Prefix Delegation for Proxy Mobile IPv6
draft-ietf-netext-pd-pmip-06
The information below is for an old version of the document.
Document | Type |
This is an older version of an Internet-Draft that was ultimately published as RFC 7148.
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Authors | Xingyue Zhou , Jouni Korhonen , Carl Williams , Sri Gundavelli , Carlos J. Bernardos | ||
Last updated | 2013-02-25 | ||
RFC stream | Internet Engineering Task Force (IETF) | ||
Formats | |||
Reviews | |||
Additional resources | Mailing list discussion | ||
Stream | WG state | WG Document | |
Document shepherd | Basavaraj Patil | ||
IESG | IESG state | Became RFC 7148 (Proposed Standard) | |
Consensus boilerplate | Unknown | ||
Telechat date | (None) | ||
Responsible AD | (None) | ||
Send notices to | (None) |
draft-ietf-netext-pd-pmip-06
Netext WG X. Zhou Internet-Draft ZTE Corporation Intended status: Standards Track J. Korhonen Expires: August 29, 2013 Nokia Siemens Networks C. Williams Consultant S. Gundavelli Cisco CJ. Bernardos UC3M February 25, 2013 Prefix Delegation for Proxy Mobile IPv6 draft-ietf-netext-pd-pmip-06 Abstract Proxy Mobile IPv6 enables IP mobility for a host without requiring its participation in any mobility signaling, being the network responsible for managing IP mobility on behalf of the host. However, Proxy Mobile IPv6 does not support assigning a prefix to a router and managing its IP mobility. This document specifies an extension to Proxy Mobile IPv6 protocol for supporting network mobility using DHCPv6-based Prefix Delegation. 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 August 29, 2013. Copyright Notice Copyright (c) 2013 IETF Trust and the persons identified as the document authors. All rights reserved. Zhou, et al. Expires August 29, 2013 [Page 1] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 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 . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Convention and Terminology . . . . . . . . . . . . . . . . . . 4 3. Message formats . . . . . . . . . . . . . . . . . . . . . . . 5 3.1. Delegated Mobile Network Prefix Option . . . . . . . . . . 5 4. DHCPv6 Prefix Delegation Support for Proxy Mobile IPv6 . . . . 7 4.1. Assumptions . . . . . . . . . . . . . . . . . . . . . . . 7 4.2. Network Mobility Service . . . . . . . . . . . . . . . . . 8 4.3. Binding association with the delegated prefix . . . . . . 8 4.3.1. Delegating Router Co-located with Mobile Access Gateway . . . . . . . . . . . . . . . . . . . . . . . 8 4.3.2. Deletion of the Delegated Prefix in Proxy Mobile IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.4. Delegating Router Co-located with the Local Mobility Anchor . . . . . . . . . . . . . . . . . . . . . . . . . . 10 4.4.1. Mobile Router initiated prefix delegation in PMIPv6 . 11 4.4.2. Refreshing the Delegated Prefix in Proxy Mobile IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 13 4.4.3. Deletion of the Delegated Prefix in Proxy Mobile IPv6 . . . . . . . . . . . . . . . . . . . . . . . . . 13 5. Mobile Access Gateway Operation . . . . . . . . . . . . . . . 14 5.1. Extension to Binding Update List Entry Data Structure . . 14 5.2. Forwarding . . . . . . . . . . . . . . . . . . . . . . . . 14 5.3. Handover . . . . . . . . . . . . . . . . . . . . . . . . . 14 6. Local Mobility Anchor Operation . . . . . . . . . . . . . . . 16 6.1. Extension to Binding Cache Entry Data Structure . . . . . 16 6.2. Forwarding . . . . . . . . . . . . . . . . . . . . . . . . 16 7. Security Considerations . . . . . . . . . . . . . . . . . . . 17 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 20 10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 21 10.1. Normative References . . . . . . . . . . . . . . . . . . . 21 10.2. Informative References . . . . . . . . . . . . . . . . . . 