IPv6 Neighbor Discovery Prefix Registration
draft-ietf-6lo-prefix-registration-15
| Document | Type | Active Internet-Draft (6lo WG) | |
|---|---|---|---|
| Author | Pascal Thubert | ||
| Last updated | 2025-07-14 (Latest revision 2025-07-04) | ||
| Replaces | draft-thubert-6lo-prefix-registration | ||
| RFC stream | Internet Engineering Task Force (IETF) | ||
| Intended RFC status | Proposed Standard | ||
| Formats | |||
| Reviews |
GENART Early review
(of
-02)
by Dan Romascanu
Ready w/issues
INTDIR Early review
(of
-02)
by Dave Thaler
On the right track
|
||
| Additional resources | Mailing list discussion | ||
| Stream | WG state | Submitted to IESG for Publication | |
| Associated WG milestone |
|
||
| Document shepherd | Shwetha Bhandari | ||
| Shepherd write-up | Show Last changed 2025-02-14 | ||
| IESG | IESG state | RFC Ed Queue | |
| Action Holders |
(None)
|
||
| Consensus boilerplate | Yes | ||
| Telechat date | (None) | ||
| Responsible AD | Éric Vyncke | ||
| Send notices to | shwetha.bhandari@gmail.com | ||
| IANA | IANA review state | Version Changed - Review Needed | |
| IANA action state | RFC-Ed-Ack | ||
| RFC Editor | RFC Editor state | EDIT | |
| Details |
draft-ietf-6lo-prefix-registration-15
6lo P. Thubert, Ed.
Internet-Draft 4 July 2025
Updates: 4861, 6550, 8505, 8928, 9010 (if
approved)
Intended status: Standards Track
Expires: 5 January 2026
IPv6 Neighbor Discovery Prefix Registration
draft-ietf-6lo-prefix-registration-15
Abstract
This document updates IPv6 Neighbor Discovery (RFC 4861) and IPv6
Subnet Neighbor Discovery (RFC 8505, RFC 8928) to enable a node that
owns or is directly connected to a prefix to register that prefix to
neighbor routers. The registration indicates that the registered
prefix can be reached via the advertising node without a loop. The
unicast prefix registration allows the node to request neighbor
router(s) to redistribute the prefix in another routing domain
regardless of the routing protocol used in that domain. This
document updates Routing Protocol for Low-Power and Lossy Networks
(RPL) (RFC 6550, RFC 9010) to enable a 6LoWPAN Router (6LR) to inject
the registered prefix in RPL.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on 5 January 2026.
Copyright Notice
Copyright (c) 2025 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Requirements Language . . . . . . . . . . . . . . . . . . 5
2.2. Inherited Terms and Concepts . . . . . . . . . . . . . . 5
2.3. Acronyms and Initialisms . . . . . . . . . . . . . . . . 6
2.4. New terms . . . . . . . . . . . . . . . . . . . . . . . . 7
3. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 7
4. Updating RFC 4861 . . . . . . . . . . . . . . . . . . . . . . 8
5. Updating RFC 7400 . . . . . . . . . . . . . . . . . . . . . . 9
6. Updating RFC 6550 . . . . . . . . . . . . . . . . . . . . . . 10
7. Updating RFC 8505 . . . . . . . . . . . . . . . . . . . . . . 11
7.1. New P-Field value . . . . . . . . . . . . . . . . . . . . 11
7.2. New EARO Prefix Length Field and F flag . . . . . . . . . 11
7.3. New EDAR Prefix Length Field . . . . . . . . . . . . . . 13
7.4. Updating the Registration Operation . . . . . . . . . . . 14
8. Updating RFC 9010 . . . . . . . . . . . . . . . . . . . . . . 17
9. Updating RFC 8928 . . . . . . . . . . . . . . . . . . . . . . 17
10. Updating RFC 8929 . . . . . . . . . . . . . . . . . . . . . . 18
11. Security Considerations . . . . . . . . . . . . . . . . . . . 19
12. Operational Considerations . . . . . . . . . . . . . . . . . 19
12.1. Partially Upgraded Networks . . . . . . . . . . . . . . 19
12.2. Application to RPL-Based Route-Over LLNs . . . . . . . . 20
12.3. Application to a Shared Link . . . . . . . . . . . . . . 21
12.4. Application to a Hub Link with Stub Spokes . . . . . . . 22
13. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 23
13.1. Updated P-Field Registry . . . . . . . . . . . . . . . . 23
13.2. New 6LoWPAN Capability Bit . . . . . . . . . . . . . . . 24
14. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 24
15. Normative References . . . . . . . . . . . . . . . . . . . . 24
16. Informative References . . . . . . . . . . . . . . . . . . . 26
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 27
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1. Introduction
The design of Low Power and Lossy Networks (LLNs) is generally
focused on saving energy, which is the most constrained resource of
all. Other design constraints, such as a limited memory capacity,
duty cycling of the LLN devices and low-power lossy transmissions,
derive from that primary concern. The radio (both transmitting or
simply listening) is a major energy drain and the LLN protocols must
be adapted to allow the nodes to remain sleeping with the radio
turned off at most times.
Examples of LLNs include hub-and-spoke access links such as (Low-
Power) Wi-Fi [IEEE80211] and Bluetooth (Low Energy) [IEEE802151],
Mesh-Under networks where the routing operation is handled at Layer-
2, and Route-Over networks such as the Wi-SUN [WI-SUN] and 6TiSCH
[RFC9030] mesh networks, which leverage 6LoWPAN [RFC4919][RFC6282]
and RPL [RFC6550] over [IEEE802154].
LLNs and constrained devices are the original domain of application
for 6LoWPAN protocols. It is thus a foremost concern, when designing
those protocols, to minimize energy spendings. In non-LLN
environments where lowering carbon emissions is also a priority, it
could make sense to apply the 6LoWPAN designs and extend some of the
6LoWPAN protocols. The general design points include:
* Placing the protocol complexity in the less-constrained routers to
simplify the host implementation and avoid expanding the control
traffic to all nodes.
* Using host-triggered operations to enable transient disconnections
with the routers, e.g., to conserve power (sleep), but also to
cope with inconsistent connectivity.
This translates into:
* Stateful proactively-built knowledge in the routers that is
available at any point of time.
* Unicast host to router operations triggered by the host and its
applications.
