Internet-Draft K. Fujisawa Sony Corporation Expires: July, 1999 January 1999 DHCP for IEEE 1394 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 view the entire list of current Internet-Drafts, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), ftp.nordu.net (Northern Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). Abstract IEEE Std 1394-1995 is a standard for a High Performance Serial Bus. Since 1394 uses different link-layer addressing method than conventional IEEE802/Ethernet, the usage of some fields must be clarified to achieve interoperability. This memo describes the 1394 specific usage of some fields of DHCP messages. K. Fujisawa Expires July 1999 [Page 1] Internet Draft draft-ietf-ip1394-dhcp-01.txt January 1999 1. Introduction IEEE Std 1394-1995 is a standard for a High Performance Serial Bus. IETF IP1394 Working Group specified the method to carry IPv4 datagrams and ARP packets over an IEEE1394 network [IP1394]. The Dynamic Host Configuration Protocol (DHCP) [RFC2131] provides a framework for passing configuration information to hosts on a TCP/IP network. Since 1394 uses different link-layer addressing method than conventional IEEE802/Ethernet, the usage of some fields must be clarified to achieve interoperability. This memo describes the 1394 specific usage of some fields of DHCP. See [RFC2131] for the mechanism of DHCP and the explanations of each fields. This document is a product of the IP1394 working group within the Internet Engineering Task Force. Comments are solicited and should be addressed to the working group's mailing list at ip1394@mailbag.intel.com and/or the author. 2. Issues related to 1394 link address By the conventional link-layer protocols, such as an Ethernet, the 'chaddr' (client hardware address) field may be used to return a reply message from a DHCP server (or relay-agent) to a client. Since 1394 link address (node_ID) is transient and will not be consistent across the 1394 bridge, we have chosen not to put it in the 'chaddr' field. A DHCP client should request the server to send a broadcast reply by setting the BROADCAST flag when ARP is not possible yet. 3. 1394 specific usage of DHCP message fields Following rules should be used when a DHCP client is connected to an IEEE1394 network. 'htype' (hardware address type) MUST be 24 [ARPPARAM]. 'hlen' (hardware address length) MUST be 0. The 'chaddr' (client hardware address) field is reserved. The recipient shall not check the value of this field. A DHCP client on 1394 SHOULD set a BROADCAST flag in DHCPDISCOVER and DHCPREQUEST messages to request the server (or the relay agent) to send a broadcast reply if its 'ciaddr' (client IP address) is zero. K. Fujisawa Expires July 1999 [Page 2] Internet Draft draft-ietf-ip1394-dhcp-01.txt January 1999 'client identifier' option MUST be used in DHCP messages from the client to the server due to the lack of the 'chaddr'. 'client identifier' option may consist of any data. When an EUI-64 (node unique ID) [EUI64] is used as a 'client identifier', the type value for the EUI-64 is 27 [ARPPARAM], and the format is illustrated as follows. Code Len Type Client-Identifier +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ | 61 | 9 | 27 | EUI-64 (node unique ID) | +-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+-----+ Note that the use of other 'client identifier' type, such as a fully qualified domain name (FQDN), is not precluded by this memo. For more details, see "9.14. Client-identifier" in [RFC2132]. Security Considerations Security issues are not discussed in this document. References [IP1394] P. Johansson, "IPv4 over IEEE 1394", draft-ietf-ip1394-ipv4-12.txt, work in progress. [RFC2131] R. Droms, "Dynamic Host Configuration Protocol", RFC2131, March 1997. [RFC2132] S. Alexander, R. Droms, "DHCP Options and BOOTP Vendor Extensions", RFC2132, March 1997. [EUI64] http://standards.ieee.org/regauth/oui/tutorials/EUI64.html [ARPPARAM] http://www.isi.edu/in-notes/iana/assignments/arp-parameters Author's address Kenji Fujisawa Sony Corporation IT Laboratories, Computer Systems Laboratory 6-7-35, Kitashinagawa, Shinagawa-ku, Tokyo, 141-0001 Japan Phone: +81-3-5448-4602 E-mail: fujisawa@sm.sony.co.jp K. Fujisawa Expires July 1999 [Page 3]