< draft-ietf-roll-turnon-rfc8138-07.txt   draft-ietf-roll-turnon-rfc8138-08.txt >
ROLL P. Thubert, Ed. ROLL P. Thubert, Ed.
Internet-Draft L. Zhao Internet-Draft L. Zhao
Updates: 6550, 8138 (if approved) Cisco Systems Updates: 8138 (if approved) Cisco Systems
Intended status: Standards Track 17 April 2020 Intended status: Standards Track 8 July 2020
Expires: 19 October 2020 Expires: 9 January 2021
A RPL Configuration Option for the 6LoWPAN Routing Header A RPL DODAG Configuration Option for the 6LoWPAN Routing Header
draft-ietf-roll-turnon-rfc8138-07 draft-ietf-roll-turnon-rfc8138-08
Abstract Abstract
This document updates RFC 8138 and RFC 6550 by defining a bit in the This document updates RFC 8138 and RFC 6550 by defining a bit in the
RPL configuration option to indicate whether RFC 8138 compression is RPL DODAG Configuration Option to indicate whether RFC 8138
used within the RPL Instance, and specify the behavior of RFC compression is used within the RPL Instance, and specify the behavior
8138-capable nodes when the bit is set and reset. of RFC 8138-capable nodes when the bit is set and reset.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/. Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on 19 October 2020. This Internet-Draft will expire on 9 January 2021.
Copyright Notice Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
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Please review these documents carefully, as they describe your rights Please review these documents carefully, as they describe your rights
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extracted from this document must include Simplified BSD License text extracted from this document must include Simplified BSD License text
as described in Section 4.e of the Trust Legal Provisions and are as described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Simplified BSD License. provided without warranty as described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. References . . . . . . . . . . . . . . . . . . . . . . . 3 2.1. References . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3. BCP 14 . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3. Requirements Language . . . . . . . . . . . . . . . . . . 4
3. Updating RFC 6550 . . . . . . . . . . . . . . . . . . . . . . 4 3. The RPL DODAG Configuration Option . . . . . . . . . . . . . 4
4. Updating RFC 8138 . . . . . . . . . . . . . . . . . . . . . . 4 4. Updating RFC 8138 . . . . . . . . . . . . . . . . . . . . . . 5
5. Transition Scenarios . . . . . . . . . . . . . . . . . . . . 5 5. Transition Scenarios . . . . . . . . . . . . . . . . . . . . 5
5.1. Inconsistent State While Migrating . . . . . . . . . . . 6 5.1. Coexistence . . . . . . . . . . . . . . . . . . . . . . . 6
5.2. Single RPL Instance Scenario . . . . . . . . . . . . . . 6 5.2. Inconsistent State While Migrating . . . . . . . . . . . 6
5.3. Double RPL Instances Scenario . . . . . . . . . . . . . . 7 5.3. Rolling Back . . . . . . . . . . . . . . . . . . . . . . 6
5.4. Rolling Back . . . . . . . . . . . . . . . . . . . . . . 8 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7. Security Considerations . . . . . . . . . . . . . . . . . . . 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 8
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 9. Normative References . . . . . . . . . . . . . . . . . . . . 8
9. Normative References . . . . . . . . . . . . . . . . . . . . 9 10. Informative References . . . . . . . . . . . . . . . . . . . 8
10. Informative References . . . . . . . . . . . . . . . . . . . 9 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10
1. Introduction 1. Introduction
The transition of a RPL [RFC6550] network to activate the compression The packet compression technique defined in [RFC8138] can only be
defined in [RFC8138] can only be done when all routers in the network activated in a RPL [RFC6550] network when all the nodes support it.
support it. Otherwise, a non-capable node acting as a router would Otherwise, a non-capable node acting as leaf-only would fail to
drop the compressed packets and black-hole its subDAG. In a mixed communicate, and acting as a router it would drop the compressed
case with both RFC8138-capable and non-capable nodes, the compression packets and black-hole a portion of the network.
may be turned on only if all the non-capable nodes act as Hosts and
their RPL parents handle the compression/decompression for them.
The original idea was to use a flag day but that proved impractical
in a number of situations such as a large metering network that is
used in production and incurs financial losses when interrupted.
