draft-ietf-6lo-rfc6775-update-17.txt   draft-ietf-6lo-rfc6775-update-18.txt 
6lo P. Thubert, Ed. 6lo P. Thubert, Ed.
Internet-Draft Cisco Internet-Draft Cisco
Updates: 6775 (if approved) E. Nordmark Updates: 6775 (if approved) E. Nordmark
Intended status: Standards Track Zededa Intended status: Standards Track Zededa
Expires: October 5, 2018 S. Chakrabarti Expires: October 8, 2018 S. Chakrabarti
Verizon Verizon
C. Perkins C. Perkins
Futurewei Futurewei
April 3, 2018 April 6, 2018
Registration Extensions for 6LoWPAN Neighbor Discovery Registration Extensions for 6LoWPAN Neighbor Discovery
draft-ietf-6lo-rfc6775-update-17 draft-ietf-6lo-rfc6775-update-18
Abstract Abstract
This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to This specification updates RFC 6775 - 6LoWPAN Neighbor Discovery, to
clarify the role of the protocol as a registration technique, clarify the role of the protocol as a registration technique,
simplify the registration operation in 6LoWPAN routers, as well as to simplify the registration operation in 6LoWPAN routers, as well as to
provide enhancements to the registration capabilities and mobility provide enhancements to the registration capabilities and mobility
detection for different network topologies including the backbone detection for different network topologies including the backbone
routers performing proxy Neighbor Discovery in a low power network. routers performing proxy Neighbor Discovery in a low power network.
skipping to change at page 1, line 40 skipping to change at page 1, line 40
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This Internet-Draft will expire on October 5, 2018. This Internet-Draft will expire on October 8, 2018.
Copyright Notice Copyright Notice
Copyright (c) 2018 IETF Trust and the persons identified as the Copyright (c) 2018 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.1. BCP 14 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. BCP 14 . . . . . . . . . . . . . . . . . . . . . . . . . 4
2.2. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . . . 3 2.2. Subset of a 6LoWPAN Glossary . . . . . . . . . . . . . . 4
2.3. References . . . . . . . . . . . . . . . . . . . . . . . 4 2.3. References . . . . . . . . . . . . . . . . . . . . . . . 5
2.4. New Terms . . . . . . . . . . . . . . . . . . . . . . . . 4 2.4. New Terms . . . . . . . . . . . . . . . . . . . . . . . . 5
3. Applicability of Address Registration Options . . . . . . . . 5 3. Applicability of Address Registration Options . . . . . . . . 7
4. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 6 4. Extended ND Options and Messages . . . . . . . . . . . . . . 8
4.1. Extended Address Registration Option (EARO) . . . . . . . 7 4.1. Extended Address Registration Option (EARO) . . . . . . . 8
4.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 8 4.2. Extended Duplicate Address Message Formats . . . . . . . 11
4.2.1. Comparing TID values . . . . . . . . . . . . . . . . 9 4.3. New 6LoWPAN Capability Bits in the Capability Indication
4.3. Registration Ownership Verifier . . . . . . . . . . . . . 10 Option . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.4. Extended Duplicate Address Messages . . . . . . . . . . . 11 5. Updating RFC 6775 . . . . . . . . . . . . . . . . . . . . . . 13
4.5. Registering the Target Address . . . . . . . . . . . . . 12 5.1. Extending the Address Registration Option . . . . . . . . 15
4.6. Link-Local Addresses and Registration . . . . . . . . . . 12 5.2. Transaction ID . . . . . . . . . . . . . . . . . . . . . 16
4.7. Maintaining the Registration States . . . . . . . . . . . 14 5.2.1. Comparing TID values . . . . . . . . . . . . . . . . 16
5. Detecting Enhanced ARO Capability Support . . . . . . . . . . 15 5.3. Registration Ownership Verifier . . . . . . . . . . . . . 18
6. Extended ND Options and Messages . . . . . . . . . . . . . . 16 5.4. Extended Duplicate Address Messages . . . . . . . . . . . 19
6.1. Extended Address Registration Option (EARO) . . . . . . . 16 5.5. Registering the Target Address . . . . . . . . . . . . . 19
6.2. Extended Duplicate Address Message Formats . . . . . . . 19 5.6. Link-Local Addresses and Registration . . . . . . . . . . 20
6.3. New 6LoWPAN Capability Bits in the Capability Indication 5.7. Maintaining the Registration States . . . . . . . . . . . 21
Option . . . . . . . . . . . . . . . . . . . . . . . . . 20 6. Backward Compatibility . . . . . . . . . . . . . . . . . . . 23
7. Backward Compatibility . . . . . . . . . . . . . . . . . . . 21 6.1. Signaling EARO Capability Support . . . . . . . . . . . . 23
7.1. Discovering the Capabilities of Router . . . . . . . . . 21 6.2. First Exchanges . . . . . . . . . . . . . . . . . . . . . 24
7.2. RFC6775-only 6LoWPAN Node . . . . . . . . . . . . . . . . 21 6.3. RFC6775-only 6LoWPAN Node . . . . . . . . . . . . . . . . 24
7.3. RFC6775-only 6LoWPAN Router . . . . . . . . . . . . . . . 22 6.4. RFC6775-only 6LoWPAN Router . . . . . . . . . . . . . . . 24
7.4. RFC6775-only 6LoWPAN Border Router . . . . . . . . . . . 22 6.5. RFC6775-only 6LoWPAN Border Router . . . . . . . . . . . 25
8. Security Considerations . . . . . . . . . . . . . . . . . . . 22 7. Security Considerations . . . . . . . . . . . . . . . . . . . 25
9. Privacy Considerations . . . . . . . . . . . . . . . . . . . 24 8. Privacy Considerations . . . . . . . . . . . . . . . . . . . 27
10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 25 9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 27
10.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . 25 9.1. ARO Flags . . . . . . . . . . . . . . . . . . . . . . . . 28
10.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 25 9.2. ICMP Codes . . . . . . . . . . . . . . . . . . . . . . . 28
10.3. New ARO Status values . . . . . . . . . . . . . . . . . 26 9.3. New ARO Status values . . . . . . . . . . . . . . . . . . 29
10.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . 27 9.4. New 6LoWPAN capability Bits . . . . . . . . . . . . . . . 30
11. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 28 10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 31
12. References . . . . . . . . . . . . . . . . . . . . . . . . . 28 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 31
12.1. Normative References . . . . . . . . . . . . . . . . . . 28 11.1. Normative References . . . . . . . . . . . . . . . . . . 31
12.2. Informative References . . . . . . . . . . . . . . . . . 29 11.2. Terminology Related References . . . . . . . . . . . . . 32
12.3. External Informative References . . . . . . . . . . . . 33 11.3. Informative References . . . . . . . . . . . . . . . . . 32
11.4. External Informative References . . . . . . . . . . . . 36
Appendix A. Applicability and Requirements Served (Not Appendix A. Applicability and Requirements Served (Not
Normative) . . . . . . . . . . . . . . . . . . . . . 33 Normative) . . . . . . . . . . . . . . . . . . . . . 36
Appendix B. Requirements (Not Normative) . . . . . . . . . . . . 34 Appendix B. Requirements (Not Normative) . . . . . . . . . . . . 37
B.1. Requirements Related to Mobility . . . . . . . . . . . . 34 B.1. Requirements Related to Mobility . . . . . . . . . . . . 37
B.2. Requirements Related to Routing Protocols . . . . . . . . 35 B.2. Requirements Related to Routing Protocols . . . . . . . . 38
B.3. Requirements Related to the Variety of Low-Power Link B.3. Requirements Related to the Variety of Low-Power Link
types . . . . . . . . . . . . . . . . . . . . . . . . . . 36 types . . . . . . . . . . . . . . . . . . . . . . . . . . 39
B.4. Requirements Related to Proxy Operations . . . . . . . . 36 B.4. Requirements Related to Proxy Operations . . . . . . . . 39
B.5. Requirements Related to Security . . . . . . . . . . . . 37 B.5. Requirements Related to Security . . . . . . . . . . . . 40
B.6. Requirements Related to Scalability . . . . . . . . . . . 38 B.6. Requirements Related to Scalability . . . . . . . . . . . 41
B.7. Requirements Related to Operations and Management . . . . 38 B.7. Requirements Related to Operations and Management . . . . 42
B.8. Matching Requirements with Specifications . . . . . . . . 39 B.8. Matching Requirements with Specifications . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 44
1. Introduction 1. Introduction
The scope of this draft is an IPv6 Low-Power Network including star The scope of this draft is an IPv6 Low-Power Network including star
and mesh topologies. This specification modifies and extends the and mesh topologies. In that context, "Neighbor Discovery
behavior and protocol elements of "Neighbor Discovery Optimization Optimization for IPv6 over Low-Power Wireless Personal Area Networks"
for IPv6 over Low-Power Wireless Personal Area Networks" (6LoWPAN ND) (6LoWPAN ND) [RFC6775] defines a registration mechanism that
[RFC6775] to enable additional capabilities and enhancements leverages a central registrar for the main purpose of Duplicate
including: Address Detection (DAD), with the intention to reduce the dependency
of the IPv6 Neighbor Discovery Protocol (IPv6 ND) [RFC4861][RFC4862]
on network-layer multicast and link-layer broadcast operations.
This specification updates 6LoWPAN ND to simplify the registration
operation in 6LoWPAN routers and to extend the protocol as a more
generic registration technique. The specified updates enable other
specifications to define new services such as Source Address
Validation (SAVI) with [I-D.ietf-6lo-ap-nd], participation as an
unaware leaf to an abstract routing protocol such as the "Routing
Protocol for Low Power and Lossy Networks" [RFC6550] (RPL) with
[I-D.thubert-roll-unaware-leaves], and registration to a backbone
routers performing proxy Neighbor Discovery in a Low-Power and Lossy
Network (LLN) with [I-D.ietf-6lo-backbone-router].
In more details, this specification modifies and extends the behavior
and protocol elements of 6LoWPAN ND to enable the following new
capabilities:
o determining the freshest location in case of mobility (TID) o determining the freshest location in case of mobility (TID)
o Simplifying the registration flow for Link-Local Addresses o Simplifying the registration flow for Link-Local Addresses
o Support of a Leaf Node in a Route-Over network o Support of a Leaf Node in a Route-Over network
o Proxy registration in a Route-Over network o Proxy registration in a Route-Over network
o Associating the registration with a variable-length Registration
Ownership Verifier (ROVR)
o Registration to a IPv6 ND proxy over a Backbone Link (6BBR) o Registration to a IPv6 ND proxy over a Backbone Link (6BBR)
o Clarification of support for privacy and temporary addresses o Clarification of support for privacy and temporary addresses
A more comprehensive set of requirements is provided in Appendix B.
2. Terminology 2. Terminology
2.1. BCP 14 2.1. BCP 14
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP "OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119][RFC8174] when, and only when, they appear in all 14 [RFC2119][RFC8174] when, and only when, they appear in all
capitals, as shown here. capitals, as shown here.
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2.4. New Terms 2.4. New Terms
This specification introduces the following terminology: This specification introduces the following terminology:
Backbone Link: An IPv6 transit link that interconnects two or more Backbone Link: An IPv6 transit link that interconnects two or more
Backbone Routers. It is expected to be of high speed compared Backbone Routers. It is expected to be of high speed compared
to the LLN in order to carry the traffic that is required to to the LLN in order to carry the traffic that is required to
federate multiple segments of the potentially large LLN into a federate multiple segments of the potentially large LLN into a
single IPv6 subnet. single IPv6 subnet.
