draft-ietf-6lo-rfc6775-update-11.txt   draft-ietf-6lo-rfc6775-update-12.txt 
6lo P. Thubert, Ed. 6lo P. Thubert, Ed.
Internet-Draft cisco Internet-Draft cisco
Updates: 6775 (if approved) E. Nordmark Updates: 6775 (if approved) E. Nordmark
Intended status: Standards Track Intended status: Standards Track Zededa
Expires: June 18, 2018 S. Chakrabarti Expires: August 24, 2018 S. Chakrabarti
Verizon Verizon
C. Perkins C. Perkins
Futurewei Futurewei
December 15, 2017 February 20, 2018
An Update to 6LoWPAN ND An Update to 6LoWPAN ND
draft-ietf-6lo-rfc6775-update-11 draft-ietf-6lo-rfc6775-update-12
Abstract Abstract
This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
clarify the role of the protocol as a registration technique, clarify the role of the protocol as a registration technique,
simplify the registration operation in 6LoWPAN routers, as well as to simplify the registration operation in 6LoWPAN routers, as well as to
provide enhancements to the registration capabilities and mobility provide enhancements to the registration capabilities and mobility
detection for different network topologies including the backbone detection for different network topologies including the backbone
routers performing proxy Neighbor Discovery in a low power network. routers performing proxy Neighbor Discovery in a low power network.
skipping to change at page 1, line 40 skipping to change at page 1, line 40
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
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working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
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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 June 18, 2018. This Internet-Draft will expire on August 24, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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described in the Simplified BSD License. described in the Simplified BSD License.
Internet-Draft An Update to 6LoWPAN ND February
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Applicability of Address Registration Options . . . . . . . . 3 2. Applicability of Address Registration Options . . . . . . . . 3
3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
4. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 6 4. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 6
4.1. Extended Address Registration Option (EARO) . . . . . . . 7 4.1. Extended Address Registration Option (EARO) . . . . . . . 7
4.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 7 4.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 7
4.2.1. Comparing TID values . . . . . . . . . . . . . . . . 7 4.2.1. Comparing TID values . . . . . . . . . . . . . . . . 8
4.3. Owner Unique ID . . . . . . . . . . . . . . . . . . . . . 9 4.3. Registration Unique ID . . . . . . . . . . . . . . . . . 9
4.4. Extended Duplicate Address Messages . . . . . . . . . . . 10 4.4. Extended Duplicate Address Messages . . . . . . . . . . . 10
4.5. Registering the Target Address . . . . . . . . . . . . . 10 4.5. Registering the Target Address . . . . . . . . . . . . . 10
4.6. Link-Local Addresses and Registration . . . . . . . . . . 11 4.6. Link-Local Addresses and Registration . . . . . . . . . . 11
4.7. Maintaining the Registration States . . . . . . . . . . . 12 4.7. Maintaining the Registration States . . . . . . . . . . . 12
5. Detecting Enhanced ARO Capability Support . . . . . . . . . . 14 5. Detecting Enhanced ARO Capability Support . . . . . . . . . . 14
6. Extended ND Options And Messages . . . . . . . . . . . . . . 14 6. Extended ND Options And Messages . . . . . . . . . . . . . . 14
6.1. Enhanced Address Registration Option (EARO) . . . . . . . 14 6.1. Enhanced Address Registration Option (EARO) . . . . . . . 14
6.2. Extended Duplicate Address Message Formats . . . . . . . 17 6.2. Extended Duplicate Address Message Formats . . . . . . . 17
6.3. New 6LoWPAN Capability Bits in the Capability Indication 6.3. New 6LoWPAN Capability Bits in the Capability Indication
Option . . . . . . . . . . . . . . . . . . . . . . . . . 18 Option . . . . . . . . . . . . . . . . . . . . . . . . . 18
7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 18 7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 19
7.1. Discovering the capabilities of an ND peer . . . . . . . 18 7.1. Discovering the capabilities of an ND peer . . . . . . . 19
7.1.1. Using the "E" Flag in the 6CIO . . . . . . . . . . . 19 7.1.1. Using the "E" Flag in the 6CIO . . . . . . . . . . . 19
7.1.2. Using the "T" Flag in the EARO . . . . . . . . . . . 19 7.1.2. Using the "T" Flag in the EARO . . . . . . . . . . . 19
7.2. Legacy 6LoWPAN Node . . . . . . . . . . . . . . . . . . . 20 7.2. Legacy 6LoWPAN Node . . . . . . . . . . . . . . . . . . . 20
7.3. Legacy 6LoWPAN Router . . . . . . . . . . . . . . . . . . 20 7.3. Legacy 6LoWPAN Router . . . . . . . . . . . . . . . . . . 20
7.4. Legacy 6LoWPAN Border Router . . . . . . . . . . . . . . 21 7.4. Legacy 6LoWPAN Border Router . . . . . . . . . . . . . . 21
8. Security Considerations . . . . . . . . . . . . . . . . . . . 21 8. Security Considerations . . . . . . . . . . . . . . . . . . . 21
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 22 9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 23
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24
10.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . 23 10.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . 24
10.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 23 10.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 24
10.3. New ARO Status values . . . . . . . . . . . . . . . . . 24 10.3. New ARO Status values . . . . . . . . . . . . . . . . . 25
10.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . 25 10.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . 26
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 25 11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 27
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 25 12. References . . . . . . . . . . . . . . . . . . . . . . . . . 27
12.1. Normative References . . . . . . . . . . . . . . . . . . 25 12.1. Normative References . . . . . . . . . . . . . . . . . . 27
12.2. Informative References . . . . . . . . . . . . . . . . . 26 12.2. Informative References . . . . . . . . . . . . . . . . . 28
12.3. External Informative References . . . . . . . . . . . . 29 12.3. External Informative References . . . . . . . . . . . . 31
Appendix A. Applicability and Requirements Served . . . . . . . 30 Appendix A. Applicability and Requirements Served . . . . . . . 32
Appendix B. Requirements . . . . . . . . . . . . . . . . . . . . 30 Appendix B. Requirements . . . . . . . . . . . . . . . . . . . . 33
B.1. Requirements Related to Mobility . . . . . . . . . . . . 31
B.2. Requirements Related to Routing Protocols . . . . . . . . 31 Internet-Draft An Update to 6LoWPAN ND February
B.1. Requirements Related to Mobility . . . . . . . . . . . . 33
B.2. Requirements Related to Routing Protocols . . . . . . . . 33
B.3. Requirements Related to the Variety of Low-Power Link B.3. Requirements Related to the Variety of Low-Power Link
types . . . . . . . . . . . . . . . . . . . . . . . . . . 32 types . . . . . . . . . . . . . . . . . . . . . . . . . . 34
B.4. Requirements Related to Proxy Operations . . . . . . . . 33 B.4. Requirements Related to Proxy Operations . . . . . . . . 35
B.5. Requirements Related to Security . . . . . . . . . . . . 33 B.5. Requirements Related to Security . . . . . . . . . . . . 35
B.6. Requirements Related to Scalability . . . . . . . . . . . 34 B.6. Requirements Related to Scalability . . . . . . . . . . . 37
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 35 B.7. Matching Requirements with Specifications . . . . . . . . 37
Appendix C. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . 38
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 39
1. Introduction 1. Introduction
The scope of this draft is an IPv6 Low Power Networks including star The scope of this draft is an IPv6 Low Power Networks including star
and mesh topologies. This specification modifies and extends the and mesh topologies. This specification modifies and extends the
behavior and protocol elements of "Neighbor Discovery Optimization behavior and protocol elements of "Neighbor Discovery Optimization
for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND) for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND)
[RFC6775] to enable additional capabilities and enhancements such as: [RFC6775] to enable additional capabilities and enhancements such as:
o Support for indicating mobility vs retry (T-bit) o Support for indicating mobility vs retry (T-bit)
o Reduce requirement of registration for link-local addresses o Simplify the registration flow for link-local addresses
o Enhancement to Address Registration Option (ARO) o Enhancement to Address Registration Option (ARO)
o Permitting registration of a target address o Permitting registration of a target address
o Clarification of support of privacy and temporary addresses o Clarification of support of privacy and temporary addresses
The applicability of 6LoWPAN ND registration is discussed in The applicability of 6LoWPAN ND registration is discussed in
Section 2, and new extensions and updates to [RFC6775] are presented Section 2, and new extensions and updates to [RFC6775] are presented
in Section 4. Considerations on Backward Compatibility, Security and in Section 4. Considerations on Backward Compatibility, Security and
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6LoWPAN ND specification is to facilitate duplicate address detection 6LoWPAN ND specification is to facilitate duplicate address detection
(DAD) for hosts as well as populate Neighbor Cache Entries (NCE) (DAD) for hosts as well as populate Neighbor Cache Entries (NCE)
[RFC4861] in the routers. This reduces the reliance on multicast [RFC4861] in the routers. This reduces the reliance on multicast
operations, which are often as intrusive as broadcast, in IPv6 ND operations, which are often as intrusive as broadcast, in IPv6 ND
operations. operations.
With this specification, a failed or useless registration can be With this specification, a failed or useless registration can be
detected for reasons other than address duplication. Examples detected for reasons other than address duplication. Examples
include: the router having run out of space; a registration bearing a include: the router having run out of space; a registration bearing a
stale sequence number perhaps denoting a movement of the host after stale sequence number perhaps denoting a movement of the host after
Internet-Draft An Update to 6LoWPAN ND February
the registration was placed; a host misbehaving and attempting to the registration was placed; a host misbehaving and attempting to
register an invalid address such as the unspecified address register an invalid address such as the unspecified address
[RFC4291]; or a host using an address which is not topologically [RFC4291]; or a host using an address which is not topologically
correct on that link. correct on that link.
In such cases the host will receive an error to help diagnose the In such cases the host will receive an error to help diagnose the
issue and may retry, possibly with a different address, and possibly issue and may retry, possibly with a different address, and possibly
registering to a different router, depending on the returned error. registering to a different router, depending on the returned error.
The ability to return errors to address registrations is not intended The ability to return errors to address registrations is not intended
to be used to restrict the ability of hosts to form and use to be used to restrict the ability of hosts to form and use multiple
addresses, as recommended in "Host Address Availability addresses, as recommended in "Host Address Availability
Recommendations" [RFC7934]. Recommendations" [RFC7934].
In particular, the freedom to form and register addresses is needed In particular, the freedom to form and register addresses is needed
for enhanced privacy; each host may register a number of addresses for enhanced privacy; each host may register a number of addresses
using mechanisms such as "Privacy Extensions for Stateless Address using mechanisms such as "Privacy Extensions for Stateless Address
Autoconfiguration (SLAAC) in IPv6" [RFC4941]. Autoconfiguration (SLAAC) in IPv6" [RFC4941].
In IPv6 ND [RFC4861], a router must have enough storage to hold In IPv6 ND [RFC4861], a router must have enough storage to hold
neighbor cache entries for all the addresses to which it may forward. neighbor cache entries for all the addresses to which it may forward.
A router using the Address Registration mechanism also needs enough A router using the Address Registration mechanism also needs enough
storage to hold NCEs for all the addresses that may be registered to storage to hold NCEs for all the addresses that may be registered to
it, regardless of whether or not they are actively communicating. it, regardless of whether or not they are actively communicating.
The number of registrations supported by a 6LoWPAN Router (6LR) or The number of registrations supported by a 6LoWPAN Router (6LR) or
6LoWPAN Border Router (6LBR) must be clearly documented. 6LoWPAN Border Router (6LBR) must be clearly documented.
A network administrator should deploy updated 6LR/6LBRs to support A network administrator should deploy updated 6LR/6LBRs to support
the number and type of devices in his network, based on the number of the number and type of devices in their network, based on the number
IPv6 addresses that those devices require and their address renewal of IPv6 addresses that those devices require and their address
rate and behaviour. renewal rate and behavior.
3. Terminology 3. Terminology
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 [RFC2119]. document are to be interpreted as described in [RFC2119].
The Terminology used in this document is consistent with and
incorporates that described in Terms Used in Routing for Low-Power
and Lossy Networks (LLNs). [RFC7102].
Other terms in use in LLNs are found in Terminology for Constrained-
Node Networks [RFC7228].
Readers are expected to be familiar with all the terms and concepts Readers are expected to be familiar with all the terms and concepts
that are discussed in that are discussed in
o "Neighbor Discovery for IP version 6" [RFC4861], o "Neighbor Discovery for IP version 6" [RFC4861],
Internet-Draft An Update to 6LoWPAN ND February
o "IPv6 Stateless Address Autoconfiguration" [RFC4862], o "IPv6 Stateless Address Autoconfiguration" [RFC4862],
o "Problem Statement and Requirements for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Routing" [RFC6606],
o "IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs): o "IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals" [RFC4919], Overview, Assumptions, Problem Statement, and Goals" [RFC4919],
o "Neighbor Discovery Optimization for Low-power and Lossy Networks" o "Neighbor Discovery Optimization for Low-power and Lossy Networks"
[RFC6775] and [RFC6775] and
o "Multi-link Subnet Support in IPv6" o "Multi-link Subnet Support in IPv6"
[I-D.ietf-ipv6-multilink-subnets], [I-D.ietf-ipv6-multilink-subnets],
as well as the following terminology: as well as the following terminology:
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Binding: The association between an IP address with a MAC address, a Binding: The association between an IP address with a MAC address, a
port and/or other information about the node that owns the IP port and/or other information about the node that owns the IP
address. address.
