Network Working Group                                        B. Sarikaya
Internet-Draft                                                Huawei USA
Intended status: Standards Track                       February 25, 2013
Expires: August 29, 2013


         IPv6 RA Options for Multiple Interface Next Hop Routes
                  draft-sarikaya-mif-6man-ra-route-02

Abstract

   This draft defines new Router Advertisement options for configuring
   next hop routes on the mobile or fixed nodes.  Using these options,
   an operator can easily configure nodes with multiple interfaces (or
   otherwise multi-homed) to enable them to select the routes to a
   destination.  Each option is defined together with definitions of
   host and router behaviors.

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 August 29, 2013.

Copyright Notice

   Copyright (c) 2013 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
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   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as



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   described in the Simplified BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 3
   3.  Default Route Configuration . . . . . . . . . . . . . . . . . . 4
   4.  Host Configuration  . . . . . . . . . . . . . . . . . . . . . . 4
   5.  Router Configuration  . . . . . . . . . . . . . . . . . . . . . 4
   6.  Route Prefix option . . . . . . . . . . . . . . . . . . . . . . 5
   7.  Next Hop Address option . . . . . . . . . . . . . . . . . . . . 5
   8.  Next Hop Address with Route Prefix option . . . . . . . . . . . 6
   9.  Security Considerations . . . . . . . . . . . . . . . . . . . . 6
   10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
   11. Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . 7
   12. References  . . . . . . . . . . . . . . . . . . . . . . . . . . 8
     12.1.  Normative References . . . . . . . . . . . . . . . . . . . 8
     12.2.  Informative References . . . . . . . . . . . . . . . . . . 8
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . . . 9































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1.  Introduction

   IPv6 Neighbor Discovery and IPv6 Stateless Address Autoconfiguration
   protocols can be used to configure fixed and mobile nodes with
   various parameters related to addressing and routing [RFC4861],
   [RFC4862], [RFC4191].  DNS Recursive Server Addresses and Domain Name
   Search Lists are additional parameters that can be configured using
   router advertisements [RFC6106].

   Router Advertisements can also be used to configure fixed and mobile
   nodes in multi-homed scenarios with route information and next hop
   address.  Different scenarios exist such as the node is
   simultaneously connected to multiple access network of e.g.  WiFi and
   3G. The node may also be connected to more than one gateway.  Such
   connectivity may be realized by means of dedicated physical or
   logical links that may also be shared with other users nodes such as
   in residential access networks.


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].



























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3.  Default Route Configuration

   A host, usually a mobile host interested in obtaining routing
   information usually sends a Router Solicitation (RS) message on the
   link.  The router, when configured to do so, provides the route
   information using zero, one or more Next Hop Address and Route
   Information options in the router advertisement (RA) messages sent in
   response.

   The route options are extensible, as well as convey detailed
   information for routes.

   RS and RA exchange is for next hop address and route information
   determination and not for determining the link-layer address of the
   router.  Subsequent Neighbor Solicitation and Neighbor Advertisement
   exchange can be used to determine link-layer address of the router.

   It should be noted that the proposed options in this document will
   need a central site-wide configuration mechanism.  The required
   values can not automatically be derived from routing tables.

   Next hop address and related route information may be provided by
   some other means such as directly by the next hop routers.  In this
   document we assume that next hop routers are not able to provide this
   information.  One solution would be to develop an inter-router
   protocol to instigate the next hop routers to provide this
   information.  However, such a solution has been singled out due to
   the complexities involved.


4.  Host Configuration

   Router advertisement options defined in this document are used by
   Type C hosts.

   As defined in [RFC4191] Type C host uses a Routing Table instead of a
   Default Router List.


5.  Router Configuration

   The router MAY send one or more Next Hop Address options that specify
   the IPv6 next hop addresses.  Each Next Hop Address option may be
   associated with zero, one or more Route Prefix options that represent
   the IPv6 destination prefixes reachable via the given next hop.
   Router includes Route Prefix option in message to indicate that given
   prefix is available directly on- link.




