draft-ietf-hip-rfc5206-bis-07.txt   draft-ietf-hip-rfc5206-bis-08.txt 
Network Working Group T. Henderson, Ed. Network Working Group T. Henderson, Ed.
Internet-Draft University of Washington Internet-Draft University of Washington
Obsoletes: 5206 (if approved) C. Vogt Obsoletes: 5206 (if approved) C. Vogt
Intended status: Standards Track J. Arkko Intended status: Standards Track J. Arkko
Expires: May 16, 2015 Ericsson Research NomadicLab Expires: July 16, 2015 Ericsson Research NomadicLab
November 12, 2014 January 12, 2015
Host Mobility with the Host Identity Protocol Host Mobility with the Host Identity Protocol
draft-ietf-hip-rfc5206-bis-07 draft-ietf-hip-rfc5206-bis-08
Abstract Abstract
This document defines mobility extensions to the Host Identity This document defines mobility extensions to the Host Identity
Protocol (HIP). Specifically, this document defines a general Protocol (HIP). Specifically, this document defines a general
"LOCATOR_SET" parameter for HIP messages that allows for a HIP host "LOCATOR_SET" parameter for HIP messages that allows for a HIP host
to notify peers about alternate addresses at which it may be reached. to notify peers about alternate addresses at which it may be reached.
This document also defines elements of procedure for mobility of a This document also defines elements of procedure for mobility of a
HIP host -- the process by which a host dynamically changes the HIP host -- the process by which a host dynamically changes the
primary locator that it uses to receive packets. While the same primary locator that it uses to receive packets. While the same
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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 http://datatracker.ietf.org/drafts/current/. Drafts is at http://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 May 16, 2015. This Internet-Draft will expire on July 16, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
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1. Introduction and Scope . . . . . . . . . . . . . . . . . . . 3 1. Introduction and Scope . . . . . . . . . . . . . . . . . . . 3
2. Terminology and Conventions . . . . . . . . . . . . . . . . . 4 2. Terminology and Conventions . . . . . . . . . . . . . . . . . 4
3. Protocol Model . . . . . . . . . . . . . . . . . . . . . . . 5 3. Protocol Model . . . . . . . . . . . . . . . . . . . . . . . 5
3.1. Operating Environment . . . . . . . . . . . . . . . . . . 5 3.1. Operating Environment . . . . . . . . . . . . . . . . . . 5
3.1.1. Locator . . . . . . . . . . . . . . . . . . . . . . . 8 3.1.1. Locator . . . . . . . . . . . . . . . . . . . . . . . 8
3.1.2. Mobility Overview . . . . . . . . . . . . . . . . . . 8 3.1.2. Mobility Overview . . . . . . . . . . . . . . . . . . 8
3.2. Protocol Overview . . . . . . . . . . . . . . . . . . . . 9 3.2. Protocol Overview . . . . . . . . . . . . . . . . . . . . 9
3.2.1. Mobility with a Single SA Pair (No Rekeying) . . . . 9 3.2.1. Mobility with a Single SA Pair (No Rekeying) . . . . 9
3.2.2. Mobility with a Single SA Pair (Mobile-Initiated 3.2.2. Mobility with a Single SA Pair (Mobile-Initiated
Rekey) . . . . . . . . . . . . . . . . . . . . . . . 11 Rekey) . . . . . . . . . . . . . . . . . . . . . . . 11
3.2.3. Using LOCATOR_SETs across Addressing Realms . . . . . 11 3.2.3. Network Renumbering . . . . . . . . . . . . . . . . . 11
3.2.4. Network Renumbering . . . . . . . . . . . . . . . . . 12 3.3. Other Considerations . . . . . . . . . . . . . . . . . . 11
3.3. Other Considerations . . . . . . . . . . . . . . . . . . 12
3.3.1. Address Verification . . . . . . . . . . . . . . . . 12 3.3.1. Address Verification . . . . . . . . . . . . . . . . 12
3.3.2. Credit-Based Authorization . . . . . . . . . . . . . 12 3.3.2. Credit-Based Authorization . . . . . . . . . . . . . 12
3.3.3. Preferred Locator . . . . . . . . . . . . . . . . . . 14 3.3.3. Preferred Locator . . . . . . . . . . . . . . . . . . 13
4. LOCATOR_SET Parameter Format . . . . . . . . . . . . . . . . 14 4. LOCATOR_SET Parameter Format . . . . . . . . . . . . . . . . 14
4.1. Traffic Type and Preferred Locator . . . . . . . . . . . 16 4.1. Traffic Type and Preferred Locator . . . . . . . . . . . 15
4.2. Locator Type and Locator . . . . . . . . . . . . . . . . 16 4.2. Locator Type and Locator . . . . . . . . . . . . . . . . 16