21 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 23 Zhou, et al. Expires August 29, 2013 [Page 2] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 1. Introduction Proxy Mobile IPv6 [RFC5213] enables network-based mobility management support for an IP host without requiring its participation in any IP mobility signaling. The mobility elements in the network allow the IP host to obtain an IPv4 address and/or a set of IPv6 prefix and be able to obtain IP mobility support for those IP addresses. However, this network-based mobility management support is specific to an IP host and currently there is no such network-based mobility management support for a mobile router with a cluster of IP hosts behind it. This specification defines extensions to Proxy Mobile IPv6 protocol for allowing a mobile router to be able to obtain one or more delegated IPv4/IPv6 prefixes for its inside networks using DHCP Prefix Delegation extensions [RFC3633]. The mobility entities in the network will provide network-based mobility management support for these delegated prefixes just as how that is supported for Home Network prefixes. Zhou, et al. Expires August 29, 2013 [Page 3] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 2. Convention and Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. All the mobility related terms used in this document are to be interpreted as defined in Mobile IPv6 (MIPv6) [RFC6275], Proxy Mobile IPv6 specifications [RFC5213], [RFC5844], DHCPv6-PD for NEMO [RFC6276], DHCPv6-PD [RFC3633] Subnet Allocation Option for DHCPv4 [RFC6656] and Mobility Related Terminology [RFC3753]. This document also provides a context-specific explanation to the following terms used in this document. Mobile Router (MR) Throughout this document, the term mobile router is used to refer to an IP router whose mobility is managed by the network while being attached to a Proxy Mobile IPv6 domain. The mobile router is not required to participate in any IP mobility related signaling for achieving mobility for an IPv4/IPv6 prefix that is obtained in that Proxy Mobile IPv6 domain. Delegated Mobile Network Prefix (DMNP) The DMNP is an IPv4 or an IPv6 prefix delegated to a mobile router and advertised in the mobile network. More than one Delegated Mobile Network Prefix could be assigned to a mobile router. The DMNP is topologically anchored on the local mobility anchor. While used by the mobile router, the mobile access gateway and local mobility anchor provide mobility service to the mobile router for the DMNP(s). Zhou, et al. Expires August 29, 2013 [Page 4] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 3. Message formats This section defines extensions to Proxy Mobile IPv6 [RFC5213] protocol messages. 3.1. Delegated Mobile Network Prefix Option A new Delegated Mobile Network Prefix option is defined for use with the Proxy Binding Update and Proxy Binding Acknowledgment messages exchanged between a local mobility anchor and a mobile access gateway. This option is used for exchanging the mobile router's IPv4/IPv6 delegated mobile network prefix information. There can be multiple Delegated Mobile Network Prefix options present in the message. The Delegated Mobile Network Prefix option has an alignment requirement of 8n+2. Its format is as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length |K| Reserved | Prefix Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | GRE Key Identifier (optional) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | . . + IPv4 or IPv6 Delegated Mobile Network Prefix + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type To be assigned by IANA. Length 8-bit unsigned integer indicating the length of the option in octets, excluding the type and length fields. Key present (K) Zhou, et al. Expires August 29, 2013 [Page 5] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 If the Key Present bit is set to 1, then it indicates that the GRE Key Identifier field includes a valide GRE Key. Otherwise, the value of the GRE Key Identifier field MUST be ignored by the receiver. Reserved This field is unused for now. The value MUST be initialized to 0 by the sender and MUST be ignored by the receiver. Prefix Length 8-bit unsigned integer indicating the prefix length of the prefix contained in the option. Generic Routing Encapsulation (GRE) key tag A four-byte