This specification is designed for the scenario where a live network
is upgraded to support [RFC8138]. During the migration, the
compression should remain inactive, until all nodes are upgraded.
This document complements [RFC8138] and dedicates a flag in the RPL This document complements [RFC8138] and dedicates a flag in the RPL
configuration option to indicate whether [RFC8138] compression should DODAG Configuration Option to indicate whether the [RFC8138]
be used within the RPL Instance. The setting of this new flag is compression should be used within the RPL DODAG.
controlled by the Root and propagates as is in the whole network.
When the bit is not set, source nodes that support [RFC8138] should
refrain from using the compression unless the information is
superseded by configuration.
With RPL, a leaf is an IPv6 Host, which implies that leaves do not The setting of this new flag is controlled by the Root and propagates
forward packets. This specification provides scenarios that force a as is in the whole network as part of the normal RPL signaling.
non-capable RPL-Aware Node (RAN) to become a leaf. The parent router
must know, e.g., by configuration, or leveraging "RPL Capabilities" The idea is to use the flag to maintain the compression inactive
[CAPABILITIES], when a leaf does not support the compression defined during the migration phase. When the migration is complete (e.g., as
in [RFC8138]. This is implicitly the case for a RPL-Unaware Leaf known by network management and/or inventory), the flag is set and
(RUL) but is not known for a RPL-Aware Leaf (RAL). The parent router the compression is globally activated in the whole DODAG.
must uncompress the packets before delivering them to a non-capable
leaf and it must compress the traffic from the leaf.
2. Terminology 2. Terminology
2.1. References 2.1. References
The Terminology used in this document is consistent with and The Terminology used in this document is consistent with and
incorporates that described in "Terms Used in Routing for Low-Power incorporates that described in "Terms Used in Routing for Low-Power
and Lossy Networks (LLNs)" [RFC7102]. Other terms in use in LLNs are and Lossy Networks (LLNs)" [RFC7102]. Other terms in use in LLNs are
found in "Terminology for Constrained-Node Networks" [RFC7228]. found in "Terminology for Constrained-Node Networks" [RFC7228].
skipping to change at page 4, line 5 skipping to change at page 4, line 5
RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks
OF: RPL Objective Function OF: RPL Objective Function
OCP: RPL Objective Code Point OCP: RPL Objective Code Point
MOP: RPL Mode of Operation MOP: RPL Mode of Operation
RPI: RPL Packet Information RPI: RPL Packet Information
RAL: RPL-Aware Leaf RAL: RPL-Aware Leaf
RAN: RPL-Aware Node RAN: RPL-Aware Node
RUL: RPL-Unaware Leaf RUL: RPL-Unaware Leaf
SRH: Source Routing Header SRH: Source Routing Header
2.3. BCP 14 2.3. Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "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.
3. Updating RFC 6550 3. The RPL DODAG Configuration Option
The DODAG Configuration Option is defined in Section 6.7.6 of
[RFC6550].
The RPL DODAG Configuration Option is typically placed in a DODAG
Information Object (DIO) message. The DIO message propagates down
the DODAG to form and then maintain its structure. The DODAG
Configuration Option is copied unmodified from parents to children.
As shown in Figure 1, the DODAG Configuration Option was designed
with 4 bit positions reserved for future use as Flags.
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 = 0x04 |Opt Length = 14| Flags |A| ... |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| ... |
Figure 1: DODAG Configuration Option (Partial View)
This specification defines a new flag "Enable RFC8138 Compression" This specification defines a new flag "Enable RFC8138 Compression"
(T). The "T" flag is set to turn on the use of the compression of (T). The "T" flag is set to turn-on the use of the compression of
RPL artifacts with [RFC8138] within a RPL Instance. If a RPL RPL artifacts with [RFC8138] within the DODAG. The new "T" flag is
Instance has multiple Roots then they must be coordinated to use the encoded in one of the reserved bits in the RPL DODAG Configuration
same setting. Option. The suggested bit position of the "T" flag is indicated in
Section 6.
