Internet DRAFT - draft-ietf-dmm-hnprenum
draft-ietf-dmm-hnprenum
DMM Working Group Z. Yan
Internet-Draft CNNIC
Intended status: Standards Track J. Lee
Expires: September 14, 2017 Sangmyung University
X. Lee
CNNIC
March 13, 2017
Home Network Prefix Renumbering in PMIPv6
draft-ietf-dmm-hnprenum-07
Abstract
In the basic Proxy Mobile IPv6 (PMIPv6) specification, a Mobile Node
(MN) is assigned with a Home Network Prefix (HNP) during its initial
attachment and the MN configures its Home Address (HoA) with the HNP.
During the movement of the MN, the HNP remains unchanged to keep
ongoing communications associated with the HoA. However, the current
PMIPv6 specification does not specify related operations when an HNP
renumbering has happened (e.g. due to change of service provider,
change of site topology, etc.). In this document, a solution to
support the HNP renumbering is proposed, as an optional extension of
the PMIPv6 specification.
Requirements Language
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]
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 14, 2017.
Yan, et al. Expires September 14, 2017 [Page 1]
Internet-Draft PMIPv6 HNP Renumbering March 2017
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Usage Scenarios . . . . . . . . . . . . . . . . . . . . . . . 2
3. HNP Renumbering Procedure . . . . . . . . . . . . . . . . . . 3
4. Session Connectivity . . . . . . . . . . . . . . . . . . . . 5
5. Message Format . . . . . . . . . . . . . . . . . . . . . . . 5
6. Other Issues . . . . . . . . . . . . . . . . . . . . . . . . 6
7. Security Considerations . . . . . . . . . . . . . . . . . . . 6
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 7
9.1. Normative References . . . . . . . . . . . . . . . . . . 7
9.2. Informative References . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
Network managers currently prefer Provider Independent (PI)
addressing for IPv6 to attempt to minimize the need for future
possible renumbering. However, a widespread use of PI addresses will
cause Border Gateway Protocol (BGP) scaling problems [RFC7010]. It
is thus desirable to develop tools and practices that make IPv6
renumbering a simpler process to reduce demand for IPv6 PI space
[RFC6879]. In this document, we aim to solve the HNP renumbering
problem when the HNP in PMIPv6 [RFC5213] is a PI prefix.
2. Usage Scenarios
There are a number of reasons why the HNP renumbering support in
PMIPv6 is useful and some scenarios are identified below:
o Scenario 1: the HNP set used by a PMIPv6 service provider is
assigned by a different Internet Service Provider (ISP), and then
Yan, et al. Expires September 14, 2017 [Page 2]
Internet-Draft PMIPv6 HNP Renumbering March 2017
the HNP renumbering MAY happen if the PMIPv6 service provider
switches to a different ISP.
o Scenario 2: multiple Local Mobility Anchors (LMAs) MAY be deployed
by the same PMIPv6 service provider, and then each LMA MAY serve
for a specific HNP set. In this case, the HNP of an MN MAY change
if the current serving LMA switches to another LMA but without
inheriting the assigned HNP set [RFC6463].
o Scenario 3: the PMIPv6 HNP renumbering MAY be caused by the re-
building of the network architecture as the companies split,
merge, grow, relocate, or reorganize. For example, the PMIPv6
service provider MAY reorganize its network topology.
In the scenario 1, we assume that only the HNP is renumbered while
the serving LMA remains unchanged and this is the basic scenario
considered in this document. In the scenario 2 and scenario 3, more
complex results MAY be caused, for example, the HNP renumbering MAY
happen due to the switchover of a serving LMA.