Registered Node: The node for which the registration is performed, Registered Node: The node for which the registration is performed,
and which owns the fields in the EARO option. and which owns the fields in the EARO option.
Registering Node: The node that performs the registration to the Registering Node: The node that performs the registration to the
6BBR, which may proxy for the registered node. 6BBR, which may proxy for the registered node.
Internet-Draft An Update to 6LoWPAN ND February
Registered Address: An address owned by the Registered Node node Registered Address: An address owned by the Registered Node node
that was or is being registered. that was or is being registered.
IPv6 ND: The IPv6 Neighbor Discovery protocol as specified in
[RFC4861] and [RFC4862].
legacy: a 6LN, a 6LR or a 6LBR that supports [RFC6775] but not this legacy: a 6LN, a 6LR or a 6LBR that supports [RFC6775] but not this
specification. specification.
updated: a 6LN, a 6LR or a 6LBR that supports this specification. updated: a 6LN, a 6LR or a 6LBR that supports this specification.
4. Updating RFC 6775 4. Updating RFC 6775
This specification introduces the Extended Address Registration This specification introduces the Extended Address Registration
Option (EARO) based on the ARO as defined in [RFC6775]; in particular Option (EARO) based on the ARO as defined [RFC6775]; in particular a
a "T" flag is added that MUST be set in NS messages when this "T" flag is added that MUST be set in NS messages when this
specification is used, and echoed in NA messages to confirm that the specification is used, and echoed in NA messages to confirm that the
protocol is supported. protocol is supported.
The extensions to the ARO option are used in the Duplicate Address The extensions to the ARO option are used in the Duplicate Address
Request (DAR) and Duplicate Address Confirmation (DAC) messages, so Request (DAR) and Duplicate Address Confirmation (DAC) messages, so
as to convey the additional information all the way to the 6LBR. In as to convey the additional information all the way to the 6LBR. In
turn the 6LBR may proxy the registration using IPv6 ND over a turn the 6LBR may proxy the registration using IPv6 ND over a
backbone as illustrated in Figure 1. Note that this specification backbone as illustrated in Figure 1. Note that this specification
avoids the extended DAR flow for Link Local Addresses in Route-Over avoids the extended DAR flow for Link Local Addresses in a Route-Over
mode. [RFC6606] mesh.
6LN 6LR 6LBR 6BBR 6LN 6LR 6LBR 6BBR
| | | | | | | |
| NS(EARO) | | | | NS(EARO) | | |
|--------------->| | | |--------------->| | |
| | Extended DAR | | | | Extended DAR | |
| |-------------->| | | |-------------->| |
| | | | | | | |
| | | proxy NS(EARO) | | | | proxy NS(EARO) |
| | |--------------->| | | |--------------->|
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| | | proxy NA(EARO) | | | | proxy NA(EARO) |
| | |<---------------| | | |<---------------|
| | Extended DAC | | | | Extended DAC | |
| |<--------------| | | |<--------------| |
| NA(EARO) | | | | NA(EARO) | | |
|<---------------| | | |<---------------| | |
| | | | | | | |
Figure 1: (Re-)Registration Flow Figure 1: (Re-)Registration Flow
Internet-Draft An Update to 6LoWPAN ND February
In order to support various types of link layers, it is RECOMMENDED In order to support various types of link layers, it is RECOMMENDED
to allow multiple registrations, including for privacy / temporary to allow multiple registrations, including for privacy / temporary
addresses, and provides new mechanisms to help clean up stale addresses, and provide new mechanisms to help clean up stale
registration states as soon as possible. registration states as soon as possible.
A Registering Node SHOULD prefer registering to a 6LR that is found Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface
to support this specification, as discussed in Section 7.1, over a and locates available 6LRs; a Registering Node SHOULD prefer
legacy one. registering to a 6LR that is found to support this specification, as
discussed in Section 7.1, over a legacy one.
4.1. Extended Address Registration Option (EARO) 4.1. Extended Address Registration Option (EARO)
The Extended ARO (EARO) deprecates the ARO and is backward compatible The Extended ARO (EARO) deprecates the ARO and is backward compatible
with it. More details on backward compatibility can be found in with it. More details on backward compatibility can be found in
Section 7. Section 7.
The semantics of the ARO are modified as follows: The semantics of the ARO are modified as follows:
o The address that is being registered with a Neighbor Solicitation o The address that is being registered with a Neighbor Solicitation
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indicate so. indicate so.
o Finally, this specification introduces new status codes to help o Finally, this specification introduces new status codes to help
diagnose the cause of a registration failure (see Table 1). diagnose the cause of a registration failure (see Table 1).
4.2. Transaction ID 4.2. Transaction ID
The Transaction ID (TID) is a sequence number that is incremented The Transaction ID (TID) is a sequence number that is incremented
with each re-registration. The TID is used to detect the freshness with each re-registration. The TID is used to detect the freshness
of the registration request and useful to detect one single of the registration request and useful to detect one single
registration by multiple 6LOWPAN border routers (e.g., 6LBRs and registration by multiple 6LoWPAN border routers (e.g., 6LBRs and
6BBRs) supporting the same 6LOWPAN. The TID may also be used by the 6BBRs) supporting the same 6LoWPAN. The TID may also be used by the
network to track the sequence of movements of a node in order to network to track the sequence of movements of a node in order to
route to the current (freshest known) location of a moving node. route to the current (freshest known) location of a moving node.
When a Registered Node is registered with multiple BBRs in parallel, Internet-Draft An Update to 6LoWPAN ND February
When a Registered Node is registered with multiple 6BBRs in parallel,
the same TID SHOULD be used, to enable the 6BBRs to determine that the same TID SHOULD be used, to enable the 6BBRs to determine that
the registrations are the same, and distinguish that situation from a the registrations are the same, and distinguish that situation from a
movement. movement.
4.2.1. Comparing TID values 4.2.1. Comparing TID values
The TID is a sequence counter and its operation is the exact match of The TID is a sequence counter and its operation is the exact match of
the path sequence specified in RPL, the IPv6 Routing Protocol for the path sequence specified in RPL, the IPv6 Routing Protocol for
Low-Power and Lossy Networks [RFC6550] specification. Low-Power and Lossy Networks [RFC6550] specification.
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2. When a sequence counter increment would cause the sequence 2. When a sequence counter increment would cause the sequence
counter to increment beyond its maximum value, the sequence counter to increment beyond its maximum value, the sequence
counter MUST wrap back to zero. When incrementing a sequence counter MUST wrap back to zero. When incrementing a sequence
counter greater than or equal to 128, the maximum value is 255. counter greater than or equal to 128, the maximum value is 255.
When incrementing a sequence counter less than 128, the maximum When incrementing a sequence counter less than 128, the maximum
value is 127. value is 127.
3. When comparing two sequence counters, the following rules MUST be 3. When comparing two sequence counters, the following rules MUST be
applied: applied:
Internet-Draft An Update to 6LoWPAN ND February
1. When a first sequence counter A is in the interval [128..255] 1. When a first sequence counter A is in the interval [128..255]
and a second sequence counter B is in [0..127]: and a second sequence counter B is in [0..127]:
1. If (256 + B - A) is less than or equal to 1. If (256 + B - A) is less than or equal to
SEQUENCE_WINDOW, then B is greater than A, A is less than SEQUENCE_WINDOW, then B is greater than A, A is less than
B, and the two are not equal. B, and the two are not equal.
2. If (256 + B - A) is greater than SEQUENCE_WINDOW, then A 2. If (256 + B - A) is greater than SEQUENCE_WINDOW, then A
is greater than B, B is less than A, and the two are not is greater than B, B is less than A, and the two are not
equal. equal.
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[RFC1982] is used to determine the relationships greater [RFC1982] is used to determine the relationships greater
than, less than, and equal. than, less than, and equal.
2. If the absolute magnitude of difference of the two 2. If the absolute magnitude of difference of the two
sequence counters is greater than SEQUENCE_WINDOW, then a sequence counters is greater than SEQUENCE_WINDOW, then a
desynchronization has occurred and the two sequence desynchronization has occurred and the two sequence
numbers are not comparable. numbers are not comparable.
4. If two sequence numbers are determined to be not comparable, i.e. 4. If two sequence numbers are determined to be not comparable, i.e.
the results of the comparison are not defined, then a node should the results of the comparison are not defined, then a node should
consider the comparison as if it has evaluated in such a way so give precedence to the sequence number that was most recently
as to give precedence to the sequence number that has most incremented. Failing this, the node should select the sequence
recently been observed to increment. Failing this, the node number in order to minimize the resulting changes to its own
should consider the comparison as if it has evaluated in such a state.
way so as to minimize the resulting changes to its own state.
4.3. Owner Unique ID 4.3. Registration Unique ID
The Owner Unique ID (OUID) enables a duplicate address registration The Registration Unique ID (RUID) enables a duplicate address
to be distinguished from a double registration or a movement. An ND registration to be distinguished from a double registration or a
message from the 6BBR over the Backbone that is proxied on behalf of movement. An ND message from the 6BBR over the Backbone that is
a Registered Node must carry the most recent EARO option seen for proxied on behalf of a Registered Node must carry the most recent
that node. A NS/NA with an EARO and a NS/NA without a EARO thus EARO option seen for that node. A NS/NA with an EARO and a NS/NA
represent different nodes; if they relate to a same target then an
address duplication is likely.
The Owner Unique ID in [RFC6775] is a EUI-64 preconfigured address, Internet-Draft An Update to 6LoWPAN ND February
under the assumption that duplicate EUI-64 addresses are avoided.
With this specification, the Owner Unique ID is allowed to be without a EARO thus represent different nodes; if they relate to a
same target then an address duplication is likely.
The Registration Unique ID in [RFC6775] is a EUI-64 globally unique
address configured at a Lower Layer, under the assumption that
duplicate EUI-64 addresses are avoided.
With this specification, the Registration Unique ID is allowed to be
extended to different types of identifier, as long as the type is extended to different types of identifier, as long as the type is
clearly indicated. For instance, the type can be a cryptographic clearly indicated. For instance, the type can be a cryptographic
string and used to prove the ownership of the registration as string and used to prove the ownership of the registration as
discussed in "Address Protected Neighbor Discovery for Low-power and discussed in "Address Protected Neighbor Discovery for Low-power and
Lossy Networks" [I-D.ietf-6lo-ap-nd]. Lossy Networks" [I-D.ietf-6lo-ap-nd]. In order to support the flows
related to the proof of ownership, this specification introduces new
status codes "Validation Requested" and "Validation Failed" in the
EARO.
The node SHOULD store the unique ID, or a way to generate that ID, in The Registering Node SHOULD store the unique ID, or a way to generate
persistent memory. Otherwise, if a reboot causes a loss of memory, that ID, in persistent memory. Otherwise, if a reboot causes a loss
re-registering the same address could be impossible until the 6LBR of memory, re-registering the same address could be impossible until
times out the previous registration. the 6LBR times out the previous registration.
4.4. Extended Duplicate Address Messages 4.4. Extended Duplicate Address Messages
In order to map the new EARO content in the DAR/DAC messages, a new In order to map the new EARO content in the DAR/DAC messages, a new
TID field is added to the Extended DAR (EDAR) and the Extended DAC TID field is added to the Extended DAR (EDAR) and the Extended DAC
(EDAC) messages as a replacement to a Reserved field, and an odd (EDAC) messages as a replacement to a Reserved field, and an odd
value of the ICMP Code indicates support for the TID, to transport value of the ICMP Code indicates support for the TID, to transport
the "T" flag. the "T" flag.
In order to prepare for future extensions, and though no option has In order to prepare for future extensions, and though no option has
skipping to change at page 10, line 36 skipping to change at page 11, line 4
4.5. Registering the Target Address 4.5. Registering the Target Address
The Registering Node is the node that performs the registration to The Registering Node is the node that performs the registration to
the 6BBR. As in [RFC6775], it may be the Registered Node as well, in the 6BBR. As in [RFC6775], it may be the Registered Node as well, in
which case it registers one of its own addresses, and indicates its which case it registers one of its own addresses, and indicates its
own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO). own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO).