optional field containing the GRE key tag as specified in [RFC2890]. If the Key Present flag is set to 0, this field MUST be initialized to 0 by the sender and MUST be ignored by the receiver. This option MAY be used by the LMA to provide differentiated service to different clients attached to the same mobile router. The MAG includes the GRE key in the Proxy Binding Update and the LMA uses that key to mark the downlink mobile network traffic from the LMA to the MAG. The LMA includes the GRE key in the Proxy Binding Acknowledgment and the MAG uses that key to mark the uplink mobile network traffic from the MAG to the LMA. Delegated Mobile Network Prefix Contains a mobile router's 4-byte IPv4 or a 16-byte IPv6 Delegated Mobile Network Prefix. Zhou, et al. Expires August 29, 2013 [Page 6] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 4. DHCPv6 Prefix Delegation Support for Proxy Mobile IPv6 4.1. Assumptions This specification extends Proxy Mobile IPv6 (PMIPv6) to delegate a mobile network IPv4/IPv6 prefix to a mobile router (MR) for supporting network mobility. The specification assumes that a mobile router is an IPv4/IPv6 router without any capability for mobility management. The mobile router after its attachment to the network obtains an IPv6 address from its home network prefix (HNP) on its egress interface facing the MAG. This is as specified in [RFC5213] and [RFC5844]. Subsequently, the DHCPv6-PD procedures get activated for obtaining the delegated IPv6/IPv4 prefixes for its ingress networks. The mobile router using the DHCP Prefix Delegation approaches specified in [RFC3633] and [RFC6656] will obtain the delegated IPv4/ IPv6 prefix from the network. The mobile router forwards outgoing packets from its mobile network to the mobile access gateway (MAG), and the MAG delivers the incoming packets to the mobile network through the MR. The mobile router must have obtained an IPv6 address from its home network prefix (HNP) before initiating DHCPv6-PD procedures for obtaining delegated IPv4 or IPv6 prefixes for its ingress networks. This IPv6 address is on the interface attached to the MN-MAG access link as specified in [RFC3633]. The MR (acting as a RR) SHOULD support Prefix Exclude Option for DHCPv6-PD as described in [RFC6603]. It essentially allows the home network prefix on the MN-MAG link and the delegated prefix can be part of the same aggregated block. This simplies address pool management aspects This specification supports the following two configuration modes: 1. The delegating router (DR) function, as specified in [RFC3633], is co-located with the MAG. The DHCP requesting router (RR) functionality is enabled on the mobile router. 2. The delegating router (DR) function, as specified in [RFC3633], is co-located with the LMA. A DHCPv6 Relay Agent (DRA) function, as specified in [RFC3633], is co-located on the mobile access gateway. The DHCP requesting router (RR), as specified in [RFC3633] functionality is enabled on the mobile router. Zhou, et al. Expires August 29, 2013 [Page 7] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 4.2. Network Mobility Service The network mobility service of a mobile router is indicated by the policy profile defined in [RFC5213]. During the mobile router's initial attachment procedure, the mobile access gateway MUST identify the mobile router and SHOULD acquire the policy profile to determine whether the network mobility service is offered to the mobile router. If the network mobility service needs to be offered to the mobile router, the mobile access gateway MUST set the Mobile Router Flag (R) when sending the Proxy Binding Update (PBU) message to the local mobility anchor. 