wdiff draft-ietf-roll-turnon-rfc8138-07.txt draft-ietf-roll-turnon-rfc8138-08.txt

ROLL P. Thubert, Ed.
Internet-Draft L. Zhao
Updates: 6550, 8138 (if approved) Cisco Systems
Intended status: Standards Track 17 April 8 July 2020
Expires: 19 October 2020 9 January 2021

A RPL DODAG Configuration Option for the 6LoWPAN Routing Header
draft-ietf-roll-turnon-rfc8138-07
draft-ietf-roll-turnon-rfc8138-08

Abstract

This document updates RFC 8138 and RFC 6550 by defining a bit in the
RPL configuration option DODAG Configuration Option to indicate whether RFC 8138
compression is used within the RPL Instance, and specify the behavior
of RFC 8138-capable nodes when the bit is set and reset.

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
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This Internet-Draft will expire on 19 October 2020. 9 January 2021.

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Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
2.1. References . . . . . . . . . . . . . . . . . . . . . . . 3
2.2. Glossary . . . . . . . . . . . . . . . . . . . . . . . . 3
2.3. BCP 14 . . . . . . . Requirements Language . . . . . . . . . . . . . . . . . . 4
3. Updating RFC 6550 . . . . . . . . . The RPL DODAG Configuration Option . . . . . . . . . . . . . 4
4. Updating RFC 8138 . . . . . . . . . . . . . . . . . . . . . . 4 5
5. Transition Scenarios . . . . . . . . . . . . . . . . . . . . 5
5.1. Inconsistent State While Migrating Coexistence . . . . . . . . . . . 6
5.2. Single RPL Instance Scenario . . . . . . . . . . . . . . 6
5.3. Double RPL Instances Scenario . . .
5.2. Inconsistent State While Migrating . . . . . . . . . . . 7
5.4. 6
5.3. Rolling Back . . . . . . . . . . . . . . . . . . . . . . 8 6
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 8 7
7. Security Considerations . . . . . . . . . . . . . . . . . . . 8 7
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 9 8
9. Normative References . . . . . . . . . . . . . . . . . . . . 9 8
10. Informative References . . . . . . . . . . . . . . . . . . . 9 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 10 9

1. Introduction

The transition of a RPL [RFC6550] network to activate the packet compression technique defined in [RFC8138] can only be done
activated in a RPL [RFC6550] network when all routers in the network nodes support it.
Otherwise, a non-capable node acting as leaf-only would fail to
communicate, and acting as a router it would drop the compressed
packets and black-hole its subDAG. In a mixed
case with both RFC8138-capable portion of the network.

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 non-capable nodes, 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
may be turned on only if should remain inactive, until all the non-capable nodes act as Hosts and
their RPL parents handle the compression/decompression for them. are upgraded.
This document complements [RFC8138] and dedicates a flag in the RPL
configuration option
DODAG Configuration Option to indicate whether the [RFC8138]
compression should be used within the RPL Instance. DODAG.

The setting of this new flag is controlled by the Root and propagates
as is in the whole network.
When network as part of the bit normal RPL signaling.

The idea is not set, source nodes that support [RFC8138] should
refrain from using the compression unless to use the information is
superseded by configuration.

With RPL, a leaf is an IPv6 Host, which implies that leaves do not
forward packets. This specification provides scenarios that force a
non-capable RPL-Aware Node (RAN) flag to become a leaf. The parent router
must know, e.g., by configuration, or leveraging "RPL Capabilities"
[CAPABILITIES], when a leaf does not support maintain the compression defined
in [RFC8138]. This is implicitly inactive
during the case for a RPL-Unaware Leaf
(RUL) but migration phase. When the migration is not complete (e.g., as
known for a RPL-Aware Leaf (RAL). The parent router
must uncompress by network management and/or inventory), the packets before delivering them to a non-capable
leaf flag is set and it must compress
the traffic from compression is globally activated in the leaf. whole DODAG.

