Network Working Group A. Muhanna
Internet-Draft M. Khalil
Intended status: Standards Track Nortel
Expires: March 14, 2010 S. Gundavelli
Cisco Systems
K. Chowdhury
Starent Networks
P. Yegani
Juniper Networks
September 10, 2009
Binding Revocation for IPv6 Mobility
draft-ietf-mext-binding-revocation-12.txt
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Copyright Notice
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This document is subject to BCP 78 and the IETF Trust's Legal
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Abstract
This document defines a binding revocation mechanism to terminate a
mobile node's mobility session and the associated resources. These
semantics are generic enough and can be used by mobility entities in
the case of Mobile IPv6 and its extensions. This mechanism allows
the mobility entity which initiates the revocation procedure to
request its peer to terminate either one, multiple or all specified
binding(s).
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. Conventions & Terminology . . . . . . . . . . . . . . . . . . 5
2.1. Conventions used in this document . . . . . . . . . . . . 5
2.2. Terminology . . . . . . . . . . . . . . . . . . . . . . . 5
3. Binding Revocation Protocol and Use Cases Overview . . . . . . 5
3.1. Binding Revocation Protocol . . . . . . . . . . . . . . . 6
3.2. MIPv6 and DSMIP6 Use Case . . . . . . . . . . . . . . . . 7
3.3. Multiple Care-of Addresses (Monami6) Use Case . . . . . . 8
3.4. Proxy MIPv6 Use Case . . . . . . . . . . . . . . . . . . . 9
3.4.1. Local Mobility Anchor Initiates PMIPv6 Binding
Revocation . . . . . . . . . . . . . . . . . . . . . . 10
3.4.2. Mobile Access Gateway Revokes Bulk PMIPv6 Bindings . . 11
4. Binding Revocation Messages over IPv4 Transport Network . . . 12
5. Binding Revocation Message . . . . . . . . . . . . . . . . . . 12
5.1. Binding Revocation Indication Message . . . . . . . . . . 14
5.2. Binding Revocation Acknowledgement Message . . . . . . . . 17
6. Binding Revocation Process Operation . . . . . . . . . . . . . 20
6.1. Sending Binding Revocation Messages . . . . . . . . . . . 20
6.2. Receiving Binding Revocation Messages . . . . . . . . . . 20
6.3. Retransmission of Binding Revocation Indication . . . . . 22
7. Home Agent Operation . . . . . . . . . . . . . . . . . . . . . 22
7.1. Sending Binding Revocation Indication . . . . . . . . . . 22
7.2. Receiving Binding Revocation Acknowledgement . . . . . . . 24
8. Local Mobility Anchor Operation . . . . . . . . . . . . . . . 24
8.1. Binding Revocation Initiator . . . . . . . . . . . . . . . 24
8.1.1. Sending Binding Revocation Indication . . . . . . . . 24
8.1.2. Receiving Binding Revocation Acknowledgement . . . . . 29
8.2. Binding Revocation Responder . . . . . . . . . . . . . . . 29
8.2.1. Receiving Binding Revocation Indication . . . . . . . 29
8.2.2. Sending Binding Revocation Acknowledgement . . . . . . 31
9. Mobile Access Gateway Operation . . . . . . . . . . . . . . . 32
9.1. Binding Revocation Responder . . . . . . . . . . . . . . . 32
9.1.1. Receiving Binding Revocation Indication . . . . . . . 32
9.1.2. Sending Binding Revocation Acknowledgement . . . . . . 34
9.2. Binding Revocation Initiator . . . . . . . . . . . . . . . 35
9.2.1. Sending Binding Revocation Indication . . . . . . . . 35
9.2.2. Receiving Binding Revocation Acknowledgement . . . . . 36
10. Mobile Node Operation . . . . . . . . . . . . . . . . . . . . 36
10.1. Receiving Binding Revocation Indication . . . . . . . . . 36
10.2. Sending Binding Revocation Acknowledgement . . . . . . . . 38
11. Protocol Configuration Variables . . . . . . . . . . . . . . . 38
12. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 39
13. Security Considerations . . . . . . . . . . . . . . . . . . . 40
14. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 41
15. References . . . . . . . . . . . . . . . . . . . . . . . . . . 41
15.1. Normative References . . . . . . . . . . . . . . . . . . . 41
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15.2. Informative References . . . . . . . . . . . . . . . . . . 42
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 42
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1. Introduction
In the case of Mobile IPv6 and for administrative reason, sometimes
it becomes necessary to inform the mobile node that its registration
has been revoked and the mobile node is no longer able to receive IP
mobility service using its Home Address. A similar Mobile IPv4
registration revocation mechanism [RFC3543] has been specified by
IETF for providing a revocation mechanism for sessions that were
established using Mobile IPv4 registration [RFC3344].
This document specifies a binding revocation mechanism that can be
used to revoke a mobile node's mobility session(s). The same
mechanism can be used to revoke bindings created using Mobile IPv6
[RFC3775] or any of its extensions, e.g. Proxy Mobile IPv6
[RFC5213]. The proposed revocation mechanism uses a new Mobility
Header (MH) type <IANA-TBD> for revocation signaling which is
applicable to Mobile IPv6 [RFC3775] and Proxy Mobile IPv6 [RFC5213]
and can be used by any two IP mobility entities. As an example, this
mechanism allows a local mobility anchor (LMA), involved in providing
IP mobility services to a mobile node, to notify the mobile access
gateway (MAG) of the termination of that mobile node binding
registration. In another example, a mobile access gateway can use
this mechanism to notify its local mobility anchor peer with a bulk
termination of all or a subset of proxy mobile IPv6 (PMIPv6) bindings
that are registered with the local mobility anchor and currently
being served by the mobile access gateway. Any mobility entity is
allowed to revoke only the registration of those mobile node(s)
mobility sessions that are currently registered with it.
2. Conventions & Terminology
2.1. Conventions used in this document
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 [RFC2119].
2.2. Terminology
All the general mobility related terminology and abbreviations are to
be interpreted as defined in Mobile IPv6 [RFC3775] and Proxy Mobile
IPv6 [RFC5213] specifications.
3. Binding Revocation Protocol and Use Cases Overview
This specification specifies a generic binding revocation mechanism
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where a mobility node can communicate to the mobile node or another
mobility node the identity of the the mobile node registration
binding that is being terminated. In the case when this mechanism is
used for bulk termination or multiple bindings, the identities of
these bindings are communicated to the mobile node or mobility node
using the same generic mechanism. The following subsections present
the protocol overview and applicable use cases.
3.1. Binding Revocation Protocol
In the case of Mobile IPv6, if the home network decides to terminate
the service of the mobile node, the home agent sends a Binding
Revocation Indication (BRI) message to the mobile node. The home
agent includes the home address (HoA) of the mobile node in the Type
2 routing header as specified in [RFC3775] to indicate the impacted
mobile node binding. In the case of Dual Stack Mobile IPv6 (DSMIPv6)
[RFC5555], the home agent may include the IPv4 Home Address option
with the mobile node assigned home IPv4 address. Additionally, if
the mobile node registered multiple care-of addresses [ID-MCoA], the
home agent includes the Binding Identifier (BID) option(s) in the
Binding Revocation Indication message to identify which binding is
being revoked. When the mobile node receives a Binding Revocation
Indication message with its HoA included in the Type 2 routing header
and the Acknowledge (A) bit is set, the mobile node responds by
sending a Binding Revocation Acknowledgement (BRA) message.
Similarly, in the case of Proxy Mobile IPv6 [RFC5213], the revocation
procedure can be initiated by the local mobility anchor by sending a
Binding Revocation Indication message to communicate the termination
of a mobile node registration binding to the mobile access gateway.
In this case, the local mobility anchor includes the mobile node Home
Network Prefix (MN-HNP) option [RFC5213] and the MN-ID option
[RFC4283] to indicate to the mobility access gateway the identity of
the PMIPv6 binding that needs to be terminated. When the mobile
access gateway receives the Binding Revocation Indication message
with the Acknowledge (A) bit set, the mobile access gateway responds
to the local mobility anchor by sending a Binding Revocation
Acknowledgement message.
On the other hand, the mobile access gateway usually sends a de-
registration message by sending a Proxy Binding Update with a
lifetime of zero to indicate to the local mobility anchor of the
termination of the PMIPv6 mobile node binding registration. In this
case, the mobile access gateway includes the MN-HNP option, the MN-ID
option and all other required mobility options as per [RFC5213] in
order for the local mobility anchor to identify the mobile node
PMIPv6 binding. Additionally, in the case when the mobile access
gateway communicates a bulk termination of PMIPv6 mobility sessions,
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the mobile access gateway sends a Binding Revocation Indication
message with the Global (G) and Acknowledge (A) bits set and includes
the mobile access gateway identity in the MN-ID option, see
Section 8.1.1 and Section 9.1.1. When the local mobility anchor
receives such Binding Revocation Indication message, it ensures that
the mobile access gateway is authorized to send such bulk termination
message and then processes the Binding Revocation Indication message
accordingly. If the local mobility anchor processes the Binding
Revocation Indication message successfully and the Acknowledge (A)
bit is set, the local mobility anchor responds to the mobile access
gateway by sending Binding Revocation Acknowledgement message.