4.3. Binding association with the delegated prefix 4.3.1. Delegating Router Co-located with Mobile Access Gateway +-----+ +-----+ + ----+ | MR | | MAG | | LMA | |(RR) | | (DR)| | | +-----+ +-----+ +-----+ 1) |-- MN Attach -----| | | |<-------- PBU/PBA ------->| | | | | |o========================o| 2) | | PMIPv6 tunnel | | |o========================o| 3) |-- Solicit ------>| | | for delegated | | | prefix | | | | | 4) | |----------PBU------------>| | | | 5) | |<---------PBA (DMNP)------| | | | - -<---+ | 6) |<- Advertise -----| | | | | | | 7) |-- Request ------>| Optional | | | | | - -<---+ | 8) |<-- Reply (DMNP) -| | | | | | | | Figure 1: Prefix Delegation in PMIPv6 when DR co-located with MAG The steps required to complete the delegation of IPv6 prefix(es) to a mobile router that is provided with network mobility service are the Zhou, et al. Expires August 29, 2013 [Page 8] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 following (see Figure 1): 1. MAG after detecting the mobile node's attachment to the access link initiates the signaling with the LMA. 2. The PMIPv6 tunnel is set up between the MAG and the LMA as described in [RFC5213]. This requires the MAG to send a regular PBU to the LMA to register the location of the mobile router and set-up the bi-directional tunnel. The LMA binds the allocated home network prefix (HNP) to the Proxy-CoA of the mobile router (i.e., the address of the mobile access gateway where the MR is attached to). It is possible that the delegated prefix(es) may have been assigned to the MAG by the LMA during this procedure of PMIPv6 tunnel establishment. That is the MAG may include one (or more) Delegated Mobile Network Prefix (DMNP) mobility options which MUST be set to the unspecified IPv6 address "::" in the PBU to request the delegated prefix(es). The LMA assigns a new set of DMNP(s) in PBA message. 3. The mobile router, acting as a "Requesting Router" as described in [RFC3633], sends a DHCPv6 SOLICIT message including one or more IA_PD option(s) to the mobile access gateway (which has a "DHCPv6 Server" function) to acquire the delegated prefix(es). 4. Upon receiving the DHCPv6 SOLICIT message, the mobile access gateway sends a proxy binding update (PBU) message to the local mobility anchor, including one (or more) Delegated Mobile Network Prefix (DMNP) mobility options. All the considerations from Section 5.3.1 of [RFC5213] MUST be applied on the encapsulated Proxy Binding Update message. If the mobile access gateway does not know the delegated prefix(es), then the delegated mobile network prefix in the DMNP option(s) MUST be set to the unspecified IPv6 address "::", or an IPv4 address of 0.0.0.0 with the prefix length of 0. The local mobility anchor either assigns the MR a new set of delegated IPv4/IPv6 prefix(es) or returns the existing one(s) that are associated with that mobility session. 5. On reception of the proxy binding update, the local mobility anchor returns the assigned prefix(es) in the DMNP option(s) conveyed in a proxy binding acknowledgment (PBA) message sent to the mobile access gateway, unless the prefix(es) included in the PBU was the IPv6 unspecified address "::". The assigned prefix(es) MUST be the same one(s) which will be assigned via DHCPv6PD in step 6. The prefix(es) MUST be added to the delegated prefix(es) in the local mobility anchor binding cache which is extended as described in Section 6.1. The LMA must set up forwarding for the delegated prefixes as reachable through the PMIPv6 tunnel. Zhou, et al. Expires August 29, 2013 [Page 9] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 6. The delegating router function on the MAG sends the delegated prefix(es) in one or more IA_PD(s) which were received in the PBA message in step 5 to the mobile router inside the DHCPv6 ADVERTISE message. 7. The mobile router sends the DHCPv6 REQUEST message with the IA_PD option(s) received from previous message to the DR function on the mobile access gateway. Note: steps 6 to 7 are not present if DHCPv6 Rapid Commit is used. 8. The DR function on the mobile access gateway responds to the REQUEST from the mobile router with a DHCPv6 REPLY message. The MAG sets up the forwarding for the delegated prefixes. The delegated prefixes are reachable over the MN-MAG interface with the MR's link-local address, or home address as the next-hop destination. 