RPL defines a Configuration Option that is registered to IANA in /[RFC6550] states, [RFC6550] states, when referring to the DODAG
section 20.14. of [RFC6550]. The "T" flag is encoded in one of the Configuration Option, that "Nodes other than the DODAG Root MUST NOT
reserved control bits in the RPL Configuration Option. The bit modify this information when propagating the DODAG Configuration
position of the "T" flag is indicated in Section 6. option". Therefore, even a legacy parent propagates the "T" flag as
set by the Root whether it supports this specification or not. So
when the "T" flag is set, it is transparently flooded to all the
nodes in the DODAG.
Section 6.3.1. of [RFC6550] defines a 3-bit Mode of Operation (MOP) Section 6.3.1. of [RFC6550] defines a 3-bit Mode of Operation (MOP)
in the DIO Base Object. The new "T" flag is defined only for MOP in the DIO Base Object. The new "T" flag is defined only for MOP
value between 0 to 6. For a MOP value of 7 or above, the flag MAY value between 0 to 6.
indicate something different and MUST NOT be interpreted as "Enable
RFC8138 Compression" unless the specification of the MOP indicates to
do so.
4. Updating RFC 8138 4. Updating RFC 8138
A node that supports this specification MUST source packets in the A node SHOULD source packets in the compressed form using [RFC8138]
compressed form using [RFC8138] if and only if the "T" flag is set. if and only if the "T" flag is set. This behaviour can be overridden
This behaviour can be overridden by the configuration of the node in by e.g., configuration or network management. Overriding may be
order to cope with intermediate implementations of the Root that needed e.g., to cope with a legacy implementations of the Root that
support [RFC8138] but not this specification and cannot set the "T" supports [RFC8138] but not this specification and cannot set the "T"
flag. flag.
The decision of using [RFC8138] is made by the originator of the The decision of using [RFC8138] is made by the originator of the
packet depending on its capabilities and its knowledge of the state packet depending on its capabilities and its knowledge of the state
of the "T" flag. A router that encapsulates a packet is the of the "T" flag. A router that encapsulates a packet is the
originator of the resulting packet and decides whether to compress originator of the resulting packet and is responsible to compress the
the outer headers as indicated above. An external target outer headers with [RFC8138], but it MUST leave the encapsulated
[USEofRPLinfo] is not expected to support [RFC8138]. An intermediate packet as is.
router MUST forward the packet in the form that the source used,
either compressed or uncompressed, unless it is forwarding to an An external target [USEofRPLinfo] is not expected to support
external target or delivering to a leaf that is not known to support [RFC8138]. In most cases, packets from/to an external target are
[RFC8138], in which cases it MUST uncompress the packet. tunneled back and forth between the RPL border router and the Root
regardless of the MOP used in the RPL DODAG. The inner packet is
typically not compressed with [RFC8138] so the 6LR just needs to
decapsulate the (compressed) outer header and forward the
(uncompressed) inner packet towards the external target.
A router MUST uncompress a packet that is to be forwarded to an
external target. Otherwise, the router MUST forward the packet in
the form that the source used, either compressed or uncompressed.
A RUL [UNAWARE-LEAVES] is both a leaf and an external target . A RUL
does not participate in RPL and depends on the parent router to
obtain connectivity. In the case of a RUL, forwarding towards an
external target actually means delivering the packet.
5. Transition Scenarios 5. Transition Scenarios
A node that supports [RFC8138] but not this specification can only be A node that supports [RFC8138] but not this specification can only be
used in an homogeneous network. Enabling the [RFC8138] compression used in an homogeneous network. Enabling the [RFC8138] compression
requires a "flag day"; all nodes must be upgraded, and then the requires a "flag day"; all nodes must be upgraded, and then the
network can be rebooted with the [RFC8138] compression turned on. network can be rebooted with the [RFC8138] compression turned on.
A node that supports this specification can work in a network with
[RFC8138] compression turned on or off with the "T" flag set
accordingly and in a network in transition from off to on or on to
off (see Section 5.1).
A node that does not support [RFC8138] can interoperate with nodes
that do in a network with [RFC8138] compression turned off. If the
compression is turned on, the node cannot forward compressed packets
and therefore it cannot act as a router. It may remain connected to
that network as a leaf, generates uncompressed packets, and can
receive packets if they are delivered by the parent router in the
uncompressed form. Unless this is known by other means, the node
SHOULD join as a RUL as an indication that its parent router needs to
uncompress the packets before delivering.
