Network Working Group F. Templin Internet-Draft Nokia Expires: December 2, 2003 June 03, 2003 Dynamic Host Configuration Protocol (DHCP-for-IPv4) Option for the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) draft-templin-isatap-dhcp-01.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 December 2, 2003. Copyright Notice Copyright (C) The Internet Society (2003). All Rights Reserved. Abstract This document specifies a Dynamic Host Configuration Protocol (DHCP-for-IPv4) option for nodes that implement the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP). 1. Introduction This document specifies a Dynamic Host Configuration Protocol [RFC2131] option for the Intra-Site Automatic Tunnel Addressing Protocol [ISATAP]. The option encodes configuration information used by clients to initialize the Potential Router List (PRL) as specified in [ISATAP], section 7.3.1. The option format is similar to [RFC3361] and allows the server to publish one or more domain names or IPv4 Templin Expires December 2, 2003 [Page 1] Internet-Draft DHCP Option for ISATAP June 2003 addresses. 2. Requirements In this document, the key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to be interpreted as described in RFC 2119 [4]. 3. ISATAP DHCP Option The ISATAP DHCP option encodes a list of one or more 32-bit IPv4 addresses or DNS [RFC1035] fully-qualified domain names (FQDNs). The elements in the list MUST NOT include a mix of IPv4 addresses and FQDNs; instead, the data type is identified by an encoding byte in the DHCP option. The ISATAP DHCP option encodes a sequence of octets using the following format: Code Len enc Potential Router List +-----+-----+-----+-----+-----+-----+-----+-----+-- | TBD | n | 0/1 | p1 | p2 | p3 | p4 | p5 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- In this format, the DHCP option code is followed immediately by a 'Len' octet that indicates the total number of octets that follow, including the 'enc' octet. When 'enc' = 0, the list contains a sequence of labels comprising one or more FQDN encoded exactly as specified in [RFC1035], section 3.1. (Note: this is the same format specified by [RFC3361], section 3.1). As an example, if the server wants to advertise the FQDNs "isatap.com" and "isatap.net", it would be encoded as follows: +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ |TBD| 25| 0 | 6 |'i'|'s'|'a'|'t'|'a'|'p'| 3 |'c'|'o'|'m'| 0 | +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ | 6 |'i'|'s'|'a'|'t'|'a'|'p'| 3 |'n'|'e'|'t'| 0 | +---+---+---+---+---+---+---+---+---+---+---+---+ When 'enc' = 1, the list contains one or more IPv4 addresses. In this case, 'Len' MUST be a minimum of 5 and a multiple of 4 plus one. (Note: this is the same format specified by [RFC3361], section 3.2). The DHCP option for this encoding has the following format: Code Len enc Address 1 Address 2 +-----+-----+-----+-----+-----+-----+-----+-----+-- | TBD | n | 1 | a1 | a2 | a3 | a4 | a1 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- Templin Expires December 2, 2003 [Page 2] Internet-Draft DHCP Option for ISATAP June 2003 Clients use the elements encoded in the ISATAP DHCP option to initialize the Potential Router List as specified in [ISATAP], section 7.3.1. 4. IANA considerations A new DHCPv4 option number for ISATAP is requested. 5. Security considerations The security considerations in [RFC2131] apply. 6. Acknowledgements The following individuals are acknowledged for providing constructive comments: Jim Bound, Ralph Droms, Mohan Parthasarathy, Pekka Savola. Normative References [ISATAP] Templin, F., Gleeson, T., Talwar, M. and D. Thaler, "Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)", draft-ietf-ngtrans-isatap-13 (work in progress), March 2003. [RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. Informative References [RFC3361] Schulzrinne, H., "Dynamic Host Configuration Protocol (DHCP-for-IPv4) Option for Session Initiation Protocol (SIP) Servers", RFC 3361, August 2002. Templin Expires December 2, 2003 [Page 3] Internet-Draft DHCP Option for ISATAP June 2003 Author's Address Fred L. Templin Nokia 313 Fairchild Drive Mountain View, CA 94110 US Phone: +1 650 625 2331 EMail: ftemplin@iprg.nokia.com Templin Expires December 2, 2003 [Page 4] Internet-Draft DHCP Option for ISATAP June 2003 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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