Network Working Group T. Hiller Internet-Draft Lucent Technologies Updates: RFC 2472 G. Zorn Category: Standards Track Cisco Systems June 2002 PPP IPV6 Control Protocol Extensions for DNS Server Addresses 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. The distribution of this memo is unlimited. It is filed as and expires December 7, 2002. Please send comments to the pppext Working Group mailing list (ietf- ppp@merit.edu) or to the authors (tom.hiller@lucent.com and gwz@cisco.com). Copyright Notice Copyright (C) The Internet Societyi (2002). All Rights Reserved, Abstract The Point-to-Point Protocol (PPP) provides a standard method for transporting multi-protocol datagrams over point-to-point links. PPP Hiller & Zorn [Page 1] INTERNET-DRAFT IPV6CP DNS Server Extensions June 2002 defines an extensible Link Control Protocol and a family of Network Control Protocols (NCPs) for establishing and configuring different network-layer protocols. This document extends the NCP for establishing and configuring Version 6 of the Internet Protocol (IPV6) over PPP, defining the negotiation of primary and secondary Domain Name System (DNS) server IPV6 addresses. 1. Introduction The Point-to-Point Protocol (PPP) [STD51] provides a standard method for transporting multi-protocol datagrams over point-to-point links. PPP defines an extensible Link Control Protocol and a family of Network Control Protocols (NCPs) for establishing and configuring different network-layer protocols. This document extends the NCP for establishing and configuring Version 6 of the Internet Protocol (IPV6) over PPP [RFC2472], defining the negotiation of primary and secondary Domain Name System (DNS) server addresses for IPV6 [RFC1034] [RFC1035] [RFC1886]. 2. Conventions used in this document 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 RFC 2119 [RFC2119]. 3. Additional IPV6CP Configuration Options The two name server address configuration options, TBD1 and TBD2, provide a method of obtaining the addresses of Domain Name System (DNS) servers on the remote IPV6 network. For implementation convenience, these options are designed to serve identical purposes, except that when both are present an attempt SHOULD be made to resolve names using the primary address before using the secondary address. 3.1. Primary DNS Server IPV6 Address Description This Configuration Option defines a method for negotiating with the remote peer the IPV6 address of the primary DNS server to be Hiller & Zorn [Page 2] INTERNET-DRAFT IPV6CP DNS Server Extensions June 2002 used on the local end of the link. the local peer requests an invalid server address (which it will typically do intentionally) the remote peer specifies the address by NAKing this option, and returning the Ipv6 address of a valid DNS server. By default, no primary DNS address is provided. A summary of the Primary DNS IPV6 Address Configuration Option format is shown below. The fields are transmitted from left to right. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Primary-DNS-IPV6-Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Primary-DNS-IPV6-Address (cont'd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Primary-DNS-IPV6-Address (cont'd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Primary-DNS-IPV6-Address (cont'd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD1 Length 20 Primary-DNS-IPV6-Address The sixteen octet Primary-DNS-Address is the address (in network byte order) of the primary DNS server to be used by the local peer. If all sixteen octets are set to zero, it indicates an explicit request that the peer provide the address information in a Config-Nak packet. Default No address is provided. 3.2. Secondary DNS Server IPV6 Address Description This Configuration Option defines a method for negotiating with the remote peer the IPV6 address of the secondary DNS server to be Hiller & Zorn [Page 3] INTERNET-DRAFT IPV6CP DNS Server Extensions June 2002 used on the local end of the link. If local peer requests an invalid server address (which it will typically do intentionally) the remote peer specifies the address by NAKing this option, and returning the IPV6 address of a valid DNS server. By default, no secondary DNS address is provided. A summary of the Secondary DNS Server IPV6 Address Configuration Option format is shown below. The fields are transmitted from left to right. 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 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Secondary-DNS-IPV6-Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Secondary-DNS-IPV6-Addresa (cont'd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Secondary-DNS-IPV6-Addresa (cont'd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Secondary-DNS-IPV6-Addresa (cont'd.) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Type TBD2 Length 20 Secondary-DNS-IPV6-Address The sixteen octet Secondary-DNS-IPV6-Address is the IPV6 address (in network byte order) of the secondary DNS server to be used by the local peer. If all sixteen octets are set to zero, it indicates an explicit request that the peer provide the address information in a Config-Nak packet. Default No address is provided. Normative References [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 Hiller & Zorn [Page 4] INTERNET-DRAFT IPV6CP DNS Server Extensions June 2002 [STD51] W. Simpson, Editor, "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661, July 1994 [RFC2472] Haskin, D., E. Allen, "IP Version 6 over PPP", RFC 2472, December 1998 [RFC1034] P. Mockapetris, "Domain Names - Concepts and Facilities", STD 13, RFC 1034, November 1987. [RFC1035] P. Mockapetris, "Domain Names - Implementation and Specification", STD 13, RFC 1035, November 1987. [RFC1886] Thomson, S. and C. Huitema, "DNS Extensions to support IP version 6", RFC 1886, December 1995. Informative References [RFC1877] S. Cobb, "PPP Internet Protocol Control Protocol Extensions for Name Server Addresses", RFC 1877, December 1995. Security Considerations The use of these extensions is as secure as the link itself. Acknowledgments A major portion of the text in this memo was stolen from RFC 1877 [RFC1877]. Authors' Addresses Tom Hiller Lucent Technologies 1960 Lucent Lane Naperville, IL 60566 USA Phone: +1 (630) 979 7673 Email: tom.hiller@lucent.com Glen Zorn Cisco Systems, Inc. 500 108th Avenue N.E., Suite 500 Hiller & Zorn [Page 5] INTERNET-DRAFT IPV6CP DNS Server Extensions June 2002 Bellevue, WA 98004 USA Phone: +1 (425) 471-4861 Email: gwz@cisco.com Full Copyright Statement "Copyright (C) The Internet Society (2002). All Rights Reserved. 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Copies of claims of rights made available for publication and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementors or users of this specification can be obtained from the IETF Secretariat. Hiller & Zorn [Page 6] INTERNET-DRAFT IPV6CP DNS Server Extensions June 2002 Expiration Date This memo is filed as and expires December 7, 2002. Hiller & Zorn [Page 7]