Network Working Group F. Xia Internet-Draft B. Sarikaya Expires: April 29, 2011 Huawei USA October 26, 2010 DHCPv4 Options for Home Information Discovery in Dual Stack MIPv6 draft-xia-mext-hioptv4-01.txt Abstract This document defines DHCPv4 options for dynamic discovery of home network information in Dual Stack Mobile IPv6. New DHCPv4 options are defined which allow a mobile node to request the home agent IPv4/v6 address, FQDN, or home network prefix and obtain it via the DHCPv4 response. Status of this Memo This Internet-Draft is submitted to IETF 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/. 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Xia & Sarikaya Expires April 29, 2011 [Page 1] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3. Home Information Discovery Using DHCPv6 . . . . . . . . . . . . 3 4. DHCPv4 options for HA Dynamic Discovery . . . . . . . . . . . . 4 4.1. Home Network Information Option . . . . . . . . . . . . . . 4 4.2. DSMIPv6 Relay Agent Option . . . . . . . . . . . . . . . . 5 5. Appearance of these options . . . . . . . . . . . . . . . . . . 6 6. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 7. IANA considerations . . . . . . . . . . . . . . . . . . . . . . 6 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 6 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 7 9.1. Normative References . . . . . . . . . . . . . . . . . . . 7 9.2. Informative References . . . . . . . . . . . . . . . . . . 7 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8 Xia & Sarikaya Expires April 29, 2011 [Page 2] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 1. Introduction Before a mobile node can exchange Mobile IPv6 signaling with a home agent, it should either know the IP address of the home agent via pre-configuration, or dynamically discover it. New DHCPv6 options are defined in [I-D.ietf-mip6-hiopt] which allow a mobile node to request the home agent IPv6 address, FQDN, or home network prefix and obtain it via the DHCP response. [I-D.ietf-mext-nemo-v4traversal](DSMIPv6) extends mobile IPv6 specification [RFC3775] to allow the registration of IPv4 addresses, and the transport of packets over IPv4 tunnels between mobile nodes and home agents. With home agent discovery in DSMIPv6, there are actually four different cases: o Discovering HA's IPv6 address with DHCPv6 o Discovering HA's IPv4 address with DHCPv6 o Discovering HA's IPv4 address with DHCPv4 o Discovering HA's IPv6 address with DHCPv4 The first two cases are dealt with in [I-D.ietf-mip6-hiopt], while the last two cases are specified in this document. DHCPv4 options are defined based on DHCPv4 protocol specified in [RFC2131]. 2. 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]. The terminology in this document is based on the definitions in [I-D.ietf-mip6-hiopt] 3. Home Information Discovery Using DHCPv6 [I-D.ietf-mip6-hiopt] introduces the following DHCPv6 options and their sub-options which are used for dynamic discovery of the home agent's IPv4/IPv6 address, IPv6 home network prefix, or FQDN information in DSMIPv6. Xia & Sarikaya Expires April 29, 2011 [Page 3] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 Home Network Information Option This option allows the exchange of home network information between the mobile node (DHCPv6 client) and the DHCPv6 server. It is used to indicate the target home network requested by the mobile node to the DHCPv6 server. It also conveys the home network information assigned by the DHCPv6 server to the mobile node as a response. MIP6 Relay Agent Option This option carries the home network information for the mobile node from the DHCPv6 relay agent to the DHCPv6 server. For instance, the NAS is collocated with the DHCPv6 relay agent, and the NAS gets the home network information from external AAA servers. This option is added to the DHCPv6 message when the NAS/ DHCP relay agent relays DHCPv6 request message from the mobile node to the DHCPv6 server, the option is added to the relayed message. Being populated with this information, the DHCPv6 server uses Home Network Information Option to reply the mobile node. Common Sub-options This sub-option is a container for a home network parameter in the Home Network Information option or in the MIP6 Relay Agent option. In this document, Home Network Information Option Section 4.1 DSMIPv6 Relay Agent Option Section 4.2 for DHCPv4 are defined to take the place of Home Network Information Option and MIP6 Relay Agent Option respectively. The difference between these options and their replacements is only on format, that is, these options are for DHCPv6 while their replacements are for DHCPv4. Common Sub-options in [I-D.ietf-mip6-hiopt] are reused in this document. 