a RPL DODAG root can disable
	enrollment announcements, or adjust the base priority for enrollment		enrollment announcements, or adjust the base priority for enrollment
	operation.		operation.
	Status of This Memo		Status of This Memo
	This Internet-Draft is submitted in full conformance with the		This Internet-Draft is submitted in full conformance with the
	provisions of BCP 78 and BCP 79.		provisions of BCP 78 and BCP 79.
	Internet-Drafts are working documents of the Internet Engineering		Internet-Drafts are working documents of the Internet Engineering
	Task Force (IETF). Note that other groups may also distribute		Task Force (IETF). Note that other groups may also distribute
	working documents as Internet-Drafts. The list of current Internet-		working documents as Internet-Drafts. The list of current Internet-
	Drafts is at https://datatracker.ietf.org/drafts/current/.		Drafts is at https://datatracker.ietf.org/drafts/current/.
	Internet-Drafts are draft documents valid for a maximum of six months		Internet-Drafts are draft documents valid for a maximum of six months
	and may be updated, replaced, or obsoleted by other documents at any		and may be updated, replaced, or obsoleted by other documents at any
	time. It is inappropriate to use Internet-Drafts as reference		time. It is inappropriate to use Internet-Drafts as reference
	material or to cite them other than as "work in progress."		material or to cite them other than as "work in progress."
	This Internet-Draft will expire on October 27, 2020.		This Internet-Draft will expire on March 29, 2021.
	Copyright Notice		Copyright Notice
	Copyright (c) 2020 IETF Trust and the persons identified as the		Copyright (c) 2020 IETF Trust and the persons identified as the
	document authors. All rights reserved.		document authors. All rights reserved.
	This document is subject to BCP 78 and the IETF Trust's Legal		This document is subject to BCP 78 and the IETF Trust's Legal
	Provisions Relating to IETF Documents		Provisions Relating to IETF Documents
	(https://trustee.ietf.org/license-info) in effect on the date of		(https://trustee.ietf.org/license-info) in effect on the date of
	publication of this document. Please review these documents		publication of this document. Please review these documents
	carefully, as they describe your rights and restrictions with respect		carefully, as they describe your rights and restrictions with respect
	to this document. Code Components extracted from this document must		to this document. Code Components extracted from this document must
	include Simplified BSD License text as described in Section 4.e of		include Simplified BSD License text as described in Section 4.e of
	the Trust Legal Provisions and are provided without warranty as		the Trust Legal Provisions and are provided without warranty as
	described in the Simplified BSD License.		described in the Simplified BSD License.
	Table of Contents		Table of Contents
	1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2		1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
	1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3		1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3
	2. Protocol Definition . . . . . . . . . . . . . . . . . . . . . 3		2. Protocol Definition . . . . . . . . . . . . . . . . . . . . . 4
	2.1. Upwards compatibility . . . . . . . . . . . . . . . . . . 4		2.1. Upwards compatibility . . . . . . . . . . . . . . . . . . 4
	3. Security Considerations . . . . . . . . . . . . . . . . . . . 5		3. Security Considerations . . . . . . . . . . . . . . . . . . . 5
	4. Privacy Considerations . . . . . . . . . . . . . . . . . . . 6		4. Privacy Considerations . . . . . . . . . . . . . . . . . . . 6
	5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6		5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 6
	6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6		6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 6
	7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6		7. References . . . . . . . . . . . . . . . . . . . . . . . . . 6
	7.1. Normative References . . . . . . . . . . . . . . . . . . 6		7.1. Normative References . . . . . . . . . . . . . . . . . . 6
	7.2. Informative References . . . . . . . . . . . . . . . . . 7		7.2. Informative References . . . . . . . . . . . . . . . . . 7
	Appendix A. Change history . . . . . . . . . . . . . . . . . . . 8		Appendix A. Change history . . . . . . . . . . . . . . . . . . . 8
	Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8		Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
	1. Introduction		1. Introduction
	[RFC7554] describes the use of the time-slotted channel hopping		[RFC7554] describes the use of the time-slotted channel hopping
	(TSCH) mode of [ieee802154]. [I-D.ietf-6tisch-minimal-security] and		(TSCH) mode of [ieee802154]. [I-D.ietf-6tisch-minimal-security] and
	[I-D.ietf-6tisch-dtsecurity-secure-join] describe mechanisms by which		[I-D.ietf-6tisch-dtsecurity-secure-join] describe mechanisms by which
	a new node (the "pledge)" can use a friendly router as a Join Proxy.		a new node (the "pledge)" can use a friendly router as a Join Proxy.