[RFC6550] states that "Nodes other than the DODAG Root MUST NOT
modify this information when propagating the DODAG Configuration
option". Therefore, even a legacy parent propagates the "T" flag as
set by the Root whether it supports this specification or not. So
when the "T" flag is set, it is transparently flooded to all the
nodes in the RPL Instance.
Sections 8.5 and 9.2 of [RFC6550] also suggests that a RAN may only
attach to a DODAG as a leaf when it does not support the Mode of
Operation of a RPL Instance, the Objective Function (OF) as indicated
by the Objective Code Point (OCP) or some other parameters in the
configuration option.
This specification reiterates that a RAN that is configured to
operate in a RPL Instance but does not support a value for a known
parameter that is mandatory for routing, such as the OCP, MUST NOT
operate as a router but MAY still join as a leaf. Note that a legacy
RAN will not recognize when a reserved field is used and will not
turn to a leaf when the "T" flag is set.
The intent for this specification is to perform a migration once and The intent for this specification is to perform a migration once and
for all without the need for a flag day. In particular it is not the for all without the need for a flag day. In particular it is not the
intention to undo the setting of the "T" flag, and though it is intention to undo the setting of the "T" flag. Though it is possible
possible to roll back (see Section 5.4), adding nodes that do not to roll back (see Section 5.3), adding nodes that do not support
support [RFC8138] after a roll back may be problematic if the roll [RFC8138] after a roll back may be problematic if the roll back did
back is not fully complete (see caveats in Section 5.2). not fully complete.
5.1. Inconsistent State While Migrating
When the "T" flag is turned on in the configuration option by the
Root, the information slowly percolates through the DODAG as the DIO
gets propagated.
Some nodes will see the flag and start sourcing packets in the
compressed form while other nodes in the same RPL Instance are still
not aware of it. Conversely, in non-storing mode, the Root will
start using [RFC8138] with a Source Routing Header 6LoRH (SRH-6LoRH)
that routes all the way to the parent router or to the leaf.
To ensure that a packet is forwarded across the RPL Instance in the
form in which it was generated, it is required that all the routers
support [RFC8138] at the time of the switch, and that all nodes that
do not support [RFC8138] only operate as leaves.
Setting the "T" flag is ultimately the responsibility of the network
administrator. In a case of upgrading a network to turn the
compression on, the network SHOULD be operated with the "T" flag
reset until all targeted nodes are upgraded to support this
specification. Section 5.2 and Section 5.3 provide possible
transition scenarios where this can be enforced.
5.2. Single RPL Instance Scenario
In a Single RPL Instance Scenario, nodes that support [RFC8138] are
configured with a new OCP, that may use the same OF operation or a
variation of it, while nodes that do not support [RFC8138] are not,
but are configured to join an unknown OCP.
The Root migrates to the new OCP before it sets the "T" flag, so that
nodes that do not support [RFC8138] are all attached as leaves when
the "T" flag is eventually set.
The parent router - which supports [RFC8138] - compresses the packets
originated from the leaf and uncompresses the packets going to the
leaf. This may be done on the fly by the parent of a non-capable
RAL, or as part of the tunneling operation between the parent and the
Root, if the leaf behaves as a RUL. This is described in section 7,
8, and 9 of [USEofRPLinfo].
Note that though tunneling from the Root to the parent is the generic
case for RULs, on paper it is possible for the Root to avoid it for
the traffic that it originates. The Root SHOULD always use tunneling
to the parent of a RUL, even for its own packets, unless it knows
that the leaf supports [RFC8138].
This scenario presents a number of caveats:
* The method consumes an extra OCP. It also forces nodes that do
not support [RFC8138] to operate as RULs, unless there is a method
to let the parent router know that it must uncompress the packet
for this RAL.
* If the RPL implementation of a node does not turn it to a leaf
when the OCP is changed to an unknown one, then the node may be
stalled.
* If the only possible parents of a node are nodes that do not 5.1. Coexistence
support [RFC8138], then that node will loose all its parent at the
time of the migration and it will be stalled until a parent is
deployed with the new capability.