In any of the above cases, the initiator of the binding revocation
procedure, e.g., home agent, local mobility anchor, or mobile access
gateway, uses the Revocation Trigger field in the Binding Revocation
Indication message to indicate to the receiving node the reason for
initiating the revocation procedure.
3.2. MIPv6 and DSMIP6 Use Case
The binding revocation mechanism is applicable to Mobile IPv6 and
DSMIPv6 session(s) when the home agent needs to inform the mobile
node that its binding registration has been revoked, e.g. for an
administrative reason. This mechanism enables the user or the mobile
node to react to the revocation, e.g., reinstate its interrupted
Mobile IPv6 services.
In this case, the home agent sends a Binding Revocation Indication
message to indicate to the mobile node that its current mobile IPv6
(MIPv6) binding has been revoked and it is no longer able to receive
IP mobility service. The home agent includes the HoA in Type 2
routing header as used in [RFC3775] and sets the Revocation Trigger
field to a proper value, e.g., Administrative Reason. In the case of
DSMIPv6 session, the home agent may additionally include the mobile
node assigned IPv4 Home Address in the IPv4 Home Address option.
When the mobile node receives the Binding Revocation Indication
message, it sends a Binding Revocation Acknowledgement message as
described in Section 10.2 to the home agent. Figure 1 illustrates
the message sequencing when home agent revokes a mobile node binding
registration.
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MN HA
| |
| HoA in Type 2 Hdr |
|<<<------------... + ...-----------------|
| BRI [seq.#, A bit, Revocation Trigger] |
| |
| |
| BRA (HoA in Dest. Option)[seq.#, Status] |
|---------------------------------------->>>|
| |
| |
Figure 1: Home Agent Revokes a Mobile Node Binding Registration
3.3. Multiple Care-of Addresses (Monami6) Use Case
In the case of multiple care-of addresses registration [ID-MCoA], the
home agent maintains different binding for each pair of care-of
address and home address. These bindings are also indexed and
identified during the mobile node registration using a BID mobility
option. The HA may revoke one or multiple bindings for the same
mobile node home address.
If the home agent revokes a single binding for a mobile node with
multiple care-of addresses registration, the home agent sends a
Binding Revocation Indication message to the mobile node with the
corresponding BID option included. If more than one of the mobile
node registered care-of addresses need to be revoked, the home agent
includes all the corresponding BID options in the same Binding
Revocation Indication message. Figure 2 illustrates the message flow
when the home agent revokes two registered Care-of addresses for the
same mobile node in a single Binding Revocation Indication message.
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HA Binding Cache
================
MN-BID1 [CoA1+HoA]
MN HA MN-BID2 [CoA2+HoA]
| | MN-BID3 [CoA3+HoA]
| | MN-BID4 [CoA4+HoA]
| HoA in Type 2 Hdr |
|<<<<-------------- + ---------------------|
| BRI [seq.#, A bit, R. Trigger, BID1, BID4] |
| |
| |
| BRA (HoA in Dest. Option) [seq.#, Status] |
|---------------------------------------->>>>|
| |
| |
Figure 2: Home Agent Revokes MN's Specific Care-of Addresses Bindings
Additionally, the home agent may revoke all of the mobile node
registered bindings, by sending a BRI message without including any
BID options while the HoA is included in the Type 2 routing header.
Figure 1 illustrates the message flow when the home agent revokes all
registered Care-of addresses bindings for a mobile node in a single
Binding Revocation Indication message.
3.4. Proxy MIPv6 Use Case
Since the mobile node does not participate in the mobility mechanism
in the case of PMIPv6, there are many scenarios where the Binding
Revocation mechanism is needed to clean resources and make sure that
the mobility entities, i.e., mobile access gateway and local mobility
anchor, are always synchronized with respect to the status of the
existing PMIPv6 bindings. The binding revocation mechanism is
generic enough that can be used for all Proxy Mobile IPv6 scenarios
that follow [RFC5213] and [ID-PMIP6-IPv4] specifications.
When the mobile access gateway receives a Binding Revocation
Indication message with the Acknowledge (A) bit set as in
Section 9.1.1, the mobile access gateway sends a Binding Revocation
Acknowledgement message to the local mobility anchor following the
rules described in Section 9.1.2. Similarly, if the local mobility
anchor receives a Binding Revocation Indication message with the
Acknowledge (A) bit is set, the local mobility anchor responds to the
mobile access gateway by sending a Binding Revocation Acknowledgement
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message.
3.4.1. Local Mobility Anchor Initiates PMIPv6 Binding Revocation
The local mobility anchor may send a Binding Revocation Indication
message with the appropriate revocation trigger value to the mobile
access gateway that hosts a specific PMIPv6 binding to indicate that
the mobile node binding has been terminated and the mobile access
gateway can clean up the applicable resources. When the mobile
access gateway receives a Binding Revocation Indication message, the
mobile access gateway identifies the respected binding and if the
Acknowledge (A) bit is set in the received Binding Revocation
Indication message, it sends a Binding Revocation Acknowledgement
message to the local mobility anchor. In this case, the mobile
access gateway could send a Router Advertisement message to the
mobile node with the home network prefix valid lifetime set to zero.
As an example, Figure 3, illustrates the message sequence for
revoking a mobile node binding at the source mobile access gateway
during the mobile node inter-MAG handover. During the inter-MAG
handover, the mobile node moves from the source MAG to the target
MAG. The target MAG sends a Proxy Binding Update with the new care-
of-address to the local mobility anchor to update the mobile node's
point of attachment. Since the mobile node binding at the local
mobility anchor points to the source MAG and upon receiving the Proxy
Binding Update from the target MAG, the local mobility anchor updates
the MN Binding Cache Entry (BCE) and send a Proxy Binding
Acknowledgement to the target MAG. The local mobility anchor can
send a Binding Revocation Indication message with the appropriate
revocation trigger value, e.g. inter-MAG handover - different Access
Types, to the source MAG in order to clean up the applicable
resources reserved for the specified mobile node binding. If the
Acknowledge (A) bit is set, the mobile access gateway acknowledges
the Binding Revocation Indication message by sending a Binding
Revocation Acknowledgement message to indicate the success or failure
of the termination of the mobile node's binding.
The process identified above can also be used by the local mobility
anchor in scenarios other than the inter-MAG handover with the proper
revocation trigger value to indicate to the peer mobile access
gateway that a specific PMIPv6 binding or bindings have been revoked.
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oldMAG newMAG LMA
| | |
| | PBU |
| |--------------------------->|
| | PBU triggers
| | BRI Msg to oldMAG
| | |
| | PBA |
| |<---------------------------|
| | |
| | |
| BRI [seq.#, R. Trigger, P, A bits, NAI] |
|<-----------------------------------------|
| | |
| | |
| | |
| | |
| BRA [seq.#, Status, P bit] |
|----------------------------------------->|
| | |
| | |
Figure 3: LMA Revokes a MN Registration During Inter-MAG Handover
In addition, the local mobility anchor can send a Binding Revocation
Indication message to indicate that all bindings which are hosted by
the peer mobile access gateway and registered with the local mobility
anchor are being revoked by setting the Global (G) bit as described
in Section 8.1.1.
3.4.2. Mobile Access Gateway Revokes Bulk PMIPv6 Bindings
The mobile access gateway sends a BRI message with the Global (G) bit
set and the Revocation Trigger field set to "Per-Peer Policy" to
indicate that all mobility bindings which are registered at the local
mobility anchor and attached to the mobile access gateway are being
revoked as in Section 9.2.1. When the local mobility anchor receives
this Binding Revocation Indication message from the specified mobile
access gateway, the local mobility anchor first checks if the mobile
access gateway is authorized to use global revocations and if the
Acknowledge (A) bit is set, then responds with the appropriate status
code by sending a Binding Revocation Acknowledgement message as in
Section 8.2.2.
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4. Binding Revocation Messages over IPv4 Transport Network
In some deployments, the network between the mobile access gateway
and the local mobility anchor may only support IPv4 transport.
Another case is when a mobile node which supports client mobile IPv6
roams to an access network where only IPv4 addressing and transport
is supported. In this case, the mobile node is required to register
an IPv4 home address with its home agent using a mobile IPv6 Binding
Update message.
If the Proxy Binding Update and Proxy Binding Acknowledgement
messages or the Binding Update and Binding Acknowledgement messages
are sent using UDP encapsulation [ID-PMIP6-IPv4] and [RFC5555] to
traverse NATs, then the Binding Revocation messages are sent using
the same UDP encapsulation. The same UDP source and destination port
numbers and IPv4 addresses used for exchanging the Proxy Binding
Update and Proxy Binding Acknowledgement or the Binding Update and
Binding Acknowledgement messages MUST be used when transporting
Binding Revocation messages over IPv4 using UDP encapsulation. For
example, the source UDP port number, the destination UDP port number,
the source IPv4 address, and the destination IPv4 address of the
Binding Revocation Indication message are set to the destination UDP
port number, the source UDP port number, destination IPv4 address,
and source IPv4 address of the latest received and successfully
processed Proxy Binding Update or Binding Update message,
respectively. For more details on tunneling Proxy Mobile IPv6 and
Mobile IPv6 signaling messages over IPv4, see [ID-PMIP6-IPv4] and
[RFC5555], respectively.