In the Mobile IPv6 (MIPv6) protocol, when a home network prefix
changes, the Home Agent (HA) will actively notify the new prefix to
its MN and then the renumbering of the Home Network Address (HoA) can
be well supported [RFC6275]. In the basic PMIPv6, the PMIPv6 binding
is triggered by a Mobile Access Gateway (MAG), which detects the
attachment of the MN. A scheme is also needed for the LMA to
immediately initiate the PMIPv6 binding state refreshment during the
HNP renumbering process. Although this issue is also mentioned in
Section 6.12 of [RFC5213], the related solution has not been
specified.
3. HNP Renumbering Procedure
When the HNP renumbering happens in PMIPv6, the LMA MUST notify a new
HNP to the MAG and then the MAG MUST announce the new HNP to the
attached MN accordingly. Also, the LMA and the MAG MUST update the
routing states for the HNP and the related addresses. To support
this procedure, [RFC7077] can be adopted which specifies an
asynchronous update from the LMA to the MAG about specific session
parameters. This document considers the following two cases:
(1) HNP is renumbered under the same LMA
In this case, the LMA remains unchanged as in the scenario 1 and
scenario 3. The operation steps are shown in Figure 1.
Yan, et al. Expires September 14, 2017 [Page 3]
Internet-Draft PMIPv6 HNP Renumbering March 2017
+-----+ +-----+ +-----+
| MN | | MAG | | LMA |
+-----+ +-----+ +-----+
| | |
| | Allocate new HNP
| | |
| |<------------- UPN ---|
| | |
| | |
| | |
|<-----RA/DHCP --------| |
| | |
Address configuration | |
| | |
| Update binding&routing states |
| | |
| |--- UPA ------------->|
| | |
| | Update binding&routing states
| | |
Figure 1: Signaling call flow of the HNP renumbering
o When a PMIPv6 service provider renumbers the HNP set under the
same LMA, the serving LMA SHOULD initiate the HNP renumbering
operation. The LMA allocates a new HNP for the related MN.
o The LMA sends the Update Notification (UPN) message to the MAG to
update the HNP information. If the Dynamic Host Configuration
Protocol (DHCP) is used to allocate the address, the new HNP MUST
be also notified to the DHCP infrastructure.
o Once the MAG receives this UPN message, it recognizes that the
related MN has the new HNP. Then the MAG MUST notify the MN about
the new HNP with a Router Advertisement (RA) message or allocate a
new address within the new HNP through a DHCP procedure.
o After the MN obtains the HNP information through the RA message,
it deletes the old HoA and configures a new HoA with the newly
allocated HNP.
o When the new HNP is announced or the new address is configured to
the MN successfully, the MAG MUST update the related binding and
routing states. Then the MAG sends back the Update Notification
Acknowledgement (UPA) message to the LMA for the notification of
successful update of the HNP, related binding state, and routing
state. Then the LMA updates the routing and binding information
corresponding to the MN to replace the old HNP with the new one.
Yan, et al. Expires September 14, 2017 [Page 4]
Internet-Draft PMIPv6 HNP Renumbering March 2017
(2) HNP renumbering caused by the LMA switchover
Since the HNP is assigned by the LMA, the HNP renumbering MAY be
caused by the LMA switchover, as in the scenario 2 and scenario 3.
The information of LMA is the basic configuration information of MAG.
When the LMA changes, the related profile SHOULD be updated by the
service provider. In this way, the MAG initiates the registration to
the new LMA as specified in [RFC5213]. When the HNP renumbering is
caused in this case, the new HNP information is sent by the LMA
during the new binding procedure. Accordingly, the MAG withdraws the
old HNP of the MN and announces the new HNP to the MN as like the
case of the HNP is renumbered under the same LMA.
4. Session Connectivity
The HNP renumbering may cause the disconnection of the ongoing
communications of the MN. Basically, there are two modes to manage
the session connectivity during the HNP renumbering.