* Minimal use of asynchronous L2-broadcast operations that would
keep the host awake and listening with no application-level need
to do so.
The "Routing Protocol for Low Power and Lossy Networks" [RFC6550]
(RPL) provides IPv6 [RFC8200] routing services within such
constraints. To save signaling and routing state in constrained
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networks, the RPL routing is only performed along a Destination-
Oriented Directed Acyclic Graph (DODAG) that is optimized to reach a
Root node, as opposed to along the shortest path between 2 peers,
whatever that would mean in each LLN.
The classical Neighbor Discovery (IPv6 ND) Protocol (NDP) [RFC4861]
[RFC4862] was defined for serial links and shared transit media such
as Ethernet at a time when L2-broadcast was cheap on those media
while memory for neighbor cache was expensive. It was thus designed
as a reactive protocol that relies on caching and multicast
operations for the Address Resolution (AR, aka Address Discovery or
Address Lookup) and Duplicate Address Detection (DAD) of IPv6 unicast
addresses. Those multicast operations typically impact every node
on-link when at most one is really targeted, which is a waste of
energy, and imply that all nodes are awake to hear the request, which
is inconsistent with power saving (sleeping) modes.
The "Architecture and Framework for IPv6 over Non-Broadcast Access"
(NBMA) [I-D.ietf-6man-ipv6-over-wireless] introduces an evolution of
IPv6 ND towards a proactive AR method. Because the IPv6 model for
NBMA depends on a routing protocol to reach inside the Subnet, the
IPv6 ND extension for NBMA is referred to as Subnet Neighbor
Discovery (SND). SND is based on work done in the context of IoT,
known as 6LoWPAN ND. As opposed to the classical IPv6 ND Protocol,
this evolution follows the energy conservation principles discussed
above:
* The original 6LoWPAN ND, "Neighbor Discovery Optimizations for
6LoWPAN networks" [RFC6775], was introduced to avoid the excessive
use of multicast messages and enable IPv6 ND for operations over
energy-constrained nodes. [RFC6775] changes the classical IPv6 ND
model to proactively establish the Neighbor Cache Entry (NCE)
associated to the unicast address of a 6LoWPAN Node (6LN) in the
6LoWPAN Router(s) (6LRs) that serve it. To that effect, [RFC6775]
defines a new Address Registration Option (ARO) that is placed in
unicast Neighbor Solicitation (NS) and Neighbor Advertisement (NA)
messages between the 6LN and the 6LRs.
* "Registration Extensions for 6LoWPAN Neighbor Discovery" [RFC8505]
updates [RFC6775] into a generic Address Registration mechanism
and is the foundation for Subnet Neighbor Discovery (SND). SND
introduces the Extended Address Registration Option (EARO) to
enable the registering node to access services such as routing
inside a subnet and ND proxy [RFC8929] operations. This provides
a routing-protocol-agnostic method for a host to request that the
router injects a unicast IPv6 address in the local routing
protocol and provide return reachability for that address.
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* "IPv6 Neighbor Discovery Multicast Address Listener Subscription"
[RFC9685] updates [RFC8505] to enable a listener to subscribe to
an IPv6 anycast or multicast address; the draft also updates
[RFC9010] to enable a 6LR to inject the anycast and multicast
addresses in RPL. Similarly, this specification updates [RFC8505]
and [RFC9010] to add the capability for a 6LN to register unicast
prefixes up to 120 bits long, as opposed to addresses, and to
signal in a routing-protocol-independent fashion to a 6LR that it
is expected to redistribute the prefixes.
This specification updates the above registration and subscription
methods to enable a node to register a unicast prefix to the routing
system and get it injected in the routing protocol. As with
[RFC8505], the prefix registration is agnostic to the routing
protocol in which the router injects the prefix, and the router is
agnostic to the method that was used to allocate the prefix to the
node. The energy conservation principles in [RFC8505] are retained
as well, meaning that the node does not have to send or expect
asynchronous multicast messages.
It can be noted that an energy-conserving node is not necessarily a
router, so even when advertising a prefix, it is a design choice not
to use Router Advertisement (RA) messages that would make the node
appear as a router to peer nodes. From the design principles above,
it is clearly a design choice not to leverage broadcasts from or to
the node, or complex state machines in the node. It is also a design
choice to use and extend the EARO as opposed to the Route Information
Option (RIO) [RFC4191] because the RIO is not intended to inject
routes in routing, and is lacking related control information like
the R bit in the EARO. Additionally, an RA with RIO cannot be
trusted for a safe injection in the routing protocol for the lack of
the equivalent of the Registration Ownership Verifier (ROVR)
[RFC8928] in the EARO.
2. Terminology
2.1. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in BCP
14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
2.2. Inherited Terms and Concepts
This document uses terms and concepts that are discussed in:
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* "Neighbor Discovery for IP version 6" [RFC4861] and
* "IPv6 Stateless Address Autoconfiguration" [RFC4862] for the
Neighbor Solicitation operation,
* Neighbor Discovery Optimization for IPv6 over Low-Power Wireless
Personal Area Networks (6LoWPANs) [RFC6775], as well as
* "Registration Extensions for 6LoWPAN Neighbor Discovery" for SND
operations [RFC8505] and
* "Routing Protocol for Low Power and Lossy Networks" [RFC6550] for
RPL, which is the routing protocol used in LLNs for SND.
