Mobile IP Working Group Jahanzeb Faizan Internet-Draft Hesham El-Rewini Expires: June, 2004 Southern Methodist University Mohammad Khalil Nortel Networks December, 2003 Virtual Home Agent Reliability Protocol (VHAR) draft-jfaizan-mipv6-vhar-00.txt Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet-Drafts. 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." The list of current Internet-Drafts can be accessed at http:// www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on June, 2004. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract Current specification of Mobile-IPv6 [1] does not provide Home Agent Reliability and Load Balancing in the Home Network [12]. The aim of this draft is to introduce Virtual Home Agent Reliability Protocol as the solution. In this protocol multiple Home Agents and Recovery Home Agents coexist on the same subnet and share the same IP Address. Only one of them is active at a time and serves the Mobile Node. The Home Agent failure and failover mechanisms are completely transparent to the Mobile Node which is required for minimal service interruption time. This protocol does not introduce any new Mobile-IPv6 message over the air interface and thus helps reducing the overall overhead. Faizan. Expires June, 2004 [Page 1] Internet-Draft VHAR Protocol December, 2003 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . .. . . . . . . . . . . . . . . . . . . . . . 3 3. Related Work . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Virtual Home Agent Reliability Protocol Overview . . . . . . . 5 4.1 Mobile Node Registration . . . . . . . . . . . . . . . . .6 4.2 VHAR Failure Detection and Recovery . . . . . . . . . . . 7 4.3 VHAR Load Balancing . . . . . . . . . . . . . . . . . . . 8 5. New ICMP Messages . . . . . . . . . . . . . . . . . . . . . . .9 5.1 VHAR Solicitation Message . . . . . . . . . . . . . . . . 9 5.2 VHAR Advertisement Message . . . . . . . . . . . . . . . .9 5.3 MN Release Request Message . . . . . . . . . . . . . . . 11 5.4 MN Release Reply Message . . . . . . . . . . . . . . . . 12 5.5 MN Context Update Request Message . . . . . . . . . . . .13 5.6 MN Context Update Reply Message . . . . . . . . . . . . .14 5.7 MN Context Migration Request Message . . . . . . . . . . 15 5.8 MN Context Migration Reply Message . . . . . . . . . . . 16 5.9 Change HA Request Message . . . . . . . . . . . . . . . .17 5.10 Change HA Reply Message . . . . . . . . . . . . . . . . .18 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 19 7. Security Considerations . . . . . . . . . . . . . . . . . . . 19 References . . . . . . . . . . . . . . . . . . . . . . . . . .19 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . .20 Intellectual Property and Copyright Statements . . . . . . . .21 Acknowledgment . . . . . . . . . . . . . . . . . . . . . . . .22 Faizan. Expires June, 2004 [Page 2] Internet-Draft VHAR Protocol December, 2003 1. Introduction Mobile-IPv6 [1] is designed to allow a Mobile Node to change its point of IP subnet attachment in the Internet at the network or IP layer. The Mobile Node is always identified by it Home Address regardless of its current network location. Its mobility is not limited by conventional IP network boundaries. The Mobile-IPv6 system consists of Mobile Node and Home Agent. Home Agent remains at conventional IPv6 subnet called the Home Subnet and when the Mobile Node is at the Home Subnet then the packets sent to it are routed through conventional IPv6 [5] routing mechanism. When the Mobile Node is not at Home Subnet it registers its remote point of attachment address called Care of Address with the Home Agent. This allows Home Agent to forward packets, addressed to the Mobile Node at its Home Network, to its current location. In Mobile-IPv6, Mobile Node registers and establish a connection with only one Home Agent which provides continuous service to it. The Mobile Node is reliant on this Home Agent for its connectivity. Thus the Home Agent represents the possibility of a single point of failure for Mobile-IPv6 network. A Home Agent may be responsible for multiple Mobile Nodes on the Home Subnet. The failure of a single Home Agent may then result in the loss of connectivity for numerous Mobile Nodes located throughout the Internet. Thus the Home Agent and Mobile Node taken together have a shared fate. A Mobile Node cannot afford the loss of its Home Agent. To overcome this problem Mobile-IPv6 allows deployment of multiple Home Agents on the Home Subnet so that upon the failure of serving Home Agent, another Home Agent can take over the functions of failed Home Agent and thus provide continuous service to the Mobile Node(s) registered with failed Home Agent. This transfer of service from the failed Home Agent to a new working Home Agent is problematic and the current specification of Mobile-IPv6 does not provide solution to these problems. In [12] these problems were discussed and guidelines for the possible solutions were proposed. The goal of this draft is to propose "Virtual Home Agent Reliability" protocol which provide Home Agent Reliability and Load Balancing in the Mobile-IPv6 networks. 