4.3. UPDATE Packet with Included LOCATOR_SET . . . . . . . . . 17 4.3. UPDATE Packet with Included LOCATOR_SET . . . . . . . . . 16
5. Processing Rules . . . . . . . . . . . . . . . . . . . . . . 17 5. Processing Rules . . . . . . . . . . . . . . . . . . . . . . 16
5.1. Locator Data Structure and Status . . . . . . . . . . . . 17 5.1. Locator Data Structure and Status . . . . . . . . . . . . 16
5.2. Sending LOCATOR_SETs . . . . . . . . . . . . . . . . . . 18 5.2. Sending LOCATOR_SETs . . . . . . . . . . . . . . . . . . 18
5.3. Handling Received LOCATOR_SETs . . . . . . . . . . . . . 20 5.3. Handling Received LOCATOR_SETs . . . . . . . . . . . . . 19
5.4. Verifying Address Reachability . . . . . . . . . . . . . 22 5.4. Verifying Address Reachability . . . . . . . . . . . . . 21
5.5. Changing the Preferred Locator . . . . . . . . . . . . . 23 5.5. Changing the Preferred Locator . . . . . . . . . . . . . 22
5.6. Credit-Based Authorization . . . . . . . . . . . . . . . 24 5.6. Credit-Based Authorization . . . . . . . . . . . . . . . 23
5.6.1. Handling Payload Packets . . . . . . . . . . . . . . 24 5.6.1. Handling Payload Packets . . . . . . . . . . . . . . 23
5.6.2. Credit Aging . . . . . . . . . . . . . . . . . . . . 26 5.6.2. Credit Aging . . . . . . . . . . . . . . . . . . . . 25
6. Security Considerations . . . . . . . . . . . . . . . . . . . 27 6. Security Considerations . . . . . . . . . . . . . . . . . . . 26
6.1. Impersonation Attacks . . . . . . . . . . . . . . . . . . 28 6.1. Impersonation Attacks . . . . . . . . . . . . . . . . . . 27
6.2. Denial-of-Service Attacks . . . . . . . . . . . . . . . . 29 6.2. Denial-of-Service Attacks . . . . . . . . . . . . . . . . 28
6.2.1. Flooding Attacks . . . . . . . . . . . . . . . . . . 29 6.2.1. Flooding Attacks . . . . . . . . . . . . . . . . . . 28
6.2.2. Memory/Computational-Exhaustion DoS Attacks . . . . . 29 6.2.2. Memory/Computational-Exhaustion DoS Attacks . . . . . 28
6.3. Mixed Deployment Environment . . . . . . . . . . . . . . 30 6.3. Mixed Deployment Environment . . . . . . . . . . . . . . 29
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 29
8. Authors and Acknowledgments . . . . . . . . . . . . . . . . . 31 8. Authors and Acknowledgments . . . . . . . . . . . . . . . . . 30
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 31 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 30
9.1. Normative references . . . . . . . . . . . . . . . . . . 31 9.1. Normative references . . . . . . . . . . . . . . . . . . 30
9.2. Informative references . . . . . . . . . . . . . . . . . 31 9.2. Informative references . . . . . . . . . . . . . . . . . 30
Appendix A. Document Revision History . . . . . . . . . . . . . 33 Appendix A. Document Revision History . . . . . . . . . . . . . 32
1. Introduction and Scope 1. Introduction and Scope
The Host Identity Protocol [I-D.ietf-hip-rfc4423-bis] (HIP) supports The Host Identity Protocol [I-D.ietf-hip-rfc4423-bis] (HIP) supports
an architecture that decouples the transport layer (TCP, UDP, etc.) an architecture that decouples the transport layer (TCP, UDP, etc.)
from the internetworking layer (IPv4 and IPv6) by using public/ from the internetworking layer (IPv4 and IPv6) by using public/
private key pairs, instead of IP addresses, as host identities. When private key pairs, instead of IP addresses, as host identities. When
a host uses HIP, the overlying protocol sublayers (e.g., transport a host uses HIP, the overlying protocol sublayers (e.g., transport
layer sockets and Encapsulating Security Payload (ESP) Security layer sockets and Encapsulating Security Payload (ESP) Security
Associations (SAs)) are instead bound to representations of these Associations (SAs)) are instead bound to representations of these
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forwarding. However, each host must also know at least one IP forwarding. However, each host must also know at least one IP
address at which its peers are reachable. Initially, these IP address at which its peers are reachable. Initially, these IP
addresses are the ones used during the HIP base exchange addresses are the ones used during the HIP base exchange
[I-D.ietf-hip-rfc5201-bis]. [I-D.ietf-hip-rfc5201-bis].