	[I-D.ietf-6tisch-enrollment-enhanced-beacon] describes an extension		[I-D.ietf-6tisch-enrollment-enhanced-beacon] describes an extension
	to the 802.15.4 Enhanced Beacon that is used by a Join Proxy to		to the 802.15.4 Enhanced Beacon that is used by a Join Proxy to
	announce its existence such that Pledges can find them.		announce its existence such that Pledges can find them.
	skipping to change at page 2, line 43 ¶		skipping to change at page 2, line 44 ¶
	The term (1)"Join" has been used in documents like		The term (1)"Join" has been used in documents like
	[I-D.ietf-6tisch-minimal-security] to denote the activity of a new		[I-D.ietf-6tisch-minimal-security] to denote the activity of a new
	node authenticating itself to the network in order to obtain		node authenticating itself to the network in order to obtain
	authorization to become a member of the network. This typically		authorization to become a member of the network. This typically
	involves a cryptographic authentication protocol in which a network		involves a cryptographic authentication protocol in which a network
	credential is provided.		credential is provided.
	In the context of the [RFC6550] RPL protocol, the term (2)"Join" has		In the context of the [RFC6550] RPL protocol, the term (2)"Join" has
	an alternate meaning: that of a node (already authenticating to the		an alternate meaning: that of a node (already authenticating to the
	network, and already authorized to be a member of the network),		network, and already authorized to be a member of the network),
	deciding which part of the RPL DODAG to attach to. The term "Join"		deciding which part of the RPL DODAG to attach to. This term "Join"
	has to do with parent selection processes.		has to do with parent selection processes.
	In order to avoid the ambiguity of this term, this document refers to		In order to avoid the ambiguity of this term, this document refers to
	the process (1)"Join" as enrollment, leaving the term "Join" to mean		the process (1)"Join" as enrollment, leaving the term "Join" to mean
	(2)"Join". The term "onboarding" (or IoT Onboarding) is sometimes		(2)"Join". The term "onboarding" (or IoT Onboarding) is sometimes
	used to describe this process. The term Join Proxy is retained with		used to describe the enrollment process. However, the term _Join
	it's meaning from [I-D.ietf-6tisch-minimal-security].		Proxy_ is retained with it's meaning from
			[I-D.ietf-6tisch-minimal-security].
	It has become clear that not every routing member of the mesh ought		It has become clear that not every routing member of the mesh ought
	to announce itself as a Join Proxy. There are a variety of local		to announce itself as a _Join Proxy_. There are a variety of local
	reasons by which a 6LR might not want to provide the Join Proxy		reasons by which a 6LR might not want to provide the _Join Proxy_
	function. They include available battery power, already committed		function. They include available battery power, already committed
	network bandwidth, and also total available memory available for Join		network bandwidth, and also total available memory available for
	proxy neighbor cache slots.		Neighbor Cache Entry slots.
	There are other situations where the operator of the network would		There are other situations where the operator of the network would
	like to selective enable or disable the enrollment process in a		like to selective enable or disable the enrollment process in a
	particular DODAG.		particular DODAG.
	As the enrollment process involves permitting unencrypted traffic		As the enrollment process involves permitting unencrypted traffic
	into the best effort part of a (TSCH) network, it would be better to		into the best effort part of a (TSCH) network, it would be better to
	have the enrollment process off when no new nodes are expected.		have the enrollment process off when no new nodes are expected.