5. Binding Revocation Message
This section defines the Binding Revocation Message format using a MH
Type <IANA-TBD> as illustrated in Figure 4. The value in the Binding
Revocation Type field defines whether the Binding Revocation message
is a Binding Revocation Indication or Binding Revocation
Acknowledgement. If the Binding Revocation type field is set to 1,
the Binding Revocation Message is a Binding Revocation Indication as
in Section 5.1. However, if the value is 2, it is a Binding
Revocation Acknowledgement message as in Section 5.2.
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Payload Proto | Header Len | MH Type | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Checksum | B.R. Type | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +
| |
. Binding Revocation Message Data .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: Binding Revocation Message
Payload Proto
8-bit selector. see [RFC3775] for more details.
Header Len
8-bit unsigned integer. representing the length of the Mobility
Header in units of 8 octets, excluding the first 8 octets. see
[RFC3775] for more details.
MH Type
<IANA-TBD> which identifies the mobility message as a Binding
Revocation message.
Reserved
8-bit field reserved for future use. The value MUST be
initialized to zero by the sender, and MUST be ignored by the
receiver.
Checksum
16-bit unsigned integer. This field contains the checksum of the
Mobility Header. The checksum is calculated as described in
[RFC3775].
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Binding Revocation Type
8-bit unsigned integer. It defines the type of the Binding
Revocation Message. It can be assigned one of the following
values:
0 Reserved
1 Binding Revocation Indication Message
2 Binding Revocation Acknowledgement Message
All other values are reserved
Binding Revocation Message Data
The Binding Revocation Message Data follows the Binding Revocation
Message format that is defined in this document for the specified
value in the Binding Revocation Type field. In this
specification, it is either a Binding Revocation Indication as in
Section 5.1 or Binding Revocation Acknowledgement as in
Section 5.2.
5.1. Binding Revocation Indication Message
The Binding Revocation Indication (BRI) message is a Binding
Revocation Message which has a MH type <IANA-TBD> and a Binding
Revocation Type value of 1. It is used by the revoking mobility node
to inform the receiving mobility entity of the identity of a specific
binding or bindings which IP mobility service have been revoked.
Binding Revocation Indication message is sent as described in
Section 7.1, Section 8.1.1, and Section 9.2.1.
When the value 1 is indicated in the B. R. type field of the Binding
Revocation Message, the format of the Binding Revocation Message Data
follows the Binding Revocation Indication message as in Figure 5
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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| B.R. Type = 1 | R. Trigger |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence # |P|V|G|A| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Mobility options .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Figure 5: Binding Revocation Indication Message
Revocation Trigger
8-bit unsigned integer indicating the event which triggered the
revoking node to send the BRI message. The Reserved and Per-MN
Revocation Trigger values are less than 128 except the reserved
values 250-255 as listed below. The per-MN revocation trigger
value is used when the BRI message intends to revoke one or more
bindings for the same mobile node. The Global Revocation Trigger
values are greater than 128 and less than 250 and used in the BRI
message with the Global (G) bit set for global revocation. The
following Revocation Trigger values are currently defined:
Reserved and Per-MN Revocation Trigger:
0 Reserved
1 Unspecified
2 Administrative Reason
3 Inter-MAG Handover - same Access Type
4 Inter-MAG Handover - different Access Type
5 Inter-MAG Handover - Unknown
6 User Initiated Session(s) Termination
7 Access Network Session(s) Termination
8 Possible Out-of Sync BCE State
250-255 Reserved For Testing Purposes only
All other values are Reserved
Global Revocation Trigger:
128 Per-Peer Policy
129 Revoking Mobility Node Local Policy
Sequence #
A 16-bit unsigned integer used by the sending mobility node to
match a returned Binding Revocation Acknowledgement with this
Binding Revocation Indication. This sequence number could be a
random number. At any time, implementations MUST ensure that
there is no collision between the sequence numbers of all
outstanding Binding Revocation Indication Messages.
Proxy Binding (P)
The Proxy Binding (P) bit is set by the sending mobility node to
indicate that the revoked binding(s) is a PMIPv6 binding.
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IPv4 HoA Binding Only (V)
The IPv4 HoA Binding Only (V) bit is set by the sending mobility
node, home agent or local mobility anchor, to indicate to the
receiving mobility entity the termination of the IPv4 Home Address
binding only as in Section 7.1, and Section 8.1.1.
Global (G)
The Global (G) bit is set by the sending mobility node, LMA or
MAG, to indicate the termination of all Per-Peer mobility Bindings
or Multiple Bindings which share a common identifier(s) that are
served by the sending and receiving mobility entities as in
Section 8.1.1 and Section 9.2.1.
Acknowledge (A)
The Acknowledge (A) bit is set by the sending mobility node, e.g.
LMA, HA, or MAG, to request a Binding Revocation Acknowledgement
be returned upon receipt of the Binding Revocation Indication as
in Section 7.1, Section 8.1.1, and Section 9.2.1. If Acknowledge
(A) bit is set in the BRI message, the sending mobility node
follows Section 6.3 for retransmitting the BRI message.
Reserved
These fields are unused. They MUST be initialized to zero by the
sender and MUST be ignored by the receiver.
Mobility Options
Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field
contains zero or more TLV-encoded mobility options. This document
does not define any new mobility option. The receiver MUST ignore
and skip any options which it does not understand. These mobility
option(s) are used by the receiving mobility entity to identify
the specific binding or bindings that the sending mobility entity
requesting to be revoked.
The following options are valid in a Binding Revocation Indication:
o Home Network Prefix option [RFC5213]. This option MAY be used
only when the (P) bit is set. This option MUST be present when
the BRI is used to revoke a single Proxy MIPv6 binding cache
entry.
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o Mobile Node Identifier Option [RFC4283]. This option MUST be
present when the (P) bit is set. Additionally, if the Global (G)
bit is set by the mobile access gateway, this option MUST carry
the MAG identity. In this specification, only Mobile Node
Identifier option with subtype 1 is required and other subtypes
are currently not supported.
o Binding Identifier mobility option [ID-MCoA]. This option MUST be
present if the sending mobility entity requests to terminate one
binding of a multiple care-of addresses bindings for the same
mobile node. The sending mobility entity may include more than
one of the BID mobility options.
o IPv4 Home Address option which contains the mobile node home IPv4
address [RFC5555]. This option MUST only be included when the
IPv4 HoA Binding only (V) bit is set.
o Alternate Care-of Address mobility option [RFC3775]. This option
MAY be included to indicate the Care-of Address of the mobile
node's binding that is being revoked. In the case when the Global
(G) bit set, this option identifies all the mobility bindings that
share the same care-of address. Additionally, if the Global (G)
bit set, more than one Alternate Care-of Address mobility options
MAY be present in the Binding Revocation Indication message.
If no mobility options are present in this message, 4 octets of
padding are necessary and the Header Len field of the Binding
Revocation Message will be set to 1.
5.2. Binding Revocation Acknowledgement Message
The Binding Revocation Acknowledgement (BRA) message is a Binding
Revocation Message which has a MH type <IANA-TBD> and a Binding
Revocation Type value of 2. It is used to acknowledge the receipt of
a Binding Revocation Indication message described in Section 5.1.
This packet is sent as described in Section 8.2.2, Section 9.1.2, and
Section 10.2.
When the value 2 is indicated in the Binding Revocation type field of
the Binding Revocation Message, the format of the Binding Revocation
Message Data follows the Binding Revocation Acknowledgement message
as in Figure 6
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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
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| B.R. Type = 2 | Status |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence # |P|V|G| Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
. .
. Mobility options .
. .
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: Binding Revocation Acknowledgement Message
Status
8-bit unsigned integer indicating the result of processing the
Binding Revocation Indication message by the receiving mobility
entity. Values of the Status field less than 128 indicate that
the Binding Revocation Indication was processed successfully by
the receiving node. Values greater than or equal to 128 indicate
that the Binding Revocation Indication was rejected by the
receiving node. The following status values are currently
defined:
0 success
1 partial success
128 Binding Does NOT Exist
129 IPv4 Home Address Option Required
130 Global Revocation NOT Authorized
131 Revoked Mobile Nodes Identity Required
132 Revocation Failed - MN is Attached
133 Revocation Trigger NOT Supported
134 Revocation Function NOT Supported
Sequence #
The sequence number in the Binding Revocation Acknowledgement is
copied from the Sequence Number field in the Binding Revocation
Indication. It is used by the revoking mobility entity, e.g., HA,
LMA, MAG, in matching this Binding Revocation Acknowledgement with
the outstanding Binding Revocation Indication.
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Proxy Binding (P)
The Proxy Binding (P) bit is set if the (P) bit is set in the
corresponding Binding Revocation Indication message.
IPv4 HoA Binding Only (V)
The IPv4 HoA Binding Only (V) bit is set if the (V) bit is set in
the corresponding Binding Revocation Indication message.
Global (G)
The Global (G) bit is set if the (G) bit is set in the
corresponding Binding Revocation Indication message.
Reserved
These fields are unused. They MUST be initialized to zero by the
sender and MUST be ignored by the receiver.