One consequence of such a decoupling is that new solutions to One consequence of such a decoupling is that new solutions to
network-layer mobility and host multihoming are possible. There are network-layer mobility and host multihoming are possible. There are
potentially many variations of mobility and multihoming possible. potentially many variations of mobility and multihoming possible.
The scope of this document encompasses messaging and elements of The scope of this document encompasses messaging and elements of
procedure for basic network-level host mobility, leaving more procedure for basic network-level host mobility, leaving more
complicated scenarios and other variations for further study. More complicated mobility scenarios, multihoming, and other variations for
specifically: further study. More specifically:
This document defines a generalized LOCATOR_SET parameter for use This document defines a generalized LOCATOR_SET parameter for use
in HIP messages. The LOCATOR_SET parameter allows a HIP host to in HIP messages. The LOCATOR_SET parameter allows a HIP host to
notify a peer about alternate locators at which it is reachable. notify a peer about alternate locators at which it is reachable.
The locators may be merely IP addresses, or they may have The locators may be merely IP addresses, or they may have
additional multiplexing and demultiplexing context to aid the additional multiplexing and demultiplexing context to aid with the
packet handling in the lower layers. For instance, an IP address packet handling in the lower layers. For instance, an IP address
may need to be paired with an ESP Security Parameter Index (SPI) may need to be paired with an ESP Security Parameter Index (SPI)
so that packets are sent on the correct SA for a given address. so that packets are sent on the correct SA for a given address.
This document also specifies the messaging and elements of This document also specifies the messaging and elements of
procedure for end-host mobility of a HIP host -- the sequential procedure for end-host mobility of a HIP host -- the sequential
change in the preferred IP address used to reach a host. In change in the preferred IP address used to reach a host. In
particular, message flows to enable successful host mobility, particular, message flows to enable successful host mobility,
including address verification methods, are defined herein. including address verification methods, are defined herein.
However, while the same LOCATOR_SET parameter is intended to However, while the same LOCATOR_SET parameter is intended to
support host multihoming (parallel support of a number of support host multihoming (simultaneous use of a number of
addresses), and experimentation is encouraged, detailed elements addresses), detailed elements of procedure for host multihoming
of procedure for host multihoming are out of scope. are out of scope.
While HIP can potentially be used with transports other than the ESP While HIP can potentially be used with transports other than the ESP
transport format [I-D.ietf-hip-rfc5202-bis], this document largely transport format [I-D.ietf-hip-rfc5202-bis], this document largely
assumes the use of ESP and leaves other transport formats for further assumes the use of ESP and leaves other transport formats for further
study. study.
There are a number of situations where the simple end-to-end There are a number of situations where the simple end-to-end
readdressing functionality is not sufficient. These include the readdressing functionality is not sufficient. These include the
initial reachability of a mobile host, location privacy, simultaneous initial reachability of a mobile host, location privacy, simultaneous
mobility of both hosts, and some modes of NAT traversal. In these mobility of both hosts, and some modes of NAT traversal. In these
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| +------------+ | | +------------+ | | +------------+ | | +------------+ |
| | | | | | | |
| | | | | | | |
| Initiator | | Responder | | Initiator | | Responder |
+--------------------+ +--------------------+ +--------------------+ +--------------------+
Figure 1: HIP Deployment Model Figure 1: HIP Deployment Model
The general deployment model for HIP is shown above, assuming The general deployment model for HIP is shown above, assuming
operation in an end-to-end fashion. This document specifies operation in an end-to-end fashion. This document specifies
extensions to the HIP protocol to enable end-host mobility and basic extensions to the HIP protocol to enable end-host mobility and
multihoming. In summary, these extensions to the HIP base protocol multihoming. In summary, these extensions to the HIP base protocol
enable the signaling of new addressing information to the peer in HIP enable the signaling of new addressing information to the peer in HIP
messages. The messages are authenticated via a signature or keyed messages. The messages are authenticated via a signature or keyed
hash message authentication code (HMAC) based on its Host Identity. hash message authentication code (HMAC) based on its Host Identity.
This document specifies the format of this new addressing This document specifies the format of this new addressing
(LOCATOR_SET) parameter, the procedures for sending and processing (LOCATOR_SET) parameter, the procedures for sending and processing
this parameter to enable basic host mobility, and procedures for a this parameter to enable basic host mobility, and procedures for a
concurrent address verification mechanism. concurrent address verification mechanism.
--------- ---------
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The scenarios below assume that the two hosts have completed a single The scenarios below assume that the two hosts have completed a single
HIP base exchange with each other. Both of the hosts therefore have HIP base exchange with each other. Both of the hosts therefore have
one incoming and one outgoing SA. Further, each SA uses the same one incoming and one outgoing SA. Further, each SA uses the same
pair of IP addresses, which are the ones used in the base exchange. pair of IP addresses, which are the ones used in the base exchange.