	A network operator might also be able to recognize when certain parts		A network operator might also be able to recognize when certain parts
	of the network are overloaded and can not accomodate additional		of the network are overloaded and can not accomodate additional
	enrollment traffic, and it would like to adjust the enrollment		enrollment traffic, and it would like to adjust the enrollment
	priority (the proxy priority field of		priority (the proxy priority field of
	[I-D.ietf-6tisch-enrollment-enhanced-beacon]) among all nodes in the		[I-D.ietf-6tisch-enrollment-enhanced-beacon]) among all nodes in the
	subtree of a congested link.		subtree of a congested link.
	This document describes an RPL DIO option that can be used to		This document describes an RPL DIO option that can be used to
	announce a minimum enrollment priority. Each potential Join Proxy		announce a minimum enrollment priority. Each potential _Join Proxy_
	would this value as a base on which to add values relating to local		would this value as a base on which to add values relating to local
	conditions. As explained in		conditions. As explained in
	[I-D.ietf-6tisch-enrollment-enhanced-beacon], higher values decrease		[I-D.ietf-6tisch-enrollment-enhanced-beacon], higher values decrease
	the likelyhood of an unenrolled node sending enrollment traffic via		the likelyhood of an unenrolled node sending enrollment traffic via
	this path.		this path.
	A network operator can set this value to the maximum value allowed,		A network operator can set this value to the maximum value allowed,
	effectively disable all new enrollment traffic.		effectively disable all new enrollment traffic.
	1.1. Terminology		1.1. Terminology
	skipping to change at page 4, line 7 ¶		skipping to change at page 4, line 14 ¶
	2. Protocol Definition		2. Protocol Definition
	The following option is defined to transmission in the DIO issued by		The following option is defined to transmission in the DIO issued by
	the DODAG root. It may also be added by a router on part of the sub-		the DODAG root. It may also be added by a router on part of the sub-
	tree as a result of some (out of scope for this document) management		tree as a result of some (out of scope for this document) management
	function.		function.
	6LRs that see this DIO Option SHOULD increment their minimum		6LRs that see this DIO Option SHOULD increment their minimum
	enrollment priority if they observe congestion on the channel used		enrollment priority if they observe congestion on the channel used
	for join traffic. The exact mechanism is a local decision, and may		for enrollment traffic. The exact mechanism is a local decision, and
	be the subject for future work.		may be the subject for future work.
	A 6LR which would otherwise be willing to act as a Join Proxy, will		A 6LR which would otherwise be willing to act as a _Join Proxy_, will
	examine the minimum priority field, and to that number, add any		examine the minimum priority field, and to that number, add any
	additional local consideration (such as upstream congestion).		additional local consideration (such as upstream congestion).
	The Join Priority can only be increased by each each 6LR in value, to		The Enrollment Priority can only be increased by each 6LR in value,
	the maximum value of 0x7f.		to the maximum value of 0x7f.
	The resulting priority, if less than 0x7f should enable the Join		The resulting priority, if less than 0x7f should enable the _Join
	Proxy function.		Proxy_ function.
	0 1 2		0 1 2
	0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4		0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	| Type = TBD01|Opt Length = 1|R| min. priority |		| Type = TBD01|Opt Length = 1|R| min. priority |
	+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+		+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
	min.priority a 7 bit field which provides a base value for the		min.priority a 7 bit field which provides a base value for the
	Enhanced Beacon Join priority. A value of 0x7f (127) disables the		Enhanced Beacon Join priority. A value of 0x7f (127) disables the
	Join Proxy function entirely.		_Join Proxy_ function entirely.
	R a reserved bit that SHOULD be set to 0 by senders, and MUST be		R a reserved bit that SHOULD be set to 0 by senders, and MUST be
	ignored by receivers. This reserved bit SHOULD be copied to		ignored by receivers. This reserved bit SHOULD be copied to
	options created.		options created.