This specification adds the capability to proxy the registration This specification adds the capability to proxy the registration
operation on behalf of a Registered Node that is reachable over a LLN operation on behalf of a Registered Node that is reachable over a LLN
Internet-Draft An Update to 6LoWPAN ND February
mesh. In that case, if the Registered Node is reachable from the mesh. In that case, if the Registered Node is reachable from the
6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC 6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC
Address of the Registered Node as SLLA in the NS(EARO). If the Address of the Registered Node as SLLA in the NS(EARO). If the
Registered Node is reachable over a Route-Over mesh from the Registered Node is reachable over a Route-Over mesh from the
Registering Node, the SLLA in the NS(ARO) is that of the Registering Registering Node, the SLLA in the NS(ARO) is that of the Registering
Node. This enables the Registering Node to attract the packets from Node. This enables the Registering Node to attract the packets from
the 6BBR and route them over the LLN to the Registered Node. the 6BBR and route them over the LLN to the Registered Node.
In order to enable the latter operation, this specification changes In order to enable the latter operation, this specification changes
the behavior of the 6LN and the 6LR so that the Registered Address is the behavior of the 6LN and the 6LR so that the Registered Address is
skipping to change at page 11, line 37 skipping to change at page 12, line 4
they are reachable over one hop and that at least one of the 2 nodes they are reachable over one hop and that at least one of the 2 nodes
acts as a 6LR. A node MUST register a Link-Local address to a 6LR in acts as a 6LR. A node MUST register a Link-Local address to a 6LR in
order to obtain reachability from that 6LR beyond the current order to obtain reachability from that 6LR beyond the current
exchange, and in particular to use the Link-Local address as source exchange, and in particular to use the Link-Local address as source
address to register other addresses, e.g. global addresses. address to register other addresses, e.g. global addresses.
If there is no collision with an address previously registered to If there is no collision with an address previously registered to
this 6LR by another 6LN, then the Link-Local address is unique from this 6LR by another 6LN, then the Link-Local address is unique from
the standpoint of this 6LR and the registration is acceptable. the standpoint of this 6LR and the registration is acceptable.
Alternatively, two different 6LRs might expose the same Link-Local Alternatively, two different 6LRs might expose the same Link-Local
Internet-Draft An Update to 6LoWPAN ND February
address but different link-layer addresses. In that case, a 6LN MUST address but different link-layer addresses. In that case, a 6LN MUST
only interact with one of the 6LRs. only interact with at most one of the 6LRs.
The DAD process between the 6LR and a 6LBR, which is based on an The DAD process between the 6LR and a 6LBR, which is based on an
exchange of Duplicate Address messages, does not need to take place exchange of Duplicate Address messages, does not need to take place
for Link-Local addresses. for Link-Local addresses.
It is preferable for a 6LR to avoid modifying its state associated to
the Source Address of an NS(EARO) message. For that reason, when
possible, an address that is already registered with a 6LR SHOULD be
used by a 6LN.
When registering to a 6LR that conforms this specification, a node When registering to a 6LR that conforms this specification, a node
MUST use a Link-Local address as the source address of the MUST use a Link-Local address as the source address of the
registration, whatever the type of IPv6 address that is being registration, whatever the type of IPv6 address that is being
registered. That Link-Local Address MUST be either already registered. That Link-Local Address MUST be either an address that
registered, or the address that is being registered. is already registered to the 6LR, or the address that is being
registered.
When a Registering Node does not have an already-Registered Address, When a Registering Node does not have an already-Registered Address,
it MUST register a Link-Local address, using it as both the Source it MUST register a Link-Local address, using it as both the Source
and the Target Address of an NS(EARO) message. In that case, it is and the Target Address of an NS(EARO) message. In that case, it is
RECOMMENDED to use a Link-Local address that is (expected to be) RECOMMENDED to use a Link-Local address that is (expected to be)
globally unique, e.g., derived from a globally unique hardware MAC globally unique, e.g., derived from a globally unique hardware MAC
address. An EARO option in the response NA indicates that the 6LR address. An EARO option in the response NA indicates that the 6LR
supports this specification. supports this specification.
Since there is no Duplicate Address exchange for Link-Local Since there is no Duplicate Address exchange for Link-Local
skipping to change at page 12, line 41 skipping to change at page 13, line 4
4.7. Maintaining the Registration States 4.7. Maintaining the Registration States
This section discusses protocol actions that involve the Registering This section discusses protocol actions that involve the Registering
Node, the 6LR and the 6LBR. It must be noted that the portion that Node, the 6LR and the 6LBR. It must be noted that the portion that
deals with a 6LBR only applies to those addresses that are registered deals with a 6LBR only applies to those addresses that are registered
to it; as discussed in Section 4.6, this is not the case for Link- to it; as discussed in Section 4.6, this is not the case for Link-
Local addresses. The registration state includes all data that is Local addresses. The registration state includes all data that is
stored in the router relative to that registration, in particular, stored in the router relative to that registration, in particular,
but not limited to, an NCE in a 6LR. 6LBRs and 6BBRs may store but not limited to, an NCE in a 6LR. 6LBRs and 6BBRs may store
additional registration information in more complex data structures additional registration information in more complex data structures
Internet-Draft An Update to 6LoWPAN ND February
and use protocols that are out of scope of this document to keep them and use protocols that are out of scope of this document to keep them
synchonized when they are distributed. synchronized when they are distributed.
When its Neighbor Cache is full, a 6LR cannot accept a new When its Neighbor Cache is full, a 6LR cannot accept a new
registration. In that situation, the EARO is returned in a NA registration. In that situation, the EARO is returned in a NA
message with a Status of 2, and the Registering Node may attempt to message with a Status of 2, and the Registering Node may attempt to
register to another 6LR. register to another 6LR.
If the registry in the 6LBR is be saturated, in which case the LBR If the registry in the 6LBR is saturated, the LBR cannot guarantee
cannot guarantee that a new address is effectively not a duplicate. that a new address is effectively not a duplicate. In that case, the
In that case, the 6LBR replies to a EDAR message with a EDAC message 6LBR replies to a EDAR message with a EDAC message that carries a new
that carries a Status code 9 indicating "6LBR Registry saturated", Status Code indicating "6LBR Registry saturated" Table 1. Note: this
and the address stays in TENTATIVE state. Note: this code is used by code is used by 6LBRs instead of Status 2 when responding to a
6LBRs instead of Status 2 when responding to a Duplicate Address Duplicate Address message exchange and passed on to the Registering
message exchange and passed on to the Registering Node by the 6LR. Node by the 6LR. There is no point for the node to retry this
There is no point for the node to retry this registration immediately registration immediately via another 6LR, since the problem is global
via another 6LR, since the problem is global to the network. The to the network. The node may either abandon that address, de-
node may either abandon that address, deregister other addresses register other addresses first to make room, or keep the address in
first to make room, or keep the address in TENTATIVE state and retry TENTATIVE state and retry later.
later.
A node renews an existing registration by sending a new NS(EARO) A node renews an existing registration by sending a new NS(EARO)
message for the Registered Address. In order to refresh the message for the Registered Address. In order to refresh the
registration state in the 6LBR, the registration MUST be reported to registration state in the 6LBR, the registration MUST be reported to
the 6LBR. the 6LBR.
A node that ceases to use an address SHOULD attempt to deregister A node that ceases to use an address SHOULD attempt to de-register
that address from all the 6LRs to which it has registered the that address from all the 6LRs to which it has registered the
address, which is achieved using an NS(EARO) message with a address, which is achieved using an NS(EARO) message with a
Registration Lifetime of 0. Registration Lifetime of 0.
A node that moves away from a particular 6LR SHOULD attempt to A node that moves away from a particular 6LR SHOULD attempt to de-
deregister all of its addresses registered to that 6LR and register register all of its addresses registered to that 6LR and register to
to a new 6LR with an incremented TID. When/if the node shows up a new 6LR with an incremented TID. When/if the node shows up
elsewhere, an asynchronous NA(EARO) or EDAC message with a status of elsewhere, an asynchronous NA(EARO) or EDAC message with a status of
3 "Moved" SHOULD be used to clean up the state in the previous 3 "Moved" SHOULD be used to clean up the state in the previous
location. For instance, the "Moved" status can be used by a 6BBR in location. For instance, as described in
a NA(EARO) message to indicate that the ownership of the proxy state [I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a
on the Backbone was transferred to another 6BBR, as the consequence 6BBR in a NA(EARO) message to indicate that the ownership of the
of a movement of the device. The receiver of the message SHOULD proxy state on the Backbone was transferred to another 6BBR, as the
propagate the status down the chain towards the Registered node and consequence of a movement of the device. The receiver of the message
clean up its state. SHOULD propagate the status down the chain towards the Registered
node (e.g. reversing an existing RPL [RFC6550] path) and then clean
up its state.
Upon receiving a NS(EARO) message with a Registration Lifetime of 0 Upon receiving a NS(EARO) message with a Registration Lifetime of 0
and determining that this EARO is the freshest for a given NCE (see and determining that this EARO is the freshest for a given NCE (see
Section 4.2), a 6LR cleans up its NCE. If the address was registered Section 4.2), a 6LR cleans up its NCE. If the address was registered
to the 6LBR, then the 6LR MUST report to the 6LBR, through a to the 6LBR, then the 6LR MUST report to the 6LBR, through a
Duplicate Address exchange with the 6LBR, or an alternate protocol,
indicating the null Registration Lifetime and the latest TID that Internet-Draft An Update to 6LoWPAN ND February
this 6LR is aware of.
Duplicate Address exchange with the 6LBR, indicating the null
Registration Lifetime and the latest TID that this 6LR is aware of.
Upon receiving the Extended DAR message, the 6LBR evaluates if this Upon receiving the Extended DAR message, the 6LBR evaluates if this
is the most recent TID it has received for that particular registry is the most recent TID it has received for that particular registry
entry. If so, then the entry is scheduled to be removed, and the entry. If so, then the entry is scheduled to be removed, and the
EDAR is answered with a EDAC message bearing a Status of 0 EDAR is answered with a EDAC message bearing a Status of 0
("Success"). Otherwise, a Status 3 ("Moved") is returned instead, ("Success"). Otherwise, a Status 3 ("Moved") is returned instead,
and the existing entry is maintained. and the existing entry is maintained.
When an address is scheduled to be removed, the 6LBR SHOULD keep its When an address is scheduled to be removed, the 6LBR SHOULD keep its
entry in a DELAY state for a configurable period of time, so as to entry in a DELAY state for a configurable period of time, so as to
protect a mobile node that deregistered from one 6LR and did not protect a mobile node that de-registered from one 6LR and did not
register yet to a new one, or the new registration did not reach yet register yet to a new one, or the new registration did not reach yet
the 6LBR due to propagation delays in the network. Once the DELAY the 6LBR due to propagation delays in the network. Once the DELAY
time is passed, the 6LBR removes silently its entry. time is passed, the 6LBR silently removes its entry.
5. Detecting Enhanced ARO Capability Support 5. Detecting Enhanced ARO Capability Support
The "Generic Header Compression for IPv6 over 6LoWPANs" [RFC7400] The "Generic Header Compression for IPv6 over 6LoWPANs" [RFC7400]
introduces the 6LoWPAN Capability Indication Option (6CIO) to introduces the 6LoWPAN Capability Indication Option (6CIO) to
indicate a node's capabilities to its peers. indicate a node's capabilities to its peers.
Section 6.3 defines new flags for the 6CIO to signal support for Section 6.3 defines new flags for the 6CIO to signal support for
EARO, as well as the node's capability to act as a 6LR, 6LBR and EARO, as well as the node's capability to act as a 6LR, 6LBR and
6BBR. Section 7.1.1 specifies how the "E" flag can be used to 6BBR. Section 7.1.1 specifies how the "E" flag can be used to
skipping to change at page 14, line 43 skipping to change at page 15, line 4
the following subsections. the following subsections.
6.1. Enhanced Address Registration Option (EARO) 6.1. Enhanced Address Registration Option (EARO)
The Address Registration Option (ARO) is defined in section 4.1. of The Address Registration Option (ARO) is defined in section 4.1. of
[RFC6775]. [RFC6775].
The Enhanced Address Registration Option (EARO) updates the ARO The Enhanced Address Registration Option (EARO) updates the ARO
option within Neighbor Discovery NS and NA messages between a 6LN and option within Neighbor Discovery NS and NA messages between a 6LN and
its 6LR. On the other hand, the Extended Duplicate Address messages, its 6LR. On the other hand, the Extended Duplicate Address messages,
Internet-Draft An Update to 6LoWPAN ND February
EDAR and EDAC, replace the DAR and DAC messages so as to transport EDAR and EDAC, replace the DAR and DAC messages so as to transport
the new information between 6LRs and 6LBRs across LLNs meshes such as the new information between 6LRs and 6LBRs across LLN meshes such as
6TiSCH networks. 6TiSCH networks.