5.3. Double RPL Instances Scenario A node that supports this specification can operate in a network with
the [RFC8138] compression turned on or off with the "T" flag set
accordingly and in a network in transition from off to on or on to
off (see Section 5.2).
An alternative to the Single RPL Instance Scenario is to deploy an A node that does not support [RFC8138] can interoperate with nodes
additional RPL Instance for the nodes that support [RFC8138]. that do in a network with [RFC8138] compression turned off. If the
compression is turned on, all the RPL-Aware Nodes are expected to be
able to handle compressed packets in the compressed form. A node
that cannot do so may remain connected to the network as a RUL, but
how the node is modified to turn into a RUL is out of scope.
The two RPL Instances operate independently as specified in 5.2. Inconsistent State While Migrating
[RFC6550]. The preexisting RPL Instance does not use [RFC8138],
whereas the new RPL Instance does. This is signaled by the "T" flag
which is only set in the configuration option in DIO messages in the
new RPL Instance.
Nodes that support [RFC8138] participate in both Instances but favor When the "T" flag is turned on by the Root, the information slowly
the new RPL Instance for the traffic that they source. By contrast, percolates through the DODAG as the DIO gets propagated. Some nodes
nodes that only support the uncompressed format would either not be will see the flag and start sourcing packets in the compressed form
configured for the new RPL Instance, or would be configured to join while other nodes in the same RPL DODAG are still not aware of it.
it as leaves only. Conversely, in non-storing mode, the Root will start using [RFC8138]
with a Source Routing Header 6LoRH (SRH-6LoRH) that routes all the
way to the parent router or to the leaf.
This method eliminates the risks of nodes being stalled that are To ensure that a packet is forwarded across the RPL DODAG in the form
described in Section 5.2 but requires implementations to support at in which it was generated, it is required that all the RPL nodes
least two RPL Instances and demands management capabilities to support [RFC8138] at the time of the switch.
introduce new RPL Instances and deprecate old ones.
The 2 instances MUST be operated with the same security guarantees, Setting the "T" flag is ultimately the responsibility of the Network
e.g., both "unsecured" with a lower layer security of a same Administrator. The expectation is that the network management or
strength, both "preinstalled" or both "authenticated" security mode upgrading tools in place enable the Network Administrator to know
(see section 3.2.3 of [RFC6550] for more details on those modes). when all the nodes that may join a DODAG were migrated. In the case
The latter mode could be use to enforce the segregation of updated of a RPL instance with multiple Roots, all nodes that participate to
and non-updated nodes, by providing the keys for joining as routers the RPL Instance may potentially join any DODAG. The network MUST be
to the updated nodes only. operated with the "T" flag reset until all nodes in the RPL Instance
are upgraded to support this specification.
5.4. Rolling Back 5.3. Rolling Back
After downgrading a network to turn the [RFC8138] compression off, When turning [RFC8138] compression off in the network, the Network
the administrator SHOULD make sure that all nodes have converged to Administrator MUST wait until all nodes have converged to the "T"
the "T" flag reset before allowing nodes that do not support the flag reset before allowing nodes that do not support the compression
compression in the network (see caveats in Section 5.2). in the network.
It is RECOMMENDED to only deploy nodes that support [RFC8138] in a It is RECOMMENDED to only deploy nodes that support [RFC8138] in a
network where the compression is turned on. A node that does not network where the compression is turned on. A node that does not
support [RFC8138] MUST only be used as a leaf. support [RFC8138] MUST only be used as a RUL.
6. IANA Considerations 6. IANA Considerations
This specification updates the Registry for the "DODAG Configuration IANA is requested to assign a new option flag from the Registry for
Option Flags" that was created for [RFC6550] as follows: the "DODAG Configuration Option Flags" that was created for [RFC6550]
as follows:
+------------+---------------------------------+-----------+ +---------------+---------------------------------+-----------+
| Bit Number | Capability Description | Reference | | Bit Number | Capability Description | Reference |
+============+=================================+===========+ +---------------+---------------------------------+-----------+
| 2 | Turn on RFC8138 Compression (T) | THIS RFC | | 2 (suggested) | Turn on RFC8138 Compression (T) | THIS RFC |
+------------+---------------------------------+-----------+ +---------------+---------------------------------+-----------+
Table 1: New DODAG Configuration Option Flag Table 1: New DODAG Configuration Option Flag
The DODAG Configuration Option Flags defined so far will be obsolete
for RPL Mode of Operation (MOP) above and including 7.