Backbone Router: A logical network function in an IPv6 router that Backbone Router: A logical network function in an IPv6 router that
federates an LLN over a Backbone Link. In order to do so, the federates an LLN over a Backbone Link. In order to do so, the
Backbone Router (6BBR) proxies the 6LoWPAN ND operations Backbone Router (6BBR) proxies the 6LoWPAN ND operations
detailed in this document onto the matching operations that run detailed in this document onto the matching operations that run
over the backbone, typically IPv6 ND. Note that 6BBR is a over the backbone, typically IPv6 ND. Note that 6BBR is a
logical function, just like 6LR and 6LBR, and that the same logical function, just like 6LR and 6LBR, and that the same
physical router may operate all three. physical router may operate all three.
Extended LLN: Multiple LLNs as defined in [RFC6550], interconnected Extended LLN: Multiple LLNs as defined in [RFC6550], interconnected
by a Backbone Link via Backbone Routers, and forming a single by a Backbone Link via Backbone Routers, and forming a single
IPv6 Multi-Link Subnet. IPv6 Multi-Link Subnet.
Registration: The process during which a 6LN registers an IPv6 Registration: The process during which a 6LN registers an IPv6
Address with a 6LR in order to obtain services such as DAD and Address with a 6LR in order to obtain services such as DAD and
routing back. In a Route-Over network, a router that provides routing back. In a Route-Over network, a router that provides
connectivity to the LLN (typically a 6LBR, e.g., collocated connectivity to the LLN (typically a 6LBR, e.g., collocated
with a RPL Root) may serve as proxy for the registration of the with a RPL Root) may serve as proxy for the registration of the
6LN to the 6BBR so the 6BBR can provide IPv6 ND proxy services 6LN to the 6BBR so the 6BBR can provide IPv6 ND proxy services
over the Backbone. over the Backbone.
Binding: The association between an IP address, a MAC address, a Binding: The association between an IP address, a MAC address, a
port, and other information about the node that owns the IP physical port on a switch, and other information about the node
Address. that owns the IP Address.
Registered Node: The 6LN for which the registration is performed, Registered Node: The 6LN for which the registration is performed,
and which owns the fields in the Extended ARO option. and which owns the fields in the Extended ARO option.
Registering Node: The node that performs the registration; this may Registering Node: The node that performs the registration; this may
be the Registered Node, or a proxy such as a 6LBR performing a be the Registered Node, or a proxy such as a 6LBR performing a
registration to a 6BBR, on behalf of the Registered Node. registration to a 6BBR, on behalf of the Registered Node.
Registered Address: An address owned by the Registered Node that was Registered Address: An address owned by the Registered Node that was
or is being registered. or is being registered.
RFC6775-only: Applied to an implementation, a type of node, or a RFC6775-only: Applied to an implementation, a type of node, or a
type of message, this adjective indicates a behavior that is type of message, this adjective indicates a behavior that is
strictly as specified by [RFC6775] as opposed to updated with strictly as specified by [RFC6775] as opposed to updated with
this specification. this specification.
updated: Qualifies a 6LN, a 6LR, or a 6LBR that supports this updated: Qualifies a 6LN, a 6LR, or a 6LBR that supports this
specification. specification.
3. Applicability of Address Registration Options 3. Applicability of Address Registration Options
The purpose of the Address Registration Option (ARO) in [RFC6775] is The purpose of the Address Registration Option (ARO) in [RFC6775] is
to facilitate duplicate address detection (DAD) for hosts as well as to facilitate duplicate address detection (DAD) for hosts as well as
to populate Neighbor Cache Entries (NCEs) [RFC4861] in the routers. to populate Neighbor Cache Entries (NCEs) [RFC4861] in the routers.
This reduces the reliance on multicast operations, which are often as This reduces the reliance on multicast operations, which are often as
intrusive as broadcast, in IPv6 ND operations. intrusive as broadcast, in IPv6 ND operations.
skipping to change at page 6, line 34 skipping to change at page 7, line 47
packets (entries that do not appear to be in use may be flushed). In packets (entries that do not appear to be in use may be flushed). In
contrast, a router serving the Address Registration mechanism needs contrast, a router serving the Address Registration mechanism needs
enough storage to hold NCEs for all the addresses that may be enough storage to hold NCEs for all the addresses that may be
registered to it, regardless of whether or not they are actively registered to it, regardless of whether or not they are actively
communicating. The number of registrations supported by a 6LoWPAN communicating. The number of registrations supported by a 6LoWPAN
Router (6LR) or 6LoWPAN Border Router (6LBR) MUST be clearly Router (6LR) or 6LoWPAN Border Router (6LBR) MUST be clearly
documented by the vendor and the dynamic use of associated resources documented by the vendor and the dynamic use of associated resources
SHOULD be made available to the network operator, e.g., to a SHOULD be made available to the network operator, e.g., to a
management console. management console.
In order to deploy this, network administrators MUST ensure that In order to deploy this, network administrators need to ensure that
6LR/6LBRs in their network support the number and type of devices 6LR/6LBRs in their network support the number and type of devices
that can register to them, based on the number of IPv6 addresses that that can register to them, based on the number of IPv6 addresses that
those devices require and their address renewal rate and behavior. those devices require and their address renewal rate and behavior.
4. Updating RFC 6775 4. Extended ND Options and Messages
This specification introduces the Extended Address Registration This specification does not introduce new options, but it modifies
Option (EARO) based on the ARO as defined [RFC6775]. A 'T' flag is existing ones and updates the associated behaviors as specified in
added to indicate that a new field, the Transaction ID (TID) is the following subsections.
populated. The 'T' flag MUST be set in NS messages when this
specification is used, and echoed in NA messages to confirm that the 4.1. Extended Address Registration Option (EARO)
protocol is supported. The EUI-64 field is overloaded to carry
different types of information and its size may be increased when The Address Registration Option (ARO) is defined in section 4.1 of
backward compatibility is not an issue. [RFC6775]. This specification introduces the Extended Address
Registration Option (EARO) based on the ARO for use in NS and NA
messages. The EARO conveys additional information such as a sequence
counter called Transaction ID (TID) that is used to determine the
latest location of a registering mobile device. A 'T' flag is added
to indicate that the TID field is populated.
The EARO also signals whether the 6LN expects routing or proxy
services from the 6LR using a new 'R' flag.
The EUI-64 field is overloaded and renamed ROVR in order to carry
different types of information, e.g., cryptographic information of
variable size. A larger ROVR size may be used if and only if
backward compatibility is not an issue in the particular deployment.
Section 5.1 discusses those changes in depth.
An NS message with an EARO is a registration if and only if it also
carries an SLLA Option [RFC6775]. The EARO is also used in NS and NA
messages between Backbone Routers [I-D.ietf-6lo-backbone-router] over
the Backbone Link to sort out the distributed registration state; in
that case, it does not carry the SLLA Option and is not confused with
a registration.
When using the EARO, the address being registered is found in the
Target Address field of the NS and NA messages.
The EARO extends the ARO and is indicated by the 'T' flag being set.
The format of the EARO is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Status | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |R|T| TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... Registration Ownership Verifier ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: EARO
Option Fields
Type: 33
Length: 8-bit unsigned integer. The length of the whole
option in units of 8 bytes. It MUST be 2 when
operating in a backward-compatible mode with a ROVR
size of 64 bits. It MAY be 3, 4 or 5, denoting a
ROVR size of 128, 192 and 256 bits respectively.
Status: 8-bit unsigned integer. Indicates the status of a
registration in the NA response. MUST be set to 0 in
NS messages. See Table 1 below.
+-------+-----------------------------------------------------------+
| Value | Description |
+-------+-----------------------------------------------------------+
| 0..2 | See [RFC6775]. Note: a Status of 1 ("Duplicate Address") |
| | applies to the Registered Address. If the Source Address |
| | conflicts with an existing registration, "Duplicate |
| | Source Address" MUST be used. |
| | |
| 3 | Moved: The registration failed because it is not the |
| | freshest. This Status indicates that the registration is |
| | rejected because another more recent registration was |
| | done, as indicated by a same ROVR and a more recent TID. |
| | One possible cause is a stale registration that has |
| | progressed slowly in the network and was passed by a more |
| | recent one. It could also indicate a ROVR collision. |
| | |
| 4 | Removed: The binding state was removed. This status may |
| | be placed in an NA(EARO) message that is sent as the |
| | rejection of a proxy registration to a Backbone Router, |
| | or in an asynchronous NA(EARO) at any time. |
| | |
| 5 | Validation Requested: The Registering Node is challenged |
| | for owning the Registered Address or for being an |
| | acceptable proxy for the registration. This Status is |
| | expected in asynchronous messages from a registrar (6LR, |
| | 6LBR, 6BBR) to indicate that the registration state is |
| | removed, for instance, due to a movement of the device. |
| | |
| 6 | Duplicate Source Address: The address used as source of |
| | the NS(ARO) conflicts with an existing registration. |
| | |
| 7 | Invalid Source Address: The address used as source of the |
| | NS(ARO) is not a Link-Local Address as prescribed by this |
| | document. |
| | |
| 8 | Registered Address topologically incorrect: The address |
| | being registered is not usable on this link, e.g., it is |
| | not topologically correct |
| | |
| 9 | 6LBR Registry saturated: A new registration cannot be |
| | accepted because the 6LBR Registry is saturated. Note: |
| | this code is used by 6LBRs instead of Status 2 when |
| | responding to a Duplicate Address message exchange and is |
| | passed on to the Registering Node by the 6LR. |
| | |
| 10 | Validation Failed: The proof of ownership of the |
| | registered address is not correct. |
+-------+-----------------------------------------------------------+
Table 1: EARO Status
Reserved: This field is unused. It MUST be initialized to zero
by the sender and MUST be ignored by the receiver.
R: One-bit flag. If the 'R' flag is set, the
Registering Node expects that the 6LR ensures
reachability for the registered address, e.g., by
injecting the address in a Route-Over routing
protocol or proxying ND over a Backbone Link.
T: One-bit flag. Set if the next octet is used as a
TID.
TID: One-byte integer; a Transaction ID that is maintained
by the node and incremented with each transaction of
one or more registrations performed at the same time
to one or more respective 6LRs. This field MUST be
ignored if the 'T' flag is not set.
Registration Lifetime: 16-bit integer; expressed in minutes. 0
means that the registration has ended and the
associated state MUST be removed.
Registration Ownership Verifier (ROVR): Enables the correlation
between multiple attempts to register a same IPv6
Address. The ROVR is stored in the 6LR and the 6LBR
in the state associated to the registration. This
can be a unique ID of the Registering Node, such as
the EUI-64 address of an interface. This can also be
a token obtained with cryptographic methods which can
be used in additional protocol exchanges to associate
a cryptographic identity (key) with this registration
to ensure that only the owner can modify it later.
The scope of a ROVR is the registration of a
particular IPv6 Address and it must not be used to
correlate registrations of different addresses.
4.2. Extended Duplicate Address Message Formats
The DAR and DAC messages are defined in section 4.4 of [RFC6775].
Those messages follow a common base format, which enables information
from the ARO to be transported over multiple hops.
Those messages are extended to adapt to the new EARO format, as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status | TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... Registration Ownership Verifier ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Registered Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: Duplicate Address Messages Format
Modified Message Fields
Code: The ICMP Code as defined in [RFC4443]. The ICMP Code
MUST be set to 1 with this specification. An non-
null value of the ICMP Code indicates support for
this specification.