An NS message with an EARO option is a registration if and only if it An NS message with an EARO option is a registration if and only if it
also carries an SLLAO option. The EARO option also used in NS and NA also carries an SLLAO option. The EARO option also used in NS and NA
messages between Backbone Routers over the Backbone link to sort out messages between Backbone Routers [I-D.ietf-6lo-backbone-router] over
the distributed registration state; in that case, it does not carry the Backbone link to sort out the distributed registration state; in
the SLLAO option and is not confused with a registration. that case, it does not carry the SLLAO option and is not confused
with a registration.
When using the EARO option, the address being registered is found in When using the EARO option, the address being registered is found in
the Target Address field of the NS and NA messages. the Target Address field of the NS and NA messages.
The EARO extends the ARO and is indicated by the "T" flag set. The The EARO extends the ARO and is indicated by the "T" flag set. The
format of the EARO option is as follows: format of the EARO option is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 2 | Status | Reserved | | Type | Length = 2 | Status | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |T| TID | Registration Lifetime | | Reserved |T| TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Owner Unique ID (EUI-64 or equivalent) + + Registration Unique ID (EUI-64 or equivalent) +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: EARO Figure 2: EARO
Option Fields Option Fields
Type: 33 Type: 33
Length: 8-bit unsigned integer. The length of the option in Length: 8-bit unsigned integer. The length of the option in
skipping to change at page 15, line 42 skipping to change at page 16, line 4
Status: 8-bit unsigned integer. Indicates the status of a Status: 8-bit unsigned integer. Indicates the status of a
registration in the NA response. MUST be set to 0 in registration in the NA response. MUST be set to 0 in
NS messages. See Table 1 below. NS messages. See Table 1 below.
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
| Value | Description | | Value | Description |
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
| 0..2 | See [RFC6775]. Note: a Status of 1 "Duplicate Address" | | 0..2 | See [RFC6775]. Note: a Status of 1 "Duplicate Address" |
| | applies to the Registered Address. If the Source Address | | | applies to the Registered Address. If the Source Address |
| | conflicts with an existing registration, "Duplicate | | | conflicts with an existing registration, "Duplicate |
Internet-Draft An Update to 6LoWPAN ND February
| | Source Address" should be used. | | | Source Address" should be used. |
| | | | | |
| 3 | Moved: The registration fails because it is not the | | 3 | Moved: The registration failed because it is not the |
| | freshest. This Status indicates that the registration is | | | freshest. This Status indicates that the registration is |
| | rejected because another more recent registration was | | | rejected because another more recent registration was |
| | done, as indicated by a same OUI and a more recent TID. | | | done, as indicated by a same OUI and a more recent TID. |
| | One possible cause is a stale registration that has | | | One possible cause is a stale registration that has |
| | progressed slowly in the network and was passed by a more | | | progressed slowly in the network and was passed by a more |
| | recent one. It could also indicate a OUI collision. | | | recent one. It could also indicate a OUI collision. |
| | | | | |
| 4 | Removed: The binding state was removed. This may be | | 4 | Removed: The binding state was removed. This may be |
| | placed in an asynchronous NS(ARO) message, or as the | | | placed in an asynchronous NS(ARO) message, or as the |
| | rejection of a proxy registration to a Backbone Router | | | rejection of a proxy registration to a Backbone Router |
skipping to change at page 16, line 40 skipping to change at page 17, line 5
| | | | | |
| 10 | Validation Failed: The proof of ownership of the | | 10 | Validation Failed: The proof of ownership of the |
| | registered address is not correct. | | | registered address is not correct. |
+-------+-----------------------------------------------------------+ +-------+-----------------------------------------------------------+
Table 1: EARO Status Table 1: EARO Status
Reserved: This field is unused. It MUST be initialized to zero Reserved: This field is unused. It MUST be initialized to zero
by the sender and MUST be ignored by the receiver. by the sender and MUST be ignored by the receiver.
Internet-Draft An Update to 6LoWPAN ND February
T: One bit flag. Set if the next octet is a used as a T: One bit flag. Set if the next octet is a used as a
TID. TID.
TID: 1-byte integer; a transaction id that is maintained TID: 1-byte integer; a transaction id that is maintained
by the node and incremented with each transaction. by the node and incremented with each transaction.
The node SHOULD maintain the TID in a persistent The node SHOULD maintain the TID in a persistent
storage. storage.
Registration Lifetime: 16-bit integer; expressed in minutes. 0 Registration Lifetime: 16-bit integer; expressed in minutes. 0
means that the registration has ended and the means that the registration has ended and the
associated state should be removed. associated state should be removed.
Owner Unique Identifier (OUI): A globally unique identifier for the Registration Unique IDentifier (OUI): A globally unique identifier
node associated. This can be the EUI-64 derived IID for the node associated. This can be the EUI-64
of an interface, or some provable ID obtained derived IID of an interface, or some provable ID
cryptographically. obtained cryptographically.
6.2. Extended Duplicate Address Message Formats 6.2. Extended Duplicate Address Message Formats
The Duplicate Address Request (DAR) and the Duplicate Address The Duplicate Address Request (DAR) and the Duplicate Address
Confirmation (DAC) messages are defined in section 4.4 of [RFC6775]. Confirmation (DAC) messages are defined in section 4.4 of [RFC6775].
Those messages follow a common base format, which enables information Those messages follow a common base format, which enables information
from the ARO to be transported over multiple hops. from the ARO to be transported over multiple hops.
The Duplicate Address Messages are extended to adapt to the Extended The Duplicate Address Messages are extended to adapt to the Extended
ARO format, as follows: ARO format, as follows:
0 1 2 3 Internet-Draft An Update to 6LoWPAN ND February
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 0 1 2 3
| Type | Code | Checksum | 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status | TID | Registration Lifetime | | Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | Status | TID | Registration Lifetime |
+ Owner Unique ID (EUI-64 or equivalent) + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + Registration Unique ID (EUI-64 or equivalent) +
| | | |
+ + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
+ Registered Address + + +
| | | |
+ + + Registered Address +
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Duplicate Address Messages Format Figure 3: Duplicate Address Messages Format
Modified Message Fields Modified Message Fields
Code: The ICMP Code as defined in [RFC4443]. The ICMP Code Code: The ICMP Code as defined in [RFC4443]. The ICMP Code
MUST be set to 1 with this specification. An odd MUST be set to 1 with this specification. An odd
value of the ICMP Code indicates that the TID field value of the ICMP Code indicates that the TID field
is present and obeys this specification. is present and obeys this specification.
TID: 1-byte integer; same definition and processing as the TID: 1-byte integer; same definition and processing as the
TID in the EARO option as defined in Section 6.1. TID in the EARO option as defined in Section 6.1.
Owner Unique Identifier (OUI): 8 bytes; same definition and Registration Unique IDentifier (OUI): 8 bytes; same definition and
processing as the OUI in the EARO option as defined processing as the OUI in the EARO option as defined
in Section 6.1. in Section 6.1.
6.3. New 6LoWPAN Capability Bits in the Capability Indication Option 6.3. New 6LoWPAN Capability Bits in the Capability Indication Option
This specification defines new capability bits for use in the 6CIO, This specification defines new capability bits for use in the 6CIO,
which was introduced by [RFC7400] for use in IPv6 ND RA messages. which was introduced by [RFC7400] for use in IPv6 ND RA messages.
Routers that support this specification SHOULD set the "E" flag and Routers that support this specification MUST set the "E" flag and 6LN
6LN SHOULD favor 6LR routers that support this specification over SHOULD favor 6LR routers that support this specification over those
those that do not. Routers that are capable of acting as 6LR, 6LBR that do not. Routers that are capable of acting as 6LR, 6LBR and
and 6BBR SHOULD set the "L", "B" and "P" flags, respectively. In 6BBR SHOULD set the "L", "B" and "P" flags, respectively. In
particular, the function 6LR is often collocated with that of 6LBR. particular, the function 6LR is often collocated with that of 6LBR.
Internet-Draft An Update to 6LoWPAN ND February
Those flags are not mutually exclusive and if a router is capable of Those flags are not mutually exclusive and if a router is capable of
performing multiple functions, it SHOULD set all the related flags. performing multiple functions, it SHOULD set all the related flags.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 1 | Reserved |L|B|P|E|G| | Type | Length = 1 | Reserved |L|B|P|E|G|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved | | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 19, line 4 skipping to change at page 19, line 35
B: Node is a 6LBR. B: Node is a 6LBR.
P: Node is a 6BBR, proxying for nodes on this link. P: Node is a 6BBR, proxying for nodes on this link.
E: This specification is supported and applied. E: This specification is supported and applied.
7. Backward Compatibility 7. Backward Compatibility
7.1. Discovering the capabilities of an ND peer 7.1. Discovering the capabilities of an ND peer
7.1.1. Using the "E" Flag in the 6CIO 7.1.1. Using the "E" Flag in the 6CIO
If the 6CIO is used in an ND message and the sending node supports If the 6CIO is used in an ND message and the sending node supports
this specification, then the "E" Flag MUST be set. this specification, then the "E" Flag MUST be set.
A router that supports this specification SHOULD indicate that with a A router that supports this specification SHOULD indicate that with a
6CIO. 6CIO.
If the Registering Node (RN) receives a 6CIO in a Router If the Registering Node receives a 6CIO in a Router Advertisement
Advertisement message, then the setting of the "E" Flag indicates message, then the setting of the "E" Flag indicates whether or not
whether or not this specification is supported. this specification is supported.
7.1.2. Using the "T" Flag in the EARO 7.1.2. Using the "T" Flag in the EARO
One alternate way for a 6LN to discover the router's capabilities to One alternate way for a 6LN to discover the router's capabilities is
first register a Link Local address, placing the same address in the to first register a Link Local address, placing the same address in
Source and Target Address fields of the NS message, and setting the the Source and Target Address fields of the NS message, and setting
"T" Flag. The node may for instance register an address that is the "T" Flag. The node may for instance register an address that is
based on EUI-64. For such address, DAD is not required and using the
SLLAO option in the NS is actually more consistent with existing ND Internet-Draft An Update to 6LoWPAN ND February
specifications such as the "Optimistic Duplicate Address Detection
(DAD) for IPv6" [RFC4429]. based on EUI-64. For such an address, DAD is not required and using
the SLLAO option in the NS is actually more consistent with existing
ND specifications such as the "Optimistic Duplicate Address Detection
(ODAD) for IPv6" [RFC4429].
Once its first registration is complete, the node knows from the Once its first registration is complete, the node knows from the
setting of the "T" Flag in the response whether the router supports setting of the "T" Flag in the response whether the router supports
this specification. If support is verified, the node may register this specification. If support is verified, the node may register
other addresses that it owns, or proxy-register addresses on behalf other addresses that it owns, or proxy-register addresses on behalf
some another node, indicating those addresses being registered in the some another node, indicating those addresses being registered in the
Target Address field of the NS messages, while using one of its own Target Address field of the NS messages, while using one of its own
previously registered addresses as source. previously registered addresses as source.
A node that supports this specification MUST always use an EARO as a A node that supports this specification MUST always use an EARO as a
replacement to an ARO in its registration to a router. This is replacement to an ARO in its registration to a router. This is
harmless since the "T" flag and TID field are reserved in [RFC6775], harmless since the "T" flag and TID field are reserved in [RFC6775],
and are ignored by a legacy router. A router that supports this and are ignored by a legacy router. A router that supports this
specification answers an ARO with an ARO and answers an EARO with an specification answers an ARO with an ARO and answers an EARO with an
EARO. EARO.
This specification changes the behavior of the peers in a This specification changes the behavior of the peers in a
registration flows. To enable backward compatibility, a 6LB that registration flow. To enable backward compatibility, a 6LN that
registers to a 6LR that is not known to support this specification registers to a 6LR that is not known to support this specification
MUST behave in a manner that is compatible with [RFC6775]. A 6LN can MUST behave in a manner that is compatible with [RFC6775]. A 6LN can
achieve that by sending a NS(EARO) message with a Link-Local Address achieve that by sending a NS(EARO) message with a Link-Local Address
used as both Source and Target Address, as described in Section 4.6. used as both Source and Target Address, as described in Section 4.6.
Once the 6LR is known to support this specification, the 6LN MUST Once the 6LR is known to support this specification, the 6LN MUST
obey this specification. obey this specification.
7.2. Legacy 6LoWPAN Node 7.2. Legacy 6LoWPAN Node
A legacy 6LN will use the Registered Address as source and will not A legacy 6LN will use the Registered Address as source and will not
skipping to change at page 20, line 23 skipping to change at page 21, line 4
The main difference with [RFC6775] is that Duplicate Address exchange The main difference with [RFC6775] is that Duplicate Address exchange
for DAD is avoided for Link-Local addresses. In any case, the 6LR for DAD is avoided for Link-Local addresses. In any case, the 6LR
SHOULD use an EARO in the reply, and may use any of the Status codes SHOULD use an EARO in the reply, and may use any of the Status codes
defined in this specification. defined in this specification.