2.3. Acronyms and Initialisms
This document uses the following abbreviations:
*6CIO:* 6LoWPAN Capability Indication Option [RFC7400]
*6LBR:* 6LoWPAN Border Router [RFC6775]
*6LN:* 6LoWPAN Node [RFC6775]
*6LR:* 6LoWPAN Router [RFC6775]
*ARO:* Address Registration Option [RFC6775]
*DAD:* Duplicate Address Detection [RFC4861]
*DAO:* Destination Advertisement Object [RFC6550]
*DODAG:* Destination-Oriented Directed Acyclic Graph
*EARO:* Extended Address Registration Option [RFC8505]
*EDAC:* Extended Duplicate Address Confirmation [RFC8505]
*EDAR:* Extended Duplicate Address Request [RFC8505]
*ESS:* Extended Service Set [IEEE80211]
*IPAM:* IP Address Management
*LLN:* Low-Power and Lossy Network
*LLA:* Link Layer Address
*LoWPAN:* Low-Rate Personal Area Network [IEEE802154]
*MAC:* Medium Access Control
*NA:* Neighbor Advertisement (message) [RFC4861]
*NBMA:* Non-Broadcast Multi-Access (full mesh)
*NCE:* Neighbor Cache Entry [RFC4861]
*ND:* Neighbor Discovery (protocol)
*NDP:* Neighbor Discovery Protocol
*NS:* Neighbor Solicitation (message) [RFC4861]
*ROVR:* Registration Ownership Verifier (pronounced "rover")
[RFC8505]
*RPL:* IPv6 Routing Protocol for LLNs (pronounced "ripple")
[RFC6550]
*RA:* Router Advertisement (message) [RFC4861]
*RS:* Router Solicitation (message) [RFC4861]
*RTO:* RPL Target Option [RFC6550]
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*SLLAO:* Source Link-Layer Address Option [RFC4861]
*SND:* Subnet Neighbor Discovery (protocol)
*TID:* Transaction ID [RFC8505]
*TIO:* Transit Information Option [RFC6550]
*TLLAO:* Target Link-Layer Address Option [RFC4861]
2.4. New terms
This document introduces the following terms:
*Origin:* The node that issued the prefix advertisement, either in
the form of a NS(EARO) or as a DAO(TIO, RTO)
*Merge:* The action of receiving multiple anycast or multicast
advertisements, either internally from self, in the form of a
NS(EARO), or as a DAO(TIO, RTO), and generating a single
DAO(TIO, RTO). The 6RPL router maintains a state per origin
for each advertised address, and merges the advertisements for
all subscriptions for the same address in a single
advertisement. A RPL router that merges then becomes the
origin of the merged advertisement and uses its own values for
the Path Sequence and ROVR fields.
3. Overview
This specification inherits from [RFC6550], [RFC8505], and [RFC9010]
to register prefixes as opposed to addresses.
An SND deployment consists of:
* One or more 6LBR(s) that act(s) as RPL Root
* intermediate routers down the RPL graph that propagate routing
information on addresses and prefixes towards the Root
* 6LRs that are RPL-aware 6LNs and can leverage RPL directly to
expose their addresses and prefixes
* and 6LNs that are the RPL-unaware destinations and need SND to
obtain reachability tover the RPL LLN for their addresses and,
with this specification, their prefixes as well.
The SND operation for prefixes inherits from that for unicast
addresses, meaning that it is the same unless specified otherwise
herein. In particular, forwarding a packet happens as specified in
section 11 of [RFC6550], including loop avoidance and detection,
though in the case of multicast multiple copies might be generated.
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[RFC8505] is a pre-requisite to this specification. A node that
implements this MUST also implement [RFC8505]. This specification
does not introduce a new option; it modifies existing options and
updates the associated behaviors to enable the Registration for
prefixes as an extension to [RFC8505].
This specification updates the P-Field introduced in [RFC9685] for
use in EARO, DAR, and RTO, with the new value of 3 to indicate the
registration of a prefix, as detailed in Section 7.2. With this
extension, the 6LN can now express its willingness to receive the
traffic for all addresses in the range of a prefix, using the P-Field
value of 3 in the EARO to signal that the registration is for such
prefix. Multiple 6LNs acting as border routers to the same external
network or as access routers to the same subnet may register the same
prefix to the same 6LR or to different 6LRs.
If the R flag is set in the registration of one or more 6LNs for the
same prefix, then, according to its redistribution policy, the 6LR
MUST redistribute the prefix in the routing protocol(s) (e.g., RPL)
that it participates in. The duration of the redistribution is based
on the longest registration lifetime across the non-expired received
registrations for the prefix.
Examples of use-cases where this specification may apply include
virtual links, shared links, and hub links as shown in Section 12.3
and Section 12.4, respectively. More generally, the 6LN may be a
router running a different routing protocol in an external network,
e.g., a stub network, and acting as a border router. Using the
prefix registration method enables decoupling the routing protocol in
the 6LN from the routing protocol that the 6LRs run in the main LLN
and provide signaling to stimulate the redistribution.
4. Updating RFC 4861
[RFC4861] expects that the NS/NA exchange is for a unicast address,
which is indicated in the Target Address field of the ND message.
Section 5.5 of [RFC8505] updates [RFC4861] to signal the Registered
Address in the Target Address field.
This specification updates [RFC4861] by allowing a 6LN to advertise a
prefix in the Target Address field when the NS or NA message is used
for a registration, per section 5.5 of [RFC8505]; in that case, the
prefix length MUST be indicated in the EARO of the NS message,
overloading the field that is used in the NA response for the Status.
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If the 6LN owns at least one an IPv6 address that is derived from the
registered prefix with a non-0 interface ID, then it MUST indicate
one of these addresses in full in the Target Address field of the
NS(EARO) message. Else, it MUST indicate the prefix padded with 0s
in the Target Address field.
5. Updating RFC 7400
This specification updates "6LoWPAN-GHC: Generic Header Compression
for IPv6 over Low-Power Wireless Personal Area Networks (6LoWPANs)"
[RFC7400] by defining a new capability bit for use in the 6CIO.
[RFC7400] was already updated by [RFC8505] for use in IPv6 ND
messages.
The new "Registration for prefixes Supported" (F) flag indicates to
the 6LN that the 6LR accepts IPv6 prefix registrations as specified
in this document and will ensure that packets for the addresses that
match this prefix will be routed to the 6LNs that registered the
prefix, and the route to the prefix will be redistributed if the R
flag is set to 1.
Figure 1 illustrates the F flag in its position (16, counting 0 to 47
in network order in the 48-bit array).
- to be confirmed by IANA
- and updated by RFC Editor if needed.
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 | Experimental |X|A|D|L|B|P|E|G|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|F| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 1: New Capability Bit in the 6CIO
New Option Field:
*F:* 1-bit flag, set to 1 to indicate "Registration for prefixes
Supported"
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6. Updating RFC 6550
[RFC6550] uses the Path Sequence in the Transit Information Option
(TIO) to retain only the freshest unicast route and remove stale
ones, e.g., in the case of mobility. [RFC9010] copies the TID from
the EARO into the Path Sequence, and the ROVR field into the
associated RPL Target Option (RTO). This way, it is possible to
identify both the registering node and the order of registration in
RPL for each individual advertisement, so the most recent path and
lifetime values are used.