TID: 1-byte integer; same definition and processing as the
TID in the EARO as defined in Section 4.1. This
field MUST be ignored if the ICMP Code is null.
Registration Ownership Verifier (ROVR): The size of the ROVR is
computed from the overall size of the IPv6 packet.
It MUST be 64bits long when operating in backward-
compatible mode. This field has the same definition
and processing as the ROVR in the EARO option as
defined in Section 4.1.
4.3. New 6LoWPAN Capability Bits in the Capability Indication Option
This specification defines 5 new capability bits for use in the 6CIO,
which was introduced by [RFC7400] for use in IPv6 ND RA messages.
This specification introduces the "E" flag to indicate that extended
ARO can be used in a registration. A 6LR that supports this
specification MUST set the "E" flag.
A similar flag "D" indicates the support of Extended Duplicate
Address Messages by the 6LBR; A 6LBR that supports this specification
MUST set the "D" flag. The "D" flag is learned from advertisements
by a 6LBR, and is propagated down a graph of 6LRs as a node acting as
6LN registers to a 6LR (which could be the 6LBR), and in turn becomes
a 6LR to which other 6LNs will register.
The new "L", "B", and "P" flags, indicate whether a router is capable
of acting as 6LR, 6LBR, and 6BBR, respectively. These flags are not
mutually exclusive and a node MUST set all the flags that are
relevant to it.
As an example, a 6LBR sets the "B" and "D" flags. If it acts as a
6LR, then it sets the "L" and "E" flags. If it is collocated with a
6BBR, then it also sets the "P" flag.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 1 | Reserved |D|L|B|P|E|G|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: New capability Bits L, B, P, E in the 6CIO
Option Fields
Type: 36
L: Node is a 6LR.
B: Node is a 6LBR.
P: Node is a 6BBR.
E: Node supports registrations based on EARO.
D: 6LBR supports EDA messages.
5. Updating RFC 6775
The Extended Address Registration Option (EARO) (see Section 4.1)
replaces the ARO used within Neighbor Discovery NS and NA messages
between a 6LN and its 6LR. Similarly, the EDA messages, EDAR and
EDAC, replace the DAR and DAC messages so as to transport the new
information between 6LRs and 6LBRs across an LLN mesh such as a
6TiSCH network.
The extensions to the ARO option are used in the Duplicate Address The extensions to the ARO option are used in the Duplicate Address
messages, the Duplicate Address Request (DAR) and Duplicate Address messages, the Duplicate Address Request (DAR) and Duplicate Address
Confirmation (DAC), so as to convey the additional information all Confirmation (DAC), so as to convey the additional information all
the way to the 6LBR. In turn the 6LBR may proxy the registration the way to the 6LBR. In turn the 6LBR may proxy the registration
using IPv6 ND over a Backbone Link as illustrated in Figure 1. Note using IPv6 ND over a Backbone Link as illustrated in Figure 4. Note
that this specification avoids the Duplicate Address message flow for that this specification avoids the Duplicate Address message flow for
Link-Local Addresses in a Route-Over [RFC6606] topology. Link-Local Addresses in a Route-Over [RFC6606] topology (see
Section 5.6).
6LN 6LR 6LBR 6BBR 6LN 6LR 6LBR 6BBR
| | | | | | | |
| NS(EARO) | | | | NS(EARO) | | |
|--------------->| | | |--------------->| | |
| | Extended DAR | | | | Extended DAR | |
| |-------------->| | | |-------------->| |
| | | | | | | |
| | | proxy NS(EARO) | | | | proxy NS(EARO) |
| | |--------------->| | | |--------------->|
skipping to change at page 7, line 31 skipping to change at page 14, line 37
| | | | <wait> | | | | <wait>
| | | | | | | |
| | | proxy NA(EARO) | | | | proxy NA(EARO) |
| | |<---------------| | | |<---------------|
| | Extended DAC | | | | Extended DAC | |
| |<--------------| | | |<--------------| |
| NA(EARO) | | | | NA(EARO) | | |
|<---------------| | | |<---------------| | |
| | | | | | | |
Figure 1: (Re-)Registration Flow Figure 4: (Re-)Registration Flow
In order to support various types of link layers, this specification In order to support various types of link layers, this specification
allows multiple registrations, including for privacy / temporary allows multiple registrations, including for privacy / temporary
addresses and provides new mechanisms to help clean up stale addresses and provides new mechanisms to help clean up stale
registration state as soon as possible, e.g., after a movement (see registration state as soon as possible, e.g., after a movement (see
Section 8). Section 7).
Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface Section 5 of [RFC6775] specifies how a 6LN bootstraps an interface
and locates available 6LRs. A Registering Node prefers registering and locates available 6LRs. A Registering Node prefers registering
to a 6LR that is found to support this specification, as discussed in to a 6LR that is found to support this specification, as discussed in
Section 5, over an RFC6775-only one, and operates in a backward- Section 6.1, over an RFC6775-only one, and operates in a backward-
compatible fashion when attaching to an RFC6775-only 6LR. compatible fashion when attaching to an RFC6775-only 6LR.
4.1. Extended Address Registration Option (EARO) 5.1. Extending the Address Registration Option
The Extended ARO (EARO) replaces the ARO and is backward compatible The Extended ARO (EARO) replaces the ARO and is backward compatible
with the ARO if and only if the Length of the option is set to 2. with the ARO if and only if the Length of the option is set to 2.
Its format is presented in Section 6.1. More details on backward Its format is presented in Section 4.1. More details on backward
compatibility can be found in Section 7. compatibility can be found in Section 6.
The semantics of the Neighbor Solicitation (NS) and the ARO are The semantics of the Neighbor Solicitation (NS) and the ARO are
modified as follows: modified as follows:
o The address that is being registered with an NS with an EARO is o The Target Address in the NS containing the EARO is now the field
now the Target Address, as opposed to the Source Address as that indicates the address that is being registered, as opposed to
specified in [RFC6775] (see Section 4.5). This change enables a the Source Address field as specified in [RFC6775] (see
6LBR to use one of its addresses as source of the proxy- Section 5.5). This change enables a 6LBR to use one of its
registration of an address that belongs to a LLN Node to a 6BBR. addresses as source of the proxy-registration of an address that
This also limits the use of an address as source address before it belongs to a LLN Node to a 6BBR. This also limits the use of an
is registered and the associated DAD process is complete. address as source address before it is registered and the
associated DAD process is complete.
o The EUI-64 field in the ARO Option is renamed Registration o The EUI-64 field in the ARO Option is renamed Registration
Ownership Verifier (ROVR) and is not required to be derived from a Ownership Verifier (ROVR) and is not required to be derived from a
MAC address (see Section 4.3). MAC address (see Section 5.3).
o The option Length MAY be different than 2 and take a value between o The option Length MAY be different than 2 and take a value between
3 and 5, in which case the EARO is not backward compatible with an 3 and 5, in which case the EARO is not backward compatible with an
ARO. The increase of size corresponds to a larger ROVR field, so ARO. The increase of size corresponds to a larger ROVR field, so
the size of the ROVR is inferred from the option Length. the size of the ROVR is inferred from the option Length.
o This document specifies a new flag in the EARO, the 'R' flag. If o This document specifies a new flag in the EARO, the 'R' flag. If
the 'R' flag is set, the Registering Node expects that the 6LR the 'R' flag is set, the Registering Node expects that the 6LR
ensures reachability for the Registered Address, e.g., by means of ensures reachability for the Registered Address, e.g., by means of
routing or proxying ND. Conversely, when it is not set, the 'R' routing or proxying ND. Conversely, when it is not set, the 'R'
flag indicates that the Registering Node is a router, which for flag indicates that the Registering Node is a router, which for
instance participates to a Route-Over routing protocol such as the instance participates to a Route-Over routing protocol such as RPL
IPv6 Routing Protocol for Low-Power and Lossy Networks [RFC6550] [RFC6550] and that it will take care of injecting its Address over
(RPL) and that it will take care of injecting its Address over the the routing protocol by itself. A 6LN that acts only as a host,
routing protocol by itself. A 6LN that acts only as a host, when when registering, MUST set the 'R' flag to indicate that it is not
registering, MUST set the 'R' flag to indicate that it is not a a router and that it will not handle its own reachability. A 6LR
router and that it will not handle its own reachability. A 6LR
that manages its reachability SHOULD NOT set the 'R' flag; if it that manages its reachability SHOULD NOT set the 'R' flag; if it
does, routes towards this router may be installed on its behalf does, routes towards this router may be installed on its behalf
and may interfere with those it injects. and may interfere with those it injects.
o The specification introduces a Transaction ID (TID) field in the o The specification introduces a Transaction ID (TID) field in the
EARO (see Section 4.2). The TID MUST be provided by a node that EARO (see Section 5.2). The TID MUST be provided by a node that
supports this specification and another new flag, the 'T' flag, supports this specification and another new flag, the 'T' flag,
MUST be set to indicate so. MUST be set to indicate so.
o Finally, this specification introduces new status codes to help o Finally, this specification introduces new status codes to help
diagnose the cause of a registration failure (see Table 1). diagnose the cause of a registration failure (see Table 1).
4.2. Transaction ID 5.2. Transaction ID
The TID is a sequence number that is incremented by the 6LN with each The TID is a sequence number that is incremented by the 6LN with each
re-registration to a 6LR. The TID is used to detect the freshness of re-registration to a 6LR. The TID is used to detect the freshness of
the registration request and to detect one single registration by the registration request and to detect one single registration by
multiple 6LoWPAN border routers (e.g., 6LBRs and 6BBRs) supporting multiple 6LoWPAN border routers (e.g., 6LBRs and 6BBRs) supporting
the same 6LoWPAN. The TID may also be used by the network to route the same 6LoWPAN. The TID may also be used by the network to route
to the current (freshest known) location of a moving node by spotting to the current (freshest known) location of a moving node by spotting
the most recent TID. the most recent TID.
When a Registered Node is registered with multiple 6BBRs in parallel, When a Registered Node is registered with multiple 6BBRs in parallel,
the same TID MUST be used. This enables the 6BBRs to determine that the same TID MUST be used. This enables the 6BBRs to determine that
the registrations are the same, and distinguish that situation from a the registrations are the same, and distinguish that situation from a
movement (see section 4 of [I-D.ietf-6lo-backbone-router] and movement (see section 4 of [I-D.ietf-6lo-backbone-router] and
Section 4.7 below). Section 5.7 below).
4.2.1. Comparing TID values 5.2.1. Comparing TID values
As a note to the implementer, the operation of the TID is fully As a note to the implementer, the operation of the TID is fully
compatible with that of the RPL Path Sequence counter as described in compatible with that of the RPL Path Sequence counter as described in
the "Sequence Counter Operation" section of the "IPv6 Routing the "Sequence Counter Operation" section of the "IPv6 Routing
Protocol for Low-Power and Lossy Networks" [RFC6550] specification. Protocol for Low-Power and Lossy Networks" [RFC6550] specification.
A TID is deemed to be fresher than another when its value is greater A TID is deemed to be fresher than another when its value is greater
per the operations detailed in this section. per the operations detailed in this section.