7.3. Legacy 6LoWPAN Router 7.3. Legacy 6LoWPAN Router
The first registration by an updated 6LN MUST be for a Link-Local The first registration by an updated 6LN MUST be for a Link-Local
address, using that Link-Local address as source. A legacy 6LR will address, using that Link-Local address as source. A legacy 6LR will
Internet-Draft An Update to 6LoWPAN ND February
not make a difference and treat that registration as if the 6LN was a not make a difference and treat that registration as if the 6LN was a
legacy node. legacy node.
An updated 6LN will always use an EARO option in the registration NS An updated 6LN will always use an EARO option in the registration NS
message, whereas a legacy 6LR will always reply with an ARO option in message, whereas a legacy 6LR will always reply with an ARO option in
the NA message. From that first registration, the updated 6LN can the NA message. From that first registration, the updated 6LN can
determine whether or not the 6LR supports this specification. determine whether or not the 6LR supports this specification.
After detecting a legacy 6LR, an updated 6LN may attempt to find an After detecting a legacy 6LR, an updated 6LN SHOULD attempt to find
alternate 6LR that is updated. an alternate 6LR that is updated for a reasonable time that depends
on the type of device and the expected deployment.
An updated 6LN SHOULD use an EARO in the request regardless of the An updated 6LN SHOULD use an EARO in the request regardless of the
type of 6LR, legacy or updated, which implies that the "T" flag is type of 6LR, legacy or updated, which implies that the "T" flag is
set. set.
If an updated 6LN moves from an updated 6LR to a legacy 6LR, the If an updated 6LN moves from an updated 6LR to a legacy 6LR, the
legacy 6LR will send a legacy DAR message, which can not be compared legacy 6LR will send a legacy DAR message, which can not be compared
with an updated one for freshness. with an updated one for freshness.
Allowing legacy DAR messages to replace a state established by the Allowing legacy DAR messages to replace a state established by the
skipping to change at page 21, line 10 skipping to change at page 21, line 41
But if legacy and updated 6LRs coexist temporarily in a network, then But if legacy and updated 6LRs coexist temporarily in a network, then
it makes sense for an administrator to install a policy that allows it makes sense for an administrator to install a policy that allows
so, and the capability to install such a policy should be so, and the capability to install such a policy should be
configurable in a 6LBR though it is out of scope for this document. configurable in a 6LBR though it is out of scope for this document.
7.4. Legacy 6LoWPAN Border Router 7.4. Legacy 6LoWPAN Border Router
With this specification, the Duplicate Address messages are extended With this specification, the Duplicate Address messages are extended
to transport the EARO information. Similarly to the NS/NA exchange, to transport the EARO information. Similarly to the NS/NA exchange,
updated 6LBR devices always use the Extended Duplicate Address updated 6LBR devices always use the Extended Duplicate Address
messages and all the associated behavior so they can amlways be messages and all the associated behavior so they can always be
differentiated from legacy ones. differentiated from legacy ones.
Note that a legacy 6LBR will accept and process an EDAR message as if Note that a legacy 6LBR will accept and process an EDAR message as if
it was a legacy DAR, so legacy support of DAD is preserved. it was a legacy DAR, so legacy support of DAD is preserved.
8. Security Considerations 8. Security Considerations
This specification extends [RFC6775], and the security section of This specification extends [RFC6775], and the security section of
that draft also applies to this as well. In particular, it is that draft also applies to this as well. In particular, it is
expected that the link layer is sufficiently protected to prevent a expected that the link layer is sufficiently protected to prevent a
rogue access, either by means of physical or IP security on the rogue access, either by means of physical or IP security on the
Backbone Link and link layer cryptography on the LLN. Backbone Link and link layer cryptography on the LLN.
Internet-Draft An Update to 6LoWPAN ND February
This specification also expects that the LLN MAC provides secure This specification also expects that the LLN MAC provides secure
unicast to/from the Backbone Router and secure Broadcast from the unicast to/from the Backbone Router and secure Broadcast from the
Backbone Router in a way that prevents tempering with or replaying Backbone Router in a way that prevents tampering with or replaying
the RA messages. the RA messages.
This specification recommends to using privacy techniques (see This specification recommends using privacy techniques (see
Section 9, and protection against address theft such as provided by Section 9), and protection against address theft such as provided by
"Address Protected Neighbor Discovery for Low-power and Lossy "Address Protected Neighbor Discovery for Low-power and Lossy
Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the
Registered Address using a cryptographic OUID. Registered Address using a cryptographic RUID.
The registration mechanism may be used by a rogue node to attack the The registration mechanism may be used by a rogue node to attack the
6LR or the 6LBR with a Denial-of-Service attack against the registry. 6LR or the 6LBR with a Denial-of-Service attack against the registry.
It may also happen that the registry of a 6LR or a 6LBR is saturated It may also happen that the registry of a 6LR or a 6LBR is saturated
and cannot take any more registration, which effectively denies the and cannot take any more registration, which effectively denies the
requesting a node the capability to use a new address. In order to requesting a node the capability to use a new address. In order to
alleviate those concerns, Section 4.7 provides a number of alleviate those concerns, Section 4.7 provides a number of
recommendations that ensure that a stale registration is removed as recommendations that ensure that a stale registration is removed as
soon as possible from the 6LR and 6LBR. In particular, this soon as possible from the 6LR and 6LBR. In particular, this
specification recommends that: specification recommends that:
o A node that ceases to use an address SHOULD attempt to deregister o A node that ceases to use an address SHOULD attempt to de-register
that address from all the 6LRs to which it is registered. See that address from all the 6LRs to which it is registered. See
Section 4.2 for the mechanism to avoid replay attacks and avoiding Section 4.2 for the mechanism to avoid replay attacks and avoiding
the use of stale registration information. the use of stale registration information.
o The Registration lifetimes SHOULD be individually configurable for o The Registration lifetimes SHOULD be individually configurable for
each address or group of addresses. The nodes SHOULD be each address or group of addresses. The nodes SHOULD be
configured with a Registration Lifetime that reflects their configured with a Registration Lifetime that reflects their
expectation of how long they will use the address with the 6LR to expectation of how long they will use the address with the 6LR to
which it is registered. In particular, use cases that involve which it is registered. In particular, use cases that involve
mobility or rapid address changes SHOULD use lifetimes that are mobility or rapid address changes SHOULD use lifetimes that are
skipping to change at page 22, line 22 skipping to change at page 23, line 5
identified at least by MAC address and preferably by security identified at least by MAC address and preferably by security
credentials. When that maximum is reached, the router should use credentials. When that maximum is reached, the router should use
a Least-Recently-Used (LRU) algorithm to clean up the addresses, a Least-Recently-Used (LRU) algorithm to clean up the addresses,
keeping at least one Link-Local address. The router SHOULD keeping at least one Link-Local address. The router SHOULD
attempt to keep one or more stable addresses if stability can be attempt to keep one or more stable addresses if stability can be
determined, e.g. from the way the IID is formed or because they determined, e.g. from the way the IID is formed or because they
are used over a much longer time span than other (privacy, are used over a much longer time span than other (privacy,
shorter-lived) addresses. Address lifetimes SHOULD be shorter-lived) addresses. Address lifetimes SHOULD be
individually configurable. individually configurable.
Internet-Draft An Update to 6LoWPAN ND February
o In order to avoid denial of registration for the lack of o In order to avoid denial of registration for the lack of
resources, administrators should take great care to deploy resources, administrators should take great care to deploy
adequate numbers of 6LRs to cover the needs of the nodes in their adequate numbers of 6LRs to cover the needs of the nodes in their
range, so as to avoid a situation of starving nodes. It is range, so as to avoid a situation of starving nodes. It is
expected that the 6LBR that serves a LLN is a more capable node expected that the 6LBR that serves a LLN is a more capable node
then the average 6LR, but in a network condition where it may then the average 6LR, but in a network condition where it may
become saturated, a particular deployment should distribute the become saturated, a particular deployment should distribute the
6LBR functionality, for instance by leveraging a high speed 6LBR functionality, for instance by leveraging a high speed
Backbone and Backbone Routers to aggregate multiple LLNs into a Backbone and Backbone Routers to aggregate multiple LLNs into a
larger subnet. larger subnet.
The LLN nodes depend on the 6LBR and the 6BBR for their operation. A The LLN nodes depend on the 6LBR and the 6BBR for their operation. A
trust model must be put in place to ensure that the right devices are trust model must be put in place to ensure that the right devices are
acting in these roles, so as to avoid threats such as black-holing, acting in these roles, so as to avoid threats such as black-holing,
or bombing attack whereby an impersonated 6LBR would destroy state in or bombing attack whereby an impersonated 6LBR would destroy state in
the network by using the "Removed" Status code. the network by using the "Removed" Status code. This trust model
could be at a minimum based on a Layer-2 access control, or could
provide role validation as well (see Req5.1 in Appendix B.5).
9. Privacy Considerations 9. Privacy Considerations
As indicated in section Section 2, this protocol does not aim at As indicated in section Section 2, this protocol does not aim at
limiting the number of IPv6 addresses that a device can form. A host limiting the number of IPv6 addresses that a device can form. A host
should be able to form and register any address that is topologically should be able to form and register any address that is topologically
correct in the subnet(s) advertised by the 6LR/6LBR. correct in the subnet(s) advertised by the 6LR/6LBR.
This specification does not mandate any particular way for forming This specification does not mandate any particular way for forming
IPv6 addresses, but it discourages using EUI-64 for forming the IPv6 addresses, but it discourages using EUI-64 for forming the
Interface ID in the Link-Local address because this method prevents Interface ID in the Link-Local address because this method prevents
the usage of "SEcure Neighbor Discovery (SEND)" [RFC3971] and the usage of "SEcure Neighbor Discovery (SEND)" [RFC3971] and
"Cryptographically Generated Addresses (CGA)" [RFC3972], and that of "Cryptographically Generated Addresses (CGA)" [RFC3972], and that of
address privacy techniques. address privacy techniques.
"Privacy Considerations for IPv6 Adaptation-Layer Mechanisms" "Privacy Considerations for IPv6 Adaptation-Layer Mechanisms"
[RFC8065] explains why privacy is important and how to form such [RFC8065] explains why privacy is important and how to form privacy-
addresses. All implementations and deployment must consider the aware addresses. All implementations and deployment must consider
option of privacy addresses in their own environment. Also future the option of privacy addresses in their own environment.
specifications involving 6LOWPAN Neighbor Discovery should consult
"Recommendation on Stable IPv6 Interface Identifiers" [RFC8064] for The IPv6 address of the 6LN in the IPv6 header can be compressed
default interface identifaction. statelessly when the Interface Identifier in the IPv6 address can be
derived from the Lower Layer address. When it is not critical to
benefit from that compression, e.g. the address can be compressed
statefully, or it is rarely used and/or it is used only over one hop,
then privacy concerns should be considered. In particular, new
implementations should follow the IETF "Recommendation on Stable IPv6
Interface Identifiers" [RFC8064] This RFC recommends the use of "A
Method for Generating Semantically Opaque Interface Identifiers with
Internet-Draft An Update to 6LoWPAN ND February
IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for
generating Interface Identifiers to be used in SLAAC.
10. IANA Considerations 10. IANA Considerations
Note to RFC Editor: please replace "This RFC" throughout this
document by the RFC number for this specification once it is
attributed.
IANA is requested to make a number of changes under the "Internet IANA is requested to make a number of changes under the "Internet
Control Message Protocol version 6 (ICMPv6) Parameters" registry, as Control Message Protocol version 6 (ICMPv6) Parameters" registry, as
follows. follows.
10.1. ARO Flags 10.1. ARO Flags
IANA is requested to create a new subregistry for "ARO Flags". This IANA is requested to create a new subregistry for "ARO Flags". This
specification defines 8 positions, bit 0 to bit 7, and assigns bit 7 specification defines 8 positions, bit 0 to bit 7, and assigns bit 7
for the "T" flag in Section 6.1. The policy is "IETF Review" or for the "T" flag in Section 6.1. The policy is "IETF Review" or
"IESG Approval" [RFC8126]. The initial content of the registry is as "IESG Approval" [RFC8126]. The initial content of the registry is as
shown in Table 2. shown in Table 2.