(1) Soft-mode
The LMA will temporarily maintain the state of the old HNP during the
HNP renumbering (after the UPA reception) in order to redirect the
packets to the MN before the MN reconnects the ongoing session and
notifies its new HoA to the Correspondent Node (CN). This mode is
aiming to reduce the packet loss during the HNP renumbering but the
binding state corresponding to the old HNP should be marked for
example as transient binding [RFC6058]. And the LMA MUST stop
broadcasting the routing information about the old HNP if the old HNP
is no longer anchored at this LMA.
(2) Hard-mode
If the HNP renumbering happens with the switchover of the LMA, the
hard-mode is recommended to keep the protocol simple. In this mode,
the LMA deletes the binding state of the old HNP after it receives
the UPA message from the MAG and the LMA silently discards the
packets destined to the old HNP.
5. Message Format
(1) UPN message
In the UPN message sent from the LMA to the MAG, the notification
reason is set to 2 (UPDATE-SESSION-PARAMETERS). Besides, the HNP
Option [RFC5213] containing the new HNP and the Mobile Node
Identifier Option [RFC4283] carrying identifier of MN are contained
Yan, et al. Expires September 14, 2017 [Page 5]
Internet-Draft PMIPv6 HNP Renumbering March 2017
as Mobility Options of UPN. The order of HNP Option and Mobile Node
Identifier Option in the UPN message is not mandated here.
(2) UPA message
The MAG sends this message in order to acknowledge that it has
received an UPN message with the (A) flag set and to indicate the
status after processing the message. When the MAG did not
successfully renumber the HNP which is required in the UPN message,
the Status Code of 128 is set in the UPA message and the following
operation of LMA is PMIPv6 service provider specific.
(3) RA Message
When the RA message is used by the MAG to advise the new HNP, two
Prefix Information Options are contained in the RA message [RFC4861]
[RFC4862]. In the first Prefix Information Option, the old HNP is
carried and the related Preferred Lifetime is set to 0. In the
second Prefix Information Option, the new HNP is carried with the
Valid Lifetime and Preferred Lifetime set to larger than 0.
(4) DHCP Message
When the DHCP is used in PMIPv6 to configure the addresses for the
MN, new IPv6 address(es) (e.g., HoA) will be generated based on the
new HNP and the related DHCP procedure is also triggered by the
reception of UPN message [RFC3315].
6. Other Issues
In order to maintain the reachability of the MN, the Domain Name
System (DNS) resource record corresponding to this MN may need to be
updated when the HNP of MN changes [RFC3007]. However, this is
beyond the scope of this document.
7. Security Considerations
This document causes no further security problem for the signaling
exchanges. The UPN and UPA messages in this document MUST be
protected using end-to-end security association(s) offering integrity
and data origin authentication as speficied in [RFC5213] and
[RFC7077].
When the HNP renumbering is triggered, a new HNP SHOULD be allocated
to the MN. The LMA MUST follow the procedure of PMIPv6 to make sure
that only an authorized HNP can be assigned for the MN. In this way,
LMA is ready to be the topological anchor point of the new HNP and
the new HNP is for that MN's exclusive use.
Yan, et al. Expires September 14, 2017 [Page 6]
Internet-Draft PMIPv6 HNP Renumbering March 2017
[RFC4862] requires an RA to be authenticated for the Valid Lifetime
in a Prefix Information Option to be set to less than 2 hours. Thus,
when the old HNP that is being deprecated is included in an RA from
the MAG, it will normally be expected that the Valid Lifetime SHOULD
be set to 2 hours (and the Preferred Lifetime set to 0) for a non-
authenticated RA. However, if the legality of the signaling messages
exchanged between MAG and MN can be guaranteed, it MAY be acceptable
to also set the Valid Lifetime to 0 for a non-authenticated RA.
8. IANA Considerations
This document presents no IANA considerations.
9. References
9.1. Normative References
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC3007] Wellington, B., "Secure Domain Name System (DNS) Dynamic
Update", RFC 3007, DOI 10.17487/RFC3007, November 2000,
<http://www.rfc-editor.org/info/rfc3007>.
