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
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   This Internet-Draft will expire on January 04, 2012.

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   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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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














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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.



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   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)


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   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?



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       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.



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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:



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        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.


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   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.








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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.






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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






























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