New subregistry for ARO Flags under the "Internet Control Message New subregistry for ARO Flags under the "Internet Control Message
Protocol version 6 (ICMPv6) [RFC4443] Parameters" Protocol version 6 (ICMPv6) [RFC4443] Parameters"
+-------------+--------------+-----------+ +-------------+--------------+-----------+
| ARO Status | Description | Document | | ARO Status | Description | Document |
+-------------+--------------+-----------+ +-------------+--------------+-----------+
| 0..6 | Unassigned | | | 0..6 | Unassigned | |
| | | |
| 7 | "T" Flag | This RFC | | 7 | "T" Flag | This RFC |
+-------------+--------------+-----------+ +-------------+--------------+-----------+
Table 2: new ARO Flags Table 2: new ARO Flags
10.2. ICMP Codes 10.2. ICMP Codes
IANA is requested to create a new entry in the ICMPv6 "Code" Fields IANA is requested to create a new entry in the ICMPv6 "Code" Fields
subregistry of the Internet Control Message Protocol version 6 subregistry of the Internet Control Message Protocol version 6
(ICMPv6) Parameters for the ICMP codes related to the ICMP type 157 (ICMPv6) Parameters for the ICMP codes related to the ICMP type 157
and 158 Duplicate Address Request (shown in Table 3) and Confirmation and 158 Duplicate Address Request (shown in Table 3) and Confirmation
(shown in Table 4), respectively, as follows: (shown in Table 4), respectively, as follows:
Internet-Draft An Update to 6LoWPAN ND February
New entries for ICMP types 157 DAR message New entries for ICMP types 157 DAR message
+-------+----------------------+------------+ +-------+----------------------+------------+
| Code | Name | Reference | | Code | Name | Reference |
+-------+----------------------+------------+ +-------+----------------------+------------+
| 0 | Original DAR message | RFC 6775 | | 0 | Original DAR message | RFC 6775 |
| | | |
| 1 | Extended DAR message | This RFC | | 1 | Extended DAR message | This RFC |
+-------+----------------------+------------+ +-------+----------------------+------------+
Table 3: new ICMPv6 Code Fields Table 3: new ICMPv6 Code Fields
New entries for ICMP types 158 DAC message New entries for ICMP types 158 DAC message
+-------+----------------------+------------+ +-------+----------------------+------------+
| Code | Name | Reference | | Code | Name | Reference |
+-------+----------------------+------------+ +-------+----------------------+------------+
| 0 | Original DAC message | RFC 6775 | | 0 | Original DAC message | RFC 6775 |
| | | |
| 1 | Extended DAC message | This RFC | | 1 | Extended DAC message | This RFC |
+-------+----------------------+------------+ +-------+----------------------+------------+
Table 4: new ICMPv6 Code Fields Table 4: new ICMPv6 Code Fields
10.3. New ARO Status values 10.3. New ARO Status values
IANA is requested to make additions to the Address Registration IANA is requested to make additions to the Address Registration
Option Status Values Registry as follows: Option Status Values Registry as follows:
Internet-Draft An Update to 6LoWPAN ND February
Address Registration Option Status Values Registry Address Registration Option Status Values Registry
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
| ARO Status | Description | Document | | ARO Status | Description | Document |
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
| 3 | Moved | This RFC | | 3 | Moved | This RFC |
| | | |
| 4 | Removed | This RFC | | 4 | Removed | This RFC |
| | | |
| 5 | Validation Requested | This RFC | | 5 | Validation Requested | This RFC |
| | | |
| 6 | Duplicate Source Address | This RFC | | 6 | Duplicate Source Address | This RFC |
| | | |
| 7 | Invalid Source Address | This RFC | | 7 | Invalid Source Address | This RFC |
| | | |
| 8 | Registered Address topologically | This RFC | | 8 | Registered Address topologically | This RFC |
| | incorrect | | | | incorrect | |
| | | |
| 9 | 6LBR registry saturated | This RFC | | 9 | 6LBR registry saturated | This RFC |
| | | |
| 10 | Validation Failed | This RFC | | 10 | Validation Failed | This RFC |
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
Table 5: New ARO Status values Table 5: New ARO Status values
10.4. New 6LoWPAN capability Bits 10.4. New 6LoWPAN capability Bits
IANA is requested to make additions to the Subregistry for "6LoWPAN IANA is requested to make additions to the Subregistry for "6LoWPAN
capability Bits" as follows: capability Bits" as follows:
Subregistry for "6LoWPAN capability Bits" under the "Internet Control Subregistry for "6LoWPAN capability Bits" under the "Internet Control
Message Protocol version 6 (ICMPv6) Parameters" Message Protocol version 6 (ICMPv6) Parameters"
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
| Capability Bit | Description | Document | | Capability Bit | Description | Document |
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
| 11 | 6LR capable (L bit) | This RFC | | 11 | 6LR capable (L bit) | This RFC |
| | | |
| 12 | 6LBR capable (B bit) | This RFC | | 12 | 6LBR capable (B bit) | This RFC |
| | | |
| 13 | 6BBR capable (P bit) | This RFC | | 13 | 6BBR capable (P bit) | This RFC |
| | | |
| 14 | EARO support (E bit) | This RFC | | 14 | EARO support (E bit) | This RFC |
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
Table 6: New 6LoWPAN capability Bits Table 6: New 6LoWPAN capability Bits
Internet-Draft An Update to 6LoWPAN ND February
11. Acknowledgments 11. Acknowledgments
Kudos to Eric Levy-Abegnoli who designed the First Hop Security Kudos to Eric Levy-Abegnoli who designed the First Hop Security
infrastructure upon which the first backbone router was implemented. infrastructure upon which the first backbone router was implemented.
Many thanks to Sedat Gormus, Rahul Jadhav and Lorenzo Colitti for Many thanks to Sedat Gormus, Rahul Jadhav and Lorenzo Colitti for
their various contributions and reviews. Also many thanks to Thomas their various contributions and reviews. Also many thanks to Thomas
Watteyne for his early implementation of a 6LN that was instrumental Watteyne for his early implementation of a 6LN that was instrumental
to the early tests of the 6LR, 6LBR and Backbone Router. to the early tests of the 6LR, 6LBR and Backbone Router.
12. References 12. References
skipping to change at page 26, line 26 skipping to change at page 28, line 5
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011, DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>. <https://www.rfc-editor.org/info/rfc6282>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)", Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012, RFC 6775, DOI 10.17487/RFC6775, November 2012,
<https://www.rfc-editor.org/info/rfc6775>. <https://www.rfc-editor.org/info/rfc6775>.
Internet-Draft An Update to 6LoWPAN ND February
[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for [RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
IPv6 over Low-Power Wireless Personal Area Networks IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
2014, <https://www.rfc-editor.org/info/rfc7400>. 2014, <https://www.rfc-editor.org/info/rfc7400>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
skipping to change at page 27, line 6 skipping to change at page 28, line 31
Wasserman, "IPv6 Neighbor Discovery Optimizations for Wasserman, "IPv6 Neighbor Discovery Optimizations for
Wired and Wireless Networks", draft-chakrabarti-nordmark- Wired and Wireless Networks", draft-chakrabarti-nordmark-
6man-efficient-nd-07 (work in progress), February 2015. 6man-efficient-nd-07 (work in progress), February 2015.
[I-D.delcarpio-6lo-wlanah] [I-D.delcarpio-6lo-wlanah]
Vega, L., Robles, I., and R. Morabito, "IPv6 over Vega, L., Robles, I., and R. Morabito, "IPv6 over
802.11ah", draft-delcarpio-6lo-wlanah-01 (work in 802.11ah", draft-delcarpio-6lo-wlanah-01 (work in
progress), October 2015. progress), October 2015.
[I-D.ietf-6lo-ap-nd] [I-D.ietf-6lo-ap-nd]
Sarikaya, B., Thubert, P., and M. Sethi, "Address Thubert, P., Sarikaya, B., and M. Sethi, "Address
Protected Neighbor Discovery for Low-power and Lossy Protected Neighbor Discovery for Low-power and Lossy
Networks", draft-ietf-6lo-ap-nd-04 (work in progress), Networks", draft-ietf-6lo-ap-nd-05 (work in progress),
November 2017. January 2018.
[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-05 (work in progress), January 2018.
[I-D.ietf-6lo-nfc] [I-D.ietf-6lo-nfc]
Choi, Y., Hong, Y., Youn, J., Kim, D., and J. Choi, Choi, Y., Hong, Y., Youn, J., Kim, D., and J. Choi,
"Transmission of IPv6 Packets over Near Field "Transmission of IPv6 Packets over Near Field
Communication", draft-ietf-6lo-nfc-08 (work in progress), Communication", draft-ietf-6lo-nfc-09 (work in progress),
October 2017. January 2018.
[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-13 (work of IEEE 802.15.4", draft-ietf-6tisch-architecture-13 (work
in progress), November 2017. in progress), November 2017.
[I-D.ietf-bier-architecture]
Wijnands, I., Rosen, E., Dolganow, A., Przygienda, T., and
S. Aldrin, "Multicast using Bit Index Explicit
Replication", draft-ietf-bier-architecture-08 (work in
progress), September 2017.
[I-D.ietf-ipv6-multilink-subnets] [I-D.ietf-ipv6-multilink-subnets]
Thaler, D. and C. Huitema, "Multi-link Subnet Support in Thaler, D. and C. Huitema, "Multi-link Subnet Support in
IPv6", draft-ietf-ipv6-multilink-subnets-00 (work in IPv6", draft-ietf-ipv6-multilink-subnets-00 (work in
progress), July 2002. progress), July 2002.
Internet-Draft An Update to 6LoWPAN ND February
[I-D.ietf-mboned-ieee802-mcast-problems]
Perkins, C., McBride, M., Stanley, D., Kumari, W., and J.
Zuniga, "Multicast Considerations over IEEE 802 Wireless
Media", draft-ietf-mboned-ieee802-mcast-problems-01 (work
in progress), February 2018.
[I-D.perkins-intarea-multicast-ieee802]
Perkins, C., Stanley, D., Kumari, W., and J. Zuniga,
"Multicast Considerations over IEEE 802 Wireless Media",
draft-perkins-intarea-multicast-ieee802-03 (work in
progress), July 2017.
[I-D.popa-6lo-6loplc-ipv6-over-ieee19012-networks] [I-D.popa-6lo-6loplc-ipv6-over-ieee19012-networks]
Popa, D. and J. Hui, "6LoPLC: Transmission of IPv6 Packets Popa, D. and J. Hui, "6LoPLC: Transmission of IPv6 Packets
over IEEE 1901.2 Narrowband Powerline Communication over IEEE 1901.2 Narrowband Powerline Communication
Networks", draft-popa-6lo-6loplc-ipv6-over- Networks", draft-popa-6lo-6loplc-ipv6-over-
ieee19012-networks-00 (work in progress), March 2014. ieee19012-networks-00 (work in progress), March 2014.
[I-D.struik-lwip-curve-representations]
Struik, R., "Alternative Elliptic Curve Representations",
draft-struik-lwip-curve-representations-00 (work in
progress), October 2017.
[RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982, [RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,
DOI 10.17487/RFC1982, August 1996, DOI 10.17487/RFC1982, August 1996,
<https://www.rfc-editor.org/info/rfc1982>. <https://www.rfc-editor.org/info/rfc1982>.
[RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with [RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with
CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September
2003, <https://www.rfc-editor.org/info/rfc3610>. 2003, <https://www.rfc-editor.org/info/rfc3610>.
[RFC3810] Vida, R., Ed. and L. Costa, Ed., "Multicast Listener [RFC3810] Vida, R., Ed. and L. Costa, Ed., "Multicast Listener
Discovery Version 2 (MLDv2) for IPv6", RFC 3810, Discovery Version 2 (MLDv2) for IPv6", RFC 3810,
skipping to change at page 28, line 23 skipping to change at page 30, line 5
<https://www.rfc-editor.org/info/rfc3971>. <https://www.rfc-editor.org/info/rfc3971>.
[RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)", [RFC3972] Aura, T., "Cryptographically Generated Addresses (CGA)",
RFC 3972, DOI 10.17487/RFC3972, March 2005, RFC 3972, DOI 10.17487/RFC3972, March 2005,
<https://www.rfc-editor.org/info/rfc3972>. <https://www.rfc-editor.org/info/rfc3972>.
[RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD) [RFC4429] Moore, N., "Optimistic Duplicate Address Detection (DAD)
for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006, for IPv6", RFC 4429, DOI 10.17487/RFC4429, April 2006,
<https://www.rfc-editor.org/info/rfc4429>. <https://www.rfc-editor.org/info/rfc4429>.
Internet-Draft An Update to 6LoWPAN ND February
[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6 [RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
over Low-Power Wireless Personal Area Networks (6LoWPANs): over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals", Overview, Assumptions, Problem Statement, and Goals",
RFC 4919, DOI 10.17487/RFC4919, August 2007, RFC 4919, DOI 10.17487/RFC4919, August 2007,
<https://www.rfc-editor.org/info/rfc4919>. <https://www.rfc-editor.org/info/rfc4919>.
[RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy [RFC4941] Narten, T., Draves, R., and S. Krishnan, "Privacy
Extensions for Stateless Address Autoconfiguration in Extensions for Stateless Address Autoconfiguration in
IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007, IPv6", RFC 4941, DOI 10.17487/RFC4941, September 2007,
<https://www.rfc-editor.org/info/rfc4941>. <https://www.rfc-editor.org/info/rfc4941>.
[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J., [RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550, Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012, DOI 10.17487/RFC6550, March 2012,
<https://www.rfc-editor.org/info/rfc6550>. <https://www.rfc-editor.org/info/rfc6550>.