[RFC9685] requires the use of the ROVR field as the indication of the
origin of a Target advertisement in the RPL DAO messages, as
specified in section 6.1 of [RFC9010]. For anycast and multicast
advertisements (in NS or DAO messages), multiple origins may
subscribe to the same address, in which case the multiple
advertisements from the different or unknown origins are merged by
the common parent; in that case, the common parent becomes the origin
of the merged advertisements and uses its own ROVR value. On the
other hand, a parent that propagates an advertisement from a single
origin uses the original ROVR in the propagated RTO, as it does for
unicast address advertisements, so the origin is recognized across
multiple hops.
This specification updates [RFC6550] to require that, for prefix
routes, the Path Sequence is used between and only between
advertisements for the same Target and from the same origin (i.e.,
with the same ROVR value); in that case, only the freshest
advertisement is retained. But the freshness comparison cannot apply
if the origin is not determined (i.e., the origin did not support
this specification).
[RFC6550] uses the Path Lifetime in the TIO to indicate the remaining
time for which the advertisement is valid for unicast route
determination, and a Path Lifetime value of 0 invalidates that route.
[RFC9010] maps the Address Registration lifetime in the EARO and the
Path Lifetime in the TIO so they are comparable when both forms of
advertisements are received.
The RPL router that merges multiple advertisements for the same
prefix uses and advertises the longest remaining lifetime across all
the origins of the advertisements for that prefix. When the lifetime
expires, the router sends a no-path DAO (i.e., the lifetime is 0)
using the same value for ROVR value as for the previous
advertisements, that is either itself or the single descendant that
advertised the Target.
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Note that the Registration Lifetime, TID and ROVR fields are also
placed in the EDAR message so the state created by EDAR is also
comparable with that created upon an NS(EARO) or a DAO message. For
simplicity the text below mentions only NS(EARO) but applies also to
EDAR.
7. Updating RFC 8505
This specification updates the EARO and EDAR messages to enable the
registration of prefixes and updates the Registration operation in
the case of a prefix, in particular from the standpoint of the 6LR,
e.g., to enable the Registration of overlapping prefixes.
7.1. New P-Field value
[RFC9685] defines a 2-bit P-Field with values 0 through 2 and
reserves the value 3 for future use. This specification defines the
semantics of P-Field value 3.
When the P-Field is set to 3, it indicates that the Registered
Address represents a prefix rather than a single address. Upon
receiving an NS(EARO) message with the P-Field set to 3, the receiver
MUST install a route to the indicated prefix via the source address
of the NS(EARO) message.
This specification assigns the value 3 to the P-Field, resulting in
the following complete set of defined values:
+-------+--------------------------------------+
| Value | Meaning |
+-------+--------------------------------------+
| *0* | Registration for a Unicast Address |
+-------+--------------------------------------+
| *1* | Registration for a Multicast Address |
+-------+--------------------------------------+
| *2* | Registration for an Anycast Address |
+-------+--------------------------------------+
| *3* | Registration for a Unicast prefix |
+-------+--------------------------------------+
Table 1: P-Field Values
7.2. New EARO Prefix Length Field and F flag
Section 4.1 of [RFC8505] defines the EARO as an extension to the ARO
option defined in [RFC6775].
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The Status field is used only when the EARO is placed in an NA
message. This specification repurposes that field to carry the
prefix length when the EARO is placed in an NS message as illustrated
in Figure 2. The prefix length is expressed as 7 bits and the most
significant bit of the field is reserved. A 7-bit value of 0 is
understood as a truncated 128, meaning that this registration is for
an address as opposed to a prefix. This approach is backward
compatible with [RFC8505] and spans both addresses and prefixes.
This specification adds a new F flag to signal that the Registered
Prefix is topologically correct through the Registering Node. This
means that the Registering Node relays packets that are sourced in
the Registered Prefix to the outside, in accordance with "Network
Ingress Filtering" [BCP38] . The receiver forwards packets to the
Registering Node address when the source address of the packets
derives from the Registered Prefix. Note that to avoid loops, the
receiver must be in the inside so packets sent by the sender towards
the outside may never reach the receiver. The notion of inside and
outside are administratively defined, e.g., inside is a particular
Layer-2 network such as an Ethernet fabric.
When the F flag is not set, the Registering Node owns the prefix and
will deliver packets to the destination if the destination address
derives from the prefix. Conversely, if the F flag is set, the
Registering Node will forward traffic whose source address derives
from the Registered Prefix into a network location (e.g., to an ISP
Provider Edge) where this source address is topologically correct
(e.g., derives from a prefix assigned by that ISP). The F flag is
encoded in the most significant bit of the EARO Status field when the
Status field is used to transport a Prefix Length as shown in
Figure 2.
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 |F|Prefix Length| Opaque |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|r|C| P | I |R|T| TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... ROVR ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 2: EARO Format for Use in NS Messages
New and updated Option Fields:
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*F:* (Forwarding Flag) A 1-bit flag. When set to 1, it indicates
that the sender expects other routers to forward packets to the
sender when those packets are sourced from within the registered
prefix.
*Prefix Length:* A 7-bit unsigned integer. When the P-Field is set
to 3 and the EARO is included in an NS message, this field MUST
contain a prefix length expressed in bits, with a value between 16
and 120 inclusive. When the EARO is included in an NA message,
this field MUST carry a status value, regardless of the setting of
the P-Field. In all other cases, this field is reserved; it MUST
be set to zero by the sender and MUST be ignored by the receiver.
*r* (reserved): A 1-bit reserved field. It MUST be set to zero by
the sender and MUST be ignored by the receiver.
7.3. New EDAR Prefix Length Field
This specification adds the new value of 3 to the P-Field to signal
that the Registered Address is a prefix. When that is the case, the
prefix is assumed to be at most 120 bits long, padded with zeros up
to 120 bits, and the remaining byte is dedicated to one reserved bit
and the prefix length.
Figure 3 illustrates the EDAR message when the value of the P-Field
is 3. Figure 4 shows the response EDAC message, with the Status
field and the echoed Prefix.
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 |CodePfx|CodeSfx| Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|P=3| Reserved | TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... ROVR ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Prefix +
| |
+ (up to 120 bits, padded with 0s) +
| |
+ +-+-+-+-+-+-+-+-+
| |r|Prefix Length|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Figure 3: EDAR Message Format with P == 3
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type |CodePfx|CodeSfx| Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status | TID | Registration Lifetime |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
... ROVR ...