Mobility Options
Variable-length field of such length that the complete Mobility
Header is an integer multiple of 8 octets long. This field
contains zero or more TLV-encoded mobility options. In the case
when the Status field is set to success, no mobility option is
required. The mobility option(s) is usually used to communicate
information of the bindings that failed the revocation procedure.
The following mobility options are valid in a Binding Revocation
Acknowledgement:
o Home Network Prefix option [RFC5213]. This option MAY be included
only when the (P) bit is set.
o Mobile Node Identifier Option [RFC4283]. This option MAY be
included when the (P) bit is set. This option SHOULD be included
if the Home Network Prefix option is included.
o Binding Identifier mobility option [ID-MCoA]. This option MAY be
included to indicate the specific BID that the receiving node
failed to revoke.
If no options are present in this message, 4 octets of padding are
necessary and the Header Len field of the Binding Revocation Message
will be set to 1.
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6. Binding Revocation Process Operation
The following subsections describe the details of the generic binding
revocation process as used by the different mobility entities.
6.1. Sending Binding Revocation Messages
When sending a Binding Revocation message, the sending mobility node,
initiator, constructs the packet as it would any other Mobility
Header with the exception of setting the MH Type field to <IANA-TBD>.
In addition, the initiator, MUST construct the Binding Revocation
Message Data following the format of the Binding Revocation
Indication message as described in Section 5.1. In the BRI message,
the initiator MUST set the Sequence Number field to a valid sequence
number for Binding Revocation. Since sending Binding Revocation
Indication message is not done on a regular basis, a 16 bit sequence
number field is large enough to allow the initiator to match the
Binding Revocation Acknowledgement to the associated Binding
Revocation Indication using the sequence number field only.
However, when the responder acknowledges the Binding Revocation
Indication message, the responder MUST construct the Binding
Revocation message packet as it would any other Mobility Header with
the exception of setting the MH Type field to <IANA-TBD>. It also
MUST construct the Binding Revocation Message Data following the
format of the Binding Revocation Acknowledgement message as described
in Section 5.2. In this case, the responder MUST set the Sequence
Number field by copying the value from the Sequence Number field of
the received Binding Revocation Indication. Additionally, it MUST
set the status field to a valid value that reflects the processing of
the received Binding Revocation Indication message.
The Binding Revocation Indication and Binding Revocation
Acknowledgement messages MUST be protected using the same underlying
security association, e.g., IPsec, that is being used between the two
peers to protect the mobile node's Mobile IPv6 and its extensions
binding registration signaling. If IPsec is not used as the
underlying security mechanism to protect the binding registration
signaling, the used underlying security mechanism MUST provide
protection against all identified security threats as described under
Security Considerations in [RFC3775] and [RFC5213].
6.2. Receiving Binding Revocation Messages
When receiving a Binding Revocation message, the receiving mobility
node MUST verify the Mobility Header as described in section 9.2. of
[RFC3775]. If the packet is dropped due to failing any of the
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Mobility Headers test check, the receiving node MUST follow the
processing rules as in Section 9.2 of [RFC3775]. If the receiving
node does not support the Binding Revocation Indication message and
does not recognize the new MH type, it sends a Binding Error message
with the Status field set to 2 as described in [RFC3775].
Since some mobility entities, e.g., local mobility anchor and mobile
access gateway, are allowed to send Binding Revocation Indication and
receive Binding Revocation Acknowledgement for different cases,
therefore, if IPsec is used to secure signaling between the local
mobility anchor and mobile access gateway, it prevents any of them
from processing a Binding Revocation message that was not constructed
by an authorized party.
Upon receiving a packet carrying a Binding Revocation Indication or
Binding Revocation Acknowledgement, the receiving mobility entity
MUST verify that the packet was received protected by the security
association that is being used to protect the binding registration
and Binding Revocation signaling between the two peers, e.g., an
IPsec SA.
Upon receiving a packet carrying a Binding Revocation
Acknowledgement, the receiving mobility entity, initiator, MUST
validate that sequence number in the Sequence Number field matches
the sequence number of an outstanding Binding Revocation Indication
that was sent by the initiator. If the sequence number does not
match any sequence number of any of the outstanding Binding
Revocation Indication, the receiving node MUST silently discard the
message but MAY log the event.
If a mobility node receives a Binding Revocation Indication message
with the Revocation Trigger field is set to a value that the mobility
node does not support and the Acknowledge (A) bit is set, the
receiving mobility node SHOULD reject the Binding Revocation
Indication message by sending a Binding Revocation Acknowledgement
message with the Status field set to "Revocation Trigger NOT
Supported".
If a mobility node receives a Binding Revocation Indication message
with a Revocation Trigger value that is NOT allowed with the Binding
Revocation Indication message intent, e.g., the Global (G) bit set
and the Revocation Trigger field value is a per-MN specific, the
receiving mobility node SHOULD reject the Binding Revocation
Indication message by sending a Binding Revocation Acknowledgement
message with the Status field set to "Revocation Function NOT
Supported".
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6.3. Retransmission of Binding Revocation Indication
If the sending mobility entity set the Acknowledge (A) bit in the BRI
and does not receive a Binding Revocation Acknowledgement in response
to the outstanding Binding Revocation Indication before the
InitMINDelayBRIs timer expires, the mobility entity, e.g. LMA,
SHOULD retransmit the same BRI message up to the BRIMaxRetriesNumber
as defined in Section 11. However, if the sending mobility entity
does not set the Acknowledge (A) bit in the BRI, the sending mobility
entity SHOULD NOT retransmit the Binding Revocation Indication
message.
The retransmissions by the sending mobility entity MUST use an
exponential back-off process in which the timeout period is doubled
upon each retransmission, until either the node receives a response
or the timeout period reaches the value MAX_BRACK_TIMEOUT. The
sending mobility entity MAY continue to send these messages at this
slower rate up to the BRIMaxRetriesNumber.
If the revoking mobility entity does not receive a Binding Revocation
Acknowledgement message after the BRIMaxRetriesNumber of retransmits
have been sent, the revoking mobility entity can clean the mobile
node binding cache and all resources associated with this binding.
The revoking mobility entity may log the event.
7. Home Agent Operation
7.1. Sending Binding Revocation Indication
To terminate a mobile node registration and its current binding with
the home agent, the home agent sends a packet to the mobile node
containing a Binding Revocation Indication, with the packet
constructed as follows:
o The Acknowledge (A) bit MAY be set to request the mobile node to
send a Binding Revocation Acknowledgement upon receipt of the
Binding Revocation Indication.
o The Revocation Trigger field MUST be set to indicate to the mobile
node the reason for revoking its IP mobility binding with the home
agent. The Revocation Trigger may be used by the mobile node to
take further steps if necessary.
o The Binding Revocation Indication MUST be sent using a Type 2
routing header which contains the mobile node's registered IPv6
home address for the binding being revoked.
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o The care-of address for the binding MUST be used as the
destination address in the packet's IPv6 header, unless an
Alternate Care-of Address mobility option is included in the
Binding Revocation Indication. If an Alternate Care-of Address
option is included in the Binding Revocation Indication message,
the destination address in the packet's IPv6 header SHOULD be set
to the source IP address of the packet that carried the latest
successful Binding Update with the Alternate Care-of address
included.
o If the home agent needs to only revoke the mobile node's IPv4 home
address binding, the home agent MUST set the IPv4 HoA Binding Only
(V) bit and MUST include the mobile node's registered IPv4 home
address that is being revoked in the IPv4 Home Address option.
The Acknowledge (A) bit in the Binding Revocation Indication requests
the mobile node to return a Binding Revocation Acknowledgement in
response to this Binding Revocation Indication. As described in
Section 6.3, the home agent SHOULD retransmit this Binding Revocation
Indication to the mobile node before terminating its IP connection
until it receives a matching Binding Revocation Acknowledgement or
the BRIMaxRetransmitNumber has been reached.
When the home agent sends a Binding Revocation Indication to the
mobile node with the Acknowledge (A) bit set, the home agent sets a
flag in the mobile node BCE to indicate that revocation is in
progress and starts the InitMINDelayBRIs timer. The home agent
maintains the mobile node BCE in this state until it receives a
Binding Revocation Acknowledgement or retransmits the Binding
Revocation Indication message as described in Section 6.3.
In a race condition case, the home agent may receive a Binding Update
from the mobile node while the mobile node's BCE has the revocation
in progress flag set, the home agent SHOULD handle this case based on
the reason for sending the Binding Revocation Indication message and
its local policy. In this case, if the home agent accepts the
Binding Update, it needs to update the mobile node BCE accordingly,
e.g. removing the revocation in progress flag.
When the home agent needs to revoke one or more of a mobile node
bindings that were created using Multiple Care-of address
registration as in [ID-MCoA], the home agent MUST include all the
related BID mobility options that identify these bindings in the
Binding Revocation Indication message. In the case when the home
agent needs to revoke all of the mobile node bindings, the home agent
SHOULD NOT include any of the BID mobility options.