The readdressing protocol is an asymmetric protocol where a mobile The readdressing protocol is an asymmetric protocol where a mobile
host informs a peer host about changes of IP addresses on affected host informs a peer host about changes of IP addresses on affected
SPIs. The readdressing exchange is designed to be piggybacked on SPIs. The readdressing exchange is designed to be piggybacked on
existing HIP exchanges. The majority of the packets on which the existing HIP exchanges. The majority of the packets on which the
LOCATOR_SET parameters are expected to be carried are UPDATE packets. LOCATOR_SET parameters are expected to be carried are UPDATE packets.
However, some implementations may want to experiment with sending
LOCATOR_SET parameters also on other packets, such as R1, I2, and
NOTIFY.
The scenarios below at times describe addresses as being in either an The scenarios below at times describe addresses as being in either an
ACTIVE, VERIFIED, or DEPRECATED state. From the perspective of a ACTIVE, UNVERIFIED, or DEPRECATED state. From the perspective of a
host, newly-learned addresses of the peer must be verified before put host, newly-learned addresses of the peer must be verified before put
into active service, and addresses removed by the peer are put into a into active service, and addresses removed by the peer are put into a
deprecated state. Under limited conditions described below deprecated state. Under limited conditions described below
(Section 5.6), an UNVERIFIED address may be used. The addressing (Section 5.6), an UNVERIFIED address may be used. The addressing
states are defined more formally in Section 5.1. states are defined more formally in Section 5.1.
Hosts that use link-local addresses as source addresses in their HIP Hosts that use link-local addresses as source addresses in their HIP
handshakes may not be reachable by a mobile peer. Such hosts SHOULD handshakes may not be reachable by a mobile peer. Such hosts SHOULD
provide a globally routable address either in the initial handshake provide a globally routable address either in the initial handshake
or via the LOCATOR_SET parameter. or via the LOCATOR_SET parameter.
3.2.1. Mobility with a Single SA Pair (No Rekeying) 3.2.1. Mobility with a Single SA Pair (No Rekeying)
A mobile host must sometimes change an IP address bound to an A mobile host must sometimes change an IP address bound to an
interface. The change of an IP address might be needed due to a interface. The change of an IP address might be needed due to a
change in the advertised IPv6 prefixes on the link, a reconnected PPP change in the advertised IPv6 prefixes on the link, a reconnected PPP
link, a new DHCP lease, or an actual movement to another subnet. In link, a new DHCP lease, or an actual movement to another subnet. In
order to maintain its communication context, the host must inform its order to maintain its communication context, the host must inform its
peers about the new IP address. This first example considers the peers about the new IP address. This first example considers the
case in which the mobile host has only one interface, IP address, a case in which the mobile host has only one interface, one IP address
single pair of SAs (one inbound, one outbound), and no rekeying in use within the HIP session, a single pair of SAs (one inbound, one
occurs on the SAs. We also assume that the new IP addresses are outbound), and no rekeying occurs on the SAs. We also assume that
within the same address family (IPv4 or IPv6) as the first address. the new IP addresses are within the same address family (IPv4 or
This is the simplest scenario, depicted in Figure 3. IPv6) as the first address. This is the simplest scenario, depicted
in Figure 3.
Mobile Host Peer Host Mobile Host Peer Host
UPDATE(ESP_INFO, LOCATOR_SET, SEQ) UPDATE(ESP_INFO, LOCATOR_SET, SEQ)
-----------------------------------> ----------------------------------->
UPDATE(ESP_INFO, SEQ, ACK, ECHO_REQUEST) UPDATE(ESP_INFO, SEQ, ACK, ECHO_REQUEST)
<----------------------------------- <-----------------------------------
UPDATE(ACK, ECHO_RESPONSE) UPDATE(ACK, ECHO_RESPONSE)
-----------------------------------> ----------------------------------->
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UPDATE(ESP_INFO, LOCATOR_SET, SEQ, [DIFFIE_HELLMAN]) UPDATE(ESP_INFO, LOCATOR_SET, SEQ, [DIFFIE_HELLMAN])
-----------------------------------> ----------------------------------->
UPDATE(ESP_INFO, SEQ, ACK, [DIFFIE_HELLMAN,] ECHO_REQUEST) UPDATE(ESP_INFO, SEQ, ACK, [DIFFIE_HELLMAN,] ECHO_REQUEST)
<----------------------------------- <-----------------------------------
UPDATE(ACK, ECHO_RESPONSE) UPDATE(ACK, ECHO_RESPONSE)
-----------------------------------> ----------------------------------->
Figure 4: Readdress with Mobile-Initiated Rekey Figure 4: Readdress with Mobile-Initiated Rekey
3.2.3. Using LOCATOR_SETs across Addressing Realms 3.2.3. Network Renumbering
It is possible for HIP associations to migrate to a state in which
both parties are only using locators in different addressing realms.