2. Terminology

2.1. References

The Terminology used in this document is consistent with and
incorporates that described in "Terms Used in Routing for Low-Power
and Lossy Networks (LLNs)" [RFC7102]. Other terms in use in LLNs are
found in "Terminology for Constrained-Node Networks" [RFC7228].

"RPL", the "RPL Packet Information" (RPI), "RPL Instance" (indexed by
a RPLInstanceID) are defined in "RPL: IPv6 Routing Protocol for
Low-Power and Lossy Networks" [RFC6550]. The RPI is the abstract
information that RPL defines to be placed in data packets, e.g., as
the RPL Option [RFC6553] within the IPv6 Hop-By-Hop Header. By
extension the term "RPI" is often used to refer to the RPL Option
itself. The DODAG Information Solicitation (DIS), Destination
Advertisement Object (DAO) and DODAG Information Object (DIO)
messages are also specified in [RFC6550].

This document uses the terms RPL-Unaware Leaf (RUL) and RPL Aware
Leaf (RAL) consistently with "Using RPI Option Type, Routing Header
for Source Routes and IPv6-in-IPv6 encapsulation in the RPL Data
Plane" [USEofRPLinfo]. The term RPL-Aware Node (RAN) refers to a
node that is either a RAL or a RPL Router. A RAN manages the
reachability of its addresses and prefixes by injecting them in RPL
by itself. In contrast, a RUL leverages "Registration Extensions for
IPv6 over Low-Power Wireless Personal Area Network (6LoWPAN) Neighbor
Discovery" [RFC8505] to obtain reachability services from its parent
router(s) as specified in "Routing for RPL Leaves" [UNAWARE-LEAVES].

2.2. Glossary

This document often uses the following acronyms:

6LoWPAN: IPv6 over Low-Power Wireless Personal Area Network
6LoRH: 6LoWPAN Routing Header
DIO: DODAG Information Object (a RPL message)
DODAG: Destination-Oriented Directed Acyclic Graph
LLN: Low-Power and Lossy Network
RPL: IPv6 Routing Protocol for Low-Power and Lossy Networks
OF: RPL Objective Function
OCP: RPL Objective Code Point
MOP: RPL Mode of Operation
RPI: RPL Packet Information
RAL: RPL-Aware Leaf
RAN: RPL-Aware Node
RUL: RPL-Unaware Leaf
SRH: Source Routing Header

2.3. BCP 14 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.

3. Updating RFC 6550 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"
(T). The "T" flag is set to turn on turn-on the use of the compression of
RPL artifacts with [RFC8138] within a RPL Instance. If a RPL
Instance has multiple Roots then they must be coordinated to use the
same setting.

RPL defines a Configuration Option that is registered to IANA in
section 20.14. of [RFC6550]. DODAG. The new "T" flag is
encoded in one of the reserved control bits in the RPL DODAG Configuration
Option. The suggested bit position of the "T" flag is indicated in
Section 6.

/[RFC6550] states, [RFC6550] states, when referring to the DODAG
Configuration Option, 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 DODAG.

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
value between 0 to 6. For a MOP value of 7 or above, the flag MAY
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

A node that supports this specification MUST SHOULD source packets in the compressed form using [RFC8138]
if and only if the "T" flag is set. This behaviour can be overridden
by the e.g., configuration of the node in
order or network management. Overriding may be
needed e.g., to cope with intermediate a legacy implementations of the Root that
support
supports [RFC8138] but not this specification and cannot set the "T"
flag.

The decision of using [RFC8138] is made by the originator of the
packet depending on its capabilities and its knowledge of the state
of the "T" flag. A router that encapsulates a packet is the
originator of the resulting packet and decides whether is responsible to compress the
outer headers with [RFC8138], but it MUST leave the encapsulated
packet as indicated above. is.

An external target [USEofRPLinfo] is not expected to support
[RFC8138]. An intermediate In most cases, packets from/to an external target are
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, unless it uncompressed.