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7.2. Receiving Binding Revocation Acknowledgement
When the home agent receives a packet carrying a valid Binding
Revocation Acknowledgement that was successfully processed as in
Section 6.2, the home agent SHOULD examine the Status field as
follows:
o If the Status field indicates that the Binding Revocation
Indication was processed successfully, the home agent MUST delete
the current timer and the mobile node bindings and all related
resources.
o If the Status field indicates any value other than success, the
home agent SHOULD examine any mobility options included in the
Binding Revocation Acknowledgement. In this case, it is based on
the home agent local policy how to handle the mobile node BCE.
The home agent MAY log the appropriate event to reflect the
received status.
8. Local Mobility Anchor Operation
8.1. Binding Revocation Initiator
8.1.1. Sending Binding Revocation Indication
To terminate a mobile node PMIPv6 registration and its current
binding with the local mobility anchor, the local mobility anchor
sends a packet to the mobile access gateway containing a Binding
Revocation Indication message following the procedure in Section 6.1
and the following rules:
o The Acknowledge (A) bit MAY be set to request the mobile access
gateway to send a Binding Revocation Acknowledgement upon receipt
of the Binding Revocation Indication.
o The Proxy Mobile IP (P) bit MUST be set to indicate that the
binding being revoked is a PMIPv6 binding.
o The Revocation Trigger field MUST be set to indicate to the mobile
access gateway the reason for removing the specified mobile node
PMIPv6 binding at the local mobility anchor. The Revocation
Trigger may be used by the mobile access gateway to learn the
mobile node's latest movement.
o The packet MUST contain the Mobile Node Identifier, MN-ID, option
which contains the mobile node's NAI that was used in the Proxy
Binding Update during the mobile node registration.
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o If the Mobile Node Identifier, MN-ID, is registered in more than
one of the mobile node's BCE and the local mobility anchor does
NOT need to revoke all of the mobile node's bindings, the Binding
Revocation Indication message MUST contain another identifier to
uniquely identify the mobile node binding(s) that is being
revoked, e.g., at least one Home Network Prefix option which
contains the mobile node's registered Home Network Prefix (HNP)
for the binding being revoked.
o In case of revoking all Per-Peer bindings, the Global (G) bit MUST
be set and the Revocation Trigger MUST contain the value "Per-Peer
Policy" to request the mobile access gateway to remove all Per-
Peer bindings that are registered with the local mobility anchor
and this mobile access gateway.
o Whenever the Global (G) bit is set in the Binding Revocation
Indication, the Acknowledge (A) bit MUST be set to request the
mobile access gateway to send a Binding Revocation
Acknowledgement.
o The care-of address for the binding MUST be used as the
destination address in the packet's IPv6 header, unless an
Alternate Care-of Address mobility option is included in the
Binding Revocation Indication message. If an Alternate Care-of
Address option is included in the Binding Revocation Indication
message, the destination address in the packet's IPv6 header
SHOULD be set to the source IP address of the packet that carried
the latest successful Proxy Binding Update with the Alternate
Care-of address included.
The Acknowledge (A) bit in the Binding Revocation Indication requests
the mobile access gateway to return a Binding Revocation
Acknowledgement. If the local mobility anchor sets the Acknowledge
(A) bit in the Binding Revocation Indication message, the local
mobility anchor SHOULD retransmit the Binding Revocation Indication
message by following the procedure described in Section 6.3 until it
receives a matching Binding Revocation Acknowledgement or the
BRIMaxRetransmitNumber is reached before deleting the mobile node IP
tunnel to the mobile access gateway. The local mobility anchor MAY
delete the mobile node(s) IP tunnel immediately after sending the
initial Binding Revocation Indication and before receiving the
Binding Revocation Acknowledgement message.
When the local mobility anchor sends a Binding Revocation Indication
to the mobile access gateway to remove a specific binding and the
Acknowledge (A) bit is set, the local mobility anchor sets a flag in
the mobile node proxy BCE to indicate that revocation is in progress
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and starts the InitMINDelayBRIs timer. The local mobility anchor
SHOULD maintain the mobile node proxy BCE in this state until it
receives a Binding Revocation Acknowledgement or the
BRIMaxRetransmitNumber is reached. In the case when the local
mobility anchor sets the Revocation Trigger field to a value which
indicates inter-MAG handover, the local mobility anchor MAY switch
the mobile node IP tunnel to the target mobile access gateway before
sending the Binding Revocation Indication to the source mobile access
gateway.
In a race condition case, the local mobility anchor may receive a
Proxy Binding Update from the mobile access gateway while the mobile
node's proxy BCE has the revocation in progress flag set. The local
mobility anchor should handle this case based on the reason for
sending the Binding Revocation Indication message and its local
policy. In this case, if the local mobility anchor accepts the Proxy
Binding Update, it needs to update the mobile node proxy BCE
accordingly, e.g. removing the revocation in progress flag.
When the local mobility anchor needs to revoke all the mobile nodes
proxy BCEs that are registered with the local mobility anchor and the
mobile access gateway, it MUST set the Global (G) bit and set the
value of the Revocation Trigger field to "Per-Peer Policy". In this
case, the local mobility anchor MUST NOT include any mobility options
in the this Binding Revocation Indication message.
When the local mobility anchor needs to revoke all mobile nodes proxy
BCEs that belong to a specific realm and are registered with the
local mobility anchor and the mobile access gateway, the local
mobility anchor MUST set the Global (G) bit and set the value of the
Revocation Trigger field to "Revoking Mobility Node Local Policy".
In this case, the local mobility anchor MUST include a mobility
option in the Binding Revocation Indication that is shared among all
the impacted mobile nodes BCEs, e.g., the mobile node identifier
option, MN-ID option, with subtype value of 1. In this case, the NAI
value in the MN-ID MUST follow the format where the content after the
"@" character defines the realm which is shared amongst all of the
impacted mobile nodes proxy BCEs. As an example: @example.com
identifies all mobile nodes which their MN-ID value contain
"example.com" as the realm, e.g., "1234abdelta@example.com",
"axxxyzd@example.com", and "abcdefg.xyz123@example.com", but not
"1234abdelta@foo.example.com".
When the local mobility anchor needs to revoke a subgroup of the
mobile nodes proxy BCEs that belong to a specific realm and are
registered with the local mobility anchor and the mobile access
gateway, the local mobility anchor MUST set the Global (G) bit and
set the value of the Revocation Trigger field to "Revoking Mobility
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Node Local Policy". In this case, the local mobility anchor MUST
include an additional mobility option to the mobile node identifier
option, MN-ID option, with subtype value of 1. In other words, the
impacted mobile node BCEs are those which have a MN-ID with a realm
as specified above and, e.g., are assigned the same proxy care-of
address as the one included in the Alternate Care-of address mobility
option.
When the mobile node is registered with multiple Home Network
Prefixes for the same proxy care-of address, the local mobility
anchor SHOULD include a HNP option for each registered HNP in the
Binding Revocation Indication. Alternatively, it MAY include only
the mobile node identifier, MN-ID, option with the mobile node NAI
included to indicate to the mobile access gateway to remove all
bindings of the specified mobile node NAI in the MN-ID option.
According to Proxy Mobile IPv6 specification [RFC5213], if the local
mobility anchor receives a Proxy Binding Update message from a new
mobile access gateway for extending the binding lifetime of the only
BCE of this mobile node with the Handoff Indicator value is set to
"Inter-MAG Handover - Unknown", the local mobility anchor waits a
period of MaxDelayBeforeNewBCEAssign to receive a de-registration
message from the previous mobile access gateway before updating the
mobile node's BCE with the new point of attachment. If a de-
registration message is not received,, the local mobility anchor
considers the received Proxy Binding Update message as a request for
a new BCE and if processed successfully, the local mobility anchor
assigns a different HNP for the new BCE.
This document updates the local mobility anchor's behavior in this
case. If the local mobility anchor supports the binding revocation
mechanism as described in this document, it SHOULD proactively send a
Binding Revocation Indication message to the previous mobile access
gateway instead of waiting for a de-registration from the previous
mobile access gateway. In the Binding Revocation Indication message,
the Acknowledge (A) bit MUST be set and the Revocation Trigger MUST
be set to "Inter-MAG Handover - Unknown".
If the local mobility anchor sent a Binding Revocation Indication
message with the Revocation Trigger field set to "Inter-MAG Handover
- Unknown" and while waiting for a Binding Revocation Acknowledgement
response, the following are possible conditions that the local
mobility anchor MUST handle as specified below:
o If the local mobility anchor receives a successful Binding
Revocation Acknowledgement message or a de-registration message
from the previous mobile access gateway, the local mobility anchor
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MUST update the mobile node BCE in a similar way as if it received
a de-registration message as described in [RFC5213].
o If the local mobility anchor receives a Binding Revocation
Acknowledgement message with the status field set to "Revocation
Failed - MN is Attached", the local mobility anchor SHOULD update
the mobile node BCE in a similar way as if it did NOT receive a
de-registration before the MaxDelayBeforeNewBCEAssign timer
expires by creating a new BCE as described in [RFC5213].
o If the local mobility anchor did not receive a Binding Revocation
Acknowledgement message nor a de-registration Proxy Binding Update
from the previous mobile access gateway after it exhausted all of
the Binding Revocation Indication message retransmissions as
described in Section 6.3, the local mobility anchor SHOULD update
the mobile node's BCE in a similar way as if it did NOT receive a
de-registration before the MaxDelayBeforeNewBCEAssign timer
expires by creating a new BCE as described in [RFC5213]. Note
that the local mobility anchor SHOULD use the recommended number
of retransmissions for the Binding Revocation Indication message
as described in Section 11 to avoid delaying the creation of a new
binding cache entry for too long, if the mobile node is actually
attaching to the new MAG with a different interface.
