--- 1/draft-ietf-dhc-server-override-03.txt 2006-10-24 22:12:34.000000000 +0200 +++ 2/draft-ietf-dhc-server-override-04.txt 2006-10-24 22:12:34.000000000 +0200 @@ -1,20 +1,20 @@ Network Working Group R. Johnson Internet-Draft J. Jumarasamy -Expires: April 24, 2006 K. Kinnear +Expires: April 25, 2007 K. Kinnear M. Stapp Cisco Systems, Inc. - October 21, 2005 + October 22, 2006 DHCP Server Identifier Override Suboption - draft-ietf-dhc-server-override-03.txt + draft-ietf-dhc-server-override-04.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -25,48 +25,48 @@ 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. - This Internet-Draft will expire on April 24, 2006. + This Internet-Draft will expire on April 25, 2007. Copyright Notice - Copyright (C) The Internet Society (2005). + Copyright (C) The Internet Society (2006). Abstract This memo defines a new suboption of the DHCP relay information option which allows the DHCP relay to specify a new value for the Server Identifier option, which is inserted by the DHCP Server. This allows the DHCP relay to act as the actual DHCP server such that RENEW DHCPREQUESTs will come to the relay instead of going to the server directly. This gives the relay the opportunity to include the Relay Agent option with appropriate suboptions even on DHCP RENEW messages. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Conventions . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Server Identifier Override Suboption Definition . . . . . . 5 - 4. Security Considerations . . . . . . . . . . . . . . . . . . 6 - 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . 7 - 6. Intellectual Property Rights and Copyright . . . . . . . . . 8 - 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 8 - Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 9 - Intellectual Property and Copyright Statements . . . . . . . 10 + 4. Security Considerations . . . . . . . . . . . . . . . . . . 7 + 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . 8 + 6. Intellectual Property Rights and Copyright . . . . . . . . . 9 + 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 9 + Authors' Addresses . . . . . . . . . . . . . . . . . . . . . 10 + Intellectual Property and Copyright Statements . . . . . . . 11 1. Introduction There are many situations where the DHCP relay is involved and can insert a relay agent option with appropriate suboptions easily into DHCP DISCOVER messages. Once the lease has been granted, however, future DHCP RENEWAL messages are sent directly to the DHCP Server as specified in the Server Identifier option. This means that the relay may not see the DHCP RENEWAL messages (depending upon network topology) and thus can not provide the same relay agent option @@ -134,20 +134,39 @@ should be made between this suboption and the Server Identifier option. If both of the Server Identifier Override Suboption and the Server Identifier Option specify the same address, then the Server should accept the DHCPREQUEST packet for processing, regardless of whether or not the Server Identifier Option matchs a DHCP Server interface. The DHCP Relay should fill in the giaddr field when relaying the packet just as it normally would do. + In a situation where the DHCP Relay is configured to forward packets + to more than one server, the DHCP Relay should forward all DHCP + packets all servers. This applies to DHCP RENEW packets as well. + + The intent is that the DHCP Relay should not need to maintain state + information about the DHCP lease. + + DHCP Relays using this suboption SHOULD also implement and use the + DHCPv4 Relay Agent Flags Suboption [7] in order to specify whether + the DHCP Relay received the original packet as a broadcast or + unicast. The DHCP Server receiving a packet containing the Server + Identifier Override Suboption may use this additional information in + processing the packet. + + Note that if the DHCP Relay becomes inaccessible by the DHCP Client + or loses network access to the DHCP Server, further DHCP RENEW + packets from the DHCP Client may not be properly processed and the + DHCP Client's lease may time out. + 4. Security Considerations Message authentication in DHCP for intradomain use where the out-of- band exchange of a shared secret is feasible is defined in [3]. Potential exposures to attack are discussed in section 7 of the DHCP protocol specification in [2]. The DHCP Relay Agent option depends on a trusted relationship between the DHCP relay agent and the server, as described in section 5 of RFC 3046. While the introduction of fraudulent relay-agent options can @@ -171,21 +190,21 @@ Identifier Override Suboption from the DHCP Relay Agent Information Option [3] suboption number space. None. 6. Intellectual Property Rights and Copyright The IETF has been notified of intellectual property rights claimed in regard to some or all of the specification contained in this document. For more information consult the online list of claimed rights. - Copyright (C) The Internet Society (2004). This document is subject + Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights." This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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. @@ -203,20 +222,24 @@ [4] Stapp, M., "The Authentication Suboption for the DHCP Relay Agent Option", RFC 4030, March 2005. [5] Narten, T. and H. Alvestrand, "Guidelines for Writing an IANA Considerations Section in RFCs", RFC 2434, October 1998. [6] Patrick, M., "DHCP Relay Agent Information Option", RFC 3046, November 2004. + [7] Kinnear, K., "DHCPv4 Relay Agent Flags Suboption", + draft-ietf-dhc-relay-agent-flags-00.txt (work in progress), + June 2006. + Authors' Addresses Richard A. Johnson Cisco Systems, Inc. 170 W. Tasman Dr. San Jose, CA 95134 US Phone: +1 408 526 4000 Email: raj@cisco.com @@ -277,18 +300,18 @@ This document and the information contained herein are provided on an "AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY AND THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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. Copyright Statement - Copyright (C) The Internet Society (2005). This document is subject + Copyright (C) The Internet Society (2006). This document is subject to the rights, licenses and restrictions contained in BCP 78, and except as set forth therein, the authors retain all their rights. Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society.