Internet DRAFT - draft-irtf-rrg-ilnp-icmpv4
draft-irtf-rrg-ilnp-icmpv4
Internet Draft RJ Atkinson
draft-irtf-rrg-ilnp-icmpv4-06.txt Consultant
Expires: 10 JAN 2013 SN Bhatti
Category: Experimental U. St Andrews
10 July 2012
ICMP Locator Update message for ILNPv4
draft-irtf-rrg-ilnp-icmpv4-06.txt
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Internet-Drafts are working documents of the Internet Engineering
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Internet-Drafts are draft documents valid for a maximum of six
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documents at any time. It is inappropriate to use Internet-Drafts
as reference material or to cite them other than as "work in
progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at
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This document is not on the IETF standards-track and does not
specify any level of standard. This document merely provides
information for the Internet community.
This document is part of the ILNP document set, which has had
extensive review within the IRTF Routing Research Group. ILNP is
one of the recommendations made by the RG Chairs. Separately,
various refereed research papers on ILNP have also been published
during this decade. So the ideas contained herein have had much
broader review than the IRTF Routing RG. The views in this
document were considered controversial by the Routing RG, but the
RG reached a consensus that the document still should be
published. The Routing RG has had remarkably little consensus on
anything, so virtually all Routing RG outputs are considered
controversial.
Abstract
This note defines an experimental ICMP message type for IPv4 used
with the Identifier-Locator Network Protocol (ILNP). The
Identifier-Locator Network Protocol (ILNP) is an experimental,
evolutionary enhancement to IP. The ICMP message defined herein
is used to dynamically update Identifier/Locator bindings for an
existing ILNP session. This is a product of the IRTF Routing RG.
Table of Contents
1. Introduction.............................2
1.1 ILNP Document Roadmap..................3
1.2 ICMPv4 Locator Update..................3
1.3 Terminology............................3
2. ICMP Locator Update message for ILNPv4...4
3. Transport Protocol Effects...............5
4. Implementation Considerations............6
5. Backwards Compatibility..................6
6. Security Considerations..................6
7. IANA Considerations......................7
8. References...............................7
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1. INTRODUCTION
At present, the Internet research and development community are
exploring various approaches to evolving the Internet
Architecture to solve a variety of issues including, but not
limited to, scalability of inter-domain routing [RFC4984]. A wide
range of other issues (e.g. site multi-homing, node multi-homing,
site/subnet mobility, node mobility) are also active concerns at
present. Several different classes of evolution are being
considered by the Internet research & development community. One
class is often called "Map and Encapsulate", where traffic would
be mapped and then tunnelled through the inter-domain core of the
Internet. Another class being considered is sometimes known as
"Identifier/Locator Split". This document relates to a proposal
that is in the latter class of evolutionary approaches.
The Identifier Locator Network Protocol (ILNP) is a proposal for
evolving the Internet Architecture. It differs from the current
Internet Architecture primarily by deprecating the concept of an
IP Address, and instead defining two new objects, each having
crisp syntax and semantics. The first new object is the Locator,
a topology-dependent name for a subnetwork. The other new object
is the Identifier, which provides a topology-independent name for
a node.
1.1 Document roadmap
This document describes a new ICMPv4 Locator Update message
used by an ILNP node to inform its correspondent nodes
of any changes to its set of valid Locators.
The ILNP architecture can have more than one engineering
instantiation. For example, one can imagine a "clean-slate"
engineering design based on the ILNP architecture. In separate
documents, we describe two specific engineering instances of
ILNP. The term ILNPv6 refers precisely to an instance of ILNP that
is based upon, and backwards compatible with, IPv6. The term ILNPv4
refers precisely to an instance of ILNP that is based upon, and
backwards compatible with, IPv4.
Many engineering aspects common to both ILNPv4 and ILNPv6 are
described in [ILNP-ENG]. A full engineering specification for
either ILNPv6 or ILNPv4 is beyond the scope of this document.
Readers are referred to other related ILNP documents for details
not described here:
a) [ILNP-ARCH] is the main architectural description of ILNP,
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including the concept of operations.
b) [ILNP-ENG] describes engineering and implementation
considerations that are common to both ILNPv4 and ILNPv6.
c) [ILNP-DNS] defines additional DNS resource records that
support ILNP.
d) [ILNP-ICMPv6] defines a new ICMPv6 Locator Update message
used by an ILNP node to inform its correspondent nodes
of any changes to its set of valid Locators.
e) [ILNP-NONCEv6] defines a new IPv6 Nonce Destination Option
used by ILNPv6 nodes (1) to indicate to ILNP correspondent
nodes (by inclusion within the initial packets of an ILNP
session) that the node is operating in the ILNP mode and
(2) to prevent off-path attacks against ILNP ICMP messages.