For example, the two hosts may initiate the HIP association when both
are using IPv6 locators, then one host may loose its IPv6
connectivity and obtain an IPv4 address. In such a case, some type
of mechanism for interworking between the different realms must be
employed; such techniques are outside the scope of the present text.
The basic problem in this example is that the host readdressing to
IPv4 does not know a corresponding IPv4 address of the peer. This
may be handled (experimentally) by possibly configuring this address
information manually or in the DNS, or the hosts exchange both IPv4
and IPv6 addresses in the locator.
3.2.4. Network Renumbering
It is expected that IPv6 networks will be renumbered much more often It is expected that IPv6 networks will be renumbered much more often
than most IPv4 networks. From an end-host point of view, network than most IPv4 networks. From an end-host point of view, network
renumbering is similar to mobility. renumbering is similar to mobility.
3.3. Other Considerations 3.3. Other Considerations
3.3.1. Address Verification 3.3.1. Address Verification
When a HIP host receives a set of locators from another HIP host in a When a HIP host receives a set of locators from another HIP host in a
LOCATOR_SET, it does not necessarily know whether the other host is LOCATOR_SET, it does not necessarily know whether the other host is
actually reachable at the claimed addresses. In fact, a malicious actually reachable at the claimed addresses. In fact, a malicious
peer host may be intentionally giving bogus addresses in order to peer host may be intentionally giving bogus addresses in order to
cause a packet flood towards the target addresses [RFC4225]. cause a packet flood towards the target addresses [RFC4225].
Likewise, viral software may have compromised the peer host, Therefore, the HIP host must first check that the peer is reachable
programming it to redirect packets to the target addresses. Thus, at the new address.
the HIP host must first check that the peer is reachable at the new
address.
An additional potential benefit of performing address verification is An additional potential benefit of performing address verification is
to allow middleboxes in the network along the new path to obtain the to allow middleboxes in the network along the new path to obtain the
peer host's inbound SPI. peer host's inbound SPI.
Address verification is implemented by the challenger sending some Address verification is implemented by the challenger sending some
piece of unguessable information to the new address, and waiting for piece of unguessable information to the new address, and waiting for
some acknowledgment from the Responder that indicates reception of some acknowledgment from the Responder that indicates reception of
the information at the new address. This may include the exchange of the information at the new address. This may include the exchange of
a nonce, or the generation of a new SPI and observation of data a nonce, or the generation of a new SPI and observation of data
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a possibility. a possibility.
5. Processing Rules 5. Processing Rules
This section describes rules for sending and receiving the This section describes rules for sending and receiving the
LOCATOR_SET parameter, testing address reachability, and using LOCATOR_SET parameter, testing address reachability, and using
Credit-Based Authorization (CBA) on UNVERIFIED locators. Credit-Based Authorization (CBA) on UNVERIFIED locators.
5.1. Locator Data Structure and Status 5.1. Locator Data Structure and Status
In a typical implementation, each outgoing locator is represented by In a typical implementation, each locator announced in a LOCATOR_SET
a piece of state that contains the following data: parameter is represented by a piece of state that contains the
following data:
o the actual bit pattern representing the locator, o the actual bit pattern representing the locator,
o the lifetime (seconds), o the lifetime (seconds),
o the status (UNVERIFIED, ACTIVE, DEPRECATED), o the status (UNVERIFIED, ACTIVE, DEPRECATED),
o the Traffic Type scope of the locator, and o the Traffic Type scope of the locator, and
o whether the locator is preferred for any particular scope. o whether the locator is preferred for any particular scope.
The status is used to track the reachability of the address embedded The status is used to track the reachability of the address embedded
within the LOCATOR_SET parameter: within the LOCATOR_SET parameter:
UNVERIFIED indicates that the reachability of the address has not UNVERIFIED indicates that the reachability of the address has not
been verified yet, been verified yet,
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A DEPRECATED address MUST NOT be changed to ACTIVE without first A DEPRECATED address MUST NOT be changed to ACTIVE without first
verifying its reachability. verifying its reachability.
Note that the state of whether or not a locator is preferred is not Note that the state of whether or not a locator is preferred is not
necessarily the same as the value of the Preferred bit in the Locator necessarily the same as the value of the Preferred bit in the Locator
sub-parameter received from the peer. Peers may recommend certain sub-parameter received from the peer. Peers may recommend certain
locators to be preferred, but the decision on whether to actually use locators to be preferred, but the decision on whether to actually use
a locator as a preferred locator is a local decision, possibly a locator as a preferred locator is a local decision, possibly
influenced by local policy. influenced by local policy.