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
+ Prefix +
| |
+ (up to 120 bits, padded with 0s) +
| |
+ +-+-+-+-+-+-+-+-+
| |r|Prefix Length|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: EDAC Message Format
New and updated Option Fields:
*Reserved:* A 6-bit field reserved for future use. It MUST be set
to zero by the sender and MUST be ignored by the receiver.
*Prefix:* A 15-byte field that carries up to 120 bits of the prefix.
If the prefix isshorter than 120 bits, the remaining bits MUST be
padded with zeros. The receiver MUST treat the padding as zeroed
and MUST overwrite any unused bits with zeros before using the
prefix.
*r* (reserved): A 1-bit reserved field. It MUST be set to zero by
the sender and MUST be ignored by the receiver.
*Prefix Length:* A 7-bit unsigned integer indicating the length of
the prefix in bits. The value MUST be in the inclusive range of
16 to 120.
All other fields follow the same definition as specified in [RFC8505]
7.4. Updating the Registration Operation
With [RFC8505]:
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* A router that expects to reboot may send a final RA message, upon
which nodes should register elsewhere or redo the registration to
the same router upon reboot. In all other cases, a node reboot is
silent. When the node comes back to life, existing registration
state might be lost if it was not safely stored, e.g., in
persistent memory.
* Only unicast addresses can be registered.
* The 6LN must register all its Unique Local Addresses (ULAs) and
Global Unicast Addresses (GUAs) with a NS(EARO).
* The 6LN may set the R flag in the EARO to obtain return
reachability services by the 6LR, e.g., through ND proxy
operations, or by injecting the route in a route-over subnet.
* The 6LR maintains a registration state per Registered Address,
including an NCE with the Link Layer Address (LLA) of the
Registered Node (the 6LN here).
The operation for registering prefixes is similar to that for
addresses from the perspective of the 6LN, but shows important
differences on the router side, which maintains a separate state for
each origin and merges them in its own advertisements. This
specification adds the following behavior, similar to that introduced
by [RFC9685] for multicast addresses:
* The EARO status indicating a "Registration Refresh Request"
applies to prefixes as well.
This status is used in asynchronous NA(EARO) messages to indicate
to peer 6LNs that they are requested to reregister all addresses
and prefixes that were previously registered to the originating
node. The NA message MAY be sent to a unicast or a multicast
link-scope address and SHOULD be contained within the L2 range
where nodes may effectively have registered/subscribed to this
router, e.g., a radio broadcast domain to preserve energy and
spectrum.
A device that wishes to refresh its state, e.g., upon reboot if it
may have lost some registration state, SHOULD send an asynchronous
NA(EARO) with this new status value. That asynchronous NA(EARO)
SHOULD be sent to the all-nodes link-scope multicast address
(ff02::1) and Target MUST be set to the link-local address that
was exposed previously by this node to accept registrations, and
the TID MUST be set to 0; the ROVR field MUST be set to all zeroes
and ignored by the receiver.
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In an environment with unreliable transmissions, the multicast
NA(EARO) message may be resent in a fast sequence, in which case
the TID is incremented each time. A 6LN that has recently
processed the NA(EARO) indicating a "Registration Refresh Request"
ignores the additional NA(EARO) also indicating a "Registration
Refresh Request" within the duration of the fast sequence. That
duration depends on the environment and has to be configured. By
default, it is 10 seconds.
* Registration for prefixes is now supported. The value of 3 in the
P-Field of the EARO and the EDAR message signals when the
registration is for a prefix as opposed to an address. DAD for
prefixes and addresses becomes a prefix overlap match. Whether
overlapping addresses and prefixes may be registered is a network
policy decision and out of scope. The same prefix may be injected
twice (multiple routes) as long as they use the same value of the
ROVR.
Overlaps may be desirable. It may happen for instance that a
router or a proxy (see Section 10) registers a prefix or an
aggregation while a host using an address from that prefix or a
prefix from that aggregation also registers its piece.
In case of an overlapping registration, the longest prefix match
wins, meaning that if the network policy allows for overlapping
registrations, then the routes for the registered prefixes are
installed towards the node that registered with the longest prefix
match, all the way to /128.
* If the 6LR acts as a border router to external prefixes or owns
the prefixes entirely, it SHOULD register all those prefixes on
all interfaces from which it might be needed to relay traffic to
that prefix. It MUST set the P-Field in the EARO to 3 for those
prefixes, and the set R flag to receive the traffic associated to
the prefixes. It MAY refrain from registering a prefix on one
interface if that prefix is already successfully registered on
another interface, or the router handled the EDAR / EDAC flow by
itself, to ensure that the prefix ownership is known and validated
by the 6LBR. Additionally, if the router expect to receive
traffic for that prefix on that interface, it needs to ensure that
the prefix is advertised some other way, e.g., over a routing
protocol such as RPL.
* The 6LN MAY set the R flag in the EARO to request the 6LR to
redistribute the prefix on other links using a routing protocol.
The 6LR MUST NOT reregister that prefix to yet another router
unless loops are avoided some way, e.g., following a tree
structure.
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* The 6LR and the 6LBR are extended to accept more than one
registration for the same prefix, since multiple 6LNs may register
it. The ROVR in the EARO identifies uniquely a registration
within the namespace of the Registered Prefix.
* The 6LR MUST maintain a registration state per tuple (IPv6 prefix/
length, ROVR) for all registered prefixes. It SHOULD notify the
6LBR with an EDAR message, unless it determined that the 6LBR is
legacy and does not support this specification (see Section 5).
In turn, the 6LBR MUST maintain a registration state per tuple
(IPv6 prefix, ROVR) for all prefixes.
8. Updating RFC 9010
With [RFC9010]:
* The 6LR injects only unicast routes in RPL.
* Upon a registration with the R flag set to 1 in the EARO, the 6LR
injects the address in the RPL unicast support.
* Upon receiving a packet directed to a unicast address for which it
has an active registration, the 6LR delivers the packet as a
unicast layer-2 frame to the LLA of the node that registered the
unicast address.
This specification adds the following behavior:
* Upon a registration with the R flag set to 1 and the P-Field set
to 3 in the EARO, the 6LR injects the prefix in RPL using a prefix
RTO. The P-Field in the RTP MUST be set to 3.
* Upon receiving a packet directed to an address that derives from a
prefix for which it has at least one registration, the 6LR
delivers a copy of the packet as a unicast layer-2 frame to the
LLA of exactly one of the nodes that registered to that prefix,
using the longest prefix match derivation to find the best 6LN.