2 Terminology The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [6]. Faizan. Expires June, 2004 [Page 3] Internet-Draft VHAR Protocol December, 2003 Mobile-IPv6 Mobile IP for IPv6 [1] Mobile Node A node that can change its point of attachment from one link to another, while still being reachable via its home address. IP Internet Protocol Version 6 (IPv6).[5] Home Address A unicast routable address assigned to a Mobile Node, used as the permanent address of the Mobile Node. This address is within the Mobile Node's Home Subnet. Conventional IPv6 routing mechanisms will deliver packets destined for a Mobile Node's Home Address to its Home Subnet. Home Network A network, possibly virtual, having a network prefix matching that of a Mobile Node's Home Address. Home Agent A router on a Mobile Node's Home Network which tunnels datagrams for delivery to the Mobile Node when it is away from home, and maintains current location information for the Mobile Node. Care of Address A unicast routable address associated with a Mobile Node while visiting a foreign network. IPsec Security Association An IPSec security association is a cooperative relationship formed by the sharing of cryptographic keying material and associated context. Security associations are simplex. That is, two security associations are needed to protect bidirectional traffic between two nodes, one for each direction. Registration The process during which a Mobile Node sends a Binding Update to its Home Agent causing a binding for the Mobile Node to be registered. Faizan. Expires June, 2004 [Page 4] Internet-Draft VHAR Protocol December, 2003 3. Related Work HAHA [7] protocol provides Home Agent Reliability and Load Balancing for Mobile-IPv6. In this protocol multiple Home Agents are provided over different links and Mobile Node has to register its binding in them. Mobile Node selects one of the Home Agents as its primary Home Agent. Primary Home Agent or any other Home Agent can tunnel packets from Correspondant Node to Mobile Node. On failure of the primary Home Agent Mobile Node can switch its service to any other Home Agent on any link. This protocol extends the fundamental specification of the Home Agent by allowing it to exists outside its Home Network which does not improve overall performance rather increases operational complexity and message overhead. Also the failure of the primary Home Agent is not transparent to the Mobile Node which results in service interruption. HAHA does not encounter the problems of delayed failure detection and IPsec Security Association with the new Home Agent as discussed in [12]. Also Load Balancing among Home Agents has been proposed in [13] but it does not provide Reliability solution. 4. Virtual Home Agent Reliability Protocol Overview Virtual Home Agent Reliability Protocol (VHAR) provide Home Agent Reliability and Load Balancing in Mobile-IPv6 network. VHAR allows multiple Home Agents on the same subnet. Some of these Home Agents are referred as "Recovery Home Agents". They provide recovery functionalities beside usual Home Agent functions. All the Home Agents including Recovery Home Agents have exact same IP address (referred as Home Agent Address) and only one of them is active on the subnet at a particular instance of time, similar to the technique used in VRRPv6 [8]. We will consider a basic deployment scenario where three Home Agents (HA_1..3) and Recovery Home Agents(RHA_1..3) coexist on the same subnet to provide continuous service to Mobile Node (MN). Currently HA_1 is active and responsible for all the Mobile-IPv6 Home Agent functions as defined in [1]. Faizan. Expires June, 2004 [Page 5] Internet-Draft VHAR Protocol December, 2003 Foreign Network Home Subnet ................... .............................. . . . . . +----+ . . +-------+ +-------+ . . |MN | .