4.3.2. Deletion of the Delegated Prefix in Proxy Mobile IPv6 If the lifetime of the delegated prefix (included in the IA_PD Prefix Option carried by the DHCPv6 Reply message) is set to zero, the mobile access gateway (which is acting as "Delegating Router") MUST send a proxy binding update message to remove the selective binding for that delegated mobile network prefix. If the request is for remove the delegeted mobile network prefix only, the proxy binding update message with the lifetime value of (0) MUST NOT include either IPv6 Home Network Prefix option [RFC5213] or IPv4 Home Address Request option [RFC5844]. 4.4. Delegating Router Co-located with the Local Mobility Anchor Zhou, et al. Expires August 29, 2013 [Page 10] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 4.4.1. Mobile Router initiated prefix delegation in PMIPv6 +-----+ +-----+ + ----+ | MR | | MAG | | LMA | |(RR) | |(DRA)| |(DR) | +-----+ +-----+ +-----+ 1) |-- MN Attach -----| | | |<------ PBU/PBA --------->| | | | | |o========================o| 2) | | PMIPv6 tunnel | | |o========================o| 3) |-- Solicit ------>| | | for delegated | | 4) | prefix |----------PBU------------>| | | | 5) | |<---------PBA (DMNP)------| | | | 6) | |--- Solicit ------------->| - - - <---+ 7) | |<-- Advertise ------------| | | | | | 8) |<- Advertise -----| | | | | | Optional 9) |-- Request ------>| | | | | | | 10) | |--- Request ------------->| | - - - <---+ 11) | |<-- Reply (DMNP) ---------| | | | 12) |<-- Reply (DMNP) -| | | | | Figure 2: Prefix Delegation in PMIPv6 when DR co-located with LMA The steps required to complete the delegation of IPv6 prefix(es) to a mobile router that is provided with network mobility service are the following (see Figure 2): 1. MAG after detecting the mobile node's attachment to the access link initiates the signaling with the LMA. 2. The PMIPv6 tunnel is set up between the MAG and the LMA as described in [RFC5213]. This requires the MAG to send a regular PBU to the LMA to register the location of the mobile router and set-up the bi-directional tunnel. The LMA binds the allocated home network prefix (HNP) to the Proxy-CoA of the mobile router (i.e., the address of the mobile access gateway where the MR is Zhou, et al. Expires August 29, 2013 [Page 11] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 attached to). 3. The mobile router, acting as a "Requesting Router" as described in [RFC3633], sends a DHCPv6 SOLICIT message including one or more IA_PD option(s) to the mobile access gateway (which has a "DHCPv6 Relay Agent" function) to acquire the delegated prefix(es). 4. Upon receiving the DHCPv6 SOLICIT message, the mobile access gateway sends a proxy binding update (PBU) message to the local mobility anchor, including one (or more) Delegated Mobile Network Prefix (DMNP) mobility options. All the considerations from Section 5.3.1 of [RFC5213] MUST be applied on the encapsulated Proxy Binding Update message. If the mobile access gateway does not know the delegated prefix(es), then the delegated mobile network prefix in the DMNP option(s) MUST be set to the unspecified IPv6 address "::", or an IPv4 address of 0.0.0.0 with the prefix length of 0. The local mobility anchor either assigns the MR a new set of delegated IPv4/IPv6 prefix(es) or returns the existing one(s) that are associated with that mobility session. 5. On reception of the proxy binding update, the local mobility anchor returns the assigned prefix(es) in the DMNP option(s) conveyed in a proxy binding acknowledgment (PBA) message sent to the mobile access gateway, unless the prefix(es) included in the PBU was the IPv6 unspecified address "::". The assigned prefix(es) MUST be the same one(s) which will be assigned via DHCPv6PD in step 6. The prefix(es) MUST be added to the delegated prefix(es) in the local mobility anchor binding cache which is extended as described in Section 6.1. The LMA must set up forwarding for the delegated prefixes as reachable through the PMIPv6 tunnel. 