	This document uses the extensions mechanism designed into [RFC6550].		This document uses the extensions mechanism designed into [RFC6550].
	It does not need any mechanism to enable it.		It does not need any mechanism to enable it.
	Future work like [I-D.ietf-roll-capabilities] will enable collection		Future work like [I-D.ietf-roll-capabilities] will enable collection
	of capabilities such as this one in reports to the DODAG root.		of capabilities such as this one in reports to the DODAG root.
	skipping to change at page 5, line 25 ¶		skipping to change at page 5, line 30 ¶
	introduced. The 0x40 is only the half-way point, so if such an		introduced. The 0x40 is only the half-way point, so if such an
	amount of congestion was present, then this sub-tree of the DODAG		amount of congestion was present, then this sub-tree of the DODAG
	simply winds up being more cautious than it needed to be.		simply winds up being more cautious than it needed to be.
	It is possible that the temporal alternation of the above two		It is possible that the temporal alternation of the above two
	situations might introduce cycles of accepting and then rejecting		situations might introduce cycles of accepting and then rejecting
	enrollment traffic. This is something an operator should consider if		enrollment traffic. This is something an operator should consider if
	when they incrementally deploy this option to an existing LLN. In		when they incrementally deploy this option to an existing LLN. In
	addition, an operator would be unable to turn off enrollment traffic		addition, an operator would be unable to turn off enrollment traffic
	by sending a maximum value enrollment priority to the sub-tree. This		by sending a maximum value enrollment priority to the sub-tree. This
	situation is unfortunately, but would be exactly the situation		situation is unfortunate, but without this option, the the situation
	without this option.		would occur all over the DODAG, rather than just in the sub-tree
			where the option was omitted.
	3. Security Considerations		3. Security Considerations
	As per [RFC7416], RPL control frames either run over a secured layer		As per [RFC7416], RPL control frames either run over a secured layer
	2, or use the [RFC6550] Secure DIO methods. This option can be		2, or use the [RFC6550] Secure DIO methods. This option can be
	placed into either a "clear" (layer-2 secured) DIO, or a layer-3		placed into either a "clear" (layer-2 secured) DIO, or a layer-3
	Secure DIO. As such this option will have both integrity and		Secure DIO. As such this option will have both integrity and
	confidentiality mechanisms applied to it.		confidentiality mechanisms applied to it.
	A malicious node (that was part of the RPL control plane) could see		A malicious node (that was part of the RPL control plane) could see
	these options and could, based upon the observed minimal enrollment		these options and could, based upon the observed minimal enrollment
	priority signal a confederate that it was a good time to send		priority signal a confederate that it was a good time to send
	malicious join traffic.		malicious join traffic.
	A malicious node (that was part of the RPL control plane) could also		Such as a malicious node, being already part of the RPL control
	send DIOs with a different minimal enrollment priority which would		plane, could also send DIOs with a different minimal enrollment
	cause downstream mesh routers to change their Join Proxy behaviour.		priority which would cause downstream mesh routers to change their
			_Join Proxy_ behaviour.
	Lower minimal priorities would cause downstream nodes to accept more		Lower minimal priorities would cause downstream nodes to accept more
	pledges than the network was expecting, and higher minimal priorities		pledges than the network was expecting, and higher minimal priorities
	cause the join process to stall.		cause the enrollment process to stall.
	The use of layer-2 or layer-3 security for RPL control messages		The use of layer-2 or layer-3 security for RPL control messages
	prevents the above two attacks, by preventing malicious nodes from		prevents the above two attacks, by preventing malicious nodes from
	becoming part of the control plane. A node that is attacked and has		becoming part of the control plane. A node that is attacked and has
	malware placed on it creates vulnerabilities in the same way such an		malware placed on it creates vulnerabilities in the same way such an
	attack on any node involved in Internet routing protocol does. The		attack on any node involved in Internet routing protocol does. The
	rekeying provisions of [I-D.ietf-6tisch-minimal-security] exist to		rekeying provisions of [I-D.ietf-6tisch-minimal-security] exist to
	permit an operator to remove such nodes from the network.		permit an operator to remove such nodes from the network easily.