<==========>. | HA_1 | | RHA_1 | . . | | . . +-------+ +-------+ . . +----+ . . . . . . +-------+ +-------+ . ................... . | HA_2 | | RHA_2 | . . +-------+ +-------+ . . . . +-------+ +-------+ . . | HA_3 | | RHA_3 | . . +-------+ +-------+ . .............................. Figure 1: VHAR Basic Deployment Scenario 4.1 Mobile Node Registration When MN wants to register its Care of Address, it sends BU using Home Address as the destination address. This BU will be intercepted by the active HA which MAY perform Duplicate Address Detection[9] (DaD) to know if this MN is already registered with any other HA or RHA on the subnet. If it is registered then first active HA will send "MN Release Request" message to the HA or RHA which is holding the binding. In response, "MN Release Reply" message will be send to the active HA which will then select a RHA as its backup and sends "MN Context Update Request" message to it. In response to this selected RHA will send "Mobile Node Context Update Reply" message to the active HA. Upon receiving this it will send the BA message to MN. Faizan. Expires June, 2004 [Page 6] Internet-Draft VHAR Protocol December, 2003 ...................................... MN . HA_1 HA_2 HA_3 RHA_1 RHA_2 RHA_3 . | . | | | | | | . |===>. | | | | | | . 1. Home Registration | . | | | | | | . | . |<--------------------------->| . 2. DaD by active HA_1. | . | | | | | | . HA_3 has binding. | . | | | | | | . | . |---------->| | | | . 3. HA_1 sent to HA_3 | | | | | | | . MN Release Request. | . | | | | | | . | . |<----------| | | | . 4. HA_3 sent to HA_1 | . | | | | | | . MN Release Reply. | . | | | | | | . | . |---------------->| | | . 5. HA_1 sent to RHA_1 | . | | | | | | . MN Context Update | . | | | | | | . Request. | . | | | | | | . | . |<----------------| | | . 6. RHA_1 sent to HA_1 | . | | | | | | . MN Context Update | . | | | | | | . Reply. | . | | | | | | . |<======| | | | | | . 7. HA_1 sent BA to MN. | . | | | | | | . ...................................... Figure 2: VHAR Mobile Node Registration Signal Flow 4.2 VHAR Failure Detection and Recovery Each HA and RHA maintains a "Status List" to keep track of all the working HAs and RHAs on the subnet. They send unsolicited multicast "VHAR Advertisement" messages periodically on the subnet. Any new HA or RHA added on the subnet starts sending and receiving the VHAR Advertisements as it boots up. These VHAR Advertisements allow maintaining the Status List. When any HA or RHA fails on the subnet all other HAs and RHAs on the subnet will not receive VHAR Advertisements from it and upon timeout they will silently delete the entry for it from the Status List. But when the active HA fails they will send unicast "VHAR Solicitation" messages to it in order to confirm its failure and if they don't receive any VHAR Advertisement message from it they will delete its entry from the Status List. Now the RHA selected by the failed HA will serve as the active HA. It will also select its RHA in the same manner as the failed active HA selected its RHA. It could also select another HA as the active HA if it is over loaded by sending Faizan. Expires June, 2004 [Page 7] Internet-Draft VHAR Protocol December, 2003 "MN Context Migration Request" message to it and receiving "MN Context Migration Reply" message in response. This will also provide Load Balancing among the RHAs and HAs. The failure detection and recovery mechanisms discussed above is completely transparent to the MN which is required to keep the service interruption time minimal. ...................................... MN . HA_1 HA_2 HA_3 RHA_1 RHA_2 RHA_3 . | . | | | | | | . | . | | | | | | . | . |<--------------------------->| . 1. All the HAs and RHAs | . | | | | | | . multicast VHAR | . | | | | | | . Advertisements. | . | | | | | | . | . |--X->| | | | | . 2. Active HA_1 failed. | . | | | | | | . | . |<----|-----|-----|-----|-----| . 3. All other HAs and RHAs | . | | | | | | . unicast VHAR | . | | | | | | . Solicitations to HA_1. | . | | | | | | . | . | |<----------| | | . 4. RHA_1 ask HA_2 to | . | | | | | | . become active by | . | | | | | | . sending MN Context | . | | | | | | . Migration Request. | . | | | | | | . | . | |---------->| | | . 5. HA_2 sent MN Context | . | | | | | | . Migration Reply to | . | | | | | | . RHA_1 and became | . | | | | | | . active. | . | | | | | | . ...................................... Figure 3: VHAR Failure Detection and Recovery Signal Flow 4.3 VHAR Load Balancing If the active HA is over loaded it could make another HA as active by sending "Change Active HA Request" message to it which could respond by sending "Change Active HA Reply" message. That's how Load Balancing is achieved among different HAs. Faizan. Expires June, 2004 [Page 8] Internet-Draft VHAR Protocol December, 2003 ...................................... MN . HA_1 HA_2 HA_3 RHA_1 RHA_2 RHA_3 . | . | | | | | | . | . |---->| | | | | . 