When the mobile node is registered with an IPv4 proxy home address in
addition to the Home Network Prefix where both of the IPv4 pHoA and
HNP are bound to the same proxy CoA, the local mobility anchor MAY
revoke the mobile node IPv4 proxy HoA binding to the current mobile
node proxy CoA while maintaining the mobile node binding of the HNP
to its current pCoA as part of the mobile node BCE. In this case, if
the local mobility anchor decides to revoke the mobile node IPv4
proxy HoA only, it MUST send a Binding Revocation Indication message
following the procedure in Section 6.1 and the following rules:
o The IPv4 HoA Binding Only (V) bit MUST be set in the BRI to
indicate that only the IPv4 home address binding is being revoked.
o The Acknowledge (A) bit MUST be set to request the mobile access
gateway to send a Binding Revocation Acknowledgement message.
o The IPv4 Home Address option MUST be included with the mobile
node's registered IPv4 home address that is being released in
addition to the MN-ID option.
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o The mobile node Home Network Prefix option MUST NOT be included.
o The Revocation Trigger field MUST be set to an appropriate value,
e.g. "User Initiated Session(s) Termination".
8.1.2. Receiving Binding Revocation Acknowledgement
When the local mobility anchor receives a packet carrying a valid
Binding Revocation Acknowledgement that was successfully processed as
in Section 6.2 and if the mobile node BCE is in the state of
Revocation in progress, the local mobility anchor SHOULD examine the
Status field before clearing the mobile node related resources as
follows:
o If the Status field indicates that the BRI was processed
successfully, the local mobility anchor MUST delete the current
timer and the mobile node proxy bindings and all associated
resources.
o If the Status field indicates partial success value or MN binding
does not exist, the local mobility anchor SHOULD examine the
mobility options that are included in the Binding Revocation
Acknowledgement, if any, before deleting the current timer and the
mobile node associated proxy bindings and other related resources.
It is based on the local mobility anchor local policy how to
handle the mobile node BCE(s) that the mobile access gateway
indicated it failed the revocation procedure, however, the LMA MAY
log the event.
8.2. Binding Revocation Responder
8.2.1. Receiving Binding Revocation Indication
When the local mobility anchor receives a packet carrying a Binding
Revocation Indication that was successfully processed as in
Section 6.2, the local mobility anchor SHOULD in addition process the
message as follows:
o Validate that Binding Revocation Indication is formatted as in
Section 5.1 and if the (P) bit is set, the local mobility anchor
MUST validate that all impacted binding(s) have the proxy binding
flag set.
o If the Global (G) bit is set and the Revocation Trigger field
value is "Per-Peer Policy", the LMA MUST validate that the Proxy
(P) bit is set and the MN-ID option is present with the mobile
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access gateway identity included. In addition, the local mobility
anchor MUST verify that the identified mobile access gateway as
per the value in the MN-ID option is authorized to use the global
revocation with revocation trigger value "Per-Peer Policy", see
Section 13. If the Acknowledge (A) bit is set and the local
mobility anchor processes the Global Binding Revocation Indication
message successfully, it MUST send a successful Binding Revocation
Acknowledgement message. However, if the Acknowledge (A) bit is
not set, the local mobility anchor SHOULD silently discard the
Binding Revocation Indication message.
o If the Global (G) bit is set and the Revocation Trigger value is
"Per-Peer Policy", and only the mobile node identifier, MN-ID,
option is included, the local mobility anchor MUST revoke all
mobile nodes bindings which proxy CoA is the one used as the
source of the IPv6 packet that carried the Binding Revocation
Indication. However, if one or more Alternate Care-of Address
options are included in addition to the mobile node identifier
option, the local mobility anchor MUST revoke all mobile nodes
bindings which proxy Care-of Address matches one of the Care-of
address(es) in the Alternate Care-of Address option(s).
o The local mobility anchor identifies all impacted mobile nodes
bindings and if the Acknowledge (A) bit is set, the local mobility
anchor MUST send a Binding Revocation Acknowledgement following
Section 8.2.2 using the appropriate status code.
o If the Global (G) bit is not set, the local mobility anchor SHOULD
use the included mobility options to identify the impacted mobile
node binding as follows:
1. If only the mobile node identifier, MN-ID, option is included,
the local mobility anchor MUST revoke all bindings for this
mobile node which use the specified mobile node NAI including
the IPv4 Home Address binding(s) if present.
2. If the mobile node identifier, MN-ID, and one Home Network
Prefix option are included, the local mobility anchor MUST
only remove the specified mobile node proxy binding.
3. If the mobile node identifier, MN-ID, option and more than one
Home Network Prefix options are included, the local mobility
anchor MUST remove all bindings which are referenced by these
Home Network Prefixes for the specified mobile node NAI.
4. If the IPv4 HoA binding Only (V) bit is set and the mobile
node identifier, MN-ID, option and the IPv4 Home Address
option are included, the local mobility anchor MUST remove
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only the IPv4 HoA address binding to the mobile node current
proxy Care-of address.
The Revocation Trigger field value in the received Binding Revocation
Indication could be used by the local mobility anchor to log an event
or update some local parameters which tracks the state of the peer
mobile access gateway.
8.2.2. Sending Binding Revocation Acknowledgement
When the local mobility anchor receives a valid Binding Revocation
Indication with the Acknowledge (A) bit set and after processing the
Binding Revocation Indication message, the local mobility anchor
sends a packet to the mobile access gateway containing a Binding
Revocation Acknowledgement following the process in Section 6.1 and
the following:
o If the (P) bit was set in the received Binding Revocation
Indication, the local mobility anchor MUST set the (P) bit in the
Binding Revocation Acknowledgement.
o If the Global (G) bit was set in the received Binding Revocation
Indication, the local mobility anchor MUST set the Global (G) bit
in the Binding Revocation Acknowledgement.
o If the IPv4 HoA Binding Only (V) bit was set in the received
Binding Revocation Indication, the local mobility anchor MUST set
the (V) bit in the Binding Revocation Acknowledgement.
o The local mobility anchor MUST set the Status field to a valid
code that reflects the processing of the received Binding
Revocation Indication. If the mobile access gateway is not
authorized to use the Per-Peer Global revocation feature or the
received Binding Revocation Indication message has the Global (G)
bit set and the Revocation Trigger field is set to "Per-Peer
Policy", but the MN-ID option is not included, the local mobility
anchor MUST set the Status field to (Global Revocation NOT
Authorized).
o In the case that one of the bindings identified in the received
Binding Revocation Indication message has already been released,
the local mobility anchor MAY set the Status field to partial
success and in this case it MAY include the mobile node identifier
or the Home Network Prefix option to identify the binding(s) that
failed the revocation procedure.
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o The destination IP address of the IPv6 packet of the Binding
Revocation Acknowledgement is set to the source IP address of the
received Binding Revocation Indication.
9. Mobile Access Gateway Operation
9.1. Binding Revocation Responder
9.1.1. Receiving Binding Revocation Indication
Upon receiving a packet carrying a Binding Revocation Indication, the
mobile access gateway MUST validate and process the packet according
to Section 6.2 and the following:
o Binding Revocation Indication MUST be formatted as in Section 5.1
and the (P) bit is set.
o If the Acknowledge (A) bit in the received Binding Revocation
Indication is set, the mobile access gateway MUST send a Binding
Revocation Acknowledgement following Section 9.1.2 using the
appropriate status value.
o If the Global (G) bit is set and the Revocation Trigger field
value is "Per-Peer policy", the mobile access gateway identifies
all bindings that are registered at the local mobility anchor and
the mobile access gateway. If this Binding Revocation Indication
message does not include any mobility options and the Acknowledge
(A) bit is set, the mobile access gateway MUST send a successful
Binding Revocation Acknowledgement with the appropriate status
code to the local mobility anchor. Since such Binding Revocation
Indication message impacts all mobility sessions that are
registered with the mobile access gateway and the local mobility
anchor, no mobility option MUST be present in this Binding
Revocation Indication message. However, if this received Binding
Revocation Indication message includes any mobility option and the
Acknowledge (A) bit set, the mobile access gateway MUST send a
Binding Revocation Acknowledgement with status code set to
"Revocation Function NOT Supported".
o If the Global (G) bit is set and the Revocation Trigger field
value is "Revoking Mobility Node Local Policy", the mobile access
gateway MUST identify all bindings that are registered at the
local mobility anchor and the mobile access gateway and share the
criteria based on the mobility option(s) included in the Binding
Revocation Indication. In this case, the mobile access gateway
MUST verify that at least the MN-ID option with the subtype value
of 1 is included in the Binding Revocation Indication and it is
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formatted as specified is Section 8.1.1. If the mobile access
gateway successfully process the Binding Revocation Indication and
the Acknowledge (A) bit is set, the mobile access gateway MUST
send a successful Binding Revocation Acknowledgement with the
appropriate status code to the local mobility anchor.
