Network Working Group S. Jiang Internet Draft Huawei Technologies Co., Ltd Intended status: Standards Track G. Chen Expires: January 04, 2012 China Mobile July 01, 2011 A Generic IPv6 Addresses Registration Solution Using DHCPv6 draft-jiang-dhc-addr-registration-01.txt Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet-Drafts is at http://datatracker.ietf.org/drafts/current/. 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." This Internet-Draft will expire on January 04, 2012. Copyright Notice Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Jiang & Chen Expires January 04, 2012 [Page 1] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 Abstract In the IPv6 address allocation scenarios, host self-generated addresses are notionally conflicted with the network managed address architecture. These addresses need to be registered in the networking management plate for the purposes of central address administration. This document introduces a generic address registration solution using DHCPv6, and defines one new ND option and three new DHCPv6 options. Table of Contents 1. Introduction & Requirements .................................. 3 2. Terminology .................................................. 3 3. Overview of Generic Address Registration Solution ............ 3 4. Propagating the Address Registration Request with Prefix Assignment ...................................................... 4 4.1. RA Address Registration Request Option .................. 5 4.2. DHCPv6 Address Registration Request Option .............. 6 5. DHCPv6 Address Registration Options .......................... 6 5.1. DHCPv6 Address Registration Option ...................... 7 5.2. DHCPv6 Address Registration Acknowledgement Option ...... 7 6. Security Considerations ...................................... 8 7. IANA Considerations .......................................... 9 8. Change Log [RFC Editor please remove] ........................ 9 9. Acknowledgments .............................................. 9 10. References ................................................. 10 10.1. Normative References .................................. 10 10.2. Informative References ................................ 10 Author's Addresses ............................................. 11 Jiang & Chen Expires January 04, 2012 [Page 2] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 1. Introduction & Requirements In the IPv6 address allocation scenarios, there are many host self- generated addresses, such as addresses in IPv6 Stateless Address Configuration [RFC4862, RFC4941] scenario and Cryptographically Generated Addresses (CGA, [RFC3972]), and etc. These addresses are notionally conflicted with the network managed address architecture, such as Dynamic Host Configuration Protocol for IPv6 (DHCPv6, [RFC3315]) managed network or network with Access Control List. Many operators of enterprise networks and similarly tightly administered networks have expressed the desire to be at least aware the hosts' addresses when moving to IPv6. Furthermore, they may want to stop the usage of some hosts' addresses for various reasons. A useful way to give network administrators most of what they want, while at the same time retaining compatibility with normal stateless configuration would be: if the self-generated IPv6 addresses are used, they may need to be registered in and granted by the networking management plate. The host may be required to perform this registration since only granted IPv6 addresses are allowed to be used to access the network. In order to fulfill the abovementioned practice, this document introduces a new Neighbor Discovery (ND) option and a new DHCPv6 option to propagate the address registration solicitation from network management to hosts. DHCPv6 protocol is suitable to perform the address registration procedure while DHCPv6 servers play as the address registration server. Two new DHCPv6 options are defined, the Address Registration Request Option and the Address Registration Acknowledgement Option. 2. Terminology 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 RFC2119 [RFC2119]. 3. Overview of Generic Address Registration Solution By current default, the hosts with self-generated addresses do not register their addresses to any network devices. However, this may result that the network may reject the access request from these devices. Jiang & Chen Expires January 04, 2012 [Page 3] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 As showed in below Figure 1, in the generic address registration solution, proposed by this document, the network management plate firstly propagates the solicitations of registering self-generated addresses, by messages from either local router (step 1a in Figure 1) or DHCPv6 server (step 1b in Figure 1). By received such solicitations, a host using the self-generated address SHOULD send an address registration request message to the network management (step 2 in Figure 1). The network management MAY check whether the requested address is accepted, for example, checking the address does not use the Reserved IPv6 Interface Identifiers [RFC5453]. If the requested address is accepted by the network management, it is registered in the address database, which MAY be used by other network functions, such as DNS or ACL, etc. An acknowledgement is sent to the host, granting the usage of this address (step 3 in Figure 1). If the requested address is not accepted by the network management, a rejected acknowledgement is sent to the host to indicate that it SHOULD generate a