In addition to state maintained about status and remaining lifetime
for each locator learned from the peer, an implementation would
typically maintain similar state about its own locators that have
been offered to the peer.
Finally, the locators used to establish the HIP association are by
default assumed to be the initial preferred locators in ACTIVE state,
with an unbounded lifetime.
5.2. Sending LOCATOR_SETs 5.2. Sending LOCATOR_SETs
The decision of when to send LOCATOR_SETs is basically a local policy The decision of when to send LOCATOR_SETs is basically a local policy
issue. However, it is RECOMMENDED that a host send a LOCATOR_SET issue. However, it is RECOMMENDED that a host send a LOCATOR_SET
whenever it recognizes a change of its IP addresses in use on an whenever it recognizes a change of its IP addresses in use on an
active HIP association, and assumes that the change is going to last active HIP association, and assumes that the change is going to last
at least for a few seconds. It is possible to delay the exposure of at least for a few seconds. Rapidly sending LOCATOR_SETs that force
additional locators to the peer, and to send data from previously the peer to change the preferred address SHOULD be avoided.
unannounced locators, as might arise in certain mobility situations.
Rapidly sending LOCATOR_SETs that force the peer to change the
preferred address SHOULD be avoided.
When a host decides to inform its peers about changes in its IP
addresses, it has to decide how to group the various addresses with
SPIs. The grouping should consider also whether middlebox
interaction requires sending the same LOCATOR_SET in separate UPDATEs
on different paths. Since each SPI is associated with a different
Security Association, the grouping policy may also be based on ESP
anti-replay protection considerations. In the typical case, simply
basing the grouping on actual kernel level physical and logical
interfaces may be the best policy. Grouping policy is outside of the
scope of this document.
Note that the purpose of announcing IP addresses in a LOCATOR_SET is
to provide connectivity between the communicating hosts. In most
cases, tunnels or virtual interfaces such as IPsec tunnel interfaces
or Mobile IP home addresses provide sub-optimal connectivity.
Furthermore, it should be possible to replace most tunnels with HIP
based "non-tunneling", therefore making most virtual interfaces
fairly unnecessary in the future. Therefore, virtual interfaces
SHOULD NOT be announced in general. On the other hand, there are
clearly situations where tunnels are used for diagnostic and/or
testing purposes. In such and other similar cases announcing the IP
addresses of virtual interfaces may be appropriate.
Hosts MUST NOT announce broadcast or multicast addresses in
LOCATOR_SETs. Link-local addresses MAY be announced to peers that
are known to be neighbors on the same link, such as when the IP
destination address of a peer is also link-local. The announcement
of link-local addresses in this case is a policy decision; link-local
addresses used as Preferred locators will create reachability
problems when the host moves to another link. In any case, link-
local addresses MUST NOT be announced to a peer unless that peer is
known to be on the same link.
Once the host has decided on the groups and assignment of addresses We now describe a few cases introduced in Section 3.2. We assume
to the SPIs, it creates a LOCATOR_SET parameter that serves as a that the Traffic Type for each locator is set to "0" (other values
complete representation of the addresses and affiliated SPIs intended for Traffic Type may be specified in documents that separate the HIP
for active use. We now describe a few cases introduced in control plane from data plane traffic). Other mobility cases are
Section 3.2. We assume that the Traffic Type for each locator is set possible but are left for further study.
to "0" (other values for Traffic Type may be specified in documents
that separate the HIP control plane from data plane traffic). Other
mobility cases are possible but are left for further experimentation.
1. Host mobility with no multihoming and no rekeying. The mobile 1. Host mobility with no multihoming and no rekeying. The mobile
host creates a single UPDATE containing a single ESP_INFO with a host creates a single UPDATE containing a single ESP_INFO with a
single LOCATOR_SET parameter. The ESP_INFO contains the current single LOCATOR_SET parameter. The ESP_INFO contains the current
value of the SPI in both the OLD SPI and NEW SPI fields. The value of the SPI in both the OLD SPI and NEW SPI fields. The
LOCATOR_SET contains a single Locator with a "Locator Type" of LOCATOR_SET contains a single Locator with a "Locator Type" of
"1"; the SPI must match that of the ESP_INFO. The Preferred bit "1"; the SPI must match that of the ESP_INFO. The Preferred bit
SHOULD be set and the "Locator Lifetime" is set according to SHOULD be set and the "Locator Lifetime" is set according to
local policy. The UPDATE also contains a SEQ parameter as usual. local policy. The UPDATE also contains a SEQ parameter as usual.