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   Router MAY send a single Next Hop Address without any Route Prefix
   options.  When router sends Next Hop Address option that is
   associated with Router Prefix option, the router MUST use Next Hop
   and Route Prefix option defined in Section 8.  The Route Prefix MAY
   contain ::/0, i.e. with Prefix Length set to zero to indicate
   available default route.


6.  Route Prefix option

       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     | Prefix Length |Resvd|Prf|Metric|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Route Lifetime                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Prefix (Variable Length)                    |
      .                                                               .
      .                                                               .
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                       Figure 1: Route Prefix option

   Fields:

   Type: TBD.

   Length: The length of the option (including the Type and Length
   fields) in units of 8 octets.

   Other fields are as in [RFC4191] except:

   Metric Route Metric. 3-bit signed integer.  The Route Metric
   indicates whether to prefer the next hop associated with this prefix
   over others, when multiple identical prefixes (for different next
   hops) have been received.


7.  Next Hop Address option

        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     |    Next Hop Address ...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                     Figure 2: Next Hop Address option



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   Fields:

   Type: TBD.

   Length: The length of the option (including the type and length
   fields) in units of 8 octets.  It's value is 3.

   Next Hop Address: An IPv6 address that specifies IPv6 address of the
   next hop.  It is 16 octets in length.


8.  Next Hop Address with Route Prefix option

       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     |    Next Hop Address ...       |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      +                        ...                                    |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                 ...           | Prefix Length |Resvd|Prf|Metric|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        Route Lifetime                         |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                   Prefix (Variable Length)                    |
      .                                                               .
      .                                                               .
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

            Figure 3: Next Hop Address with Route Prefix option

   Fields:

   Type: TBD.

   Length: The length of the option (including the type and length
   fields) in units of 8 octets.  For example, the length for a prefix
   of length 16 is 5.

   Other fields are as in Section 6 and Section 7.


9.  Security Considerations

   Neighbor Discovery is subject to attacks that cause IP packets to
   flow to unexpected places.  Because of this, neighbor discovery
   messages MUST be secured, possibly using Secure Neighbor Discovery
   (SEND) protocol [RFC3971].



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10.  IANA Considerations

   Authors of this document request IANA to assign three new RA options:

               +-----------------------------------+------+
               | Option Name                       | Type |
               +-----------------------------------+------+
               | Route Prefix                      |      |
               | Next Hop Address                  |      |
               | Next Hop Address and Route Prefix |      |
               +-----------------------------------+------+

                                 Table 1:


11.  Acknowledgements

   Brian Carpenter provided comments that have led to improvements in
   the document.  We are also grateful to Zhen Cao for his comments.
































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12.  References

12.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

   [RFC2629]  Rose, M., "Writing I-Ds and RFCs using XML", RFC 2629,
              June 1999.

   [RFC3971]  Arkko, J., Kempf, J., Zill, B., and P. Nikander, "SEcure
              Neighbor Discovery (SEND)", RFC 3971, March 2005.

   [RFC4191]  Draves, R. and D. Thaler, "Default Router Preferences and
              More-Specific Routes", RFC 4191, November 2005.

   [RFC4605]  Fenner, B., He, H., Haberman, B., and H. Sandick,
              "Internet Group Management Protocol (IGMP) / Multicast
              Listener Discovery (MLD)-Based Multicast Forwarding
              ("IGMP/MLD Proxying")", RFC 4605, August 2006.

   [RFC4861]  Narten, T., Nordmark, E., Simpson, W., and H. Soliman,
              "Neighbor Discovery for IP version 6 (IPv6)", RFC 4861,
              September 2007.

   [RFC4862]  Thomson, S., Narten, T., and T. Jinmei, "IPv6 Stateless
              Address Autoconfiguration", RFC 4862, September 2007.

12.2.  Informative References

   [RFC6106]  Jeong, J., Park, S., Beloeil, L., and S. Madanapalli,
              "IPv6 Router Advertisement Options for DNS Configuration",
              RFC 6106, November 2010.


















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Author's Address

   Behcet Sarikaya
   Huawei USA
   5340 Legacy Dr. Building 175
   Plano, TX  75024

   Phone:
   Email: sarikaya@ieee.org










































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