The TID range is subdivided in a 'lollipop' fashion ([Perlman83]), The TID range is subdivided in a 'lollipop' fashion ([Perlman83]),
skipping to change at page 10, line 27 skipping to change at page 17, line 42
2. In the case where both sequence counters to be compared are 2. In the case where both sequence counters to be compared are
less than or equal to 127, and in the case where both less than or equal to 127, and in the case where both
sequence counters to be compared are greater than or equal to sequence counters to be compared are greater than or equal to
128: 128:
1. If the absolute magnitude of difference between the two 1. If the absolute magnitude of difference between the two
sequence counters is less than or equal to sequence counters is less than or equal to
SEQUENCE_WINDOW, then a comparison as described in SEQUENCE_WINDOW, then a comparison as described in
[RFC1982] is used to determine the relationships greater [RFC1982] is used to determine the relationships greater
than, less than, and equal. than, less than, and equal.
2. If the absolute magnitude of difference of the two 2. If the absolute magnitude of difference of the two
sequence counters is greater than SEQUENCE_WINDOW, then a sequence counters is greater than SEQUENCE_WINDOW, then a
desynchronization has occurred and the two sequence desynchronization has occurred and the two sequence
numbers are not comparable. numbers are not comparable.
4. If two sequence numbers are determined to be not comparable, 4. If two sequence numbers are determined to be not comparable,
i.e., the results of the comparison are not defined, then a node i.e., the results of the comparison are not defined, then a node
should give precedence to the sequence number that was most should give precedence to the sequence number that was most
recently incremented. Failing this, the node should select the recently incremented. Failing this, the node should select the
sequence number in order to minimize the resulting changes to its sequence number in order to minimize the resulting changes to its
own state. own state.
4.3. Registration Ownership Verifier 5.3. Registration Ownership Verifier
The ROVR field generalizes the EUI-64 field of the ARO defined in The ROVR field generalizes the EUI-64 field of the ARO defined in
[RFC6775]. It is scoped to a registration and enables recognizing [RFC6775]. It is scoped to a registration and enables recognizing
and blocking an attempt to register a duplicate address, which is and blocking an attempt to register a duplicate address, which is
characterized by a different ROVR in the conflicting registrations. characterized by a different ROVR in the conflicting registrations.
It can also be used to protect the ownership of a Registered Address, It can also be used to protect the ownership of a Registered Address,
if the proof-of-ownership of the ROVR can be obtained (more in if the proof-of-ownership of the ROVR can be obtained (more in
Section 4.6). Section 5.6).
The ROVR can be of different types, as long as the type is signaled The ROVR can be of different types, as long as the type is signaled
in the message that carries the new type. For instance, the type can in the message that carries the new type. For instance, the type can
be a cryptographic string and used to prove the ownership of the be a cryptographic string and used to prove the ownership of the
registration as specified in "Address Protected Neighbor Discovery registration as specified in "Address Protected Neighbor Discovery
for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd]. In order to for Low-power and Lossy Networks" [I-D.ietf-6lo-ap-nd]. In order to
support the flows related to the proof-of-ownership, this support the flows related to the proof-of-ownership, this
specification introduces new status codes "Validation Requested" and specification introduces new status codes "Validation Requested" and
"Validation Failed" in the EARO. "Validation Failed" in the EARO.
skipping to change at page 11, line 39 skipping to change at page 19, line 9
will not collision with that of an IPv6 Address derived from EUI-64 will not collision with that of an IPv6 Address derived from EUI-64
and using the EUI-64 as ROVR per [RFC6775]. and using the EUI-64 as ROVR per [RFC6775].
The Registering Node SHOULD store the ROVR, or enough information to The Registering Node SHOULD store the ROVR, or enough information to
regenerate it, in persistent memory. If this is not done and an regenerate it, in persistent memory. If this is not done and an
event such as a reboot causes a loss of state, re-registering the event such as a reboot causes a loss of state, re-registering the
same address could be impossible until the 6LRs and the 6LBR time out same address could be impossible until the 6LRs and the 6LBR time out
the previous registration, or a management action is taken to clear the previous registration, or a management action is taken to clear
the relevant state in the network. the relevant state in the network.
4.4. Extended Duplicate Address Messages 5.4. Extended Duplicate Address Messages
In order to map the new EARO content in the Extended Duplicate In order to map the new EARO content in the Extended Duplicate
Address (EDA) messages, a new TID field is added to the Extended DAR Address (EDA) messages, a new TID field is added to the Extended DAR
(EDAR) and the Extended DAC (EDAC) messages as a replacement of the (EDAR) and the Extended DAC (EDAC) messages as a replacement of the
Reserved field, and a non-null value of the ICMP Code indicates Reserved field, and a non-null value of the ICMP Code indicates
support for this specification. The format of the EDA messages is support for this specification. The format of the EDA messages is
presented in Section 6.2. presented in Section 4.2.
As with the EARO, the Extended Duplicate Address messages are As with the EARO, the Extended Duplicate Address messages are
backward compatible with the RFC6775-only versions as long as the backward compatible with the RFC6775-only versions as long as the
ROVR field is 64 bits long. Remarks concerning backwards ROVR field is 64 bits long. Remarks concerning backwards
compatibility for the protocol between the 6LN and the 6LR apply compatibility for the protocol between the 6LN and the 6LR apply
similarly between a 6LR and a 6LBR. similarly between a 6LR and a 6LBR.
4.5. Registering the Target Address 5.5. Registering the Target Address
The Registering Node is the node that performs the registration to The Registering Node is the node that performs the registration to
the 6BBR. As in [RFC6775], it may be the Registered Node as well, in the 6BBR. As in [RFC6775], it may be the Registered Node as well, in
which case it registers one of its own addresses and indicates its which case it registers one of its own addresses and indicates its
own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO). own MAC Address as Source Link Layer Address (SLLA) in the NS(EARO).
This specification adds the capability to proxy the registration This specification adds the capability to proxy the registration
operation on behalf of a Registered Node that is reachable over an operation on behalf of a Registered Node that is reachable over an
LLN mesh. In that case, if the Registered Node is reachable from the LLN mesh. In that case, if the Registered Node is reachable from the
6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC 6BBR over a Mesh-Under mesh, the Registering Node indicates the MAC
skipping to change at page 12, line 36 skipping to change at page 20, line 5
found in the Target Address field of the NS and NA messages as found in the Target Address field of the NS and NA messages as
opposed to the Source Address. With this convention, a TLLA option opposed to the Source Address. With this convention, a TLLA option
indicates the link-layer address of the 6LN that owns the address. indicates the link-layer address of the 6LN that owns the address.
If Registering Node expects packets for the 6LN, e.g., a 6LBR also If Registering Node expects packets for the 6LN, e.g., a 6LBR also
acting as RPL Root, then it MUST place its own Link Layer Address in acting as RPL Root, then it MUST place its own Link Layer Address in
the SLLA Option that MUST always be placed in a registration NS(EARO) the SLLA Option that MUST always be placed in a registration NS(EARO)
message. This maintains compatibility with RFC6775-only 6LoWPAN ND message. This maintains compatibility with RFC6775-only 6LoWPAN ND
[RFC6775]. [RFC6775].
4.6. Link-Local Addresses and Registration 5.6. Link-Local Addresses and Registration
Considering that LLN nodes are often not wired and may move, there is Considering that LLN nodes are often not wired and may move, there is
no guarantee that a Link-Local Address stays unique between a no guarantee that a Link-Local Address stays unique between a
potentially variable and unbounded set of neighboring nodes. potentially variable and unbounded set of neighboring nodes.
Compared to [RFC6775], this specification only requires that a Link- Compared to [RFC6775], this specification only requires that a Link-
Local Address be unique from the perspective of the two nodes that Local Address be unique from the perspective of the two nodes that
use it to communicate (e.g., the 6LN and the 6LR in an NS/NA use it to communicate (e.g., the 6LN and the 6LR in an NS/NA
exchange). This simplifies the DAD process in a Route-Over topology exchange). This simplifies the DAD process in a Route-Over topology
for Link-Local Addresses by avoiding an exchange of EDA messages for Link-Local Addresses by avoiding an exchange of EDA messages
skipping to change at page 13, line 24 skipping to change at page 20, line 39
the standpoint of this 6LR and the registration is not a duplicate. the standpoint of this 6LR and the registration is not a duplicate.
Alternatively, two different 6LRs might expose the same Link-Local Alternatively, two different 6LRs might expose the same Link-Local
Address but different link-layer addresses. In that case, a 6LN MUST Address but different link-layer addresses. In that case, a 6LN MUST
only interact with at most one of the 6LRs. only interact with at most one of the 6LRs.
The DAD process between the 6LR and a 6LBR, which is based on an The DAD process between the 6LR and a 6LBR, which is based on an
exchange of EDA messages, does not need to take place for Link-Local exchange of EDA messages, does not need to take place for Link-Local
Addresses. Addresses.
When registering to a 6LR that conforms to this specification (see When registering to a 6LR that conforms to this specification (see
Section 7.1, a node MUST use a Link-Local Address as the source Section 6.2, a node MUST use a Link-Local Address as the source
address of the registration, whatever the type of IPv6 address that address of the registration, whatever the type of IPv6 address that
is being registered. That Link-Local Address MUST be either an is being registered. That Link-Local Address MUST be either an
address that is already registered to the 6LR, or the address that is address that is already registered to the 6LR, or the address that is
being registered. being registered.
When a Registering Node does not have an already-registered Address, When a Registering Node does not have an already-registered Address,
it MUST register a Link-Local Address, using it as both the Source it MUST register a Link-Local Address, using it as both the Source
and the Target Address of an NS(EARO) message. In that case, it is and the Target Address of an NS(EARO) message. In that case, it is
RECOMMENDED to use a Link-Local Address that is (expected to be) RECOMMENDED to use a Link-Local Address that is (expected to be)
globally unique, e.g., derived from a globally unique EUI-64 address. globally unique, e.g., derived from a globally unique EUI-64 address.
skipping to change at page 14, line 5 skipping to change at page 21, line 20
A node needs to register its IPv6 Global Unicast Addresses (GUAs) to A node needs to register its IPv6 Global Unicast Addresses (GUAs) to
a 6LR in order to establish global reachability for these addresses a 6LR in order to establish global reachability for these addresses
via that 6LR. When registering with an updated 6LR, a Registering via that 6LR. When registering with an updated 6LR, a Registering
Node does not use a GUA as Source Address, in contrast to a node that Node does not use a GUA as Source Address, in contrast to a node that
complies to [RFC6775]. For non-Link-Local Addresses, the exchange of complies to [RFC6775]. For non-Link-Local Addresses, the exchange of
EDA messages MUST conform to [RFC6775], but the extended formats EDA messages MUST conform to [RFC6775], but the extended formats
described in this specification for the DAR and the DAC are used to described in this specification for the DAR and the DAC are used to
relay the extended information in the case of an EARO. relay the extended information in the case of an EARO.
4.7. Maintaining the Registration States 5.7. Maintaining the Registration States
This section discusses protocol actions that involve the Registering This section discusses protocol actions that involve the Registering
Node, the 6LR, and the 6LBR. It must be noted that the portion that Node, the 6LR, and the 6LBR. It must be noted that the portion that
deals with a 6LBR only applies to those addresses that are registered deals with a 6LBR only applies to those addresses that are registered
to it; as discussed in Section 4.6, this is not the case for Link- to it; as discussed in Section 5.6, this is not the case for Link-
Local Addresses. The registration state includes all data that is Local Addresses. The registration state includes all data that is
stored in the router relative to that registration, in particular, stored in the router relative to that registration, in particular,
but not limited to, an NCE. 6LBRs and 6BBRs may store additional but not limited to, an NCE. 6LBRs and 6BBRs may store additional
registration information in more complex abstract data structures and registration information in more complex abstract data structures and
use protocols that are out of scope of this document to keep them use protocols that are out of scope of this document to keep them
synchronized when they are distributed. synchronized when they are distributed.