IANA is requested to update the name of the Registry from "DODAG
Configuration Option Flags" to "DODAG Configuration Option Flags for
RPL MOP 0..6".
When MOP values of 7 and more are defined, a new registry will be
needed.
7. Security Considerations 7. Security Considerations
First of all, it is worth noting that with [RFC6550], every node in First of all, it is worth noting that with [RFC6550], every node in
the LLN that is RPL-aware can inject any RPL-based attack in the the LLN that is RPL-aware can inject any RPL-based attack in the
network. A trust model MUST be put in place so that rogue nodes are network. A trust model has to be put in place in an effort to
excluded from participating to the RPL and the 6LowpAN signaling, and exclude rogue nodes from participating to the RPL and the 6LoWPAN
from the data packet exchange. This trust model could be at a signaling, as well as from the data packet exchange. This trust
minimum based on a Layer-2 Secure joining and the Link-Layer model could be at a minimum based on a Layer-2 Secure joining and the
security. This is a generic RPL and 6LoWPAN requirement, see Req5.1 Link-Layer security. This is a generic RPL and 6LoWPAN requirement,
in Appendix of [RFC8505]. see Req5.1 in Appendix of [RFC8505].
Setting the "T" flag before some routers are upgraded may cause a Setting the "T" flag before all routers are upgraded may cause a loss
loss of packets. The new bit is protected as the rest of the of packets. The new bit is protected as the rest of the
configuration so this is just one of the many attacks that can happen configuration so this is just one of the many attacks that can happen
if an attacker manages to inject a corrupted configuration. if an attacker manages to inject a corrupted configuration.
Setting and resetting the "T" flag may create inconsistencies in the Setting and resetting the "T" flag may create inconsistencies in the
network but as long as all nodes are upgraded to [RFC8138] support network but as long as all nodes are upgraded to [RFC8138] support
they will be able to forward both forms. The source is responsible they will be able to forward both forms. The source is responsible
for selecting whether the packet is compressed or not, and all for selecting whether the packet is compressed or not, and all
routers must use the format that the source selected. So the result routers must use the format that the source selected. So the result
of an inconsistency is merely that both forms will be present in the of an inconsistency is merely that both forms will be present in the
network, at an additional cost of bandwidth for packets in the network, at an additional cost of bandwidth for packets in the
uncompressed form. uncompressed form.
8. Acknowledgments 8. Acknowledgments
The authors wish to thank Dominique Barthel and Rahul Jadhav for The authors wish to thank Alvaro Retana, Dominique Barthel and Rahul
their in-depth reviews and constructive suggestions. Jadhav for their in-depth reviews and constructive suggestions.
Also many thanks to Michael Richardson for being always helpful and
responsive when need comes.
9. Normative References 9. 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>.
[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,
skipping to change at page 9, line 32 skipping to change at page 8, line 35
Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur, Kelsey, R., Levis, P., Pister, K., Struik, R., Vasseur,
JP., and R. Alexander, "RPL: IPv6 Routing Protocol for JP., and R. Alexander, "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks", RFC 6550, Low-Power and Lossy Networks", RFC 6550,
DOI 10.17487/RFC6550, March 2012, DOI 10.17487/RFC6550, March 2012,
<https://www.rfc-editor.org/info/rfc6550>. <https://www.rfc-editor.org/info/rfc6550>.
[RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and [RFC7102] Vasseur, JP., "Terms Used in Routing for Low-Power and
Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January Lossy Networks", RFC 7102, DOI 10.17487/RFC7102, January
2014, <https://www.rfc-editor.org/info/rfc7102>. 2014, <https://www.rfc-editor.org/info/rfc7102>.
[RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for [RFC8138] Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie,
Constrained-Node Networks", RFC 7228, "IPv6 over Low-Power Wireless Personal Area Network
DOI 10.17487/RFC7228, May 2014, (6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138,
<https://www.rfc-editor.org/info/rfc7228>. April 2017, <https://www.rfc-editor.org/info/rfc8138>.
[USEofRPLinfo]
Robles, I., Richardson, M., and P. Thubert, "Using RPI
Option Type, Routing Header for Source Routes and IPv6-in-
IPv6 encapsulation in the RPL Data Plane", Work in
Progress, Internet-Draft, draft-ietf-roll-useofrplinfo-38,
23 March 2020, <https://tools.ietf.org/html/draft-ietf-
roll-useofrplinfo-38>.
[UNAWARE-LEAVES]
Thubert, P. and M. Richardson, "Routing for RPL Leaves",
Work in Progress, Internet-Draft, draft-ietf-roll-unaware-
leaves-14, 11 April 2020, <https://tools.ietf.org/html/
draft-ietf-roll-unaware-leaves-14>.
10. Informative References 10. Informative References
[RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low- [RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low-
Power and Lossy Networks (RPL) Option for Carrying RPL Power and Lossy Networks (RPL) Option for Carrying RPL
Information in Data-Plane Datagrams", RFC 6553, Information in Data-Plane Datagrams", RFC 6553,
DOI 10.17487/RFC6553, March 2012, DOI 10.17487/RFC6553, March 2012,
<https://www.rfc-editor.org/info/rfc6553>. <https://www.rfc-editor.org/info/rfc6553>.
[RFC8138] Thubert, P., Ed., Bormann, C., Toutain, L., and R. Cragie, [RFC7228] Bormann, C., Ersue, M., and A. Keranen, "Terminology for
"IPv6 over Low-Power Wireless Personal Area Network Constrained-Node Networks", RFC 7228,
(6LoWPAN) Routing Header", RFC 8138, DOI 10.17487/RFC8138, DOI 10.17487/RFC7228, May 2014,
April 2017, <https://www.rfc-editor.org/info/rfc8138>. <https://www.rfc-editor.org/info/rfc7228>.
[RFC8505] Thubert, P., Ed., Nordmark, E., Chakrabarti, S., and C. [RFC8505] Thubert, P., Ed., Nordmark, E., Chakrabarti, S., and C.
Perkins, "Registration Extensions for IPv6 over Low-Power Perkins, "Registration Extensions for IPv6 over Low-Power
Wireless Personal Area Network (6LoWPAN) Neighbor Wireless Personal Area Network (6LoWPAN) Neighbor
Discovery", RFC 8505, DOI 10.17487/RFC8505, November 2018, Discovery", RFC 8505, DOI 10.17487/RFC8505, November 2018,
<https://www.rfc-editor.org/info/rfc8505>. <https://www.rfc-editor.org/info/rfc8505>.
[CAPABILITIES] [UNAWARE-LEAVES]
Jadhav, R., Thubert, P., Richardson, M., and R. Sahoo, Thubert, P. and M. Richardson, "Routing for RPL Leaves",
"RPL Capabilities", Work in Progress, Internet-Draft, Work in Progress, Internet-Draft, draft-ietf-roll-unaware-
draft-ietf-roll-capabilities-02, 11 March 2020, leaves-18, 12 June 2020, <https://tools.ietf.org/html/
<https://tools.ietf.org/html/draft-ietf-roll-capabilities- draft-ietf-roll-unaware-leaves-18>.
02>.
[USEofRPLinfo]
Robles, I., Richardson, M., and P. Thubert, "Using RPI
Option Type, Routing Header for Source Routes and IPv6-in-
IPv6 encapsulation in the RPL Data Plane", Work in
Progress, Internet-Draft, draft-ietf-roll-useofrplinfo-40,
25 June 2020, <https://tools.ietf.org/html/draft-ietf-
roll-useofrplinfo-40>.
Authors' Addresses Authors' Addresses
Pascal Thubert (editor) Pascal Thubert (editor)
Cisco Systems, Inc Cisco Systems, Inc
Building D Building D
45 Allee des Ormes - BP1200 45 Allee des Ormes - BP1200
06254 MOUGINS - Sophia Antipolis 06254 MOUGINS - Sophia Antipolis
France France
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