Network Working Group Pratik Gupta, IBM INTERNET DRAFT Glenn Stump, IBM July 1997 Expires January 1998 The Domain Search Option for DHCP Status of this Memo This document is an Internet-Draft. 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.'' To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). 1.0 Abstract The Dynamic Host Configuration Protocol (DHCP) [1] provides a framework for passing configuration information to hosts on a TCP/IP network. This document defines a new option which is passed form the DHCP server to the DHCP Client to configure the domain search list which is used by the clients to resolve hostnames in the Domain Name System. 2.0 Introduction RFC 2132 allows the Domain Name option (option 15) and the Domain Name Server (option 6) to be passed to the DHCP client. These options are usually used to configure resolv.conf file on most operating systems. This information is used to resolve names in the Domain Name System[]. This option allowes a list of domain names in the order of preference to be passed to the DHCP client such that the search directive can be specified for name resolution. 3.0 Definitions Gupta,Stump draft-ietf-dhc-domsrch-00.txt [Page 1] INTERNET DRAFT July 1997 Throughout this document, the words that are used to define the significance of the particular requirements are capitalized. These words are: MUST This word or the adjective "REQUIRED" means that the item is an absolute requirement of this specification. MUST NOT This phrase means the item is an absolute prohibition of this specification. SHOULD This word or the adjective "RECOMMENDED" means that there may exist valid reasons in particular circumstances to ignore this item, but the full implications should be understood and the case carefully weighed before choosing a different course. SHOULD NOT This phrase means that there may exist valid reasons in particular circumstances when the listed behavior is acceptable or even useful, but the full implications should be understood and the case carefully weighted before implementing any behavior described with this label. MAY This word or the adjective "OPTIONAL" means that this item is truly optional. One vendor may choose to include the item because a particular marketplace requires it or because it enhances the product, for example, another vendor may omit the same item. This document also uses the following terms: o "DHCP client" DHCP client or "client" is an Internet host using DHCP to obtain configuration parameters such as a network address. o "DHCP server" A DHCP server of "server"is an Internet host that returns Gupta,Stump draft-ietf-dhc-domsrch-00.txt [Page 2] INTERNET DRAFT July 1997 configuration parameters to DHCP clients. 3.0 Domain Search Option Format The code for this option is TBD, and its minimum length is 2 bytes. Code Len Priority +-------+-------+-------+--------+---------+---------+-- | TBD | n | d1 | 0 | d2 | 0 | +-------+-------+-------+--------+---------+---------+-- where: d1 & d2 are domain names 4.0 DHCP Client Behavior If a DHCP client is given both a Domain Name Option and a Domain Search Option, the Domain Search Option will take precedence. 5.0 Security Considerations DHCP currently provides no authentication or security mechanisms. Potential exposures to attack are discussed in section 7 of the DHCP protocol specification [1]. 6.0 References [RFC1533] S. Alexander, R. Droms, "DHCP Options and BOOTP Vendor Extensions" [RFC1541] R. Droms, "Dynamic Host Configuration Protocol" 7.0 Acknowledgments 8.0 Author Information Pratik Gupta IBM, Inc. 4205 S.Miami Blvd Research Triangle Park, NC 27709 Phone: (919)254-5654 email: pratik_gupta@vnet.ibm.com Gupta,Stump draft-ietf-dhc-domsrch-00.txt [Page 3] INTERNET DRAFT July 1997 Glenn Stump IBM, Inc. 4205 S.Miami Blvd Research Triangle Park, NC 27709 Phone: (919)254-5616 email: glennstump@vnet.ibm.com Gupta,Stump draft-ietf-dhc-domsrch-00.txt [Page 4]