When its resource available to store registration states are When its resource available to store registration states are
exhausted, a 6LR cannot accept a new registration. In that exhausted, a 6LR cannot accept a new registration. In that
situation, the EARO is returned in an NA message with a Status Code situation, the EARO is returned in an NA message with a Status Code
skipping to change at page 14, line 50 skipping to change at page 22, line 16
A node that ceases to use an address SHOULD attempt to de-register A node that ceases to use an address SHOULD attempt to de-register
that address from all the 6LRs to which it has registered the that address from all the 6LRs to which it has registered the
address. This is achieved using an NS(EARO) message with a address. This is achieved using an NS(EARO) message with a
Registration Lifetime of 0. If this is not done, the associated Registration Lifetime of 0. If this is not done, the associated
state will remain in the network till the current Registration state will remain in the network till the current Registration
Lifetime expires and this may lead to a situation where the 6LR Lifetime expires and this may lead to a situation where the 6LR
resources become saturated, even if they are correctly planned to resources become saturated, even if they are correctly planned to
start with. The 6LR may then take defensive measures that may start with. The 6LR may then take defensive measures that may
prevent this node or some other nodes from owning as many addresses prevent this node or some other nodes from owning as many addresses
as they would expect (see Section 8). as they would expect (see Section 7).
A node that moves away from a particular 6LR SHOULD attempt to de- A node that moves away from a particular 6LR SHOULD attempt to de-
register all of its addresses registered to that 6LR and register to register all of its addresses registered to that 6LR and register to
a new 6LR with an incremented TID. When/if the node shows up a new 6LR with an incremented TID. When/if the node shows up
elsewhere, an asynchronous NA(EARO) or EDAC message with a Status elsewhere, an asynchronous NA(EARO) or EDAC message with a Status
Code of "Moved" SHOULD be used to clean up the state in the previous Code of "Moved" SHOULD be used to clean up the state in the previous
location. For instance, as described in location. For instance, as described in
[I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a [I-D.ietf-6lo-backbone-router], the "Moved" status can be used by a
6BBR in an NA(EARO) message to indicate that the ownership of the 6BBR in an NA(EARO) message to indicate that the ownership of the
proxy state on the Backbone Link was transferred to another 6BBR as proxy state on the Backbone Link was transferred to another 6BBR as
the consequence of a movement of the device. If the receiver of the the consequence of a movement of the device. If the receiver of the
message has a state corresponding to the related address, it SHOULD message has a state corresponding to the related address, it SHOULD
propagate the status down the forwarding path to the Registered node propagate the status down the forwarding path to the Registered node
(e.g., reversing an existing RPL [RFC6550] path as prescribed in (e.g., reversing an existing RPL [RFC6550] path as prescribed in
[I-D.ietf-roll-efficient-npdao]). Whether it could do so or not, the [I-D.ietf-roll-efficient-npdao]). Whether it could do so or not, the
receiver MUST clean up said state. receiver MUST clean up said state.
Upon receiving an NS(EARO) message with a Registration Lifetime of 0 Upon receiving an NS(EARO) message with a Registration Lifetime of 0
and determining that this EARO is the freshest for a given NCE (see and determining that this EARO is the freshest for a given NCE (see
Section 4.2), a 6LR cleans up its NCE. If the address was registered Section 5.2), a 6LR cleans up its NCE. If the address was registered
to the 6LBR, then the 6LR MUST report to the 6LBR, through a to the 6LBR, then the 6LR MUST report to the 6LBR, through a
Duplicate Address exchange with the 6LBR, indicating the null Duplicate Address exchange with the 6LBR, indicating the null
Registration Lifetime and the latest TID that this 6LR is aware of. Registration Lifetime and the latest TID that this 6LR is aware of.
Upon receiving the EDAR message, the 6LBR evaluates if this is the Upon receiving the EDAR message, the 6LBR evaluates if this is the
most recent TID it has received for that particular registry entry. most recent TID it has received for that particular registry entry.
If so, then the EDAR is answered with an EDAC message bearing a If so, then the EDAR is answered with an EDAC message bearing a
Status of "Success" and the entry is scheduled to be removed. Status of "Success" and the entry is scheduled to be removed.
Otherwise, a Status Code of "Moved" is returned instead, and the Otherwise, a Status Code of "Moved" is returned instead, and the
existing entry is maintained. existing entry is maintained.
When an address is scheduled to be removed, the 6LBR SHOULD keep its When an address is scheduled to be removed, the 6LBR SHOULD keep its
entry in a DELAY state for a configurable period of time, so as to entry in a DELAY state for a configurable period of time, so as to
protect a mobile node that de-registered from one 6LR and did not protect a mobile node that de-registered from one 6LR and did not
register yet to a new one, or the new registration did not yet reach register yet to a new one, or the new registration did not yet reach
the 6LBR due to propagation delays in the network. Once the DELAY the 6LBR due to propagation delays in the network. Once the DELAY
time is passed, the 6LBR silently removes its entry. time is passed, the 6LBR silently removes its entry.
5. Detecting Enhanced ARO Capability Support 6. Backward Compatibility
This specification changes the behavior of the peers in a
registration flow. To enable backward compatibility, a 6LN that
registers to a 6LR that is not known to support this specification
MUST behave in a manner that is backward-compatible with [RFC6775].
On the contrary, if the 6LR is found to support this specification,
then the 6LN MUST conform to this specification when communicating
with that 6LR.
A 6LN that supports this specification MUST always use an EARO as a
replacement for an ARO in its registration to a router. This is
backward-compatible since the 'T' flag and TID field are reserved in
[RFC6775], and are ignored by an RFC6775-only router. A router that
supports this specification MUST answer an NS(ARO) and an NS(EARO)
with an NA(EARO). A router that does not support this specification
will consider the ROVR as an EUI-64 address and treat it the same,
which has no consequence if the Registered Addresses are different.
6.1. Signaling EARO Capability Support
"Generic Header Compression for IPv6 over 6LoWPANs" [RFC7400] "Generic Header Compression for IPv6 over 6LoWPANs" [RFC7400]
introduces the 6LoWPAN Capability Indication Option (6CIO) to introduces the 6LoWPAN Capability Indication Option (6CIO) to
indicate a node's capabilities to its peers. The 6CIO MUST be indicate a node's capabilities to its peers. The 6CIO MUST be
present in both Router Solicitation (RS) and Router Advertisement present in both Router Solicitation (RS) and Router Advertisement
(RA) messages, unless the information therein was already shared. (RA) messages, unless the information therein was already shared.
This can have happened in recent exchanges. The information can also This can have happened in recent exchanges. The information can also
be implicit, or pre-configured in all nodes in a network. In any be implicit, or pre-configured in all nodes in a network. In any
case, a 6CIO MUST be placed in an RA message that is sent in response case, a 6CIO MUST be placed in an RA message that is sent in response
to an RS with a 6CIO. to an RS with a 6CIO.
Section 6.3 defines a new flag for the 6CIO to signal support for Section 4.3 defines a new flag for the 6CIO to signal support for
EARO by the issuer of the message and Section 7.1 specifies how the EARO by the issuer of the message and Section 6.2 specifies how the
flag is to be used. New flags are also added to the 6CIO to signal flag is to be used. New flags are also added to the 6CIO to signal
the sender's capability to act as a 6LR, 6LBR, and 6BBR (see the sender's capability to act as a 6LR, 6LBR, and 6BBR (see
Section 6.3). Section 4.3).
Section 6.3 also defines a new flag that indicates the support of EDA Section 4.3 also defines a new flag that indicates the support of EDA
messages by the 6LBR. This flag is valid in RA messages but not in messages by the 6LBR. This flag is valid in RA messages but not in
RS messages. More information on the 6LBR is found in a separate RS messages. More information on the 6LBR is found in a separate
Authoritative Border Router Option (ABRO). The ABRO is placed in RA Authoritative Border Router Option (ABRO). The ABRO is placed in RA
messages as prescribed by [RFC6775]; in particular, it MUST be placed messages as prescribed by [RFC6775]; in particular, it MUST be placed
in an RA message that is sent in response to an RS with a 6CIO in an RA message that is sent in response to an RS with a 6CIO
indicating the capability to act as a 6LR, since the RA propagates indicating the capability to act as a 6LR, since the RA propagates
information between routers. information between routers.
6. Extended ND Options and Messages 6.2. First Exchanges
This specification does not introduce new options, but it modifies
existing ones and updates the associated behaviors as specified in
the following subsections.
6.1. Extended Address Registration Option (EARO)
The Address Registration Option (ARO) is defined in section 4.1 of
[RFC6775].
The Extended Address Registration Option (EARO) replaces the ARO used
within Neighbor Discovery NS and NA messages between a 6LN and its
6LR. Similarly, the EDA messages, EDAR and EDAC, replace the DAR and
DAC messages so as to transport the new information between 6LRs and
6LBRs across LLN meshes such as 6TiSCH networks.
An NS message with an EARO is a registration if and only if it also
carries an SLLA Option. The EARO is also used in NS and NA messages
between Backbone Routers [I-D.ietf-6lo-backbone-router] over the
Backbone Link to sort out the distributed registration state; in that
case, it does not carry the SLLA Option and is not confused with a
registration.
When using the EARO, the address being registered is found in the
Target Address field of the NS and NA messages.
The EARO extends the ARO and is indicated by the 'T' flag being set.
The format of the EARO is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length | Status | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |R|T| TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... Registration Ownership Verifier ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: EARO
Option Fields
Type: 33
Length: 8-bit unsigned integer. The length of the option in
units of 8 bytes. It MUST be 2 when operating in
backward-compatible mode. It MAY be 3, 4 or 5,
denoting a ROVR size of 128, 192 and 256 bits
respectively.
Status: 8-bit unsigned integer. Indicates the status of a
registration in the NA response. MUST be set to 0 in
NS messages. See Table 1 below.
+-------+-----------------------------------------------------------+
| Value | Description |
+-------+-----------------------------------------------------------+
| 0..2 | See [RFC6775]. Note: a Status of 1 ("Duplicate Address") |
| | applies to the Registered Address. If the Source Address |
| | conflicts with an existing registration, "Duplicate |
| | Source Address" MUST be used. |
| | |
| 3 | Moved: The registration failed because it is not the |
| | freshest. This Status indicates that the registration is |
| | rejected because another more recent registration was |
| | done, as indicated by a same ROVR and a more recent TID. |
| | One possible cause is a stale registration that has |
| | progressed slowly in the network and was passed by a more |
| | recent one. It could also indicate a ROVR collision. |
| | |
| 4 | Removed: The binding state was removed. This status may |
| | be placed in an NA(EARO) message that is sent as the |
| | rejection of a proxy registration to a Backbone Router, |
| | or in an asynchronous NA(EARO) at any time. |
| | |
| 5 | Validation Requested: The Registering Node is challenged |
| | for owning the Registered Address or for being an |
| | acceptable proxy for the registration. This Status is |
| | expected in asynchronous messages from a registrar (6LR, |
| | 6LBR, 6BBR) to indicate that the registration state is |
| | removed, for instance, due to a movement of the device. |
| | |
| 6 | Duplicate Source Address: The address used as source of |
| | the NS(ARO) conflicts with an existing registration. |
| | |
| 7 | Invalid Source Address: The address used as source of the |
| | NS(ARO) is not a Link-Local Address as prescribed by this |
| | document. |
| | |
| 8 | Registered Address topologically incorrect: The address |
| | being registered is not usable on this link, e.g., it is |
| | not topologically correct |
| | |
| 9 | 6LBR Registry saturated: A new registration cannot be |
| | accepted because the 6LBR Registry is saturated. Note: |
| | this code is used by 6LBRs instead of Status 2 when |
| | responding to a Duplicate Address message exchange and is |
| | passed on to the Registering Node by the 6LR. |
| | |
| 10 | Validation Failed: The proof of ownership of the |
| | registered address is not correct. |
+-------+-----------------------------------------------------------+
Table 1: EARO Status
Reserved: This field is unused. It MUST be initialized to zero
by the sender and MUST be ignored by the receiver.