1. Active HA_1 wants to | . | | | | | | . make HA_2 active. It | . | | | | | | . sent Change Active HA | . | | | | | | . Request to HA_2. | . | | | | | | . | . |<----| | | | | . 2. HA_2 became active. It | . | | | | | | . sent Change Active HA | . | | | | | | . Reply to HA_1. | . | | | | | | . ...................................... Figure 4: VHAR Load Balancing Signal Flow 5. New ICMP Messages 5.1 VHAR Solicitation Message The VHAR Solicitation message is used to confirm the failure of the active HA or the RHA selected by it. Source and Destination address fields of the IPv6 header MUST be set to sender's and receiver's link-local unicast addresses. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options ... +-+-+-+-+-+-+-+-+-+-+-+- The fields of a VHAR Solicitation message are same as the Router Solicitation message [10] except for the Type field which is 160 (To Be Assigned by IANA). 5.2 VHAR Advertisement Message The VHAR Advertisement messages are sent among HAs and RHAs to maintain their Status Lists. The Source and Destination address fields of the IPv6 header MUST be set to sender's link-local unicast address and multicast address respectively. Faizan. Expires June, 2004 [Page 9] Internet-Draft VHAR Protocol December, 2003 VHAR modifies the format of the Router Advertisement message defined in Mobile-IPv6 [1] by the addition of three flag bits to indicate the status of sender sending the Advertisement message. Also the Type and Reserved fields are changed. VHAR Advertisement message 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 | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Cur Hop Limit |M|O|H|A|R|S|Res| Router Lifetime | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Reachable Time | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Retrans Timer | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Options ... +-+-+-+-+-+-+-+-+-+-+-+- This format represents the following changes over the Router Advertisement message defined in Mobile-IPv6 [1] Type 161 (To be Assigned by IANA) Active HA bit(A) The Active HA bit (A) is set to indicate that the sender of this message is also functioning as active HA on this link. RHA bit (R) The RHA bit (R) is set to indicate that the sender of this message is also functioning as RHA on this link. Selected RHA bit (S) The Selected RHA bit (S) is set to indicate that the sender of this message is also functioning as the selected RHA for the active HA on this link. Reserved (Res) Reduced from a 5-bit field to a 2-bit field to account for the addition of the above bits. Faizan. Expires June, 2004 [Page 10] Internet-Draft VHAR Protocol December, 2003 5.3 MN Release Request Message The MN Release Request message is sent by the active HA to the HA or RHA, at which MN is currently registered. The purpose of this message is to request de-registration of the MN's binding at its current HA. The Source and Destination address fields of the IPv6 header MUST be set to sender's and receiver's unicast link-local addresses. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Home Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Care of Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 162 (To Be Assigned by IANA) Code 0 Checksum The ICMP checksum [11]. Identifier An identifier to aid in matching MN Release Reply message to this MN Release Request message. Faizan. Expires June, 2004 [Page 11] Internet-Draft VHAR Protocol December, 2003 Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. Home Address The Home Address that was contained in the Home Address destination option of BU. Care of Address Specified by the BU from MN in the Source Address field of the IPv6 header. 5.4 MN Release Reply Message The MN Release Reply message is sent by the current HA of the MN to the active HA. The purpose of this message is to confirm the de-registration of the MN at its current HA. The Source and Destination address fields of the IPv6 header MUST be set to sender's and receiver's unicast link-local addresses. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 163 (To Be Assigned by IANA) Code 0 Checksum The ICMP checksum [11]. Identifier The identifier from the invoking MN Release Request message. Faizan. Expires June, 2004 [Page 12] Internet-Draft VHAR Protocol December, 2003 Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. 