[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem
Statement and Requirements for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Routing",
RFC 6606, DOI 10.17487/RFC6606, May 2012,
<https://www.rfc-editor.org/info/rfc6606>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <https://www.rfc-editor.org/info/rfc7102>.
[RFC7217] Gont, F., "A Method for Generating Semantically Opaque [RFC7217] Gont, F., "A Method for Generating Semantically Opaque
Interface Identifiers with IPv6 Stateless Address Interface Identifiers with IPv6 Stateless Address
Autoconfiguration (SLAAC)", RFC 7217, Autoconfiguration (SLAAC)", RFC 7217,
DOI 10.17487/RFC7217, April 2014, DOI 10.17487/RFC7217, April 2014,
<https://www.rfc-editor.org/info/rfc7217>. <https://www.rfc-editor.org/info/rfc7217>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.
[RFC7428] Brandt, A. and J. Buron, "Transmission of IPv6 Packets [RFC7428] Brandt, A. and J. Buron, "Transmission of IPv6 Packets
over ITU-T G.9959 Networks", RFC 7428, over ITU-T G.9959 Networks", RFC 7428,
DOI 10.17487/RFC7428, February 2015, DOI 10.17487/RFC7428, February 2015,
<https://www.rfc-editor.org/info/rfc7428>. <https://www.rfc-editor.org/info/rfc7428>.
[RFC7668] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B., [RFC7668] Nieminen, J., Savolainen, T., Isomaki, M., Patil, B.,
Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low Shelby, Z., and C. Gomez, "IPv6 over BLUETOOTH(R) Low
Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015, Energy", RFC 7668, DOI 10.17487/RFC7668, October 2015,
<https://www.rfc-editor.org/info/rfc7668>. <https://www.rfc-editor.org/info/rfc7668>.
Internet-Draft An Update to 6LoWPAN ND February
[RFC7934] Colitti, L., Cerf, V., Cheshire, S., and D. Schinazi, [RFC7934] Colitti, L., Cerf, V., Cheshire, S., and D. Schinazi,
"Host Address Availability Recommendations", BCP 204, "Host Address Availability Recommendations", BCP 204,
RFC 7934, DOI 10.17487/RFC7934, July 2016, RFC 7934, DOI 10.17487/RFC7934, July 2016,
<https://www.rfc-editor.org/info/rfc7934>. <https://www.rfc-editor.org/info/rfc7934>.
[RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu, [RFC8064] Gont, F., Cooper, A., Thaler, D., and W. Liu,
"Recommendation on Stable IPv6 Interface Identifiers", "Recommendation on Stable IPv6 Interface Identifiers",
RFC 8064, DOI 10.17487/RFC8064, February 2017, RFC 8064, DOI 10.17487/RFC8064, February 2017,
<https://www.rfc-editor.org/info/rfc8064>. <https://www.rfc-editor.org/info/rfc8064>.
skipping to change at page 29, line 35 skipping to change at page 31, line 32
M., and D. Barthel, "Transmission of IPv6 Packets over M., and D. Barthel, "Transmission of IPv6 Packets over
Digital Enhanced Cordless Telecommunications (DECT) Ultra Digital Enhanced Cordless Telecommunications (DECT) Ultra
Low Energy (ULE)", RFC 8105, DOI 10.17487/RFC8105, May Low Energy (ULE)", RFC 8105, DOI 10.17487/RFC8105, May
2017, <https://www.rfc-editor.org/info/rfc8105>. 2017, <https://www.rfc-editor.org/info/rfc8105>.
[RFC8163] Lynn, K., Ed., Martocci, J., Neilson, C., and S. [RFC8163] Lynn, K., Ed., Martocci, J., Neilson, C., and S.
Donaldson, "Transmission of IPv6 over Master-Slave/Token- Donaldson, "Transmission of IPv6 over Master-Slave/Token-
Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163, Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163,
May 2017, <https://www.rfc-editor.org/info/rfc8163>. May 2017, <https://www.rfc-editor.org/info/rfc8163>.
[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>.
12.3. External Informative References 12.3. External Informative References
[IEEEstd802154] [IEEEstd802154]
IEEE, "IEEE Standard for Low-Rate Wireless Networks", IEEE, "IEEE Standard for Low-Rate Wireless Networks",
IEEE Standard 802.15.4, DOI 10.1109/IEEE IEEE Standard 802.15.4, DOI 10.1109/IEEE
P802.15.4-REVd/D01, June 2017, P802.15.4-REVd/D01, June 2017,
<http://ieeexplore.ieee.org/document/7460875/>. <http://ieeexplore.ieee.org/document/7460875/>.
[Perlman83] [Perlman83]
Perlman, R., "Fault-Tolerant Broadcast of Routing Perlman, R., "Fault-Tolerant Broadcast of Routing
Information", North-Holland Computer Networks 7: 395-405, Information", North-Holland Computer Networks 7: 395-405,
1983, <http://www.cs.illinois.edu/~pbg/courses/cs598fa09/ 1983, <http://www.cs.illinois.edu/~pbg/courses/cs598fa09/
readings/p83.pdf>. readings/p83.pdf>.
Internet-Draft An Update to 6LoWPAN ND February
Appendix A. Applicability and Requirements Served Appendix A. Applicability and Requirements Served
This specification extends 6LoWPAN ND to sequence the registration This specification extends 6LoWPAN ND to provide a sequence number to
and serves the requirements expressed Appendix B.1 by enabling the the registration and serves the requirements expressed Appendix B.1
mobility of devices from one LLN to the next based on the by enabling the mobility of devices from one LLN to the next based on
complementary work in the "IPv6 Backbone Router" the complementary work in the "IPv6 Backbone Router"
[I-D.ietf-6lo-backbone-router] specification. [I-D.ietf-6lo-backbone-router] specification.
In the context of the the TimeSlotted Channel Hopping (TSCH) mode of In the context of the the TimeSlotted Channel Hopping (TSCH) mode of
IEEE Std. 802.15.4 [IEEEstd802154], the "6TiSCH architecture" IEEE Std. 802.15.4 [IEEEstd802154], the "6TiSCH architecture"
[I-D.ietf-6tisch-architecture] introduces how a 6LoWPAN ND host could [I-D.ietf-6tisch-architecture] introduces how a 6LoWPAN ND host could
connect to the Internet via a RPL mesh Network, but this requires connect to the Internet via a RPL mesh Network, but this requires
additions to the 6LOWPAN ND protocol to support mobility and additions to the 6LoWPAN ND protocol to support mobility and
reachability in a secured and manageable environment. This reachability in a secured and manageable environment. This
specification details the new operations that are required to specification details the new operations that are required to
implement the 6TiSCH architecture and serves the requirements listed implement the 6TiSCH architecture and serves the requirements listed
in Appendix B.2. in Appendix B.2.
The term LLN is used loosely in this specification to cover multiple The term LLN is used loosely in this specification to cover multiple
types of WLANs and WPANs, including Low-Power Wi-Fi, BLUETOOTH(R) Low types of WLANs and WPANs, including Low-Power Wi-Fi, BLUETOOTH(R) Low
Energy, IEEE Std.802.11AH and IEEE Std.802.15.4 wireless meshes, so Energy, IEEE Std.802.11AH and IEEE Std.802.15.4 wireless meshes, so
as to address the requirements discussed in Appendix B.3. as to address the requirements discussed in Appendix B.3.
This specification can be used by any wireless node to associate at This specification can be used by any wireless node to associate at
Layer-3 with a 6BBR and register its IPv6 addresses to obtain routing Layer-3 with a 6BBR and register its IPv6 addresses to obtain routing
services including proxy-ND operations over the Backbone, effectively services including proxy-ND operations over the Backbone, effectively
providing a solution to the requirements expressed in Appendix B.4. providing a solution to the requirements expressed in Appendix B.4.
This specification is extended by "Address Protected Neighbor
Discovery for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd] to
providing a solution to some of the security-related requirements
expressed in Appendix B.5.
"Efficiency aware IPv6 Neighbor Discovery Optimizations" "Efficiency aware IPv6 Neighbor Discovery Optimizations"
[I-D.chakrabarti-nordmark-6man-efficient-nd] suggests that 6LoWPAN ND [I-D.chakrabarti-nordmark-6man-efficient-nd] suggests that 6LoWPAN ND
[RFC6775] can be extended to other types of links beyond IEEE Std. [RFC6775] can be extended to other types of links beyond IEEE Std.
802.15.4 for which it was defined. The registration technique is 802.15.4 for which it was defined. The registration technique is
beneficial when the Link-Layer technique used to carry IPv6 multicast beneficial when the Link-Layer technique used to carry IPv6 multicast
packets is not sufficiently efficient in terms of delivery ratio or packets is not sufficiently efficient in terms of delivery ratio or
energy consumption in the end devices, in particular to enable energy consumption in the end devices, in particular to enable
energy-constrained sleeping nodes. The value of such extension is energy-constrained sleeping nodes. The value of such extension is
especially apparent in the case of mobile wireless nodes, to reduce especially apparent in the case of mobile wireless nodes, to reduce
the multicast operations that are related to IPv6 ND ([RFC4861], the multicast operations that are related to IPv6 ND ([RFC4861],
[RFC4862]) and plague the wireless medium. This serves scalability [RFC4862]) and affect the operation of the wireless medium
[I-D.ietf-mboned-ieee802-mcast-problems]
[I-D.perkins-intarea-multicast-ieee802]. This serves the scalability
requirements listed in Appendix B.6. requirements listed in Appendix B.6.
Internet-Draft An Update to 6LoWPAN ND February
Finally Appendix B.7 provides a matching of requirements with the
specifications that serves them.
Appendix B. Requirements Appendix B. Requirements
This section lists requirements that were discussed at 6lo for an This section lists requirements that were discussed at 6lo for an
update to 6LoWPAN ND. This specification meets most of them, but update to 6LoWPAN ND. This specification meets most of them, but
those listed in Appendix B.5 which are deferred to a different those listed in Appendix B.5 which are deferred to a different
specification such as [I-D.ietf-6lo-ap-nd], and those related to specification such as [I-D.ietf-6lo-ap-nd], and those related to
multicast. multicast.
B.1. Requirements Related to Mobility B.1. Requirements Related to Mobility
Due to the unstable nature of LLN links, even in a LLN of immobile Due to the unstable nature of LLN links, even in a LLN of immobile
nodes a 6LN may change its point of attachment to a 6LR, say 6LR-a, nodes a 6LN may change its point of attachment to a 6LR, say 6LR-a,
and may not be able to notify 6LR-a. Consequently, 6LR-a may still and may not be able to notify 6LR-a. Consequently, 6LR-a may still
attract traffic that it cannot deliver any more. When links to a 6LR attract traffic that it cannot deliver any more. When links to a 6LR
change state, there is thus a need to identify stale states in a 6LR change state, there is thus a need to identify stale states in a 6LR
and restore reachability in a timely fashion. and restore reachability in a timely fashion.
Req1.1: Upon a change of point of attachment, connectivity via a new Req1.1: Upon a change of point of attachment, connectivity via a new
6LR MUST be restored timely without the need to de-register from the 6LR MUST be restored in a timely fashion without the need to de-
previous 6LR. register from the previous 6LR.
Req1.2: For that purpose, the protocol MUST enable to differentiate Req1.2: For that purpose, the protocol MUST enable to differentiate
between multiple registrations from one 6LoWPAN Node and between multiple registrations from one 6LoWPAN Node and
registrations from different 6LoWPAN Nodes claiming the same address. registrations from different 6LoWPAN Nodes claiming the same address.
Req1.3: Stale states MUST be cleaned up in 6LRs. Req1.3: Stale states MUST be cleaned up in 6LRs.
Req1.4: A 6LoWPAN Node SHOULD also be capable to register its Address Req1.4: A 6LoWPAN Node SHOULD also be capable to register its Address
to multiple 6LRs, and this, concurrently. concurrently to multiple 6LRs.
B.2. Requirements Related to Routing Protocols B.2. Requirements Related to Routing Protocols
The point of attachment of a 6LN may be a 6LR in an LLN mesh. IPv6 The point of attachment of a 6LN may be a 6LR in an LLN mesh. IPv6
routing in a LLN can be based on RPL, which is the routing protocol routing in a LLN can be based on RPL, which is the routing protocol
that was defined at the IETF for this particular purpose. Other that was defined at the IETF for this particular purpose. Other
routing protocols than RPL are also considered by Standard Defining routing protocols than RPL are also considered by Standard Defining
Organizations (SDO) on the basis of the expected network Organizations (SDO) on the basis of the expected network
characteristics. It is required that a 6LoWPAN Node attached via ND characteristics. It is required that a 6LoWPAN Node attached via ND
to a 6LR would need to participate in the selected routing protocol to a 6LR would need to participate in the selected routing protocol
to obtain reachability via the 6LR. to obtain reachability via the 6LR.