R: One-bit flag. If the 'R' flag is set, the
Registering Node expects that the 6LR ensures
reachability for the registered address, e.g., by
injecting the address in a Route-Over routing
protocol or proxying ND over a Backbone Link.
T: One-bit flag. Set if the next octet is used as a
TID.
TID: One-byte integer; a Transaction ID that is maintained
by the node and incremented with each transaction.
Registration Lifetime: 16-bit integer; expressed in minutes. 0
means that the registration has ended and the
associated state MUST be removed.
Registration Ownership Verifier (ROVR): Enables the correlation
between multiple attempts to register a same IPv6
Address. This can be a unique ID of the Registering
Node, such as the EUI-64 address of an interface.
This can also be a token obtained with cryptographic
methods and used as proof of ownership of the
registration. The scope of a ROVR is the
registration of a particular IPv6 Address and it
cannot be used to correlate registrations of
different addresses.
6.2. Extended Duplicate Address Message Formats
The DAR and DAC messages are defined in section 4.4 of [RFC6775].
Those messages follow a common base format, which enables information
from the ARO to be transported over multiple hops.
Those messages are extended to adapt to the new EARO format, as
follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status | TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... Registration Ownership Verifier ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ +
| |
+ Registered Address +
| |
+ +
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3: Duplicate Address Messages Format
Modified Message Fields
Code: The ICMP Code as defined in [RFC4443]. The ICMP Code
MUST be set to 1 with this specification. An non-
null value of the ICMP Code indicates support for
this specification.
TID: 1-byte integer; same definition and processing as the
TID in the EARO as defined in Section 6.1.
Registration Ownership Verifier (ROVR): The size of the ROVR is
computed from the overall size of the IPv6 packet.
It MUST be 64bits long when operating in backward-
compatible mode. This field has the same definition
and processing as the ROVR in the EARO option as
defined in Section 6.1.
6.3. New 6LoWPAN Capability Bits in the Capability Indication Option
This specification defines 5 new capability bits for use in the 6CIO,
which was introduced by [RFC7400] for use in IPv6 ND RA messages.
This specification introduces the "E" flag to indicate that extended
ARO can be used in a registration. A 6LR that supports this
specification MUST set the "E" flag.
A similar flag "D" indicates the support of Extended Duplicate
Address Messages by the 6LBR; A 6LBR that supports this specification
MUST set the "D" flag. The "D" flag is learned from advertisements
by a 6LBR, and is propagated down a graph of 6LRs as a node acting as
6LN registers to a 6LR (which could be the 6LBR), and in turn becomes
a 6LR to which other 6LNs will register.
The new "L", "B", and "P" flags, indicate whether a router is capable
of acting as 6LR, 6LBR, and 6BBR, respectively. These flags are not
mutually exclusive and a node MUST set all the flags that are
relevant to it.
As an example, a 6LBR sets the "B" and "D" flags. If it acts as a
6LR, then it sets the "L" and "E" flags. If it is collocated with a
6BBR, then it also sets the "P" flag.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Length = 1 | Reserved |D|L|B|P|E|G|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: New capability Bits L, B, P, E in the 6CIO
Option Fields
Type: 36
L: Node is a 6LR.
B: Node is a 6LBR.
P: Node is a 6BBR.
E: Node supports registrations based on EARO.
D: 6LBR supports EDA messages.
7. Backward Compatibility
7.1. Discovering the Capabilities of Router
A 6LR that supports this specification MUST place a 6CIO in its RA
messages. A typical flow when a node starts up is that it sends a
multicast RS and receives one or more unicast RA messages. If the
6LR can process Extended ARO, then the "E" Flag is set in the RA.
This specification changes the behavior of the peers in a A typical flow when a node starts up is that it sends a multicast RS
registration flow. To enable backward compatibility, a 6LN that and receives one or more unicast RA messages. If the 6LR can process
registers to a 6LR that is not known to support this specification Extended ARO, then it places a 6CIO in its RA message back with the
MUST behave in a manner that is backward-compatible with [RFC6775]. "E" Flag set as required in Section 6.1.
On the contrary, if the 6LR is known to support this specification,
then the 6LN MUST conform to this specification when communicating
with that 6LR.
In order to ensure that it registers a first address successfully a In order to ensure that it registers a first address successfully a
6LN MAY register a Link Local Address that is derived from an EUI-64, 6LN MAY register a Link Local Address that is derived from an EUI-64,
placing the same address in the Source and Target Address fields of placing the same address in the Source and Target Address fields of
the NS(EARO) message. For such an address, DAD is not required (see the NS(EARO) message. For such an address, DAD is not required (see
[RFC6775]) and using the SLLA Option in the NS is actually more [RFC6775]) and using the SLLA Option in the NS is actually more
consistent with existing ND specifications such as the "Optimistic consistent with existing ND specifications such as the "Optimistic
Duplicate Address Detection (ODAD) for IPv6" [RFC4429]. The 6LN MAY Duplicate Address Detection (ODAD) for IPv6" [RFC4429]. The 6LN MAY
then use that address to register one or more other addresses. then use that address to register one or more other addresses.
A 6LN that supports this specification MUST always use an EARO as a 6.3. RFC6775-only 6LoWPAN Node
replacement for an ARO in its registration to a router. This is
harmless since the 'T' flag and TID field are reserved in [RFC6775],
and are ignored by an RFC6775-only router. A router that supports
this specification MUST answer an NS(ARO) and an NS(EARO) with an
NA(EARO). A router that does not support this specification will
consider the ROVR as an EUI-64 address and treat it the same, which
has no consequence if the Registered Addresses are different.
7.2. RFC6775-only 6LoWPAN Node
An RFC6775-only 6LN will use the Registered Address as the source An RFC6775-only 6LN will use the Registered Address as the source
address of the NS message and will not use an EARO. An updated 6LR address of the NS message and will not use an EARO. An updated 6LR
MUST accept that registration if it is valid per [RFC6775], and it MUST accept that registration if it is valid per [RFC6775], and it
MUST manage the binding cache accordingly. The updated 6LR MUST then MUST manage the binding cache accordingly. The updated 6LR MUST then
use the RFC6775-only EDA messages as specified in [RFC6775] to use the RFC6775-only EDA messages as specified in [RFC6775] to
indicate to the 6LBR that the TID is not present in the messages. indicate to the 6LBR that the TID is not present in the messages.
The main difference from [RFC6775] is that the exchange of EDA The main difference from [RFC6775] is that the exchange of EDA
messages for the purpose of DAD is avoided for Link-Local Addresses. messages for the purpose of DAD is avoided for Link-Local Addresses.
skipping to change at page 22, line 4 skipping to change at page 24, line 32
An RFC6775-only 6LN will use the Registered Address as the source An RFC6775-only 6LN will use the Registered Address as the source
address of the NS message and will not use an EARO. An updated 6LR address of the NS message and will not use an EARO. An updated 6LR
MUST accept that registration if it is valid per [RFC6775], and it MUST accept that registration if it is valid per [RFC6775], and it
MUST manage the binding cache accordingly. The updated 6LR MUST then MUST manage the binding cache accordingly. The updated 6LR MUST then
use the RFC6775-only EDA messages as specified in [RFC6775] to use the RFC6775-only EDA messages as specified in [RFC6775] to
indicate to the 6LBR that the TID is not present in the messages. indicate to the 6LBR that the TID is not present in the messages.
The main difference from [RFC6775] is that the exchange of EDA The main difference from [RFC6775] is that the exchange of EDA
messages for the purpose of DAD is avoided for Link-Local Addresses. messages for the purpose of DAD is avoided for Link-Local Addresses.
In any case, the 6LR MUST use an EARO in the reply, and can use any In any case, the 6LR MUST use an EARO in the reply, and can use any
of the Status codes defined in this specification. of the Status codes defined in this specification.
7.3. RFC6775-only 6LoWPAN Router 6.4. RFC6775-only 6LoWPAN Router
An updated 6LN discovers the capabilities of the 6LR in the 6CIO in An updated 6LN discovers the capabilities of the 6LR in the 6CIO in
RA messages from that 6LR; if the 6CIO was not present in the RA, RA messages from that 6LR; if the 6CIO was not present in the RA,
then the 6LR is assumed to be a RFC6775-only 6LoWPAN Router. then the 6LR is assumed to be a RFC6775-only 6LoWPAN Router.
An updated 6LN MUST use an EARO in the request regardless of the type An updated 6LN MUST use an EARO in the request regardless of the type
of 6LR, RFC6775-only or updated, which implies that the 'T' flag is of 6LR, RFC6775-only or updated, which implies that the 'T' flag is
set. It MUST use a ROVR of 64 bits if the 6LR is an RFC6775-only set. It MUST use a ROVR of 64 bits if the 6LR is an RFC6775-only
6LoWPAN Router. 6LoWPAN Router.
skipping to change at page 22, line 30 skipping to change at page 25, line 8
the RFC6775-only 6LR will send an RFC6775-only DAR message, which the RFC6775-only 6LR will send an RFC6775-only DAR message, which
cannot be compared with an updated one for freshness. Allowing cannot be compared with an updated one for freshness. Allowing
RFC6775-only DAR messages to replace a state established by the RFC6775-only DAR messages to replace a state established by the
updated protocol in the 6LBR would be an attack vector and that updated protocol in the 6LBR would be an attack vector and that
cannot be the default behavior. But if RFC6775-only and updated 6LRs cannot be the default behavior. But if RFC6775-only and updated 6LRs
coexist temporarily in a network, then it makes sense for an coexist temporarily in a network, then it makes sense for an
administrator to install a policy that allows this, and the administrator to install a policy that allows this, and the
capability to install such a policy should be configurable in a 6LBR capability to install such a policy should be configurable in a 6LBR
though it is out of scope for this document. though it is out of scope for this document.
7.4. RFC6775-only 6LoWPAN Border Router 6.5. RFC6775-only 6LoWPAN Border Router
With this specification, the Duplicate Address messages are extended With this specification, the Duplicate Address messages are extended
to transport the EARO information. Similarly to the NS/NA exchange, to transport the EARO information. Similarly to the NS/NA exchange,
an updated 6LBR MUST always use the EDA messages. an updated 6LBR MUST always use the EDA messages.
Note that an RFC6775-only 6LBR will accept and process an EDAR Note that an RFC6775-only 6LBR will accept and process an EDAR
message as if it were an RFC6775-only DAR, as long as the ROVR is 64 message as if it were an RFC6775-only DAR, as long as the ROVR is 64
bits long. An updated 6LR discovers the capabilities of the 6LBR in bits long. An updated 6LR discovers the capabilities of the 6LBR in
the 6CIO in RA messages from the 6LR; if the 6CIO was not present in the 6CIO in RA messages from the 6LR; if the 6CIO was not present in
any RA, then the 6LBR si assumed to be a RFC6775-only 6LoWPAN Border any RA, then the 6LBR si assumed to be a RFC6775-only 6LoWPAN Border
Router. Router.