9. Updating RFC 8928
Address-Protected Neighbor Discovery for Low-Power and Lossy Networks
[RFC8928] was defined to protect the ownership of unicast IPv6
addresses that are registered with [RFC8505].
With [RFC8928], it is possible for a node to autoconfigure a pair of
public and private keys and use them to sign the registration of
addresses that are either autoconfigured or obtained through other
methods.
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The first hop router (the 6LR) can then validate a registration and
perform source address validation on packets coming from the sender
node (the 6LN).
As multiple nodes may register the same prefix, the method specified
in [RFC8928] cannot be used with node-local autoconfigured keypairs,
which protect a single ownership only.
For a prefix, as for an anycast or a multicast address, it is still
possible to leverage [RFC8928] to enforce the right to register. If
[RFC8928] is used, a keypair MUST be created and associated with the
prefix before the prefix is deployed, and a ROVR MUST be generated
from that keypair as specified in [RFC8928]. The prefix and the ROVR
MUST then be installed in the 6LBR at the first registration, or by
an external mechanism such as IP Address Management (IPAM) or DHCPv6
snooping prior to the first registration. This way, the 6LBR can
recognize the prefix on the future registrations and validate the
right to register based on the ROVR.
The keypair MUST then be provisioned in each node that needs to
register the prefix or a prefix within, so the node can follow the
steps in [RFC8928] to register the prefix.
Upon receiving an NA message with the status set to 5 "Validation
Requested", the node that registered the address or prefix performs
the proof of ownership based on that longest prefix match.
10. Updating RFC 8929
"IPv6 Backbone Router" [RFC8929] defines a proxy operation whereby a
6LoWPAN Border Router (6LBR) may impersonate a 6LN when performing an
address registration. In that case, [RFC8505] messages are used as
is, with one change that the SLLAO in the proxied NS(EARO) messages
indicates the Registering Node (the 6LBR) as opposed to the
Registered Node (the 6LN). See figure 5 of [RFC8929] for an example
of proxy operation by the 6LBR, which generates an NS(EARO) upon
receiving an EDAR message.
This specification updates that proxy operation with the updates in
[RFC9685] and this on the formats and content of the EARO, the EDAR,
and the EDAC messages, to support the P-Field and the signaling of
prefixes. The proxy MUST use the P-Field as received in the EDAR or
NS(EARO) message to generate the proxied NS(EARO), and it MUST use
the exact same prefix and prefix length as received in the case of a
prefix registration.
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11. Security Considerations
This specification updates [RFC8505], and the security section of
that document also applies to this document. In particular, the link
layer SHOULD be sufficiently protected to prevent rogue access, else
a rogue node with physical Access to the network may inject packets
and perform an attack from within.
Section 9 leverages [RFC8928] to prevent a rogue node to register a
unicast address that it does not own. The mechanism could be
extended to anycast and multicast addresses if the values of the ROVR
they use are known in advance, but how this is done is not in scope
for this specification. One way would be to authorize in advance the
ROVR of the valid users. A less preferred way could be to
synchronize the ROVR and TID values across the valid registering
nodes as a preshared key material.
In the latter case, it could be possible to update the keys
associated to a prefix in all the 6LNs, but the flow is not clearly
documented and may not complete in due time for all nodes in LLN use
cases. It may be simpler to install an all-new address with new keys
over a period of time, and switch the traffic to that address when
the migration is complete.
12. Operational Considerations
12.1. Partially Upgraded Networks
A mix of devices that support only [RFC8505], both [RFC8505] and
[RFC9685], and all of the above plus this specification, may coexist.
Different cases may occur:
* A legacy 6LN will not register prefixes and the service will be
the same when the network is upgraded.
* A legacy 6LR will not set the F flag in the 6CIO and an upgraded
6LN will not register prefixes with that router, though it may
with other 6LRs that do support this specification.
* Upon an EDAR message, a legacy 6LBR may not realize that the
address being registered comes with a whole prefix, and return
that it is duplicate in the EDAC status. The 6LR MUST ignore a
duplicate status in the EDAR for prefixes.
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12.2. Application to RPL-Based Route-Over LLNs
This specification also updates [RFC6550] and [RFC9010] in the case
of a route-over multilink subnet based on the RPL routing protocol,
to add multicast ingress replication in Non-Storing Mode and anycast
support in both Storing and Non-Storing modes. A 6LR that implements
the RPL extensions specified therein MUST also implement [RFC9010].
Figure 5 illustrates the classical situation of an LLN as a single
IPv6 Subnet, with a 6LoWPAN Border Router (6LBR) that acts as Root
for RPL operations and as Address Registrar for 6LowPAN ND.
.- -- .
.-( ).
( Internet )
(___.________.___)
|
---+-------+--
|
+--------+
| 6LBR |
| (Root) |
+--------+
o o o o
o o o
o o o o o o
o o o LLN o +-------+
o o o | 6LR | RPL Router
o o o o +-------+
o o o o +-------+ RPL
o | 6LN | leaf
+-------+ L
o : LLN node
Figure 5: RPL-Based Route-Over LLN
A RPL leaf L acting as a 6LN registers its addresses and prefixes to
a RPL router acting as a 6LR, using a layer-2 unicast NS message with
an EARO as specified in [RFC8505] and [RFC9685]. Note that a RPL
leaf acting as 6LN may still be a border router for another routing
protocol, an access router for an IP link, or a virtual Router
serving virtual machines or applications within the same physical
node. Note also that a RPL-aware Leaf would preferably leverage RPL
directly to inject routes, to fully leverage the routing protocol.
The registration state is periodically renewed by the Registering
Node (the 6LN), before the lifetime indicated in the EARO expires (at
the 6LR). As for unicast IPv6 addresses, the 6LR uses an Extended
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Duplicate Address Request/Confirmation (EDAR/EDAC) exchange with the
6LBR to notify the 6LBR of the presence of the listeners. With this
specification, a router that owns a prefix or provides reachability
to an external prefix but is not a RPL router can also register those
prefixes with the R flag set, to enable reachability to the Prefix
within the RPL domain.