new address. +--------+ +------------+ +-------------+ | Host | |Local Router| |DHCPv6 Server| +--------+ +------------+ +-------------+ | | | |Addr Register Solicitation(1a)| | |<-----------------------------| | | Addr Register Solicitation(1b) | |<------------------------------------------------| | | |Send self-generation addr registration request(2)| |------------------------------------------------>| | |Register | |the addr | Reply granting or rejected acknowledgment (3) | |<------------------------------------------------| Figure 1: address registration procedure 4. Propagating the Address Registration Solicitation with Prefix Assignment In order to indicate or force the hosts with self-generated addresses to register their addresses and the appointed address registration server, new solicitation options need to be defined. There are more than one mechanism in which configuration parameters could be pushed to the end hosts. The address registration solicitation option can be carried in Router Advertisement (RA) Jiang & Chen Expires January 04, 2012 [Page 4] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 message, which is broadcasted by local routers. In the DHCPv6 managed network, it can also be carried in DHCPv6 messages. By receiving the address registration solicitation option(s), a host SHOULD register its self-generated addresses, if there are any, to the appointed registration server. The solicitation options may include the IPv6 address(es) of address registration server. In principle, hosts must receive a prefix from either RA message [RFC4861] or DHCPv6 message [I-D.ietf-dhc-host-gen-id] so that they can generate an IPv6 address by themselves. The Address Registration Solicitation options could be propagated together with prefix assignment information. 4.1. ND Address Registration Solicitation Option The ND Address Registration Solicitation Option allows routers to propagate the solicitation for hosts to register their self-generated address. This option also carries an IPv6 address of the default address registration server. This option SHOULD be propagated together with ND Prefix Information Option, Section 4.6.2, [RFC4861]. The format of the ND Address Registration Solicitation Option is described as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | | + Address (Address + | Registration Server) | + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + | Reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ [Open Question to WG] Should the new ND option carry IPv6 address of the default address registration server? Or this can be discovered by DHCPv6 discovery mechanism. Should we design a mark bit for the scenario that ND does NOT appoint an address registration server? Should we use FQDN instead of Address? Multiple address registration servers? Jiang & Chen Expires January 04, 2012 [Page 5] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 Fields: Type (TBA1) Length 4 (in units of 8 octets, Type and Length themselves are included). Address 128-bit IPv6 address of the default Address Registration Server Reserved Padding bits. For future use also. The value MUST be initialized to zero by the sender, and MUST be ignored by the receiver. 4.2. DHCPv6 Address Registration Solicitation Option The DHCPv6 Address Registration Solicitation Option allows DHCPv6 server to propagate the solicitation for hosts to register their self-generated address. Assuming the DHCPv6 server itself is the address registration server, this option does NOT carries the IPv6 address of the default address registration server. This option SHOULD be propagated together with DHCPv6 Prefix Information Option, Section 5, [I-D.ietf-dhc-host-gen-id]. The format of the DHCPv6 Address Registration Solicitation Option is described as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_Addr_Reg_Solicitation | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code OPTION_Addr_Reg_Solicitation (TBA2). option-len 0. length of this option in octets (option-code and option-len are not included). [Open Question to WG: is 0 allowed?] 5. DHCPv6 Address Registration Options The current DHCPv6 protocol is reused as the address registration protocol while a DHCPv6 serve plays as address registration server. Two new DHCPv6 options, the Address Registration Request Option and the Address Registration Acknowledgement Option, are defined in this section in order to fulfill the address registration interactions. Jiang & Chen Expires January 04, 2012 [Page 6] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 5.1. DHCPv6 Address Registration Request Option A new DHCPv6 Address Registration Request Option is defined in order to carry the requested address from hosts to the address registration server. The format of the DHCPv6 Address Registration Request Option is described as follows: 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |OPTION_Addr_Registration_Reques| option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | + IPv6 Address + | (host requested address) | + + | | + + | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ option-code OPTION_Addr_Registration_Request (TBA3). option-len 16. length of this option in octets (option-code and option-len are not included). Address 128-bit requested IPv6 address, which generated by the host By received, the DHCPv6 server MAY check whether the requested address is accepted, for example, checking the address does not use the Reserved IPv6 Interface Identifiers [RFC5453]. If the requested address is accepted, the DHCPv6 server MUST register it in the address database, which MAY be used by other network functions, such as DNS or ACL, etc. A DCHPv6 reply message with the below-defined Acknowledgement Option is sent back to the host for notification. [Open Question to WG] Should we ack only when address is rejected or both accepted and rejected? 