This packet is retransmitted as defined in the HIP protocol This packet is retransmitted as defined in the HIP protocol
skipping to change at page 20, line 19 skipping to change at page 19, line 5
single LOCATOR_SET parameter (with a single address). The single LOCATOR_SET parameter (with a single address). The
ESP_INFO contains the current value of the SPI in the OLD SPI and ESP_INFO contains the current value of the SPI in the OLD SPI and
the new value of the SPI in the NEW SPI, and a KEYMAT Index as the new value of the SPI in the NEW SPI, and a KEYMAT Index as
selected by local policy. Optionally, the host may choose to selected by local policy. Optionally, the host may choose to
initiate a Diffie Hellman rekey by including a DIFFIE_HELLMAN initiate a Diffie Hellman rekey by including a DIFFIE_HELLMAN
parameter. The LOCATOR_SET contains a single Locator with parameter. The LOCATOR_SET contains a single Locator with
"Locator Type" of "1"; the SPI must match that of the NEW SPI in "Locator Type" of "1"; the SPI must match that of the NEW SPI in
the ESP_INFO. Otherwise, the steps are identical to the case in the ESP_INFO. Otherwise, the steps are identical to the case in
which no rekeying is initiated. which no rekeying is initiated.
The sending of multiple LOCATOR_SETs, locators with Locator Type "0",
and multiple ESP_INFO parameters is for further study. Note that the
inclusion of LOCATOR_SET in an R1 packet requires the use of Type "0"
locators since no SAs are set up at that point.
5.3. Handling Received LOCATOR_SETs 5.3. Handling Received LOCATOR_SETs
A host SHOULD be prepared to receive a LOCATOR_SET parameter in the A host SHOULD be prepared to receive a single LOCATOR_SET parameter
following HIP packets: R1, I2, UPDATE, and NOTIFY. in a HIP UPDATE packet. Reception of multiple LOCATOR_SET parameters
in a single packet, or in HIP packets other than UPDATE, is outside
of the scope of this specification.
This document describes sending both ESP_INFO and LOCATOR_SET This document describes sending both ESP_INFO and LOCATOR_SET
parameters in an UPDATE. The ESP_INFO parameter is included when parameters in an UPDATE. The ESP_INFO parameter is included when
there is a need to rekey or key a new SPI, and is otherwise included there is a need to rekey or key a new SPI, and is otherwise included
for the possible benefit of HIP-aware middleboxes. The LOCATOR_SET for the possible benefit of HIP-aware middleboxes. The LOCATOR_SET
parameter contains a complete map of the locators that the host parameter contains a complete listing of the locators that the host
wishes to make or keep active for the HIP association. wishes to make or keep active for the HIP association.
In general, the processing of a LOCATOR_SET depends upon the packet In general, the processing of a LOCATOR_SET depends upon the packet
type in which it is included. Here, we describe only the case in type in which it is included. Here, we describe only the case in
which ESP_INFO is present and a single LOCATOR_SET and ESP_INFO are which ESP_INFO is present and a single LOCATOR_SET and ESP_INFO are
sent in an UPDATE message; other cases are for further study. The sent in an UPDATE message; other cases are for further study. The
steps below cover each of the cases described in Section 5.2. steps below cover each of the cases described in Section 5.2.
The processing of ESP_INFO and LOCATOR_SET parameters is intended to The processing of ESP_INFO and LOCATOR_SET parameters is intended to
be modular and support future generalization to the inclusion of be modular and support future generalization to the inclusion of
skipping to change at page 31, line 12 skipping to change at page 30, line 12
46) should have its reference updated from RFC5206 to this 46) should have its reference updated from RFC5206 to this
specification. specification.
8. Authors and Acknowledgments 8. Authors and Acknowledgments
Pekka Nikander and Jari Arkko originated this document, and Christian Pekka Nikander and Jari Arkko originated this document, and Christian
Vogt and Thomas Henderson (editor) later joined as co-authors. Greg Vogt and Thomas Henderson (editor) later joined as co-authors. Greg
Perkins contributed the initial draft of the security section. Petri Perkins contributed the initial draft of the security section. Petri
Jokela was a co-author of the initial individual submission. Jokela was a co-author of the initial individual submission.
The authors thank Miika Komu, Mika Kousa, Jeff Ahrenholz, Jan Melen, The authors thank Jeff Ahrenholz, Baris Boyvat, Rene Hummen, Miika
Baris Boyvat, and Samu Varjonen for many improvements to the Komu, Mika Kousa, Jan Melen, and Samu Varjonen for improvements to
document. the document.
9. References 9. References
9.1. Normative references 9.1. Normative references
[I-D.ietf-hip-rfc5201-bis] [I-D.ietf-hip-rfc5201-bis]
Moskowitz, R., Heer, T., Jokela, P., and T. Henderson, Moskowitz, R., Heer, T., Jokela, P., and T. Henderson,
"Host Identity Protocol Version 2 (HIPv2)", draft-ietf- "Host Identity Protocol Version 2 (HIPv2)", draft-ietf-
hip-rfc5201-bis-14 (work in progress), October 2013. hip-rfc5201-bis-20 (work in progress), October 2014.