[RFC3315] Droms, R., Ed., Bound, J., Volz, B., Lemon, T., Perkins,
C., and M. Carney, "Dynamic Host Configuration Protocol
for IPv6 (DHCPv6)", RFC 3315, DOI 10.17487/RFC3315, July
2003, <http://www.rfc-editor.org/info/rfc3315>.
[RFC4283] Patel, A., Leung, K., Khalil, M., Akhtar, H., and K.
Chowdhury, "Mobile Node Identifier Option for Mobile IPv6
(MIPv6)", RFC 4283, DOI 10.17487/RFC4283, November 2005,
<http://www.rfc-editor.org/info/rfc4283>.
[RFC4861] Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
"Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
DOI 10.17487/RFC4861, September 2007,
<http://www.rfc-editor.org/info/rfc4861>.
[RFC4862] Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
Address Autoconfiguration", RFC 4862,
DOI 10.17487/RFC4862, September 2007,
<http://www.rfc-editor.org/info/rfc4862>.
Yan, et al. Expires September 14, 2017 [Page 7]
Internet-Draft PMIPv6 HNP Renumbering March 2017
[RFC5213] Gundavelli, S., Ed., Leung, K., Devarapalli, V.,
Chowdhury, K., and B. Patil, "Proxy Mobile IPv6",
RFC 5213, DOI 10.17487/RFC5213, August 2008,
<http://www.rfc-editor.org/info/rfc5213>.
[RFC6275] Perkins, C., Ed., Johnson, D., and J. Arkko, "Mobility
Support in IPv6", RFC 6275, DOI 10.17487/RFC6275, July
2011, <http://www.rfc-editor.org/info/rfc6275>.
[RFC6463] Korhonen, J., Ed., Gundavelli, S., Yokota, H., and X. Cui,
"Runtime Local Mobility Anchor (LMA) Assignment Support
for Proxy Mobile IPv6", RFC 6463, DOI 10.17487/RFC6463,
February 2012, <http://www.rfc-editor.org/info/rfc6463>.
[RFC7077] Krishnan, S., Gundavelli, S., Liebsch, M., Yokota, H., and
J. Korhonen, "Update Notifications for Proxy Mobile IPv6",
RFC 7077, DOI 10.17487/RFC7077, November 2013,
<http://www.rfc-editor.org/info/rfc7077>.
9.2. Informative References
[RFC6058] Liebsch, M., Ed., Muhanna, A., and O. Blume, "Transient
Binding for Proxy Mobile IPv6", RFC 6058,
DOI 10.17487/RFC6058, March 2011,
<http://www.rfc-editor.org/info/rfc6058>.
[RFC6879] Jiang, S., Liu, B., and B. Carpenter, "IPv6 Enterprise
Network Renumbering Scenarios, Considerations, and
Methods", RFC 6879, DOI 10.17487/RFC6879, February 2013,
<http://www.rfc-editor.org/info/rfc6879>.
[RFC7010] Liu, B., Jiang, S., Carpenter, B., Venaas, S., and W.
George, "IPv6 Site Renumbering Gap Analysis", RFC 7010,
DOI 10.17487/RFC7010, September 2013,
<http://www.rfc-editor.org/info/rfc7010>.
Authors' Addresses
Zhiwei Yan
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing 100190
China
EMail: yan@cnnic.cn
Yan, et al. Expires September 14, 2017 [Page 8]
Internet-Draft PMIPv6 HNP Renumbering March 2017
Jong-Hyouk Lee
Sangmyung University
31, Sangmyeongdae-gil, Dongnam-gu
Cheonan 31066
Republic of Korea
EMail: jonghyouk@smu.ac.kr
Xiaodong Lee
CNNIC
No.4 South 4th Street, Zhongguancun
Beijing 100190
China
EMail: xl@cnnic.cn
Yan, et al. Expires September 14, 2017 [Page 9]