5.2. DHCPv6 Address Registration Acknowledgement Option In order to response to registration requests, an acknowledgement DHCPv6 option is also defined below. It is used to indicate whether the registration of an IPv6 address is accepted. The format of the DHCPv6 Address Registration Acknowledgement Option is described as follows: Jiang & Chen Expires January 04, 2012 [Page 7] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 0 1 2 3 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | OPTION_Addr_Registration_Ack | option-len | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Ack Info | | +-+-+-+-+-+-+-+-+ + | | + Associated Address + | (host requested address) | + + | | + +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+ option-code OPTION_Addr_Registration_Ack (TBA4). option-len 17. length of this option in octets (option-code and option-len are not included). Ack Info 8 bit. Indicate the associated address is correctly registered or rejected. All zero means correctly registered. Otherwise, the associated address is rejected. [Open Question to WG] With in the rejected scenarios, should we also give the different reasons by different value? Associated Address 128-bit IPv6 address. Indicate the acknowledgement is associated with which address. An acknowledgement is sent to the host, granting the usage of this address (step 3 in Figure 1). If the requested address is not accepted by the network management, a rejected acknowledgement is sent to the host to indicate that it SHOULD generate a new address. 6. Security Considerations An attacker may use a faked address registration request option to indicate hosts reports their address to a malicious server and collect the user information. These attacks may be prevented by using Secure Neighbor Discovery (SEND, [RFC3971]) if RA Address Registration Request Option is used, or AUTH option or Secure DHCP [I-D.ietf-dhc-secure-dhcpv6] if DHCPv6 Address Registration Request Option is used. Jiang & Chen Expires January 04, 2012 [Page 8] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 An attacker could generate IPv6 address registration requests in order to exhaust the server resources (or to impact on any other operation that depend on the registration of the address). The DHCPv6 address registration procedure is as vulnerable as all other mechanisms based on DHCPv6 to DOS attacks to the server. Proper use of DHCPv6 autoconfiguration facilities [RFC3315], such as AUTH option or Secure DHCP [I-D.ietf-dhc-secure-dhcpv6] can prevent these threats. 7. IANA Considerations This document defines a new Neighbor Discovery [RFC4861] option, which MUST be assigned Option Type values within the option numbering space for Neighbor Discovery Option Type: The Address Registration Solicitation Option (TBA1), described in Section 4.1. This document defines two new DHCPv6 [RFC3315] options, which MUST be assigned Option Type values within the option numbering space for DHCPv6 options: The OPTION_Addr_Reg_Solicitation (TBA2), described in Section 4.2; The OPTION_Addr_Registration_Request (TBA3), described in Section 5.1; The OPTION_Addr_Registration_Ack (TBA4), described in Section 5.2. 8. Change Log [RFC Editor please remove] draft-jiang-dhc-addr-registration-00, original version, 2011-07-01 9. Acknowledgments The authors would like to thank Ralph Dorm, Ted Lemon and other member of DHC WG for valuable comments. Jiang & Chen Expires January 04, 2012 [Page 9] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 10. References 10.1. Normative References [RFC2119] S. Bradner, "Key words for use in RFCs to Indicate Requirement Levels", RFC2119, March 1997. [RFC3315] R. Droms, Ed., J. Bound, B. Volz, T. Lemon, C. Perkins and M. Carne, "Dynamic Host Configure Protocol for IPv6", RFC3315, July 2003. [RFC3971] J. Arkko, J. Kempf, B. Zill, P. Nikander, "SEcure Neighbor Discovery (SEND) ", RFC 3971, March 2005. [RFC3972] T. Aura, "Cryptographically Generated Address", RFC3972, March 2005. [RFC4861] T. Narten, E. Nordmark, W. Simpson, and H. Soliman, "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861, September 2007 [RFC4862] S. Thomson, T. Narten and T. Jinmei, "IPv6 Stateless Address Autoconfiguration", RFC4862, September 2007. [RFC4941] T. Narten, R. Draves and S. Krishnan, "Privacy Extensions for Stateless Address Autoconfiguration in IPv6", RFC 4941, September 2007. [RFC5453] S. Krishnan, "Reserved IPv6 Interface Identifiers", RFC 4543, February 2009. 10.2. Informative References [I-D.ietf-dhc-secure-dhcpv6] S. Jiang and S. Shen, "Secure DHCPv6 Using CGAs", draft- ietf-dhc-secure-dhcpv6 (work in progress), June, 2011. [I-D.ietf-dhc-host-gen-id] S. Jiang, F. Xia, and B. Sarikaya, "Prefix Assignment in DHCPv6", draft-ietf-dhc-host-gen-id (work in progress), April, 2011. Jiang & Chen Expires January 04, 2012 [Page 10] Internet-Draft draft-jiang-dhc-addr-registration-00.txt July 2011 Author's Addresses Sheng Jiang Huawei Technologies Co., Ltd Huawei Building, No.3 Xinxi Rd., Hai-Dian District, Beijing 100085 P.R. China Phone: 86-10-82882681 Email: jiangsheng@huawei.com Gang Chen China Mobile 53A,Xibianmennei Ave., Xuanwu District, Beijing 100053 China Phone: +86-13910710674 Email: phdgang@gmail.com Jiang & Chen Expires January 04, 2012 [Page 11]