[I-D.ietf-hip-rfc5202-bis] [I-D.ietf-hip-rfc5202-bis]
Jokela, P., Moskowitz, R., and J. Melen, "Using the Jokela, P., Moskowitz, R., and J. Melen, "Using the
Encapsulating Security Payload (ESP) Transport Format with Encapsulating Security Payload (ESP) Transport Format with
the Host Identity Protocol (HIP)", draft-ietf-hip- the Host Identity Protocol (HIP)", draft-ietf-hip-
rfc5202-bis-05 (work in progress), November 2013. rfc5202-bis-07 (work in progress), September 2014.
[I-D.ietf-hip-rfc5204-bis] [I-D.ietf-hip-rfc5204-bis]
Laganier, J. and L. Eggert, "Host Identity Protocol (HIP) Laganier, J. and L. Eggert, "Host Identity Protocol (HIP)
Rendezvous Extension", draft-ietf-hip-rfc5204-bis-04 (work Rendezvous Extension", draft-ietf-hip-rfc5204-bis-05 (work
in progress), June 2014. in progress), December 2014.
[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, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing [RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, February 2006. Architecture", RFC 4291, February 2006.
9.2. Informative references 9.2. Informative references
[CBA-MIPv6] [CBA-MIPv6]
Vogt, C. and J. Arkko, "Credit-Based Authorization for Vogt, C. and J. Arkko, "Credit-Based Authorization for
Mobile IPv6 Early Binding Updates", February 2005. Mobile IPv6 Early Binding Updates", February 2005.
[I-D.ietf-hip-rfc4423-bis] [I-D.ietf-hip-rfc4423-bis]
Moskowitz, R. and M. Komu, "Host Identity Protocol Moskowitz, R. and M. Komu, "Host Identity Protocol
Architecture", draft-ietf-hip-rfc4423-bis-08 (work in Architecture", draft-ietf-hip-rfc4423-bis-09 (work in
progress), April 2014. progress), October 2014.
[RFC4225] Nikander, P., Arkko, J., Aura, T., Montenegro, G., and E. [RFC4225] Nikander, P., Arkko, J., Aura, T., Montenegro, G., and E.
Nordmark, "Mobile IP Version 6 Route Optimization Security Nordmark, "Mobile IP Version 6 Route Optimization Security
Design Background", RFC 4225, December 2005. Design Background", RFC 4225, December 2005.
[SIMPLE-CBA] [SIMPLE-CBA]
Vogt, C. and J. Arkko, "Credit-Based Authorization for Vogt, C. and J. Arkko, "Credit-Based Authorization for
Concurrent Reachability Verification", February 2006. Concurrent Reachability Verification", February 2006.
Appendix A. Document Revision History Appendix A. Document Revision History
skipping to change at page 33, line 34 skipping to change at page 32, line 34
| | | | | |
| | issue 14: use of UPDATE packet's IP address | | | issue 14: use of UPDATE packet's IP address |
| | | | | |
| draft-04 | Document refresh; no other changes. | | draft-04 | Document refresh; no other changes. |
| | | | | |
| draft-05 | Document refresh; no other changes. | | draft-05 | Document refresh; no other changes. |
| | | | | |
| draft-06 | Document refresh; no other changes. | | draft-06 | Document refresh; no other changes. |
| | | | | |
| draft-07 | Document refresh; IANA considerations updated. | | draft-07 | Document refresh; IANA considerations updated. |
| | |
| draft-08 | Remove sending LOCATOR_SET in R1, I2, and NOTIFY |
| | (multihoming) |
| | |
| | State that only one LOCATOR_SET parameter may be sent |
| | in an UPDATE packet (according to this draft) |
| | (multihoming) |
| | |
| | Remove text about cross-family handovers (multihoming) |
+----------+--------------------------------------------------------+ +----------+--------------------------------------------------------+
Authors' Addresses Authors' Addresses
Thomas R. Henderson (editor) Thomas R. Henderson (editor)
University of Washington University of Washington
Campus Box 352500 Campus Box 352500
Seattle, WA Seattle, WA
USA USA
EMail: tomhend@u.washington.edu EMail: tomhend@u.washington.edu
Christian Vogt Christian Vogt
Ericsson Research NomadicLab Ericsson Research NomadicLab
Hirsalantie 11 Hirsalantie 11
JORVAS FIN-02420 JORVAS FIN-02420
FINLAND FINLAND
EMail: christian.vogt@ericsson.com EMail: christian.vogt@ericsson.com
Jari Arkko Jari Arkko
Ericsson Research NomadicLab Ericsson Research NomadicLab
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