6. The DHCPv6 Relay Agent function on the mobile access gateway relays the DHCPv6 SOLICIT message to the delegating router (as described in [RFC3633] ). The delegating router inserts one or more IA_PD option(s) including the delegated prefix(es) in the reply message. Note: steps 6 to 9 are not present if DHCPv6 Rapid Commit is used. 7. The delegating router sends the delegated prefix(es) in one or more IA_PD(s) to the mobile access gateway (acting as "DHCPv6 Relay Agent") inside the DHCPv6 ADVERTISE message. Zhou, et al. Expires August 29, 2013 [Page 12] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 8. The mobile access gateway relays the DHCPv6 ADVERTISE message to the mobile router. 9. The mobile router sends the DHCPv6 REQUEST message with the IA_PD option(s) received from previous message to the mobile access gateway (which is acting as "DHCPv6 Relay Agent"). 10. The DRA function on the mobile access gateway relays the DHCPv6 REQUEST message to the DR. 11. The DR function on the local mobility anchor responds to the REQUEST from the mobile access gateway with a DHCPv6 REPLY message. 12. The RR function on the mobile router receives one or more IA_PD prefix(es) in the DHCPv6 REPLY message sent by the mobile access gateway. The MAG sets up the forwarding for the delegated prefixes. The delegated prefixes are reachable over the MN-MAG interface with the MR's link-local address, or home address as the next-hop destination. 4.4.2. Refreshing the Delegated Prefix in Proxy Mobile IPv6 When the mobile router sends DHCPv6 Renew messages to extend the lifetime of the delegated prefix, these messages are also intercepted by the mobile access gateway (acting as "DHCPv6 Relay Agent") and are relayed to the local mobility anchor (which is acting as "Delegating Router"). 4.4.3. Deletion of the Delegated Prefix in Proxy Mobile IPv6 If the lifetime of the delegated prefix (included in the IA_PD Prefix Option carried by the DHCPv6 Reply message) is set to zero, the mobile access gateway (which is acting as "DHCPv6 Relay Agent") MUST send a proxy binding update message to remove the selective binding for that delegated mobile network prefix. If the request is for remove the delegeted mobile network prefix only, the proxy binding update message with the lifetime value of (0) MUST NOT include either IPv6 Home Network Prefix option [RFC5213] or IPv4 Home Address Request option [RFC5844]. Zhou, et al. Expires August 29, 2013 [Page 13] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 5. Mobile Access Gateway Operation 5.1. Extension to Binding Update List Entry Data Structure In order to support this specification, the conceptual Binding Update List Entry (BULE) data structure needs to be extended with a new prefix information field. This field is used to store the delegated IPv4/IPv6 mobile network prefix assigned to the mobile router, which is included in the proxy binding acknowledgment. 5.2. Forwarding Forwarding packets sent to the MR's delegated mobile network prefix: o On receiving a packet from the bi-directional tunnel established with the local mobility anchor, the mobile access gateway MUST first decapsulate the packet (removing the outer header) and then use the destination address of the (inner) packet to forward it on the interface through which the destination delegated mobile network prefix is reachable. Forwarding packets sent by the mobile router: o On receiving packets from a mobile router connected to one access link, the mobile access gateway MUST ensure that there is an established binding for the mobile router and the local mobility anchor for the source delegated mobile network prefix before tunneling the packet to the MR's local mobility anchor. Other considerations from Section 6.10.5 of [RFC5213] also apply here. 5.3. Handover When the mobile router moves from the previously attached mobile access gateway to the target MAG, the newly attached mobile access gateway MAY know the delegated mobile network prefix(es) which were assigned to the mobile router during the previous attachment. It is out of scope of this specification how the new mobile access gateway could obtain the previously assigned delegated mobile network prefix(es) (e.g., from some network element such as the previous MAG). After moving to the new MAG, a proxy binding update message including the