Network Working Group J. Bound Internet-Draft Compaq Computer Corporation Expires: July 2, 2002 M. Carney Sun Microsystems, Inc. C. Perkins Nokia Research Center T. Lemon Nominum B. Volz Ericsson R. Droms Cisco Systems Jan 2002 DSTM Options for DHCPv6 draft-ietf-dhc-dhcpv6-opt-dstm-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 July 2, 2002. Copyright Notice Copyright (C) The Internet Society (2002). All Rights Reserved. Abstract The DSTM Global IPv4 Address option and the DSTM Tunnel Endpoint Option provide DSTM (Dual Stack Transition Mechanism) configuration Bound, et al. Expires July 2, 2002 [Page 1] Internet-Draft DSTM Options Jan 2002 information to DHCPv6 hosts. 1. Introduction This document describes two options for DHCPv6 [2] that provide information for hosts using the "Dual Stack Transition Mechanism" (DSTM) [3]. 2. Requirements The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD NOT, RECOMMENDED, MAY, and OPTIONAL, when they appear in this document, are to be interpreted as described in RFC 2119 [1] 3. Terminology This document uses terminology specific to IPv6 and DHCPv6 as defined in section "Terminology" of the DHCPv6 specification. 4. DSTM Global IPv4 Address option The DSTM Global IPv4 Address option encapsulates other options that a DHCP client is to use for DSTM. The DSTM Global IPv4 Address option must include at least one Identity Association (IA) (see section "Identity Association" of the DHCPv6 specification [2]) that carries IPv4-mapped IPv6 addresses [4] as used in DSTM. The format of the DSTM Global IPv4 Address option is: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_DSTM | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . options . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code : OPTION_DSTM option-length: Length of the 'options' field in octets options : Options associated with DSTM One Identity Association option (see section "Identity Association option" of the DHCPv6 specification) MUST be encapsulated within the options field in the DSTM Global IPv4 Address option. That IA option Bound, et al. Expires July 2, 2002 [Page 2] Internet-Draft DSTM Options Jan 2002 MUST be used only for IPv4-mapped IPv6 addresses. A DSTM Tunnel End Point option (Section 5) MAY be encapsulated in the DSTM Global IPv4 Address option to specify one or more tunnel endpoints. 5. DSTM Tunnel Endpoint Option The DSTM Tunnel Endpoint option carries an IP address that is to be used as a tunnel endpoint (TEP) to encapsulate IP datagrams within IP. The format of the DSTM Tunnel Endpoint option is: 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_DSTM_TEP | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . . tep . . (16 octets) . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code: OPTION_DSTM_TEP option-length: 16 tep: Tunnel endpoint A DSTM Tunnel EndPoint Option MUST NOT be used except when encapsulated in a DSTM Global IPv4 Address option. 6. Appearance of these options The DSTM Global IPv4 Address option MUST only appear in the options section of the following DHCP messages: Solicit, Advertise, Request, Confirm, Renew, Rebind, Decline, Release, Reply. The DSTM Tunnel Endpoint option MUST only appear as an encapsulated option in a DSTM Global IPv4 Address option. 7. Security Considerations The DSTM Global IPv4 Address option may be used by an intruder DHCP server to assign an invalid IPv4-mapped address to a DHCP client in a denial of service attack. The DSTM Tunnel Endpoint option may be used by an intruder DHCP server to configure a DHCP client with an Bound, et al. Expires July 2, 2002 [Page 3] Internet-Draft DSTM Options Jan 2002 endpoint that would cause the client to route packets through an intruder system. To avoid these security hazards, a DHCP client MUST use authenticated DHCP to confirm that it is exchanging the DSTM options with an authorized DHCP server. 8. IANA Considerations IANA is requested to assign an option code to this option from the option-code space defined in section "DHCP Options" of the DHCPv6 specification [2]. References [1] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [2] Bound, J., Carney, M., Perkins, C., Lemon, T., Volz, B. and R. Droms (ed.), "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", draft-ietf-dhc-dhcpv6-23 (work in progress), February 2002. [3] Bound, J., "Dual Stack Transition Mechanism (DSTM)", draft-ietf- ngtrans-dstm-05 (work in progress), November 2001. [4] Hinden, R. and S. Deering, "IP Version 6 Addressing Architecture", RFC 2373, July 1998. Authors' Addresses Jim Bound Compaq Computer Corporation ZK3-3/W20 110 Spit Brook Road Nashua, NH 03062-2698 USA Phone: +1 603 884 0062 EMail: Jim.Bound@compaq.com Bound, et al. Expires July 2, 2002 [Page 4] Internet-Draft DSTM Options Jan 2002 Mike Carney Sun Microsystems, Inc. Mail Stop: UMPK17-202 901 San Antonio Road Palo Alto, CA 94303-4900 USA> Phone: +1 650 786 4171 EMail: mwc@eng.sun.com Charlie Perkins Nokia Research Center Communications Systems Lab 313 Fairchild Drive Mountain View, CA 94043 USA Phone: +1 650 625 2503 EMail: charliep@iprg.nokia.com Nominum EMail: mellon@nominum.com Bernie Volz Ericsson 959 Concord Street Framingham, MA 01701 USA Phone: +1 508 875 3162 EMail: bernie.volz@ericsson.com Ralph Droms Cisco Systems 250 Apollo Drive Chelmsford, MA 01824 USA Phone: +1 978 497 4733 EMail: rdroms@cisco.com Bound, et al. Expires July 2, 2002 [Page 5] Internet-Draft DSTM Options Jan 2002 Full Copyright Statement Copyright (C) The Internet Society (2002). All Rights Reserved. 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