A RUL [UNAWARE-LEAVES] is forwarding to both a leaf and an external target or delivering to a leaf that is . A RUL
does not known to support
[RFC8138], participate in which cases it MUST uncompress 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

A node that supports [RFC8138] but not this specification can only be
used in an homogeneous network. Enabling the [RFC8138] compression
requires a "flag day"; all nodes must be upgraded, and then the
network can be rebooted with the [RFC8138] compression turned on.

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
intention to undo the setting of the "T" flag. Though it is possible
to roll back (see Section 5.3), adding nodes that do not support
[RFC8138] after a roll back may be problematic if the roll back did
not fully complete.

5.1. Coexistence

A node that supports this specification can work 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 5.1). 5.2).

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, all the node cannot forward compressed packets
and therefore it cannot act as a router. It may remain connected RPL-Aware Nodes are expected to
that network as a leaf, generates uncompressed packets, and can
receive be
able to handle compressed packets if they are delivered by the parent router in the
uncompressed compressed form. Unless this is known by other means, the A 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 cannot do so 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 remain connected 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 network as a router RUL, 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
how the "T" flag is set.

The intent for this specification node is modified to perform a migration once and
for all without the need for turn into a flag day. In particular it RUL is not the
intention to undo the setting out of the "T" flag, and though it is
possible to roll back (see Section 5.4), adding nodes that do not
support [RFC8138] after a roll back may be problematic if the roll
back is not fully complete (see caveats in Section 5.2).

5.1. scope.

5.2. 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 DODAG 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 DODAG in the form
in which it was generated, it is required that all the routers RPL nodes
support [RFC8138] at the time of the switch, and that all nodes that
do not support [RFC8138] only operate as leaves. switch.

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. Network
Administrator. 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 expectation 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 that the parent of a non-capable
RAL, network management or as part of the tunneling operation between the parent and the
Root, if the leaf behaves as a RUL. This is described
upgrading tools 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 place enable 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 Network Administrator 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 all 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
support [RFC8138], then that node will loose all its parent at may join a DODAG were migrated. In the
time case
of the migration and it will be stalled until a parent is
deployed with the new capability.

5.3. Double RPL Instances Scenario

An alternative to the Single RPL Instance Scenario is to deploy an
additional RPL Instance for the instance with multiple Roots, all nodes that support [RFC8138].

The two RPL Instances operate independently as specified in
[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 to
the new RPL Instance for the traffic that they source. By contrast,
nodes that only support the uncompressed format would either not be
configured for the new RPL Instance, or would be configured to may potentially join
it as leaves only.

This method eliminates the risks of nodes being stalled that are
described in Section 5.2 but requires implementations to support at
least two RPL Instances and demands management capabilities to
introduce new RPL Instances and deprecate old ones. any DODAG. The 2 instances network MUST be
operated with the same security guarantees,
e.g., both "unsecured" with a lower layer security of a same
strength, both "preinstalled" or both "authenticated" security mode
(see section 3.2.3 of [RFC6550] for more details on those modes).
The latter mode could be use to enforce the segregation of updated
and non-updated nodes, by providing "T" flag reset until all nodes in the keys for joining as routers RPL Instance
are upgraded to the updated nodes only.

5.4. support this specification.

5.3. Rolling Back

After downgrading a network to turn the

When turning [RFC8138] compression off, off in the administrator SHOULD make sure that network, the Network
Administrator MUST wait until all nodes have converged to the "T"
flag reset before allowing nodes that do not support the compression
in the network (see caveats in Section 5.2). network.

It is RECOMMENDED to only deploy nodes that support [RFC8138] in a
network where the compression is turned on. A node that does not
support [RFC8138] MUST only be used as a leaf. RUL.