5.5 MN Context Update Request Message The MN Context Update Request message is sent by the active HA to the selected RHA. The purpose of this message is to request RHA to store the binding of MN. Source and Destination address fields of the IPv6 header MUST be set to sender's and receiver's unicast link-local addresses. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Home Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Care of Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 164 (To Be Assigned by IANA) Code 0 Checksum The ICMP checksum [11]. Faizan. Expires June, 2004 [Page 13] Internet-Draft VHAR Protocol December, 2003 Identifier An identifier to aid in matching MN Context Update Reply message to this MN Context Update Request message. Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. Home Address The Home Address that was contained in the Home Address destination option of BU. Care of Address Specified by the BU from MN in the Source Address field of the IPv6 header. 5.6 MN Context Update Reply Message The MN Context Update Reply message is sent by the selected RHA to the active HA. The purpose of this message is to acknowledge the storage of MN's binding. Source and Destination address fields of the IPv6 header MUST be set to the unicast link-local addresses of the active HA and selected RHA respectively. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 165 (To Be Assigned by IANA) Code 0 Checksum The ICMP checksum [11]. Faizan. Expires June, 2004 [Page 14] Internet-Draft VHAR Protocol December, 2003 Identifier The identifier from the invoking MN Context Update Request message. Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. 5.7 MN Context Migration Request Message The MN Context Migration Request message is sent by the selected RHA of the failed active HA to another HA. The purpose of this message is to assign a new active HA after the active HA failure. Source and Destination address fields of the IPv6 header MUST be set to the unicast link-local addresses of the selected RHA and the new active HA. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Home Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + + | | + Care of Address + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 166 (To Be Assigned by IANA) Faizan. Expires June, 2004 [Page 15] Internet-Draft VHAR Protocol December, 2003 Code 0 Checksum The ICMP checksum [11]. Identifier An identifier to aid in matching MN Context Migration Reply message to this MN Context Migration Request message. Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. Home Address The Home Address that was contained in the Home Address destination option of BU. Care of Address Specified by the BU from MN in the Source Address field of the IPv6 header. 5.8 MN Context Migration Reply Message The MN Context Migration Reply message is sent by the new HA to the selected RHA of the failed active HA. The purpose of this message is to acknowledge the request of selected RHA for the sender to serve as active HA. Source and Destination address fields of the IPv6 header MUST be set to the unicast link-local addresses of the new active HA and the selected RHA respectively. 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Faizan. Expires June, 2004 [Page 16] Internet-Draft VHAR Protocol December, 2003 Type 167 (To Be Assigned by IANA) Code 0 Checksum The ICMP checksum [11]. Identifier The identifier from the invoking MN Context Migration Request message. Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. 5.9 Change HA Request Message The Change HA Request message is sent by the active HA to an another HA. The purpose of this message is to request the HA to become active for the subnet. It is used to share the load among HAs. Source and Destination address fields of the IPv6 header MUST be set to the unicast link-local addresses of the current active HA and new active HA. 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 168 (To Be Assigned by IANA) Code 0 Faizan. Expires June, 2004 [Page 17] Internet-Draft VHAR Protocol December, 2003 Checksum The ICMP checksum [11]. Identifier An identifier to aid in matching Change HA Reply message to this Change HA Request message. Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. 5.10 Change HA Reply Message The Change HA Reply message is sent by the new active HA to the previously active HA. The purpose of this message is to acknowledge the request for becoming active HA for the subnet. Source and Destination address fields of the IPv6 header MUST be set to the unicast link-local addresses of the new active HA and the previously active HA respectively. 