This Nonce is used, for example, with all ILNP ICMPv6
Locator Update messages that are exchanged among ILNP
correspondent nodes.
f) [ILNP-v4OPTS] defines a new IPv4 Nonce Option used by ILNPv4
nodes to carry a security nonce to prevent off-path attacks
against ILNP ICMP messages and also defines a new IPv4
Identifier Option used by ILNPv4 nodes.
g) [ILNP-ARP] describes extensions to ARP for use with ILNPv4.
h) [ILNP-ADV] describes optional engineering and deployment
functions for ILNP. These are not required for the operation
or use of ILNP and are provided as additional options.
1.2 ICMPv4 Locator Update
As described in [ILNP-ARCH] and [ILNP-ENG], an ILNP for IPv4
(ILNPv4) node might need to inform correspondent ILNPv4 nodes of
changes to the set of valid Locator values. The new ICMPv4
Locator Update message described in this document enables an
ILNP-capable node to update its correspondents about the
currently valid set of Locators valid to use in reaching the node
sending this message [RFC2460] [RFC4443].
This new ICMPv4 message MUST ONLY be used for ILNPv4 sessions.
Authentication is always required, as described in the Security
Considerations section later in this note.
Some might consider any and all use of ICMP to be undesirable.
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In that context, please note that while this specification uses
ICMP, on grounds that this is a control message, there is no
architectural difference between using ICMP and using some
different framing, for example UDP.
1.3 Terminology
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL
NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described
in RFC 2119. [RFC2119]
2. ICMP Locator Update message for ILNPv4
The ICMP for IPv4 message described in this section has ICMP Type
253 (as defined for experimental use in Section 8 of [RFC4727])
and is used ONLY with a current ILNPv4 session. This message
enables an ILNPv4 node to advertise changes to the active Locator
set for the ILNPv4 node that originates this message to its
unicast ILNP correspondent nodes. It also enables those
correspondents to acknowledge receipt of the advertisement.
This particular ICMP for IPv4 message MUST ONLY be used with
ILNPv4 sessions. The Checksum field for this message is
calculated identically as for any other IPv4 ICMP message.
ICMP Locator Update message
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | Code | Checksum |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Num of Locs | Operation | RESERVED |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Locator [1] /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference [1] | Lifetime [1] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
/ Locator [2] /
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Preference [2] | Lifetime [2] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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ICMP Fields:
Type 253
This type value is taken from Section 8
of [RFC4727], and is allocated for
experimental use.
Code 0
Checksum The 16-bit one's complement of the
one's complement sum of the ICMP
message, starting with the ICMP Type.
For computing the checksum, the
Checksum field is set to 0.
Num of Locs The number of 32-bit Locator values
that are advertised in this message.
Locator[i], The 32-bit Locator values currently
i = 1..Num of Locs valid for the sending ILNPv4 node.
Preference[i], The preferability of each Locator[i],
i = 1..Num of Locs relative to other valid Locator[i]
values. The Preference numbers here
are identical, both in syntax and
semantics, to the Preference values
for L32 records that are specified by
[ILNP-DNS].
Lifetime[i] The maximum number of seconds that this
i = 1..Num of Locs particular Locator may be considered
valid. Normally, this is identical
to the DNS lifetime of the
corresponding L32 record, if one
exists.
Operation The value in this field indicates
whether this is a Locator Update
Advertisement (0x01) or a Locator
Update Acknowledgement (0x02).
RESERVED A field reserved for possible future
use. At present, the sender MUST
initialise this field to zero.
Receivers should ignore this field at
present. The field might be used for
some protocol function in future.
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NOTE WELL: The ICMP TYPE value is allocated for shared
experimental use in Section 8 of [RFC4727].
It is not uniquely assigned to ILNPv4. So
implementations need to code particularly
defensively as other IPv4 experiments might be
using this same ICMP TYPE value for an
entirely different purpose with a different
ICMP packet format.
The Operation field has value 1 (hexadecimal 0x01) for a Locator
Update Advertisement. The Operation field has value 2
(hexadecimal 0x02) for a Locator Update Acknowledgement. All
other values of the Operation field are reserved for future use
by future revisions of this specification.