	4. Privacy Considerations		4. Privacy Considerations
	There are no new privacy issues caused by this extension.		There are no new privacy issues caused by this extension.
	5. IANA Considerations		5. IANA Considerations
	Allocate a new number TBD01 from Registry RPL Control Message		Allocate a new number TBD01 from Registry RPL Control Message
	Options. This entry should be called Minimum Enrollment Priority.		Options. This entry should be called Minimum Enrollment Priority.
	skipping to change at page 7, line 32 ¶		skipping to change at page 7, line 37 ¶
	<https://www.rfc-editor.org/info/rfc7554>.		<https://www.rfc-editor.org/info/rfc7554>.
	[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC		[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
	2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,		2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
	May 2017, <https://www.rfc-editor.org/info/rfc8174>.		May 2017, <https://www.rfc-editor.org/info/rfc8174>.
	7.2. Informative References		7.2. Informative References
	[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-28 (work		of IEEE 802.15.4", draft-ietf-6tisch-architecture-29 (work
	in progress), October 2019.		in progress), August 2020.
	[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.
	[I-D.ietf-6tisch-terminology]		[I-D.ietf-6tisch-terminology]
	Palattella, M., Thubert, P., Watteyne, T., and Q. Wang,		Palattella, M., Thubert, P., Watteyne, T., and Q. Wang,
	"Terms Used in IPv6 over the TSCH mode of IEEE 802.15.4e",		"Terms Used in IPv6 over the TSCH mode of IEEE 802.15.4e",
	draft-ietf-6tisch-terminology-10 (work in progress), March		draft-ietf-6tisch-terminology-10 (work in progress), March
	2018.		2018.
	[I-D.ietf-roll-capabilities]		[I-D.ietf-roll-capabilities]
	Jadhav, R., Thubert, P., Richardson, M., and R. Sahoo,		Jadhav, R., Thubert, P., Richardson, M., and R. Sahoo,
	"RPL Capabilities", draft-ietf-roll-capabilities-02 (work		"RPL Capabilities", draft-ietf-roll-capabilities-07 (work
	in progress), March 2020.		in progress), September 2020.
	[RFC8137] Kivinen, T. and P. Kinney, "IEEE 802.15.4 Information		[RFC8137] Kivinen, T. and P. Kinney, "IEEE 802.15.4 Information
	Element for the IETF", RFC 8137, DOI 10.17487/RFC8137, May		Element for the IETF", RFC 8137, DOI 10.17487/RFC8137, May
	2017, <https://www.rfc-editor.org/info/rfc8137>.		2017, <https://www.rfc-editor.org/info/rfc8137>.
	[RFC8366] Watsen, K., Richardson, M., Pritikin, M., and T. Eckert,		[RFC8366] Watsen, K., Richardson, M., Pritikin, M., and T. Eckert,
	"A Voucher Artifact for Bootstrapping Protocols",		"A Voucher Artifact for Bootstrapping Protocols",
	RFC 8366, DOI 10.17487/RFC8366, May 2018,		RFC 8366, DOI 10.17487/RFC8366, May 2018,
	<https://www.rfc-editor.org/info/rfc8366>.		<https://www.rfc-editor.org/info/rfc8366>.
	Appendix A. Change history		Appendix A. Change history
	version 00.		version 00.
	Author's Address		Authors' Addresses
	Michael Richardson		Michael Richardson
	Sandelman Software Works		Sandelman Software Works
	Email: mcr+ietf@sandelman.ca		Email: mcr+ietf@sandelman.ca
			Rahul Arvind Jadhav
			Huawei Tech
			Email: rahul.ietf@gmail.com
End of changes. 24 change blocks.
	37 lines changed or deleted		42 lines changed or added
This html diff was produced by rfcdiff 1.48. The latest version is available from http://tools.ietf.org/tools/rfcdiff/