If the 6LBR is RFC6775-only, and the ROVR in the NS(EARO) was more If the 6LBR is RFC6775-only, and the ROVR in the NS(EARO) was more
than 64 bits long, then the 6LR MUST truncate the ROVR to the 64 than 64 bits long, then the 6LR MUST truncate the ROVR to the 64
rightmost bit and place the result in the EDAR message to maintain rightmost bit and place the result in the EDAR message to maintain
compatibility. This way, the support of DAD is preserved. compatibility. This way, the support of DAD is preserved.
8. Security Considerations 7. Security Considerations
This specification extends [RFC6775], and the security section of This specification extends [RFC6775], and the security section of
that document also applies to this as well. In particular, it is that document also applies to this as well. In particular, it is
expected that the link layer is sufficiently protected to prevent expected that the link layer is sufficiently protected to prevent
rogue access, either by means of physical or IP security on the rogue access, either by means of physical or IP security on the
Backbone Link and link-layer cryptography on the LLN. Backbone Link and link-layer cryptography on the LLN.
[RFC6775] does not protect the content of its messages and expects a [RFC6775] does not protect the content of its messages and expects a
lower layer encryption to defeat potential attacks. This lower layer encryption to defeat potential attacks. This
specification also expects that the LLN MAC provides secure unicast specification also expects that the LLN MAC provides secure unicast
to/from the Backbone Router and secure Broadcast or Multicast from to/from the Backbone Router and secure Broadcast or Multicast from
the Backbone Router in a way that prevents tampering with or the Backbone Router in a way that prevents tampering with or
replaying the Neighbor Discovery messages. replaying the Neighbor Discovery messages.
This specification recommends using privacy techniques (see This specification recommends using privacy techniques (see
Section 9) and protecting against address theft such as provided by Section 8) and protecting against address theft such as provided by
"Address Protected Neighbor Discovery for Low-power and Lossy "Address Protected Neighbor Discovery for Low-power and Lossy
Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the Networks" [I-D.ietf-6lo-ap-nd], which guarantees the ownership of the
Registered Address using a cryptographic ROVR. Registered Address using a cryptographic ROVR.
The registration mechanism may be used by a rogue node to attack the The registration mechanism may be used by a rogue node to attack the
6LR or the 6LBR with a Denial-of-Service attack against the registry. 6LR or the 6LBR with a Denial-of-Service attack against the registry.
It may also happen that the registry of a 6LR or a 6LBR is saturated It may also happen that the registry of a 6LR or a 6LBR is saturated
and cannot take any more registrations, which effectively denies the and cannot take any more registrations, which effectively denies the
requesting node the capability to use a new address. In order to requesting node the capability to use a new address. In order to
alleviate those concerns, Section 4.7 provides a number of alleviate those concerns, Section 5.7 provides a number of
recommendations that ensure that a stale registration is removed as recommendations that ensure that a stale registration is removed as
soon as possible from the 6LR and 6LBR. In particular, this soon as possible from the 6LR and 6LBR. In particular, this
specification recommends that: specification recommends that:
o A node that ceases to use an address SHOULD attempt to de-register o A node that ceases to use an address SHOULD attempt to de-register
that address from all the 6LRs to which it is registered. See that address from all the 6LRs to which it is registered. See
Section 4.2 for the mechanism to avoid replay attacks and avoiding Section 5.2 for the mechanism to avoid replay attacks and avoiding
the use of stale registration information. the use of stale registration information.
o The Registration lifetimes SHOULD be individually configurable for o The Registration lifetimes SHOULD be individually configurable for
each address or group of addresses. The nodes SHOULD be each address or group of addresses. The nodes SHOULD be
configured with a Registration Lifetime that reflects their configured with a Registration Lifetime that reflects their
expectation of how long they will use the address with the 6LR to expectation of how long they will use the address with the 6LR to
which it is registered. In particular, use cases that involve which it is registered. In particular, use cases that involve
mobility or rapid address changes SHOULD use lifetimes that are mobility or rapid address changes SHOULD use lifetimes that are
larger yet of a same order as the duration of the expectation of larger yet of a same order as the duration of the expectation of
presence. presence.
o The router (6LR or 6LBR) SHOULD be configurable so as to limit the o The router (6LR or 6LBR) SHOULD be configurable so as to limit the
number of addresses that can be registered by a single node, but number of addresses that can be registered by a single node, but
as a protective measure only. In any case, a router MUST be able as a protective measure only. In any case, a router MUST be able
to keep a minimum number of addresses per node. That minimum to keep a minimum number of addresses per node. That minimum
depends on the type of device and ranges between 3 for a very depends on the type of device and ranges between 3 for a very
constrained LLN and 10 for a larger device. A node may be constrained LLN and 10 for a larger device. A node may be
identified by its MAC address, as long as it is not obfuscated by identified by its MAC address, as long as it is not obfuscated by
privacy measures. A stronger identification (e.g., by security privacy measures. A stronger identification (e.g., by security
credentials) is RECOMMENDED. When the maximum is reached, the credentials) is RECOMMENDED. When the maximum is reached, the
router should use a Least-Recently-Used (LRU) algorithm to clean router should use a Least-Recently-Used (LRU) algorithm to clean
skipping to change at page 24, line 28 skipping to change at page 27, line 10
a larger subnet. a larger subnet.
The LLN nodes depend on the 6LBR and the 6BBR for their operation. A The LLN nodes depend on the 6LBR and the 6BBR for their operation. A
trust model must be put in place to ensure that the right devices are trust model must be put in place to ensure that the right devices are
acting in these roles so as to avoid threats such as black-holing or acting in these roles so as to avoid threats such as black-holing or
bombing attack whereby an impersonated 6LBR would destroy state in bombing attack whereby an impersonated 6LBR would destroy state in
the network by using the "Removed" Status code. This trust model the network by using the "Removed" Status code. This trust model
could be at a minimum based on a Layer-2 access control, or could could be at a minimum based on a Layer-2 access control, or could
provide role validation as well (see Req5.1 in Appendix B.5). provide role validation as well (see Req5.1 in Appendix B.5).
9. Privacy Considerations 8. Privacy Considerations
As indicated in Section 3, this protocol does not inherently limit As indicated in Section 3, this protocol does not inherently limit
the number of IPv6 addresses that each device can form. However, to the number of IPv6 addresses that each device can form. However, to
mitigate denial-of-service attacks, it can be useful as a protective mitigate denial-of-service attacks, it can be useful as a protective
measure to have a limit that is high enough not to interfere with the measure to have a limit that is high enough not to interfere with the
normal behavior of devices in the network. A host should be able to normal behavior of devices in the network. A host should be able to
form and register any address that is topologically correct in the form and register any address that is topologically correct in the
subnet(s) advertised by the 6LR/6LBR. subnet(s) advertised by the 6LR/6LBR.
This specification does not mandate any particular way for forming This specification does not mandate any particular way for forming
skipping to change at page 25, line 14 skipping to change at page 27, line 44
derived from the Lower Layer address. When it is not critical to derived from the Lower Layer address. When it is not critical to
benefit from that compression, e.g., the address can be compressed benefit from that compression, e.g., the address can be compressed
statefully, or it is rarely used and/or it is used only over one hop, statefully, or it is rarely used and/or it is used only over one hop,
then privacy concerns should be considered. In particular, new then privacy concerns should be considered. In particular, new
implementations should follow the IETF "Recommendation on Stable IPv6 implementations should follow the IETF "Recommendation on Stable IPv6
Interface Identifiers" [RFC8064]. [RFC8064] recommends the use of "A Interface Identifiers" [RFC8064]. [RFC8064] recommends the use of "A
Method for Generating Semantically Opaque Interface Identifiers with Method for Generating Semantically Opaque Interface Identifiers with
IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for IPv6 Stateless Address Autoconfiguration (SLAAC)" [RFC7217] for
generating Interface Identifiers to be used in SLAAC. generating Interface Identifiers to be used in SLAAC.
10. IANA Considerations 9. IANA Considerations
Note to RFC Editor, to be removed: please replace "This RFC" Note to RFC Editor, to be removed: please replace "This RFC"
throughout this document by the RFC number for this specification throughout this document by the RFC number for this specification
once it is allocated. once it is allocated.
IANA is requested to make a number of changes under the "Internet IANA is requested to make a number of changes under the "Internet
Control Message Protocol version 6 (ICMPv6) Parameters" registry, as Control Message Protocol version 6 (ICMPv6) Parameters" registry, as
follows. follows.
10.1. ARO Flags 9.1. ARO Flags
IANA is requested to create a new subregistry for "ARO Flags". This IANA is requested to create a new subregistry for "ARO Flags". This
specification defines 8 positions, bit 0 to bit 7, and assigns bit 6 specification defines 8 positions, bit 0 to bit 7, and assigns bit 6
for the 'R' flag and bit 7 for the 'T' flag (see Section 6.1). The for the 'R' flag and bit 7 for the 'T' flag (see Section 4.1). The
policy is "IETF Review" or "IESG Approval" [RFC8126]. The initial policy is "IETF Review" or "IESG Approval" [RFC8126]. The initial
content of the registry is as shown in Table 2. content of the registry is as shown in Table 2.