o If the Global (G) bit is set and the Revocation Trigger field
value is "Revoking Mobility Node Local Policy", and no mobility
options are included in the Binding Revocation Indication message
or the mobile access gateway is not able to identify the impacted
mobile nodes bindings based on the included mobility options, the
mobile access gateway MUST treat this as an error scenario. In
this case, if the Acknowledge (A) bit is set, the mobile access
gateway MUST send a Binding Revocation Acknowledgement message
with status "Revoked Mobile Nodes Identity Required".
o If the Revocation Trigger field value in the received Binding
Revocation Indication message indicates inter-MAG handover, e.g.,
Inter-MAG Handover - Unknown, and the Acknowledge (A) bit is set,
the mobile access gateway uses the mobility option(s) included in
the Binding Revocation Indication message to identify the mobile
node binding. The mobile access gateway SHOULD ensure that the
mobile node is no longer attached to the mobile access gateway
before sending a successful Binding Revocation Acknowledgement
message to the local mobility anchor. However, if the mobile
access gateway verified that the mobile node is still directly
attached, the mobile access gateway MUST set the status field in
the Binding Revocation Acknowledgement to "Revocation failed - MN
is Attached".
o If the IPv4 HoA Binding Only (V) bit is set, the mobile access
gateway uses the MN-ID option to identify the mobile node binding
entry in the Binding Update List (BUL). It MUST verify that the
IPv4 address included in the IPv4 Home Address option in the
received Binding Revocation Indication is the same as the IPv4
proxy HoA that is assigned to the mobile node. After the mobile
access gateway successfully validates the received IPv4 home
address as the mobile node IPv4 HoA, it MUST consider this as an
indication to ONLY release the mobile node IPv4 proxy HoA binding
to the mobile node current proxy CoA. Consequently, it MUST
continue to maintain the mobile node IPv6 proxy HoA or HNP binding
to the current mobile node proxy CoA as part of the mobile node
binding in the BUL entry and release all resources associated with
the MN IPv4 proxy HoA binding to the MN pCoA. In this case, if
the Acknowledge (A) bit is set, the mobile access gateway MUST
send a Binding Revocation Acknowledgement message with the Status
field is set to success. On the other hand, if the mobile access
gateway is able to identify the mobile node binding using the
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MN-ID but failed to identify the received IPv4 proxy HoA, it MUST
send a Binding Revocation Acknowledgement with Status field is set
to "Binding Does NOT Exist".
The Revocation Trigger field value in the received Binding Revocation
Indication could be used by the mobile access gateway to define what
actions the mobile access gateway could do to inform the mobile node
that its IP connectivity to the current HNP has been terminated,
e.g., if the Revocation Trigger field is set to "Administrative
Reason", the mobile access gateway may send a RA message after
setting the Home Network Prefix valid lifetime to zero.
9.1.2. Sending Binding Revocation Acknowledgement
When the mobile access gateway receives a valid Binding Revocation
Indication with the Acknowledge (A) bit set and after processing it,
the mobile access gateway MUST send a packet to the local mobility
anchor containing a Binding Revocation Acknowledgement according to
the procedure in Section 6.1 and the following:
o The mobile access gateway MUST set the (P) bit in the Binding
Revocation Acknowledgement if it is set in the received Binding
Revocation Indication.
o If the Global (G) bit was set in the received Binding Revocation
Indication, the mobile access gateway MUST set the Global (G) bit
in the Binding Revocation Acknowledgement.
o If the IPv4 HoA Binding Only (V) bit was set in the received
Binding Revocation Indication, the mobile access gateway MUST set
the (V) bit in the Binding Revocation Acknowledgement.
o The mobile access gateway MUST set the Status field to a valid
code that reflects the processing of the received Binding
Revocation Indication.
o In the case that one or more of the bindings identified in the
received Binding Revocation Indication message has already been
released before receiving the Binding Revocation Indication, the
mobile access gateway MAY set the Status field to "partial
success" and include the mobile node identifier, MN-ID, or the
Home Network Prefix option to identify the binding(s) that failed
to be removed as part of the revocation procedure.
o The destination IP address of the IPv6 packet of the Binding
Revocation Acknowledgement is set to the source IP address of the
received Binding Revocation Indication.
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9.2. Binding Revocation Initiator
9.2.1. Sending Binding Revocation Indication
The mobile access gateway could send a Binding Revocation Indication
message to indicate the termination of multiple mobile node bindings,
e.g., when using the global revocation with the Global (G) bit set.
In this case when an event occurs which requires the mobile access
gateway to inform the local mobility anchor to terminate all mobile
nodes bindings which are registered at the local mobility anchor and
the mobile access gateway, the mobile access gateway sends a Binding
Revocation Indication message following Section 6.1 and the
following:
o The Acknowledge (A) bit MUST be set to request the local mobility
anchor to send a Binding Revocation Acknowledgement upon receipt
of the Binding Revocation Indication.
o The Proxy Binding (P) bit MUST be set to indicate that the
binding(s) being revoked is a PMIPv6 binding.
o The Global (G) bit MUST be set and the Revocation Trigger MUST
contain a value of "Per-Peer Policy" in the Binding Revocation
Indication to request the local mobility anchor to remove all Per-
Peer bindings that are registered with the local mobility anchor
and this mobile access gateway. In this case, the MN-ID option
MUST be included in the Binding Revocation Indication and contain
the mobile access gateway identity. In addition, the mobile
access gateway MAY include one or more Alternate Care-of Address
option(s). The Alternate Care-of Address option(s) contain the
proxy Care-of address(es) the bindings of which are being impacted
by this Binding Revocation Indication message.
o The mobile access gateway address MAY be used as the source
address in the packet's IPv6 header.
The Acknowledge (A) bit in the Binding Revocation Indication requests
the local mobility anchor to return a Binding Revocation
Acknowledgement in response to this Binding Revocation Indication.
As described in Section 6.3, if the Acknowledge (A) bit is set, the
mobile access gateway SHOULD retransmit this Binding Revocation
Indication to the local mobility anchor until it receives a matching
Binding Revocation Acknowledgement or the BRIMaxRetransmitNumber is
reached. The mobile access gateway MAY delete the mobile nodes IP
tunnels immediately after sending the Binding Revocation Indication
and before receiving a Binding Revocation Acknowledgement message
from the LMA.
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9.2.2. Receiving Binding Revocation Acknowledgement
When the mobile access gateway receives a packet carrying a valid
Binding Revocation Acknowledgement that was successfully processed
according to Section 6.2, the mobile access gateway MUST process the
received Binding Revocation Acknowledgement as per the followings:
o When the mobile access gateway receives a packet carrying a valid
Binding Revocation Acknowledgement and the Global (G) and Proxy
Binding (P) bits are set and the mobile nodes BCEs are in the
state of Revocation in Progress, the mobile access gateway SHOULD
examine the Status field as follows:
* If the Status field indicates that the Binding Revocation
Indication was processed successfully, the mobile access
gateway MUST delete the current timer and the mobile nodes
proxy bindings and all associated resources.
* If the Status field indicates (Global Revocation NOT
Authorized), the mobile access gateway is not authorized to
participate in a Per-Peer Global Revocation. The mobile access
gateway SHOULD NOT retry sending a Binding Revocation
Indication with the Global (G) bit set and the Revocation
Trigger field value set to "Per-Peer Policy" to the same local
mobility agent. The mobile access gateway should raise an
alarm or log an event to indicate this rejection.
10. Mobile Node Operation
10.1. Receiving Binding Revocation Indication
Upon receiving a packet carrying a Binding Revocation Indication, the
mobile node MUST validate the packet according to Section 6.2 and the
following tests:
o The mobile node MUST verify that the IP address in the Type 2
routing header is its Home Address and that its Binding Update
List contains an entry for that Home Address. If one of the
tests, fails the mobile node SHOULD silently discard the received
Binding Revocation Indication message.
o If the Acknowledge (A) bit is set in the Binding Revocation
Indication and its Binding Update List contains an entry for the
IP address in the Type 2 routing header, the mobile node MUST send
a Binding Revocation Acknowledgement. However, in all other cases
when the Acknowledge (A) bit is set in the BRI, the mobile node
SHOULD sends a Binding Revocation Acknowledgement, the mobile node
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MUST do so according to Section 10.2.
o If the IPv4 HoA Binding Only (V) bit is set in the received BRI
message, the mobile node MUST verify that there is an IPv4 Home
Address option in the received Binding Revocation Indication and
the IPv4 address included in the IPv4 Home Address option is the
same as its IPv4 HoA that is assigned to the mobile node. If this
verification is successful, the mobile node MUST consider this
Binding Revocation Indication as an indication to ONLY release the
mobile node IPv4 HoA binding to its current Care-of Address.
Consequently, the mobile node MUST continue to maintain its IPv6
HoA binding to the current CoA as part of the mobile node binding
in the BUL entry and release all resources associated with the MN
IPv4 HoA binding. In this case, if the Acknowledge (A) bit is
set, the mobile node MUST send a Binding Revocation
Acknowledgement message with the Status field is set to "success".