A node whose set of valid Locators has changed MUST send Locator
Update Advertisement messages to each correspondent node for each
active unicast ILNP session. For unicast ILNP sessions, the
receiver of a valid (i.e. authentication checks all passed,
advertisement is received from a current correspondent node)
Locator Update Advertisement addressed to the receiver MUST send
a Locator Update Acknowledgement back to the sender of the
Locator Update Advertisement. The Acknowledgement message body
is identical to the received Advertisement message body, except
for the Operation value.
All ILNPv4 ICMP Locator Update messages MUST contain a valid
ILNPv4 Identifier option and MUST contain an ILNPv4 Nonce Option.
ILNPv4 ICMP Locator Update messages also MAY be protected using
IP Security for ILNP [ILNP-ENG] [RFC4301]. Deployments in
high-threat environments SHOULD also protect ILNPv4 ICMP Locator
Update messages using IP Security. While IPsec ESP can protect a
payload, no form of IPsec ESP is able to protect an IPv4 option
that appears prior to the ESP header. Note that even when IP
Security for ILNP is in use, the ILNPv4 Nonce Option still MUST
be present. This simplifies protocol processing, and it also
means that a receiver can perform the inexpensive check of the
Nonce value before performing any (potentially expensive)
cryptographic calculation.
3. Transport Protocol Effects
The ICMP Locator Update message has no impact on any transport protocol.
The ICMP Locator Update message might affect where packets for
a given transport-layer session are sent, but an ILNP design
objective is to decouple transport protocols (e.g., TCP, UDP,
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SCTP) and transport-layer sessions network-layer changes.
4. Implementation Considerations
Implementers may use any internal implementation they wish,
provided that the external appearance is the same as this
implementation approach.
To support ILNPv4, and to retain the incremental deployability
and backwards compatibility needed, the network layer needs a
mode bit in the Transport Control Block (or its equivalent) to
track which IP sessions are using the classic IPv4 mode and which
IP sessions are using ILNPv4 mode.
Further, when supporting ILNPv4, nodes will need to support a
Identifier Locator Communication Cache (ILCC) in the network
layer as described in [ILNP-ENG].
A node sending an ICMP Locator Update message MUST include all
currently valid Locator values in that message. A node receiving
a valid ICMP Locator Update message MUST replace the previously
current set of Locator values for that correspondent node in its
own ILCC with the newly received set of Locator values.
Every implementation needs to support a large number of Locator
values being sent or received in a single ICMP Locator Update
message, because a multi-homed node or multi-homed site might
have a large number of upstream links to different service
providers, each with its own Locator value.
It should be noted that as the ICMP Type uses an experimental
value from RFC4727 [RFC4727], care should be taken when using
with other protocols also using experimental values.
5. Backwards Compatibility
This IPv4 ICMP message uses the same checksum calculations as any
other IPv4 ICMP message.
When ILNPv4 is not in use, the receiving IPv4 mode MUST discard
the ICMP Locator Update packet without processing the packet.
6. SECURITY CONSIDERATIONS
Security considerations for the overall ILNP Architecture
are described in [ILNP-ARCH]. Additional common security
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considerations are described in [ILNP-ENG]. This section
describes security considerations specific to ILNPv4 topics
discussed in this document.
The ICMPv4 Locator Update message MUST ONLY be used for
ILNPv4 sessions.
The ILNPv4 Nonce Option [ILNP-v4OPTS] MUST be present in packets
containing an ICMPv4 Locator Update message. Further, the
received Nonce Destination Option must contain the correct nonce
value for the packet to be accepted by the recipient and then
passed to the ICMPv4 protocol for processing. If either of these
requirements are not met, the received packet MUST be discarded
as a forgery, and a security event SHOULD be logged by the system
receiving the non-authentic packet.
ILNP sessions operating in higher risk environments SHOULD use
IP Security for ILNP [ILNP-ENG] [RFC4301] *in addition* to the
ILNPv4 Nonce Option. Use of IP Security for ILNP to protect a
packet does NOT permit the packet to be sent without the Nonce
Option.
Implementations need to support the case where a single ICMP
Locator Update message contains a large number of Locator and
Preference values and ought not develop a security fault
(e.g. stack overflow) due to a received message containing more
Locator values than expected.
If the ILNP Nonce value is predictable, then an off-path attacker
might be able to forge data or control packets. This risk also
is mitigated by the existing common practice of IP Source Address
filtering [RFC2827] [RFC3704].
7. IANA CONSIDERATIONS
This document makes no request of IANA.
If in future the IETF decided to standardise ILNPv4, then
allocation of a unique ICMP Type for the Locator Update
as part of the IETF standardisation process would be sensible.
8. REFERENCES
This document has both Normative and Informational References.
