INTERNET DRAFT Jae-Hoon Jeong Expires: April 2003 Jung-Soo Park Hyoung-Jun Kim ETRI October, 2002 Generation of Unique Domain Name based on Network Device Identifier Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026 except that the right to produce derivative works is not granted. 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. Abstract This document describes a mechanism of generating a unique domain name based on Network Device Identifier. This mechanism is useful when we configure a unique domain name of a node automatically in the environment where there is no dedicated name server such as unmanaged home-network and ad-hoc network. Table of Contents Status of this Memo Abstract 1. Introduction 2. Mechanism Overview Jeong, Park, Kim Expires April 2003 [Page 1] INTERNET-DRAFT Generation of Unique Domain Name October 2002 3. Implementation Considerations 4. Security Considerations 5. References Authors' Addresses 1. Introduction This document describes a simple mechanism which generates a unique domain name for a node in home-network or ad-hoc network where there is no network manager. This mechanism is useful when we configure a unique domain name of a node automatically in the environment where there is no dedicated name server and network manager such as unmanaged home-network and ad-hoc network. 2. Mechanism Overview This mechanism for name generation makes a unique domain name with user-id, device-id (network device's address extended into EUI-64) and domain like Figure 1 [1]. ---------------------------------------------- | user-id | device-id | domain | ---------------------------------------------- Figure 1. Format of domain name user-id is the user identifier selected by user and device-id is EUI-64 identifier derived from the network device's built-in 48-bit IEEE 802 address [1]. @- domain indicates the domain which a node belongs to and it -@ SHOULD include "EUI-64" sub-domain which indicates that the domain name is based on EUI-64. We define the domain for ad-hoc network as EUI-64.ADHOC and the domain for home-network as EUI-64.HOMENET. For example, when user-id is "PAUL", device-id is "36-56-78-FF-FE- 9A-BC-DE", and domain is "EUI-64.ADHOC", a unique domain name would be "PAUL.36-56-78-FF-FE-9A-BC-DE.EUI-64.ADHOC" [2]. The merit of the above mechanism guarantees that no name conflict happens although users in other nodes use the same user-id. For example, like Figure 2, there are node A, B and C in the same subnet and they all use the same user-id, "PAUL". Their domain is "EUI-64.ADHOC". The domain name of each node is made through Table 1. The domain name "NAME1" is for node A, the domain name "NAME2" is for node B. When node C generates its domain name on the basis of its user-id "PAUL" and its network device address "MAC3". Though node C uses the same user-id as node A and B, it can configure a unique domain name owing to the difference of network device address without the procedure of verifying the uniqueness of domain Jeong, Park, Kim Expires April 2003 [Page 2] INTERNET-DRAFT Generation of Unique Domain Name October 2002 name [3]. (NAME1: PAUL+MAC1) (NAME3: PAUL+MAC3) (NAME2: PAUL+MAC2) [Node A] [Node C] [Node B] | | | | | | --------------------------------------------------------- Figure 2. Network configuration regarding the generation of a unique domain name Table 1 shows how nodes with the same user-id can configure a unique domain name with their different EUI-64 id made from their own network device address. ----------------------------------------------------------------- | | | | | | | name | user-id| n/w device address | EUI-64 id | domain | | (node) | | | | | ================================================================= | NAME1 | PAUL | MAC1 | EUI64-1 |EUI-64.ADHOC| |(Node A)| | | | | ----------------------------------------------------------------- | NAME2 | PAUL | MAC2 | EUI64-2 |EUI-64.ADHOC| |(Node B)| | | | | ----------------------------------------------------------------- | NAME3 | PAUL | MAC3 | EUI64-3 |EUI-64.ADHOC| |(Node C)| | | | | ----------------------------------------------------------------- Table 1. Configuration of domain names of nodes in Figure 2 Generally nodes can configure their unique domain name regardless of their user-id but name conflict might happen if the manaul configuration of MAC address is allowed. Verifying if the generated name is unique in such a network MAY be performed through dynamic update request [3][4]. When a name conflict happens, we SHOULD generate a new name of which device-id is EUI-64 identifier derived from 48-bit random number. This new name SHOULD also be verified through dynamic update request. For example, Figure 3 shows the procedure of managing the name conflict. There are node A, B and C in the same subnet. Node A tries to configure its name as NAME1 which is the name of node B. Jeong, Park, Kim Expires April 2003 [Page 3] INTERNET-DRAFT Generation of Unique Domain Name October 2002 (NAME1: PAUL+MAC1) (NAME2: PAUL+MAC2) (NAME2: PAUL+MAC2) [Node A] [Node C] [Node B] | | | | | | --------------------------------------------------------- DNS-UPDATE request <--------- ---------> DNS-UPDATE request (C, NAME2) (C, NAME2) <--------- DNS-UPDATE response (B, NAME2) { Node C generates a new name "NAME3", where NAME3: PAUL+MAC3 } DNS-UPDATE request <--------- ---------> DNS-UPDATE request (C, NAME3) (C, NAME3) ..... no response Figure 3. Management of name conflict Node C makes a new name "NAME2" on the basis of its network device identifier and verifies the uniqueness of the new name through dynamic update request in multicast [3][4]. Because node B finds that any other node, node C, tries to use its domain name, it sends node C DNS-UPDATE response indicating that NAME2 is used by node B. As node C receives node B's response, it makes a new name on the basis of a new device-id which is derived from a new network device identifier "MAC3", 48-bit random number. Node C verifies the uniqueness of the new one through dynamic update request again. Because in this time there is no response from any other node, node C configures the verified name as its domain name. 3. Implementation Considerations user-id and domain are registered in options statement of configuration file of name server as follows; options { user-id "PAUL"; domain "EUI-64.ADHOC"; }; The generated domain name is registered in name server's zone file. 4. Security Considerations Jeong, Park, Kim Expires April 2003 [Page 4] INTERNET-DRAFT Generation of Unique Domain Name October 2002 As network device identifier is exposed in domain name, there would be security attack. To prevent the attack, we SHOULD use the message digest mechanism suggested in RFC3041 [5]. 5. References [1] "Guidelines For 64-bit Global Identifier (EUI-64)", http://standards.ieee.org/regauth/oui/tutorials/EUI64.html [2] M. Crawford, "Transmission of IPv6 Packets over Ethernet Networks", RFC2464, December 1998. [3] Levon Esibov and Dave Thalor, "Linklocal Multicast Name Resolution (LLMNR)", I-D draft-ietf-dnsext-mdns-12, February 2003. [4] P. Vixie et al., "Dynamic Updates in the Domain Name System (DNS UPDATE)", RFC2136, April 1997. [5] T. Narten and R. Draves, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC3041, January 2001. Authors' Addresses Jae-Hoon Jeong ETRI / PEC 161 Gajong-Dong, Yusong-Gu Daejon 305-350 Korea Phone: +82 42 860 1664 EMail: paul@etri.re.kr Jung-Soo Park ETRI / PEC 161 Gajong-Dong, Yusong-Gu Daejon 305-350 Korea Phone: +82 42 860 6514 EMail: pjs@etri.re.kr Hyoung-Jun Kim ETRI / PEC 161 Gajong-Dong, Yusong-Gu Daejon 305-350 Korea Phone: +82 42 860 6576 EMail: khj@etri.re.kr Jeong, Park, Kim Expires April 2003 [Page 5] INTERNET-DRAFT Generation of Unique Domain Name October 2002 Expiration date: April 2003 Jeong, Park, Kim Expires April 2003 [Page 6]