6. IANA Considerations

This specification updates

IANA is requested to assign a new option flag from the Registry for
the "DODAG Configuration Option Flags" that was created for [RFC6550]
as follows:

+------------+---------------------------------+-----------+

+---------------+---------------------------------+-----------+
| Bit Number | Capability Description | Reference |
+============+=================================+===========+
+---------------+---------------------------------+-----------+
| 2 (suggested) | Turn on RFC8138 Compression (T) | THIS RFC |
+------------+---------------------------------+-----------+
+---------------+---------------------------------+-----------+

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

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
network. A trust model MUST has to be put in place so that in an effort to
exclude rogue nodes are
excluded from participating to the RPL and the 6LowpAN 6LoWPAN
signaling, and as well as from the data packet exchange. This trust
model could be at a minimum based on a Layer-2 Secure joining and the
Link-Layer security. This is a generic RPL and 6LoWPAN requirement,
see Req5.1 in Appendix of [RFC8505].

Setting the "T" flag before some all routers are upgraded may cause a loss
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
if an attacker manages to inject a corrupted configuration.

Setting and resetting the "T" flag may create inconsistencies in the
network but as long as all nodes are upgraded to [RFC8138] support
they will be able to forward both forms. The source is responsible
for selecting whether the packet is compressed or not, and all
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
network, at an additional cost of bandwidth for packets in the
uncompressed form.

8. Acknowledgments

The authors wish to thank Alvaro Retana, Dominique Barthel and Rahul
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

[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>.

[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>.

[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>.

[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]

[RFC8138] Thubert, P., Ed., Bormann, C., Ersue, M., Toutain, L., and A. Keranen, "Terminology for
Constrained-Node Networks", R. Cragie,
"IPv6 over Low-Power Wireless Personal Area Network
(6LoWPAN) Routing Header", RFC 7228, 8138, DOI 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.

[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 10.17487/RFC8138,
April 2020, <https://tools.ietf.org/html/
draft-ietf-roll-unaware-leaves-14>. 2017, <https://www.rfc-editor.org/info/rfc8138>.

10. Informative References

[RFC6553] Hui, J. and JP. Vasseur, "The Routing Protocol for Low-
Power and Lossy Networks (RPL) Option for Carrying RPL
Information in Data-Plane Datagrams", RFC 6553,
DOI 10.17487/RFC6553, March 2012,
<https://www.rfc-editor.org/info/rfc6553>.

[RFC8138] Thubert, P., Ed.,

[RFC7228] Bormann, C., Toutain, L., Ersue, M., and R. Cragie,
"IPv6 over Low-Power Wireless Personal Area Network
(6LoWPAN) Routing Header", A. Keranen, "Terminology for
Constrained-Node Networks", RFC 8138, 7228,
DOI 10.17487/RFC8138,
April 2017, <https://www.rfc-editor.org/info/rfc8138>. 10.17487/RFC7228, May 2014,
<https://www.rfc-editor.org/info/rfc7228>.

[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>.

[CAPABILITIES]
Jadhav, R.,

[UNAWARE-LEAVES]
Thubert, P., P. and M. Richardson, "Routing for RPL Leaves",
Work in Progress, Internet-Draft, draft-ietf-roll-unaware-
leaves-18, 12 June 2020, <https://tools.ietf.org/html/
draft-ietf-roll-unaware-leaves-18>.

[USEofRPLinfo]
Robles, I., Richardson, M., and R. Sahoo,
"RPL Capabilities", 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-capabilities-02, 11 March draft-ietf-roll-useofrplinfo-40,
25 June 2020,
<https://tools.ietf.org/html/draft-ietf-roll-capabilities-
02>. <https://tools.ietf.org/html/draft-ietf-
roll-useofrplinfo-40>.

Authors' Addresses

Pascal Thubert (editor)
Cisco Systems, Inc
Building D
45 Allee des Ormes - BP1200
06254 MOUGINS - Sophia Antipolis
France

Phone: +33 497 23 26 34
Email: pthubert@cisco.com

Li Zhao
Cisco Systems, Inc
Xinsi Building
No. 926 Yi Shan Rd
SHANGHAI
200233
China

Email: liz3@cisco.com