On the other hand, if the IPv4 Home Address Option was NOT
included in the received BRI with the (V) bit set and the
Acknowledge (A) bit is set, the MN SHOULD send a Binding
Revocation Acknowledgement message with the Status field set to
"IPv4 Home Address Option Required". Additionally, if the IPv4
HoA received in the IPv4 Home Address Option is NOT the one
assigned to the mobile node, the mobile node SHOULD send a Binding
Revocation Acknowledgement with the status field set to "Binding
Does NOT Exist".
o The mobile node MUST verify that the (P) bit in the Binding
Revocation Indication is NOT set. If the (P) bit is set, the
mobile node MUST silently discard the Binding Revocation
Indication message.
o If the mobile node has registered multiple care-of addresses with
its home agent, the mobile node MUST verify which binding is being
revoked by examining the content of the Binding Revocation
Indication message. If the mobile node received a Binding
Revocation Indication with a single or more than one BID options
and its home address is included in the Type 2 routing header, the
mobile node MUST consider all of the care-of address(es)
binding(s), identified in the BID options, with this home address
as being revoked.
o If the mobile node has multiple Care-of Address bindings with its
home agent and received a Binding Revocation Indication, without
any BID option included and its home address was included in the
Type 2 routing header, the mobile node MUST consider all of its
registered care-of addresses bindings with this home address as
being revoked.
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The Revocation Trigger field value in the received Binding Revocation
Indication could be used by the mobile node to define what action the
mobile node could do to be able to register again and receive its IP
mobility service, e.g., contacting its home operator.
10.2. Sending Binding Revocation Acknowledgement
When the mobile node receives a Binding Revocation Indication from
its home agent, the mobile node processes the received Binding
Revocation Indication as in Section 10.1. If the mobile node is
required to send a Binding Revocation Acknowledgement message in
response to the received Binding Revocation Indication, the mobile
node sends a packet to its home agent containing a Binding Revocation
Acknowledgement according to the procedure in Section 6.1 and the
following:
o The mobile node MUST set the Status field to an appropriate value.
The mobile node sets the Status field to success to reflect that
it has received the Binding Revocation Indication and acknowledge
that its IP connectivity with its home agent has been revoked.
o The destination IP address of the IPv6 packet of the Binding
Revocation Acknowledgement is set to the source IP address of the
received IPv6 packet of the Binding Revocation Indication. The
Mobile Node MUST include its home address in the Home Address
Destination Option.
11. Protocol Configuration Variables
Any mobility entity which is allowed to invoke the binding revocation
procedure by sending a Binding Revocation Indication message SHOULD
allow the following variables to be configured.
BRI Maximum Number of Retries (BRIMaxRetriesNumber)
This variable specifies the maximum Number of times a mobility
entity can retransmit a Binding Revocation Indication message
before receiving a Binding Revocation Acknowledgement message.
The default value for this parameter is 1.
Initial Minimum Delay Between BRI messages (InitMINDelayBRIs)
This variable specifies the initial delay timeout in seconds
before the revoking mobility entity retransmits a BRI message.
The default is 1 second but not less than 0.5 seconds.
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Maximum BRA TIMEOUT (MAX_BRACK_TIMEOUT)
This variable specifies the maximum delay timeout in seconds
before the revoking mobility entity retransmits a BRI message.
The default is 2 seconds.
12. IANA Considerations
This specification defines a new Binding Revocation Message using a
new Mobility Header Type <IANA-TBD>, as described in Section 5. The
new Mobility Header type value needs to be assigned from the same
numbering space as allocated for the other Mobility Header types
registry.
This document also creates a new registry "Binding Revocation Type"
which indicates the type of the binding revocation message. The
current binding revocation message types are described in Section 5.1
and Section 5.2, and are the following:
0 Reserved
1 Binding Revocation Indication
2 Binding Revocation Acknowledgement
All other values are reserved
Future values of the Binding Revocation Type can be allocated using
Standards Action or IESG Approval [RFC5226].
In addition, this document also creates a second new registry for the
Revocation Trigger which indicates the reason behind sending the
Binding Revocation Indication message. The current Revocation
Trigger values are described in Section 5.1, and are the following:
Reserved and Per-MN Revocation Trigger Values:
0 Reserved
1 Unspecified
2 Administrative Reason
3 Inter-MAG Handover - same Access Type
4 Inter-MAG Handover - different Access Type
5 Inter-MAG Handover - Unknown
6 User Initiated Session(s) Termination
7 Access Network Session(s) Termination
8 Possible Out-of Sync BCE State
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250-255 Reserved For Testing Purposes only
All other values are Reserved
Global Revocation Trigger Values:
128 Per-Peer Policy
129 Revoking Mobility Node Local Policy
Future values of the Revocation Trigger can be allocated using
Standards Action or IESG Approval [RFC5226].
Furthermore, this document creates a third new registry "Status Code"
for the Status field in the Binding Revocation Acknowledgement
message. The current values are described in Section 5.2, and are
the following:
0 success
1 partial success
128 Binding Does NOT Exist
129 IPv4 Home Address Option Required
130 Global Revocation NOT Authorized
131 Revoked Mobile Nodes Identity Required
132 Revocation Failed - MN is Attached
133 Revocation Trigger NOT Supported
134 Revocation Function NOT Supported
Future values of the Status field can be allocated using Standards
Action or IESG Approval [RFC5226].
All fields labeled "Reserved" are only to be assigned through
Standards Action or IESG Approval.
13. Security Considerations
This specification allows the mobility node which initiates the
binding revocation procedure to revoke mobility session(s) that is
currently registered with it. It is NOT allowed for any mobility
node to revoke a mobile node mobility session that is not registered
with this mobility node.
The binding revocation protocol described in this specification uses
the same security association between the mobile node and the home
agent or the mobile access gateway and the local mobility anchor that
is being used to exchange the MIPv6 or PMIPv6 Binding Update and
Binding Acknowledgement signaling. If IPsec is used, the traffic
selectors associated with the SPD entry protecting the Binding Update
and Binding Acknowledgement MUST be extended to include Binding
Revocation Message MH type <IANA-TBD>. Extending the traffic
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selectors of the SPD entry in order to reuse the SA protecting the
Binding Update and Binding Acknowledgement (instead of creating new
ones) ensures that those SA will be up and running when the revoking
entity needs to send a binding revocation signaling message.
On the other hand, if IPsec is not used as the underlying security
mechanism to protect the Mobile IPv6 and its extensions binding
registration signaling, the used underlying security mechanism MUST
provide protection against all identified security threats as
described under Security Considerations in [RFC3775] and [RFC5213].
The Proxy Mobile IPv6 [RFC5213] requires the local mobility anchor to
restrict the creation and manipulation of proxy bindings to
specifically authorized mobile access gateways. Therefore, the
mobile access gateway which is authorized to create or manipulate the
mobile node proxy BCE is also authorized to revoke such mobile node
registration by sending a de-registration with lifetime of zero.
However, since bulk termination using Binding Revocation Indication
with the Global (G) bit set and the Revocation Trigger field set to
"Per-Peer Policy" impacts all mobility sessions that are registered
with the mobile access gateway and its local mobility anchor peer,
the local mobility anchor MUST be locally configurable to authorize
such specific functionality. Additional mechanisms, such as a policy
store or Authentication, Authorization, and Accounting (AAA) may be
employed, but these are outside the scope of this specification.
14. Acknowledgements
The authors would like to thank Ryuji Wakikawa, Bruno Mongazon-
Cazavet, Domagoj Premec, Arnaud Ebalard, Patrick Stupar, Vijay
Devarapalli, and Joel Hortelius for their review and comments of this
draft and all colleagues who have supported the advancement of this
draft effort.
15. References
15.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.
[RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support
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in IPv6", RFC 3775, June 2004.
[RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
(MIPv6)", RFC 4283, November 2005.
[RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K.,
and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008.
[ID-PMIP6-IPv4]
Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy
Mobile IPv6", draft-ietf-netlmm-pmip6-ipv4-support-15
(work in progress), August 2009.
[ID-MCoA] Wakikawa, R., Devarapalli, V., Ernst, T., and K. Nagami,
"Multiple Care-of Addresses Registration",
draft-ietf-monami6-multiplecoa-14 (work in progress),
May 2009.
[RFC5555] Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts and
Routers", RFC 5555, June 2009.
15.2. Informative References
[RFC3344] Perkins, C., "IP Mobility Support for IPv4", RFC 3344,
August 2002.
[RFC3543] Glass, S. and M. Chandra, "Registration Revocation in
Mobile IPv4", RFC 3543, August 2003.
Authors' Addresses
Ahmad Muhanna
Nortel
2221 Lakeside Blvd.
Richardson, TX 75082
USA
Email: amuhanna@nortel.com
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Mohamed Khalil
Nortel
2221 Lakeside Blvd.
Richardson, TX 75082
USA
Email: mkhalil@nortel.com
Sri Gundavelli
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134
USA
Email: sgundave@cisco.com
Kuntal Chowdhury
Starent Networks
30 International Place
Tewksbury, MA 01876
USA
Email: kchowdhury@starentnetworks.com
Parviz Yegani
Juniper Networks
1194 North Mathilda Avenue
Sunnyvale, CA 94089
USA
Email: pyegani@juniper.net
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