Next to the 6LBR unicast address registered by ND, other addresses Next to the 6LBR unicast address registered by ND, other addresses
including multicast addresses are needed as well. For example a including multicast addresses are needed as well. For example a
routing protocol often uses a multicast address to register changes routing protocol often uses a multicast address to register changes
Internet-Draft An Update to 6LoWPAN ND February
to established paths. ND needs to register such a multicast address to established paths. ND needs to register such a multicast address
to enable routing concurrently with discovery. to enable routing concurrently with discovery.
Multicast is needed for groups. Groups may be formed by device type Multicast is needed for groups. Groups may be formed by device type
(e.g. routers, street lamps), location (Geography, RPL sub-tree), or (e.g. routers, street lamps), location (Geography, RPL sub-tree), or
both. both.
The Bit Index Explicit Replication (BIER) Architecture The Bit Index Explicit Replication (BIER) Architecture [RFC8279]
[I-D.ietf-bier-architecture] proposes an optimized technique to proposes an optimized technique to enable multicast in a LLN with a
enable multicast in a LLN with a very limited requirement for routing very limited requirement for routing state in the nodes.
state in the nodes.
Related requirements are: Related requirements are:
Req2.1: The ND registration method SHOULD be extended so that the 6LR Req2.1: The ND registration method SHOULD be extended so that the 6LR
is able to advertise the Address of a 6LoWPAN Node over the selected is able to advertise the Address of a 6LoWPAN Node over the selected
routing protocol and obtain reachability to that Address using the routing protocol and obtain reachability to that Address using the
selected routing protocol. selected routing protocol.
Req2.2: Considering RPL, the Address Registration Option that is used Req2.2: Considering RPL, the Address Registration Option that is used
in the ND registration SHOULD be extended to carry enough information in the ND registration SHOULD be extended to carry enough information
skipping to change at page 32, line 42 skipping to change at page 35, line 4
Communication [I-D.ietf-6lo-nfc], IEEE Std. 802.11ah Communication [I-D.ietf-6lo-nfc], IEEE Std. 802.11ah
[I-D.delcarpio-6lo-wlanah], as well as IEEE1901.2 Narrowband [I-D.delcarpio-6lo-wlanah], as well as IEEE1901.2 Narrowband
Powerline Communication Networks Powerline Communication Networks
[I-D.popa-6lo-6loplc-ipv6-over-ieee19012-networks] and BLUETOOTH(R) [I-D.popa-6lo-6loplc-ipv6-over-ieee19012-networks] and BLUETOOTH(R)
Low Energy [RFC7668]. Low Energy [RFC7668].
Related requirements are: Related requirements are:
Req3.1: The support of the registration mechanism SHOULD be extended Req3.1: The support of the registration mechanism SHOULD be extended
to more LLN links than IEEE Std.802.15.4, matching at least the LLN to more LLN links than IEEE Std.802.15.4, matching at least the LLN
Internet-Draft An Update to 6LoWPAN ND February
links for which an "IPv6 over foo" specification exists, as well as links for which an "IPv6 over foo" specification exists, as well as
Low-Power Wi-Fi. Low-Power Wi-Fi.
Req3.2: As part of this extension, a mechanism to compute a unique Req3.2: As part of this extension, a mechanism to compute a unique
Identifier should be provided, with the capability to form a Link- Identifier should be provided, with the capability to form a Link-
Local Address that SHOULD be unique at least within the LLN connected Local Address that SHOULD be unique at least within the LLN connected
to a 6LBR discovered by ND in each node within the LLN. to a 6LBR discovered by ND in each node within the LLN.
Req3.3: The Address Registration Option used in the ND registration Req3.3: The Address Registration Option used in the ND registration
SHOULD be extended to carry the relevant forms of unique Identifier. SHOULD be extended to carry the relevant forms of unique Identifier.
skipping to change at page 33, line 41 skipping to change at page 36, line 5
durations, in the order of multiple days to a month. durations, in the order of multiple days to a month.
B.5. Requirements Related to Security B.5. Requirements Related to Security
In order to guarantee the operations of the 6LoWPAN ND flows, the In order to guarantee the operations of the 6LoWPAN ND flows, the
spoofing of the 6LR, 6LBR and 6BBRs roles should be avoided. Once a spoofing of the 6LR, 6LBR and 6BBRs roles should be avoided. Once a
node successfully registers an address, 6LoWPAN ND should provide node successfully registers an address, 6LoWPAN ND should provide
energy-efficient means for the 6LBR to protect that ownership even energy-efficient means for the 6LBR to protect that ownership even
when the node that registered the address is sleeping. when the node that registered the address is sleeping.
Internet-Draft An Update to 6LoWPAN ND February
In particular, the 6LR and the 6LBR then should be able to verify In particular, the 6LR and the 6LBR then should be able to verify
whether a subsequent registration for a given address comes from the whether a subsequent registration for a given address comes from the
original node. original node.
In a LLN it makes sense to base security on layer-2 security. During In a LLN it makes sense to base security on layer-2 security. During
bootstrap of the LLN, nodes join the network after authorization by a bootstrap of the LLN, nodes join the network after authorization by a
Joining Assistant (JA) or a Commissioning Tool (CT). After joining Joining Assistant (JA) or a Commissioning Tool (CT). After joining
nodes communicate with each other via secured links. The keys for nodes communicate with each other via secured links. The keys for
the layer-2 security are distributed by the JA/CT. The JA/CT can be the layer-2 security are distributed by the JA/CT. The JA/CT can be
part of the LLN or be outside the LLN. In both cases it is needed part of the LLN or be outside the LLN. In both cases it is needed
skipping to change at page 34, line 14 skipping to change at page 36, line 28
Related requirements are: Related requirements are:
Req5.1: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for Req5.1: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for
the 6LR, 6LBR and 6BBR to authenticate and authorize one another for the 6LR, 6LBR and 6BBR to authenticate and authorize one another for
their respective roles, as well as with the 6LoWPAN Node for the role their respective roles, as well as with the 6LoWPAN Node for the role
of 6LR. of 6LR.
Req5.2: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for Req5.2: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for
the 6LR and the 6LBR to validate new registration of authorized the 6LR and the 6LBR to validate new registration of authorized
nodes. Joining of unauthorized nodes MUST be impossible. nodes. Joining of unauthorized nodes MUST be prevented.
Req5.3: 6LoWPAN ND security mechanisms SHOULD lead to small packet Req5.3: 6LoWPAN ND security mechanisms SHOULD lead to small packet
sizes. In particular, the NS, NA, DAR and DAC messages for a re- sizes. In particular, the NS, NA, DAR and DAC messages for a re-
registration flow SHOULD NOT exceed 80 octets so as to fit in a registration flow SHOULD NOT exceed 80 octets so as to fit in a
secured IEEE Std.802.15.4 [IEEEstd802154] frame. secured IEEE Std.802.15.4 [IEEEstd802154] frame.
Req5.4: Recurrent 6LoWPAN ND security operations MUST NOT be Req5.4: Recurrent 6LoWPAN ND security operations MUST NOT be
computationally intensive on the LoWPAN Node CPU. When a Key hash computationally intensive on the LoWPAN Node CPU. When a Key hash
calculation is employed, a mechanism lighter than SHA-1 SHOULD be calculation is employed, a mechanism lighter than SHA-1 SHOULD be
preferred. preferred.
skipping to change at page 34, line 42 skipping to change at page 37, line 5
present on the device for upper layer security such as TLS. present on the device for upper layer security such as TLS.
Req5.7: Public key and signature sizes SHOULD be minimized while Req5.7: Public key and signature sizes SHOULD be minimized while
maintaining adequate confidentiality and data origin authentication maintaining adequate confidentiality and data origin authentication
for multiple types of applications with various degrees of for multiple types of applications with various degrees of
criticality. criticality.
Req5.8: Routing of packets should continue when links pass from the Req5.8: Routing of packets should continue when links pass from the
unsecured to the secured state. unsecured to the secured state.
Internet-Draft An Update to 6LoWPAN ND February
Req5.9: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for Req5.9: 6LoWPAN ND security mechanisms SHOULD provide a mechanism for
the 6LR and the 6LBR to validate whether a new registration for a the 6LR and the 6LBR to validate whether a new registration for a
given address corresponds to the same 6LoWPAN Node that registered it given address corresponds to the same 6LoWPAN Node that registered it
initially, and, if not, determine the rightful owner, and deny or initially, and, if not, determine the rightful owner, and deny or
clean-up the registration that is duplicate. clean-up the registration that is duplicate.
B.6. Requirements Related to Scalability B.6. Requirements Related to Scalability
Use cases from Automatic Meter Reading (AMR, collection tree Use cases from Automatic Meter Reading (AMR, collection tree
operations) and Advanced Metering Infrastructure (AMI, bi-directional operations) and Advanced Metering Infrastructure (AMI, bi-directional
skipping to change at page 35, line 15 skipping to change at page 37, line 29
to the 6LBR over a large number of LLN hops (e.g. 15). to the 6LBR over a large number of LLN hops (e.g. 15).
Related requirements are: Related requirements are:
Req6.1: The registration mechanism SHOULD enable a single 6LBR to Req6.1: The registration mechanism SHOULD enable a single 6LBR to
register multiple thousands of devices. register multiple thousands of devices.
Req6.2: The timing of the registration operation should allow for a Req6.2: The timing of the registration operation should allow for a
large latency such as found in LLNs with ten and more hops. large latency such as found in LLNs with ten and more hops.
B.7. Matching Requirements with Specifications
I-drafts/RFCs addressing requirements
+-------------+-----------------------------------------+
| Requirement | Document |
+-------------+-----------------------------------------+
| Req1.1 | [I-D.ietf-6lo-backbone-router] |
| | |
| Req1.2 | [RFC6775] |
| | |
| Req1.3 | [RFC6775] |
| | |
| Req1.4 | This RFC |
| | |
| Req2.1 | This RFC |
| | |
| Req2.2 | This RFC |
| | |
| Req2.3 | |
| | |
| Req3.1 | Technology Dependant |
| | |
| Req3.2 | Technology Dependant |
| | |
| Req3.3 | Technology Dependant |
Internet-Draft An Update to 6LoWPAN ND February
| | |
| Req3.4 | Technology Dependant |
| | |
| Req4.1 | This RFC |
| | |
| Req4.2 | This RFC |
| | |
| Req4.3 | [RFC6775] |
| | |
| Req5.1 | |
| | |
| Req5.2 | [I-D.ietf-6lo-ap-nd] |
| | |
| Req5.3 | |
| | |
| Req5.4 | |
| | |
| Req5.5 | [I-D.ietf-6lo-ap-nd] |
| | |
| Req5.6 | [I-D.struik-lwip-curve-representations] |
| | |
| Req5.7 | [I-D.ietf-6lo-ap-nd] |
| | |
| Req5.8 | |
| | |
| Req5.9 | [I-D.ietf-6lo-ap-nd] |
| | |
| Req6.1 | This RFC |
| | |
| Req6.2 | This RFC |
+-------------+-----------------------------------------+
Table 7: Addressing requirements
Appendix C. Subset of a 6LoWPAN Glossary
This document often uses the followng acronyms:
6BBR: 6LoWPAN Backbone Router (proxy for the registration)
6LBR: 6LoWPAN Border Router (authoritative on DAD)
6LN: 6LoWPAN Node
6LR: 6LoWPAN Router (relay to the registration process)
6CIO: Capability Indication Option
Internet-Draft An Update to 6LoWPAN ND February
(E)ARO: (Extended) Address Registration Option
DAD: Duplicate Address Detection
LLN: Low Power Lossy Network (a typical IoT network)
NCE: Neighbor Cache Entry
TSCH: TimeSlotted Channel Hopping
TID: Transaction ID (a sequence counter in the EARO)
Authors' Addresses Authors' Addresses
Pascal Thubert (editor) Pascal Thubert (editor)
Cisco Systems, Inc Cisco Systems, Inc
Building D (Regus) 45 Allee des Ormes Building D (Regus) 45 Allee des Ormes
MOUGINS - Sophia Antipolis Mougins - Sophia Antipolis
FRANCE France
Phone: +33 4 97 23 26 34 Phone: +33 4 97 23 26 34
Email: pthubert@cisco.com Email: pthubert@cisco.com
Erik Nordmark Erik Nordmark
Zededa
Santa Clara, CA Santa Clara, CA
USA United States of America
Email: nordmark@sonic.net Email: nordmark@sonic.net
Samita Chakrabarti Samita Chakrabarti
Verizon Verizon
San Jose, CA San Jose, CA
USA United States of America
Email: samitac.ietf@gmail.com Email: samitac.ietf@gmail.com
Charles E. Perkins Charles E. Perkins
Futurewei Futurewei
2330 Central Expressway 2330 Central Expressway
Santa Clara 95050 Santa Clara 95050
Unites States United States of America
Email: charliep@computer.org Email: charliep@computer.org
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