12.3. Application to a Shared Link
A shared link is a situation where more than one prefix is deployed
over a L2 link (say a switched Ethernet fabric, or a Wi-Fi Extended
Service Set (ESS) federating multiple Access Points (APs)), and not
necessarily all nodes are aware of all prefixes. Figure 6 depicts
such a situation, with 2 routers 6LR1 and 6LR2 that own respective
prefixes P1:: and P2::, and expose those in their RA messages over
the same link. Note that the shared link maybe operated with any
combination of NDP and SND as discussed in section 7 of
[I-D.ietf-6man-ipv6-over-wireless].
.- -- .
.-( ).
( Internet )
(___.________.___)
|
+----+--+ +-------+
| P1::a | | P2::b |
| 6LR1 | | 6LR2 |
+---+---+ +---+---+
| |
----+--+------+---------+-+-------+---------+----
| | | | |
+--+--+ +--+--+ +--+--+ +--+--+ +--+--+
|P1::c| |P2::d| |P2::e| |P1::f| |P1::g|
+-----+ +-----+ +-----+ +-----+ +-----+
Figure 6: Shared Link
Say that 6LR1 is the router providing access to the outside, and 6LR2
is aware of 6LR1 as its default gateway. With this specification,
6LR2 registers P2:: to 6LR1 and 6LR1 installs a route to P2:: via
6LR2. This way, addresses that derive from P2:: can still be reached
via 6LR1 and then 6LR2. 6LR2 may then leverage ICMP Redirect
messages [RFC4861] to shorten the path between 6LR1 and the nodes
that own those addresses.
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If P2 was delegated by 6LR1, e.g., using the "Dynamic Host
Configuration Protocol for IPv6" [RFC8415] (DHCPv6), then the
expectation is that 6LR1 aggregates P1:: and P2:: in its
advertisements to the outside, and there is no need to set the R
flag. But unless 6LR2 knows about such a situation, e.g., through
configuration, 6LR2 SHOULD set the R flag requesting 6LR1 to
advertise P2:: so as to obtain reachability.
12.4. Application to a Hub Link with Stub Spokes
A hub link is a situation where stub links are deployed around a
backbone and interconnected by routers. Figure 7 depicts such a
situation, with one router 6LR1 serving the hub link and at least one
router like 6LR2 and 6LR3 providing connectivity from the stub links
to the hub link. In this example, say that there is one prefix on
each link, P1:: on the hub link and P2:: and P3:: on the stub links.
+-----+ +-----+ +-----+ +-----+
|P2::s| |P2::d| |P2::e| |P2::f|
+--+--+ +--+--+ +--+--+ +--+--+
| | | |
----+----+----+---------+--STUB-LINK--+-----
|
+---+---+ +-------+
| P2::r | | | .- --..
| 6LR2 | | 6LR1 +---- .-( ).
| P1::b | | P1::a | ( Internet )
+---+---+ +---+---+ (___._______.___)
| | |
-------+-+---------+--HUB-LINK--+-----+-- |
| | | |
+---+---+ +--+--+ +---+---+ |
| P1::c | |P1::n| | P1::q | |
| 6LR3 | +-----+ | 6LR4 +----+
| P3::m | | P3::a |
+---+---+ +---+---+
| |
----+--+------+---------+--STUB-LINK--+-+-----
| | | |
+--+--+ +--+--+ +--+--+ +--+--+
|P3::h| |P3::i| |P3::j| |P3::k|
+-----+ +-----+ +-----+ +-----+
Figure 7: Hub and Stubs
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As before, say that 6LR1 is the router providing access to the
outside, and 6LR2 is aware of 6LR1 as its default gateway. With this
specification, 6LR2 registers P2:: to 6LR1 and 6LR1 installs a route
to P2:: via 6LR2. This way, nodes on the stub link behind 6LR2 that
derive their addresses from P2:: can still be reached via 6LR1 and
then 6LR2. The same goes for 6LR3 and any other routers serving stub
links.
If P2 was delegated by 6LR1, then the expectation is that 6LR1
aggregates P1:: and P2:: in its advertisements to the outside, and
there is no need to set the R flag. But unless 6LR2 knows about such
a situation, e.g., through configuration, 6LR2 SHOULD set the R flag
requesting 6LR1 to advertise P2:: so as to obtain reachability.
In this example, routers 6LR3 and 6LR4 both connect to the same stub
link where subnet P3 is installed. They may both register P3 to
6LR1, and 6LR1 will apply its own load balancing logic to use either
of the routers.
13. IANA Considerations
Note to RFC Editor, to be removed: please replace "This RFC"
throughout this document by the RFC number for this specification
once it is allocated.
IANA is requested to make changes under the "Internet Control Message
Protocol version 6 (ICMPv6) Parameters" [IANA.ICMP] and the "Routing
Protocol for Low Power and Lossy Networks (RPL)" [IANA.RPL] registry
groupings, as follows:
13.1. Updated P-Field Registry
This specification updates the P-Field introduced in [RFC9685] to
assign the value of 3, which is the only remaining unassigned value
for the 2-bit field. To that effect, IANA is requested to update the
"P-Field values" registry under the heading "Internet Control Message
Protocol version 6 (ICMPv6) Parameters" as indicated in Table 2:
+-------+---------------------------+-----------+
| Value | Meaning | Reference |
+-------+---------------------------+-----------+
| *3* | Registration for a prefix | This RFC |
+-------+---------------------------+-----------+
Table 2: New P-Field value
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13.2. New 6LoWPAN Capability Bit
IANA is requested to make an addition to the "6LoWPAN Capability
Bits" [IANA.ICMP.6CIO] registry under the heading "Internet Control
Message Protocol version 6 (ICMPv6) Parameters" as indicated in
Table 3:
IANA is also requested to fix the description of bit 9 (the "A" flag
defined in [RFC8928]). It is not called "1" but "A".
+------------------+---------------------------+-----------+
| Bit | Description | Reference |
+------------------+---------------------------+-----------+
| *9* | AP-ND Enabled (A bit) | [RFC8928] |
+------------------+---------------------------+-----------+
| *16 (suggested)* | Registration for prefixes | This RFC |
| | Supported (F bit) | |
+------------------+---------------------------+-----------+
Table 3: New 6LoWPAN Capability Bit
14. Acknowledgments
Many thanks to Dave Thaler and Dan Romascanu for their early reviews,
Adnan Rashid for all his contributions, and Eric Vyncke for his in-
depth AD review. Many thanks as well to the reviewers of the IETF
last call and IESG rounds, Shuping Peng, Mohamed Boucadair, Paul
Wouters, Ketan Talaulikar, Gunter Van de Velde, Mike Bishop, Roman
Danyliw, ...
15. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/info/rfc2119>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<https://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007,
<https://www.rfc-editor.org/info/rfc4862>.
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[RFC6550] Winter, T., Ed., Thubert, P., Ed., Brandt, A., Hui, J.,
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012,
<https://www.rfc-editor.org/info/rfc6550>.
[RFC6775] Shelby, Z., Ed., Chakrabarti, S., Nordmark, E., and C.
Bormann, "Neighbor Discovery Optimization for IPv6 over
Low-Power Wireless Personal Area Networks (6LoWPANs)",
RFC 6775, DOI 10.17487/RFC6775, November 2012,
<https://www.rfc-editor.org/info/rfc6775>.
[RFC7400] Bormann, C., "6LoWPAN-GHC: Generic Header Compression for
IPv6 over Low-Power Wireless Personal Area Networks
(6LoWPANs)", RFC 7400, DOI 10.17487/RFC7400, November
2014, <https://www.rfc-editor.org/info/rfc7400>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/info/rfc8174>.
[RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6
(IPv6) Specification", STD 86, RFC 8200,
DOI 10.17487/RFC8200, July 2017,
<https://www.rfc-editor.org/info/rfc8200>.
[RFC8505] Thubert, P., Ed., Nordmark, E., Chakrabarti, S., and C.
Perkins, "Registration Extensions for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Neighbor
Discovery", RFC 8505, DOI 10.17487/RFC8505, November 2018,
<https://www.rfc-editor.org/info/rfc8505>.
[RFC8928] Thubert, P., Ed., Sarikaya, B., Sethi, M., and R. Struik,
"Address-Protected Neighbor Discovery for Low-Power and
Lossy Networks", RFC 8928, DOI 10.17487/RFC8928, November
2020, <https://www.rfc-editor.org/info/rfc8928>.
[RFC8929] Thubert, P., Ed., Perkins, C.E., and E. Levy-Abegnoli,
"IPv6 Backbone Router", RFC 8929, DOI 10.17487/RFC8929,
November 2020, <https://www.rfc-editor.org/info/rfc8929>.
[RFC9010] Thubert, P., Ed. and M. Richardson, "Routing for RPL
(Routing Protocol for Low-Power and Lossy Networks)
Leaves", RFC 9010, DOI 10.17487/RFC9010, April 2021,
<https://www.rfc-editor.org/info/rfc9010>.
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Internet-Draft Prefix Registration July 2025
[RFC9685] Thubert, P., Ed., "Listener Subscription for IPv6 Neighbor
Discovery Multicast and Anycast Addresses", RFC 9685,
DOI 10.17487/RFC9685, November 2024,
<https://www.rfc-editor.org/info/rfc9685>.
[IANA.ICMP]
IANA, "IANA Registry for ICMPv6", IANA,
https://www.iana.org/assignments/icmpv6-parameters/
icmpv6-parameters.xhtml.
[IANA.ICMP.6CIO]
IANA, "IANA Registry for the 6LoWPAN Capability Bits",
IANA, https://www.iana.org/assignments/icmpv6-parameters/
icmpv6-parameters.xhtml#sixlowpan-capability-bits.
[IANA.RPL] IANA, "IANA Registry for the RPL",
IANA, https://www.iana.org/assignments/rpl/rpl.xhtml.
16. Informative References
[BCP38] Ferguson, P. and D. Senie, "Network Ingress Filtering:
Defeating Denial of Service Attacks which employ IP Source
Address Spoofing", BCP 38, RFC 2827, DOI 10.17487/RFC2827,
May 2000, <https://www.rfc-editor.org/info/rfc2827>.
[RFC4191] Draves, R. and D. Thaler, "Default Router Preferences and
More-Specific Routes", RFC 4191, DOI 10.17487/RFC4191,
November 2005, <https://www.rfc-editor.org/info/rfc4191>.
[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
Datagrams over IEEE 802.15.4-Based Networks", RFC 6282,
DOI 10.17487/RFC6282, September 2011,
<https://www.rfc-editor.org/info/rfc6282>.
[RFC8415] Mrugalski, T., Siodelski, M., Volz, B., Yourtchenko, A.,
Richardson, M., Jiang, S., Lemon, T., and T. Winters,
"Dynamic Host Configuration Protocol for IPv6 (DHCPv6)",
RFC 8415, DOI 10.17487/RFC8415, November 2018,
<https://www.rfc-editor.org/info/rfc8415>.
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[RFC9030] Thubert, P., Ed., "An Architecture for IPv6 over the Time-
Slotted Channel Hopping Mode of IEEE 802.15.4 (6TiSCH)",
RFC 9030, DOI 10.17487/RFC9030, May 2021,
<https://www.rfc-editor.org/info/rfc9030>.
[I-D.ietf-6man-ipv6-over-wireless]
Thubert, P. and M. Richardson, "Architecture and Framework
for IPv6 over Non-Broadcast Access", Work in Progress,
Internet-Draft, draft-ietf-6man-ipv6-over-wireless-08, 19
May 2025, <https://datatracker.ietf.org/doc/html/draft-
ietf-6man-ipv6-over-wireless-08>.
[IEEE802154]
IEEE standard for Information Technology, "IEEE Std
802.15.4, Part. 15.4: Wireless Medium Access Control (MAC)
and Physical Layer (PHY) Specifications for Low-Rate
Wireless Personal Area Networks".
[IEEE80211]
IEEE standard for Information Technology, "IEEE Standard
802.11 - IEEE Standard for Information Technology -
Telecommunications and information exchange between
systems Local and metropolitan area networks - Specific
requirements - Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications.",
<https://ieeexplore.ieee.org/document/9363693>.
[WI-SUN] "Wi-SUN Alliance", <https://wi-sun.org/>.
[IEEE802151]
IEEE standard for Information Technology, "IEEE Standard
for Information Technology - Telecommunications and
Information Exchange Between Systems - Local and
Metropolitan Area Networks - Specific Requirements. - Part
15.1: Wireless Medium Access Control (MAC) and Physical
Layer (PHY) Specifications for Wireless Personal Area
Networks (WPANs)".
Author's Address
Pascal Thubert (editor)
06330 Roquefort-les-Pins
France
Email: pascal.thubert@gmail.com
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