assigned delegated mobile network prefix(es) (if available) MUST be sent by the MAG to the LMA. The local mobility anchor MUST check the delegated mobile network prefix(es) included in the PBU message and return the same assigned delegated mobile network prefix(es) in the proxy binding acknowledgment message. If the previously assigned mobile network prefix(es) are not known by new Zhou, et al. Expires August 29, 2013 [Page 14] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 MAG, the mobile network prefix(es) MUST be set to unspecified address "::" and the prefix length MUST be set to 0 in the proxy binding update message sent by the new mobile access gateway to the local mobility anchor. In this case, the local mobility anchor MUST return the same previously assigned mobile network prefix(es) in proxy binding acknowledgment message. Zhou, et al. Expires August 29, 2013 [Page 15] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 6. Local Mobility Anchor Operation 6.1. Extension to Binding Cache Entry Data Structure In order to support this specification, the conceptual Binding Cache Entry (BCE) data structure needs to be extended with a new prefix information field. This field is used to store the IPv4/IPv6 delegated mobile network prefix(es) assigned to the mobile router and included in the proxy binding update (as described in Section 4.2). 6.2. Forwarding Intercepting packets sent to the MR's delegated mobile network prefix: o When the local mobility anchor is serving the mobile router, it MUST be able to receive/intercept packets destined to the network behind the mobile router. In order to receive these packets, the local mobility anchor MUST be the topological anchor of the MR's delegated mobile network prefix(es). Forwarding packets to the mobile router: o On receiving a packet from a correspondent node with the destination address matching the MR's delegated mobile network prefix(es), the local mobility anchor MUST forward the packet through the bi-directional tunnel set up with the mobile router. Other considerations from Section 5.6.2 of [RFC5213] also apply here. Zhou, et al. Expires August 29, 2013 [Page 16] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 7. Security Considerations This document describes extensions to the Proxy Mobile IPv6 protocol for supporting network mobility using DHCPv6-based Prefix Delegation. The security considerations for DHCPv6 described in the "Security Considerations" section of the DHCPv6 base specification [RFC3315], the "Security Considerations" of the DHCPv6 Prefix Delegation specification [RFC3633], and the security considerations from the base Proxy Mobile IPv6 [RFC5213] apply when using the extensions defined in this document. The use of DHCPv6, as described in this document, requires message integrity protection and source authentication. The IPsec security mechanism mandated by Proxy Mobile IPv6 [RFC5213] MUST be used to secure the DHCPv6 signaling between the mobile access gateway and the local mobility anchor. In the following, we describe the Security Policy Database (SPD) and Security Association Database (SAD) entries necessary to protect the DHCPv6 signaling. We use the same format used by [RFC4877]. The SPD and SAD entries are only example configurations. A particular mobile access gateway implementation and a local mobility anchor implementation could configure different SPD and SAD entries as long as they provide the required security of the DHCPv6 signaling messages. For the examples described in this document, a mobile access gateway with address "mag_address_1", and a local mobility anchor with address "lma_address_1" are assumed. mobile access gateway SPD-S: - IF local_address = mag_address_1 & remote_address = lma_address_1 & proto = UDP & local_port = any & remote_port = DHCP Then use SA1 (OUT) and SA2 (IN) mobile access gateway SAD: - SA1(OUT, spi_a, lma_address_1, ESP, TRANSPORT): local_address = mag_address_1 & remote_address = lma_address_1 & proto = UDP & remote_port = DHCP - SA2(IN, spi_b, mag_address_1, ESP, TRANSPORT): local_address = lma_address_1 & remote_address = mag_address_1 & proto = UDP & local_port = DHCP local mobility anchor SPD-S: - IF local_address = lma_address_1 & remote_address = mag_address_1 & proto = UDP & local_port = DHCP & remote_port = any Zhou, et al. Expires August 29, 2013 [Page 17] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 Then use SA2 (OUT) and SA1 (IN) local mobility anchor SAD: - SA2(OUT, spi_b, mag_address_1, ESP, TRANSPORT): local_address = lma_address_1 & remote_address = mag_address_1 & proto = UDP & local_port = DHCP - SA1(IN, spi_a, lma_address_1, ESP, TRANSPORT): local_address = mag_address_1 & remote_address = lma_address_1 & proto = UDP & remote_port = DHCP Zhou, et al. Expires August 29, 2013 [Page 18] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 8. IANA Considerations This document requires the following IANA action. o Action-1: This specification defines a new Mobility Header option, Delegated Mobile Network Prefix option. This mobility option is described in Section 3.1. The Type value for this option needs to be assigned from the same numbering space as allocated for the other mobility options, as defined in [RFC6275]. Zhou, et al. Expires August 29, 2013 [Page 19] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 9. Acknowledgments The work of Carlos J. Bernardos has also been partially supported by the European Community's Seventh Framework Programme (FP7-ICT-2009-5) under grant agreement n. 258053 (MEDIEVAL project) and by the Ministry of Science and Innovation of Spain under the QUARTET project (TIN2009-13992-C02-01). Zhou, et al. Expires August 29, 2013 [Page 20] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 10. References 10.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2890] Dommety, G., "Key and Sequence Number Extensions to GRE", RFC 2890, September 2000. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C., and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC3633] Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic Host Configuration Protocol (DHCP) version 6", RFC 3633, December 2003. [RFC3963] Devarapalli, V., Wakikawa, R., Petrescu, A., and P. Thubert, "Network Mobility (NEMO) Basic Support Protocol", RFC 3963, January 2005. [RFC4877] Devarapalli, V. and F. Dupont, "Mobile IPv6 Operation with IKEv2 and the Revised IPsec Architecture", RFC 4877, April 2007. [RFC5213] Gundavelli, S., Leung, K., Devarapalli, V., Chowdhury, K., and B. Patil, "Proxy Mobile IPv6", RFC 5213, August 2008. [RFC5844] Wakikawa, R. and S. Gundavelli, "IPv4 Support for Proxy Mobile IPv6", RFC 5844, May 2010. [RFC6275] Perkins, C., Johnson, D., and J. Arkko, "Mobility Support in IPv6", RFC 6275, July 2011. [RFC6276] Droms, R., Thubert, P., Dupont, F., Haddad, W., and C. Bernardos, "DHCPv6 Prefix Delegation for Network Mobility (NEMO)", RFC 6276, July 2011. [RFC6603] Korhonen, J., Savolainen, T., Krishnan, S., and O. Troan, "Prefix Exclude Option for DHCPv6-based Prefix Delegation", RFC 6603, May 2012. 10.2. Informative References [RFC3753] Manner, J. and M. Kojo, "Mobility Related Terminology", RFC 3753, June 2004. Zhou, et al. Expires August 29, 2013 [Page 21] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 [RFC6656] Johnson, R., Kinnear, K., and M. Stapp, "Description of Cisco Systems' Subnet Allocation Option for DHCPv4", RFC 6656, July 2012. Zhou, et al. Expires August 29, 2013 [Page 22] Internet-Draft Prefix Delegation Support for PMIPv6 February 2013 Authors' Addresses Xingyue Zhou ZTE Corporation No.50 Software Avenue, Yuhuatai District Nanjing China Phone: +86-25-8801-4634 Email: zhou.xingyue@zte.com.cn Jouni Korhonen Nokia Siemens Networks Linnoitustie 6 Espoo FIN-02600 Finland Email: jouni.nospam@gmail.com Carl Williams Consultant San Jose, CA USA Email: carlw@mcsr-labs.org Sri Gundavelli Cisco 170 West Tasman Drive San Jose, CA 95134 USA Email: sgundave@cisco.com Carlos J. Bernardos Universidad Carlos III de Madrid Av. Universidad, 30 Leganes, Madrid 28911 Spain Phone: +34 91624 6236 Email: cjbc@it.uc3m.es URI: http://www.it.uc3m.es/cjbc/ Zhou, et al. Expires August 29, 2013 [Page 23]