Subject: draft-ietf-ip1394-dhcp-01.txt

From: Thomas Narten <[email-masked]>
Date: Wed, 23 Jun 1999 12:40:46 -0400 (EDT)

DHCP WG:

The following document is a product of the ip1394 WG, but the document
arguably should be a joint DHCP/1394 effort. It describes how DHCP
should work over 1394 networks. 1394 is different from common
link-layers in that it can't just use a link-layer address for the
'chaddr' field.

I've appended the entire draft in this note (it's less than three
pages of meat), on the hope that some of you need a quick diversion
and might be able to return some quick comments.

I also think it might be good to discuss this in Oslo.

Thanks!!!
Thomas

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
   [email-masked] 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: [email-masked]

K. Fujisawa                Expires July 1999                    [Page 3]