4. DHCPv4 options for HA Dynamic Discovery 4.1. Home Network Information Option The option allows the exchange of home network information between the mobile node (DHCPv4 client) and the DHCPv4 server. It is used to indicate the target home network requested by the mobile node to the DHCPv4 server. It also conveys the home network information assigned by the DHCPv4 server to the mobile node as a response. Xia & Sarikaya Expires April 29, 2011 [Page 4] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | option-code | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Id-type | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-options | | ... ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Option-code OPTION_DSMIP6_HNINF (TDB) Option-len Length of the 'options' field in octets; MUST be a multiple of four (4). Id-type The type of Home Network Information. 0 Visited domain (local ASP) 1 Target MSP 2 No preference by the mobile node Sub-options A series of sub-options as specified in [I-D.ietf-mip6-hiopt]. 4.2. DSMIPv6 Relay Agent Option As a replacement of MIP6 Relay Agent Option in [I-D.ietf-mip6-hiopt], this option carries the home network information for the mobile node from the DHCPv4 relay agent to the DHCPv4 server. Xia & Sarikaya Expires April 29, 2011 [Page 5] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | option-code | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Sub-options | | ... ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Option-code OPTION_DSMIP6_RELAY (TBD) Option-len Length of the 'options' field in octets; MUST be a multiple of four (4). Sub-options A series of sub-options as specified in [I-D.ietf-mip6-hiopt]. 5. Appearance of these options The Home Network Information Option MUST NOT appear in any message other than the following messages: DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPACK,DHCPINFORM. The DSMIPv6 Relay Agent Option MUST NOT appear in any message other than the following messages: DHCPDISCOVER, DHCPREQUEST, DHCPINFORM. 6. Security Considerations The security considerations in [RFC2131] and [RFC2132]apply. Special considerations in [I-D.ietf-mip6-hiopt] are also applicable. 7. IANA considerations IANA is requested to assign the OPTION_DSMIP6_HNINF and OPTION_DSMIP6_RELAY Option Codes in the registry maintained in http://www.iana.org/assignments/dhcpv6-parameters. 8. Acknowledgements Xia & Sarikaya Expires April 29, 2011 [Page 6] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 9. References 9.1. Normative References [RFC1981] McCann, J., Deering, S., and J. Mogul, "Path MTU Discovery for IP version 6", RFC 1981, August 1996. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3775] Johnson, D., Perkins, C., and J. Arkko, "Mobility Support in IPv6", RFC 3775, June 2004. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2132] Alexander, S. and R. Droms, "DHCP Options and BOOTP Vendor Extensions", RFC 2132, March 1997. [IANAADFAM] "IANA", . 9.2. Informative References [I-D.ietf-mip6-hiopt] Jang, H., Yegin, A., Chowdhury, K., and J. Choi, "DHCP Options for Home Information Discovery in MIPv6", draft-ietf-mip6-hiopt-17 (work in progress), May 2008. [I-D.ietf-mext-nemo-v4traversal] Soliman, H., "Mobile IPv6 Support for Dual Stack Hosts and Routers", draft-ietf-mext-nemo-v4traversal-10 (work in progress), April 2009. Xia & Sarikaya Expires April 29, 2011 [Page 7] Internet-Draft DHCPv4 Options for DSMIPv6 October 2010 Authors' Addresses Frank Xia Huawei USA 1700 Alma Dr. Suite 500 Plano, TX 75075 Phone: +1 972-509-5599 Email: xiayangsong@huawei.com Behcet Sarikaya Huawei USA 1700 Alma Dr. Suite 500 Plano, TX 75075 Phone: +1 972-509-5599 Email: sarikaya@ieee.org Xia & Sarikaya Expires April 29, 2011 [Page 8]