8.1 Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to
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Indicate Requirement Levels", BCP 14, RFC 2119,
March 1997.
[RFC2460] S. Deering & R. Hinden, "Internet Protocol
Version 6 Specification", RFC2460,
December 1998.
[RFC4443] A. Conta, S. Deering, and M. Gupta, "Internet Control
Message Protocol Version 6 (ICMPv6) Specification",
RFC 4443, March 2006.
[RFC4301] S. Kent and K. Seo, "Security Architecture for
the Internet Protocol", RFC 4301, December 2005.
[RFC4727] B. Fenner, "Experimental Values in IPv4, IPv6, ICMPv4,
ICMPv6, UDP, and TCP Headers", RFC 4727, Nov 2006.
[ILNP-ARCH] R.J. Atkinson & S.N. Bhatti,
"ILNP Architectural Description",
draft-irtf-rrg-ilnp-arch, 10 July 2012.
[ILNP-ARP] R.J. Atkinson & S.N. Bhatti, "ARP Extension for
ILNPv4", draft-irtf-rrg-ilnp-arp, 10 July 2012.
[ILNP-ENG] R.J. Atkinson & S.N. Bhatti,
"ILNP Engineering and Implementation Considerations",
draft-irtf-rrg-ilnp-eng, 10 July 2012.
[ILNP-v4OPTS] R.J. Atkinson & S.N. Bhatti,
"IPv4 Options for ILNP",
draft-irtf-rrg-ilnp-v4opts, 10 July 2012.
8.2 Informative References
[RFC2827] P. Ferguson and D. Senie, "Network Ingress
Filtering: Defeating Denial of Service Attacks
which employ IP Source Address Spoofing",
RFC 2827, May 2000.
[RFC2780] S. Bradner and V. Paxson, "IANA Allocation
Guidelines For Values In the Internet Protocol
and Related Headers", RFC 2780, March 2000.
[RFC3704] F. Baker and P. Savola, "Ingress Filtering for
Multihomed Networks", RFC 3704, March 2004.
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[RFC4884] R. Bonica, D. Gan, D. Tappan, C. Pignataro,
"Extended ICMP to Support Multi-Part Messages",
RFC 4884, April 2007.
[ILNP-DNS] R.J. Atkinson, S.N. Bhatti, & S Rose,
"DNS Resource Records for ILNP",
draft-irtf-rrg-ilnp-dns, 10 July 2012.
[ILNP-ADV] R.J. Atkinson & S.N. Bhatti,
"Optional Advanced Deployment Scenarios for ILNP",
draft-irtf-rrg-ilnp-adv, 10 July 2012.
[ILNP-ICMPv6] R.J. Atkinson & S.N. Bhatti,
"ICMPv6 Locator Update message"
draft-irtf-rrg-ilnp-icmpv6, 10 July 2012.
[ILNP-NONCEv6] R.J. Atkinson & S.N. Bhatti,
"IPv6 Nonce Destination Option for ILNPv6",
draft-irtf-rrg-ilnp-noncev6, 10 July 2012.
ACKNOWLEDGEMENTS
Steve Blake, Stephane Bortzmeyer, Mohamed Boucadair, Noel
Chiappa, Wes George, Steve Hailes, Joel Halpern, Mark Handley,
Volker Hilt, Paul Jakma, Dae-Young Kim, Tony Li, Yakov Rehkter,
Bruce Simpson, Robin Whittle and John Wroclawski (in alphabetical
order) provided review and feedback on earlier versions of this
document. Steve Blake provided an especially thorough review of
an early version of the entire ILNP document set, which was
extremely helpful. We also wish to thank the anonymous reviewers
of the various ILNP papers for their feedback.
Roy Arends provided expert guidance on technical and procedural
aspects of DNS issues.
RFC EDITOR NOTE
This section is to be removed prior to publication.
Please note that this document is written in British English, so
British English spelling is used throughout. This is consistent
with existing practice in several other RFCs, for example
RFC-5887.
This document tries to be very careful with history, in the
interest of correctly crediting ideas to their earliest
identifiable author(s). So in several places the first published
RFC about a topic is cited, rather than the most recent published
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RFC about that topic.
AUTHOR'S ADDRESS
RJ Atkinson
Consultant
San Jose, CA
95125 USA
Email: rja.lists@gmail.com
SN Bhatti
School of Computer Science
University of St Andrews
North Haugh, St Andrews
Fife, Scotland
KY16 9SX, UK
Email: saleem@cs.st-andrews.ac.uk
Expires: 10 JAN 2013
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