Network Working Group Nirupma Kulshreshtha INTERNET DRAFT Novell Inc. December 1999 Expires June 2000 The Migration Agent List Option for DHCP 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-Drafts Shadow Directories can be accessed at http://www.ietf.org/ietf/shadow.html. This document is a submission to the Dynamic Host Configuration Working Group of the Internet Engineering Task Force (IETF). Comments should be submitted to the dhcp-v4@bucknell.edu mailing list. Abstract This document defines a new DHCP option for delivering configuration information to hosts utilizing the Compatibility Mode Driver (CMD) provided with NovellÆs NetWare 5. This option is passed from the DHCP server to the DHCP Client to provide the addresses of one or more Migration Agents along with their CMD network number. Introduction The Dynamic Host Configuration Protocol (DHCP)[1] provides a framework for passing configuration information to hosts on a TCP/IP network. The Compatibility Mode Driver (CMD) provided with NetWare 5 facilitates smooth migration of networks from IPX and NetWare/IP, to Pure IP. This component provides the necessary connectivity for IPX Client/Server applications to communicate with nodes that connect to the IP internet. It also allows IPX Client/Server applications to run on IP Nodes. Connectivity between IPX Nodes and IP Nodes is achieved through the use of gateways called Migration Agents. Kulshreshtha [Page 1] Internet Draft December 1999 This document describes a DHCP option that carries addresses of one or more Migration Agents along with their CMD Network number. The addresses of Migration Agents are required by other Migration Agents to discover new IPX Nodes. Definitions 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 [3]. This document also uses the following terms: "DHCP client" DHCP client or "client" is an Internet host using DHCP to obtain configuration parameters such as a network address. "DHCP server" A DHCP server or "server" is an Internet host that returns configuration parameters to DHCP clients. Migration Agent List Option Format The code for this option is TBD. The minimum length specified in the æLenÆ field is 8 bytes, and this length MUST be a multiple of 8. This option can contain addresses of multiple migration agents along with their CMD Network number. The first four bytes specifies the IP address (in hexadecimal format) of the Migration Agent, and the next four bytes specifies the CMD Network number (in hexadecimal format) of the Migration Agent. Code Len IP Address CMD Network Number +-----+----+----+----+----+----+----+----+----+----+- | TBD | 08 | a1 | a2 | a3 | a4 | n1 | n2 | n3 | n4 | +-----+----+----+----+----+----+----+----+----+----+- In the above example, (0xa1a2a3a4) specifies the IP address of the Migration Agent and (0xn1n2n3n4) specifies the CMD Network number of the Migration Agent. DHCP Client Behavior The DHCP client will use this option to get the IP addresses of all the Migration Agents in the CMD network in which the client is present. Kulshreshtha [Page 2] Internet Draft December 1999 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]. In particular, these DHCP options allow an unauthorized DHCP server to misdirect any client to a non existent Migration Agent. References [1] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [2] Alexander, S. and Droms, R., "DHCP Options and BOOTP Vendor Extensions", RFC 2132, March 1997. [3] Bradner, S., "Key words for use in RFCs to indicate requirement levels", RFC 2119, March 1997. Author Information Nirupma Kulshreshtha Novell Software Development (I) Ltd. 49/1 & 49/3, Garvebhavipalya 7th Mile, Hosur Road, Bangalore - 560 068. INDIA Phone: +91(80)572-1856 email: knirupama@novell.com Expiration This document will expire on June 6, 2000. Full Copyright Statement Copyright (C) The Internet Society (1998). All Rights Reserved. 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Kulshreshtha [Page 3] Internet Draft December 1999 This document and the information contained herein is provided on an "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. Kulshreshtha [Page 4]