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Code | Checksum | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Identifier | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type 169 (To Be Assigned by IANA) Code 0 Checksum The ICMP checksum [11]. Identifier The identifier from the invoking Change HA Request message. Faizan. Expires June, 2004 [Page 18] Internet-Draft VHAR Protocol December, 2003 Reserved This field is unused. It MUST be initialized to zero by the sender and MUST be ignored by the receiver. 6. IANA Considerations This document defines ten new ICMP messages - VHAR Solicitation Message - VHAR Advertisement Message - MN Release Request Message - MN Release Reply Message - MN Context Update Request Message - MN Context Update Reply Message - MN Context Migration Request Message - MN Context Migration Reply Message - Change HA Request Message - Change HA Reply Message 7. Security Considerations Security Considerations are not discussed in this draft. References [1] Perkins, C., Johnson, D. and J. Arkko, "Mobility Support in IPv6", draft-ietf-mobileip-ipv6-24 (work in progress), August 2003. [2] Harkins, D. and D. Carrel, "The Internet Key Exchange (IKE)", RFC 2409, November 1998. [3] Arkko, J., Devarapalli, V. and F. Dupont, "Using IPsec to Protect Mobile IPv6 Signaling between Mobile Nodes and Home Agents", draft-ietf-mobileip-mipv6-ha-ipsec-06 (work in Faizan. Expires June, 2004 [Page 19] Internet-Draft VHAR Protocol December, 2003 progress), June 2003. [4] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [5] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, December 1998. [6] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [7] Wakikawa, R., Devarapalli, V. and P.Thubert, "Inter Home Agents Protocol (HAHA)", draft-wakikawa-mip6-nemo-haha-00.txt (work in progress), October 2003. [8] Hinden, R., "Virtual Router Redundancy Protocol", draft-ietf-vrrp-spec-v2-09.txt.(work in progress), August 2003. [9] Thomson, S. and T. Narten, "IPv6 Stateless Address Autoconfiguration", RFC 1971, August 1996. [10] Narten, T., Nordmark, E. and W. Simpson, "Neighbor Discovery for IP Version 6 (IPv6)", RFC 2461, December 1998. [11] Conta, A. and S. Deering, "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", RFC 2463, December 1998. [12] Faizan, J., El-Rewini, H. and M.Khalil, "Problem Statement:Home Agent Reliability", draft-jfaizan-mipv6-ha-reliability-00.txt (work in progress), November 2003. [13] Deng, H., Zhang, R., Huang, X. and K.Zhang, "Load Balance for Distributed Home Agents in Mobile IPv6", draft-deng-mip6-ha- loadbalance-00.txt (work in progress), November 2003. Authors' Addresses Jahanzeb Faizan Southern Methodist University Computer Science and Engineering Department. 6425 N Ownby Dr., SIC #300D Dallas, TX, 75205, USA Phone +1 214-768-3712, Fax +1 214-768-3085 EMail: jfaizan@smu.edu Faizan. Expires June, 2004 [Page 20] Internet-Draft VHAR Protocol December, 2003 Hesham El-Rewini Southern Methodist University Computer Science and Engineering Department. 6425 N Ownby Dr., SIC #306C Dallas, TX, 75205, USA Phone +1 214-768-3278, Fax +1 214-768-3085 EMail: rewini@engr.smu.edu Mohammad Khalil Nortel Networks Richardson, TX, USA Phone: +1 972-685-0564 EMail: mkhalil@nortelnetworks Intellectual Property Statement The IETF takes no position regarding the validity or scope of any intellectual property or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; neither does it represent that it has made any effort to identify any such rights. Information on the IETF's procedures with respect to rights in standards-track and standards-related documentation can be found in BCP-11. 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Expires June, 2004 [Page 21] Internet-Draft VHAR Protocol December, 2003 document itself may not be modified in any way, such as by removing the copyright notice or references to the Internet Society or other Internet organizations, except as needed for the purpose of developing Internet standards in which case the procedures for copyrights defined in the Internet Standards process must be followed, or as required to translate it into languages other than English. The limited permissions granted above are perpetual and will not be revoked by the Internet Society or its successors or assignees. This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. 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