DHC Working Group R. Yan Internet Draft Y. Jiang Expiration Date:
December 2006 L. GuiMay 2007 Alcatel Shanghai Bell X. Duan China Mobile Domain Suffix Option for DHCPv6 <draft-ietf-dhc-dhcpv6-opt-dnsdomain-03.txt> June 6,<draft-ietf-dhc-dhcpv6-opt-dnsdomain-04.txt> November 10, 2006 Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. 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 DecemberMay 6, 2006.2007. Copyright Notice Copyright (C) The Internet Society (2006). Abstract This document describes a new option for DHCPv6 (DHCP for IPv6) that provides a mechanism for specifying a domain name suffix. 1. Introduction This document describes a new option for DHCPv6 [RFC3315] that provides a mechanism for specifying a domain name suffix. Using this option, the DHCPv6 server can specify a domain name suffix to the DHCPv6 client. 1.1 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]. Domain suffix In this document, the domain suffix is defined as the suffix of a fully qualified domain name (FQDN). It is starts with lower-level domain name and continues all the way up to the top-level domain name. This document should be read in conjunction with the DHCPv6 specification, [RFC3315]. Definitions for terms and acronyms used in this document are defined in RFC3315. 2. Domain Suffix Option The domain suffix option for DHCPv6 is used by the DHCPv6 server to tell the DHCPv6 client the domain suffix that the DHCPv6 server administrator has specified for that DHCPv6 client. The format of the domain suffix 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-code | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | ~ domain suffix ~ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code: OPTION_DOMAIN_SUFFIX (TBD). option-length: length of the "domain suffix" field in octets. domain suffix: the specification of a domain suffix. The domain suffix in the 'domain suffix' field MUST include only one item, and MUSTbe encoded as specified in thesection of RFC3315 titled "Representation and use of domain names".names", except that it SHOULD only include one domain name, being a series of labels terminated by exactly one root label. If more than one root label is present, the DHCP client implementations MUST select the first name, ignoring any subsequent labels. 2.1 Usage A DHCPv6 client MUST include the option code in Option Request Option [RFC3315] if it desires the domain suffix option, and the DHCPv6 server SHOULD include this option in an Advertise or Reply if requested by the client in the Option Request Option. A DHCPv6 server may provide different values for the domain suffix option to different clients. The mechanism for choosing which suffix to assign to which client is a matter of implementation and administrative policy, and is therefore not specified in this document. 3. Security Considerations Security considerations in DHCP are described in section 23, "Security Considerations" of RFC3315. 4. IANA Considerations IANA is requested to assign a DHCPv6 option code for the OPTION_DOMAIN_SUFFIX. 5. Acknowledgements The authors thank Ralph Droms, Ted Lemon, Stig Venaas, Bernie Volz, Tatuya Jinmei, Joe Quanaim and Stefaan De Cnodder for valuable discussions and comments. 6. References 6.1 Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC3315] Bound, J., Carney, M., Perkins, C., Lemon, T., Volz, B. and R. Droms (ed.), "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, May 2003. [RFC3633] O. Troan, R. Droms, "IPv6 prefix option for DHCPv6", RFC3633, December 2003. Appendix: Examples The examples defined below are intended to give a reference usage of the domain suffix option. Example 1: Used for host One obvious example for the option is in a case where a DHCP client is not configured to assert a particular domain. The client could request the domain suffix in the ORO option to request the domain name it could use, as the usage for option 15 in DHCPv4. Example 2: Used for IPv6 residential gateway In IPv6 home network, it is easy to imagine that each device can get a globally unique IPv6 address, so that the device could be visited from outside network easily. It will be better if these devices could be accessed using domain name other than the tedious IPv6 address. Usually, residential gateway in home network works as a prefix requesting router [RFC3633] to request IPv6 prefix from prefix delegation router and allocate the address to home device using stateless configuration or through an embedded DHCPv6 server. One method to configure the domain suffix in CPEs in large scale is using domain suffix option. During DHCP session initiated by residential gateway, domain suffix name (e.g. example.com) could be specified. The domain suffix can then be used to update domain name for the hosts in subscriber network, by an embedded DHCPv6 server in residencial gateway or by other means of DNS update mechanism for stateless IPv6 configuration. To avoid frequent domain name conflicts, aggregation device might allocate different domain suffix name for the CPE. An example way can be selection based on an external authority such as a RADIUS server, in which an unique domain suffix name prefix, called "home name", are negotiated between user and ISP when subscribing. For example, "user1.example.com" and "user2.example.com". Authors' Addresses Renxiang Yan Yinglan Jiang Luoning GuiResearch & Innovation Center Alcatel Shanghai Bell Co., Ltd. 388#, NingQiao Road, Pudong Jinqiao, Shanghai 201206 P.R. China Phone: +86 (21) 5854-1240, ext. 7169 Email: email@example.com Yinglan.firstname.lastname@example.org Luoning.email@example.comXiaodong Duan Research & Development Center China Mobile Communications Corporation 53A, Xibianmennei Ave., Xuanwu District, Beijing, 100053 P.R. China Phone: +86 (10) 6600-6688, ext. 3062 Email: firstname.lastname@example.org Full Copyright Statement Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. 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