New subregistry for ARO Flags under the "Internet Control Message New subregistry for ARO Flags under the "Internet Control Message
Protocol version 6 (ICMPv6) [RFC4443] Parameters" Protocol version 6 (ICMPv6) [RFC4443] Parameters"
+-------------+--------------+-----------+ +-------------+--------------+-----------+
| ARO Status | Description | Document | | ARO Status | Description | Document |
+-------------+--------------+-----------+ +-------------+--------------+-----------+
| 0..5 | Unassigned | | | 0..5 | Unassigned | |
| | | | | | | |
| 6 | 'R' Flag | This RFC | | 6 | 'R' Flag | This RFC |
| | | | | | | |
| 7 | 'T' Flag | This RFC | | 7 | 'T' Flag | This RFC |
+-------------+--------------+-----------+ +-------------+--------------+-----------+
Table 2: new ARO Flags Table 2: new ARO Flags
10.2. ICMP Codes 9.2. ICMP Codes
IANA is requested to create 2 new subregistries of the ICMPv6 "Code" IANA is requested to create 2 new subregistries of the ICMPv6 "Code"
Fields registry, which itself is a subregistry of the Internet Fields registry, which itself is a subregistry of the Internet
Control Message Protocol version 6 (ICMPv6) Parameters for the ICMP Control Message Protocol version 6 (ICMPv6) Parameters for the ICMP
codes. The new subregistries relate to the ICMP type 157, Duplicate codes. The new subregistries relate to the ICMP type 157, Duplicate
Address Request (shown in Table 3), and 158, Duplicate Address Address Request (shown in Table 3), and 158, Duplicate Address
Confirmation (shown in Table 4), respectively. The range of an Confirmation (shown in Table 4), respectively. The range of an
ICMPv6 "Code" Field is 0..255 in all cases. The policy is "IETF ICMPv6 "Code" Field is 0..255 in all cases. The policy is "IETF
Review" or "IESG Approval" [RFC8126] for both subregistries. The new Review" or "IESG Approval" [RFC8126] for both subregistries. The new
subregistries are initialized as follows: subregistries are initialized as follows:
skipping to change at page 26, line 39 skipping to change at page 29, line 33
+---------+----------------------+------------+ +---------+----------------------+------------+
| 0 | Original DAC message | RFC 6775 | | 0 | Original DAC message | RFC 6775 |
| | | | | | | |
| 1 | Extended DAC message | This RFC | | 1 | Extended DAC message | This RFC |
| | | | | | | |
| 2...255 | Unassigned | | | 2...255 | Unassigned | |
+---------+----------------------+------------+ +---------+----------------------+------------+
Table 4: new ICMPv6 Code Fields Table 4: new ICMPv6 Code Fields
10.3. New ARO Status values 9.3. New ARO Status values
IANA is requested to make additions to the Address Registration IANA is requested to make additions to the Address Registration
Option Status Values Registry as follows: Option Status Values Registry as follows:
Address Registration Option Status Values Registry Address Registration Option Status Values Registry
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
| ARO Status | Description | Document | | ARO Status | Description | Document |
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
| 3 | Moved | This RFC | | 3 | Moved | This RFC |
skipping to change at page 27, line 30 skipping to change at page 30, line 30
| 8 | Registered Address topologically | This RFC | | 8 | Registered Address topologically | This RFC |
| | incorrect | | | | incorrect | |
| | | | | | | |
| 9 | 6LBR Registry saturated | This RFC | | 9 | 6LBR Registry saturated | This RFC |
| | | | | | | |
| 10 | Validation Failed | This RFC | | 10 | Validation Failed | This RFC |
+-------------+-----------------------------------------+-----------+ +-------------+-----------------------------------------+-----------+
Table 5: New ARO Status values Table 5: New ARO Status values
10.4. New 6LoWPAN capability Bits 9.4. New 6LoWPAN capability Bits
IANA is requested to make additions to the Subregistry for "6LoWPAN IANA is requested to make additions to the Subregistry for "6LoWPAN
capability Bits" as follows: capability Bits" as follows:
Subregistry for "6LoWPAN capability Bits" under the "Internet Control Subregistry for "6LoWPAN capability Bits" under the "Internet Control
Message Protocol version 6 (ICMPv6) Parameters" Message Protocol version 6 (ICMPv6) Parameters"
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
| Capability Bit | Description | Document | | Capability Bit | Description | Document |
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
skipping to change at page 28, line 5 skipping to change at page 31, line 5
| | | | | | | |
| 12 | 6LBR capable (B bit) | This RFC | | 12 | 6LBR capable (B bit) | This RFC |
| | | | | | | |
| 13 | 6BBR capable (P bit) | This RFC | | 13 | 6BBR capable (P bit) | This RFC |
| | | | | | | |
| 14 | EARO support (E bit) | This RFC | | 14 | EARO support (E bit) | This RFC |
+-----------------+----------------------+-----------+ +-----------------+----------------------+-----------+
Table 6: New 6LoWPAN capability Bits Table 6: New 6LoWPAN capability Bits
11. Acknowledgments 10. Acknowledgments
Kudos to Eric Levy-Abegnoli who designed the First Hop Security Kudos to Eric Levy-Abegnoli who designed the First Hop Security
infrastructure upon which the first backbone router was implemented. infrastructure upon which the first backbone router was implemented.
Many thanks to Sedat Gormus, Rahul Jadhav, Tim Chown, Juergen Many thanks to Sedat Gormus, Rahul Jadhav, Tim Chown, Juergen
Schoenwaelder, Chris Lonvick, Dave Thaler, Adrian Farrel, Peter Yee, Schoenwaelder, Chris Lonvick, Dave Thaler, Adrian Farrel, Peter Yee,
Warren Kumari, and Lorenzo Colitti for their various contributions Warren Kumari, Benjamin Kaduk, Mirja Kuhlewind, and Lorenzo Colitti
and reviews. Also, many thanks to Thomas Watteyne for the world for their various contributions and reviews. Also, many thanks to
first implementation of a 6LN that was instrumental to the early Thomas Watteyne for the world first implementation of a 6LN that was
tests of the 6LR, 6LBR and Backbone Router. instrumental to the early tests of the 6LR, 6LBR and Backbone Router.
12. References 11. References
12.1. Normative References 11.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997, DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>. <https://www.rfc-editor.org/info/rfc2119>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>. 2006, <https://www.rfc-editor.org/info/rfc4291>.
skipping to change at page 28, line 45 skipping to change at page 31, line 45
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman, [RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007, DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>. <https://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless [RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862, Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007, DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>. <https://www.rfc-editor.org/info/rfc4862>.
[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals",
RFC 4919, DOI 10.17487/RFC4919, August 2007,
<https://www.rfc-editor.org/info/rfc4919>.
[RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6 [RFC6282] Hui, J., Ed. and P. Thubert, "Compression Format for IPv6
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282, Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011, DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>. <https://www.rfc-editor.org/info/rfc6282>.
[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem
Statement and Requirements for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Routing",
RFC 6606, DOI 10.17487/RFC6606, May 2012,
<https://www.rfc-editor.org/info/rfc6606>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C. [RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)", Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012, RFC 6775, DOI 10.17487/RFC6775, November 2012,
<https://www.rfc-editor.org/info/rfc6775>. <https://www.rfc-editor.org/info/rfc6775>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <https://www.rfc-editor.org/info/rfc7102>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.
[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for [RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
IPv6 over Low-Power Wireless Personal Area Networks IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November (6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
2014, <https://www.rfc-editor.org/info/rfc7400>. 2014, <https://www.rfc-editor.org/info/rfc7400>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26, Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017, RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>. <https://www.rfc-editor.org/info/rfc8126>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>. May 2017, <https://www.rfc-editor.org/info/rfc8174>.
12.2. Informative References 11.2. Terminology Related References
[RFC4919] Kushalnagar, N., Montenegro, G., and C. Schumacher, "IPv6
over Low-Power Wireless Personal Area Networks (6LoWPANs):
Overview, Assumptions, Problem Statement, and Goals",
RFC 4919, DOI 10.17487/RFC4919, August 2007,
<https://www.rfc-editor.org/info/rfc4919>.
[RFC6606] Kim, E., Kaspar, D., Gomez, C., and C. Bormann, "Problem
Statement and Requirements for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Routing",
RFC 6606, DOI 10.17487/RFC6606, May 2012,
<https://www.rfc-editor.org/info/rfc6606>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <https://www.rfc-editor.org/info/rfc7102>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
Constrained-Node Networks", RFC 7228,
DOI 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.
11.3. Informative References
[I-D.chakrabarti-nordmark-6man-efficient-nd] [I-D.chakrabarti-nordmark-6man-efficient-nd]
Chakrabarti, S., Nordmark, E., Thubert, P., and M. Chakrabarti, S., Nordmark, E., Thubert, P., and M.
Wasserman, "IPv6 Neighbor Discovery Optimizations for Wasserman, "IPv6 Neighbor Discovery Optimizations for
Wired and Wireless Networks", draft-chakrabarti-nordmark- Wired and Wireless Networks", draft-chakrabarti-nordmark-
6man-efficient-nd-07 (work in progress), February 2015. 6man-efficient-nd-07 (work in progress), February 2015.
[I-D.delcarpio-6lo-wlanah] [I-D.delcarpio-6lo-wlanah]
Vega, L., Robles, I., and R. Morabito, "IPv6 over Vega, L., Robles, I., and R. Morabito, "IPv6 over
802.11ah", draft-delcarpio-6lo-wlanah-01 (work in 802.11ah", draft-delcarpio-6lo-wlanah-01 (work in
skipping to change at page 31, line 10 skipping to change at page 34, line 16
Perkins, C., Stanley, D., Kumari, W., and J. Zuniga, Perkins, C., Stanley, D., Kumari, W., and J. Zuniga,
"Multicast Considerations over IEEE 802 Wireless Media", "Multicast Considerations over IEEE 802 Wireless Media",
draft-perkins-intarea-multicast-ieee802-03 (work in draft-perkins-intarea-multicast-ieee802-03 (work in
progress), July 2017. progress), July 2017.
[I-D.struik-lwip-curve-representations] [I-D.struik-lwip-curve-representations]
Struik, R., "Alternative Elliptic Curve Representations", Struik, R., "Alternative Elliptic Curve Representations",
draft-struik-lwip-curve-representations-00 (work in draft-struik-lwip-curve-representations-00 (work in
progress), October 2017. progress), October 2017.
[I-D.thubert-roll-unaware-leaves]
Thubert, P., "Routing for RPL Leaves", draft-thubert-roll-
unaware-leaves-04 (work in progress), March 2018.
[RFC1958] Carpenter, B., Ed., "Architectural Principles of the [RFC1958] Carpenter, B., Ed., "Architectural Principles of the
Internet", RFC 1958, DOI 10.17487/RFC1958, June 1996, Internet", RFC 1958, DOI 10.17487/RFC1958, June 1996,
<https://www.rfc-editor.org/info/rfc1958>. <https://www.rfc-editor.org/info/rfc1958>.
[RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982, [RFC1982] Elz, R. and R. Bush, "Serial Number Arithmetic", RFC 1982,
DOI 10.17487/RFC1982, August 1996, DOI 10.17487/RFC1982, August 1996,
<https://www.rfc-editor.org/info/rfc1982>. <https://www.rfc-editor.org/info/rfc1982>.
[RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with [RFC3610] Whiting, D., Housley, R., and N. Ferguson, "Counter with
CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September CBC-MAC (CCM)", RFC 3610, DOI 10.17487/RFC3610, September
skipping to change at page 33, line 5 skipping to change at page 36, line 16
Donaldson, "Transmission of IPv6 over Master-Slave/Token- Donaldson, "Transmission of IPv6 over Master-Slave/Token-
Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163, Passing (MS/TP) Networks", RFC 8163, DOI 10.17487/RFC8163,
May 2017, <https://www.rfc-editor.org/info/rfc8163>. May 2017, <https://www.rfc-editor.org/info/rfc8163>.
[RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A., [RFC8279] Wijnands, IJ., Ed., Rosen, E., Ed., Dolganow, A.,
Przygienda, T., and S. Aldrin, "Multicast Using Bit Index Przygienda, T., and S. Aldrin, "Multicast Using Bit Index
Explicit Replication (BIER)", RFC 8279, Explicit Replication (BIER)", RFC 8279,
DOI 10.17487/RFC8279, November 2017, DOI 10.17487/RFC8279, November 2017,
<https://www.rfc-editor.org/info/rfc8279>. <https://www.rfc-editor.org/info/rfc8279>.
12.3. External Informative References 11.4. External Informative References
[IEEEstd802154] [IEEEstd802154]
IEEE, "IEEE Standard for Low-Rate Wireless Networks", IEEE, "IEEE Standard for Low-Rate Wireless Networks",
IEEE Standard 802.15.4, DOI 10.1109/IEEE IEEE Standard 802.15.4, DOI 10.1109/IEEE
P802.15.4-REVd/D01, June 2017, P802.15.4-REVd/D01, June 2017,
<http://ieeexplore.ieee.org/document/7460875/>. <http://ieeexplore.ieee.org/document/7460875/>.
[Perlman83] [Perlman83]
Perlman, R., "Fault-Tolerant Broadcast of Routing Perlman, R., "Fault-Tolerant Broadcast of Routing
Information", North-Holland Computer Networks 7: 395-405, Information", North-Holland Computer Networks 7: 395-405,
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