Network Working Group F. Templin Internet-Draft Nokia Expires: August 18, 2003 February 17, 2003 Dynamic Host Configuration Protocol (DHCP-for-IPv4) Option for the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) draft-templin-isatap-dhcp-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 August 18, 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 that provides two lists of configuration data for nodes that implement the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP). 1. Introduction This document specifies a Dynamic Host Configuration Protocol (DHCP-for-IPv4) option for the Intra-Site Automatic Tunnel Addressing Protocol (ISATAP) [1]. The option encodes two lists; the site's Potential Router List (PRL) ([1], section 7.3.1) and the list of DHCPv6 [2] servers for the site. The option is similar to the one Templin Expires August 18, 2003 [Page 1] Internet-Draft DHCP Option for ISATAP February 2003 specified in RFC 3361 [3] and allows ISATAP site administrators to publish the site's PRL and DHCPv6 server lists as zero or more domain names or IPv4 addresses. 2. ISATAP DHCP Option The ISATAP DHCP option carries two lists. Each list may contain zero or more 32-bit IPv4 addresses or DNS (RFC 1035 [4]) fully-qualified domain names (FQDNs). The elements in each list MUST NOT include a mix of IPv4 addresses and FQDNs; instead, the data type for each list is identified by an 'enc' byte in the DHCP option. The ISATAP DHCP option has the following format: Code len enc Potential Router List +-----+-----+-----+-----+-----+-----+-----+-----+-- | TBD | m | x | p1 | p2 | p3 | p4 | p5 | ... +-----+-----+-----+-----+-----+-----+-----+-----+-- ... | n | y | d1 | d2 | d3 | d4 | d5 | ... ---+-----+-----+-----+-----+-----+-----+-----+-- ... | len enc DHCPv6 Server List ---+ As can be seen in the figure, the ISATAP DHCP option encodes 'm' octets of Potential Router List entries of encoding type 'x' followed by 'n' octets of DHCPv6 Server List entires of encoding type 'y'. When an 'enc' byte has a value of 0, the list contains a sequence of zero or more labels comprising FQDNs encoded exactly as specified in ([3], section 3.1). When an 'enc' byte has a value of 1, the list contains zero or more IPv4 addresses encoded exactly as specified in ([3], section 3.2). The 'len' and 'enc' fields for both the Potential Router List and DHCPv6 Server List are always present (i.e., even if one or both lists are empty). ISATAP nodes use the elements encoded in the Potential Router List exactly as specified in ([1], section 7.3.1). When the elements encoded in the DHCPv6 Server List are IPv4 addresses, they are used by ISATAP nodes to construct link-local ISATAP addresses exactly as specified in ([1], section 5.1). When the elements encoded in the DHCPv6 Server List are FQDNs, they are used by ISATAP nodes in DNS queries to obtain IPv4 addresses for link-local ISATAP address construction as specified above. 3. IANA considerations The DHCPv4 option number for ISATAP is TBD. Templin Expires August 18, 2003 [Page 2] Internet-Draft DHCP Option for ISATAP February 2003 4. Security considerations The security considerations in RFC 2131 [5] apply. 5. Acknowledgements TBD Normative References [1] Thaler, D., Gleeson, T., Talwar, M. and F. Templin, "Intra-Site Automatic Tunnel Addressing Protocol (ISATAP)", draft-ietf-ngtrans-isatap-12 (work in progress), January 2003. [2] Droms, R., "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", draft-ietf-dhc-dhcpv6-28 (work in progress), November 2002. [3] Schulzrinne, H., "Dynamic Host Configuration Protocol (DHCP-for-IPv4) Option for Session Initiation Protocol (SIP) Servers", RFC 3361, August 2002. [4] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [5] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. Informative References 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 August 18, 2003 [Page 3] Internet-Draft DHCP Option for ISATAP February 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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