IPv6 6RD IPCP configuration option for PPP
draft-freedman-pppext-ipv6-6rd-00

Versions: 00                                                            
Internet Engineering Task Force                              D. Freedman
Internet-Draft                                                  Claranet
Intended status: Informational                               M. Townsley
Expires: January 26, 2012                                          Cisco
                                                           July 25, 2011


               IPv6 6RD IPCP configuration option for PPP
                   draft-freedman-pppext-ipv6-6rd-00

Abstract

   The Point-to-Point Protocol (PPP) (RFC1661) provides a standard
   method for transporting multi-protocol datagrams over point-to-point
   links.  PPP defines an extensible Link Control Protocol and a family
   of Network Control Protocols (NCPs) for establishing and configuring
   different network-layer protocols.

   This document extends the NCP for establishing and configuring the
   Internet Protocol over PPP (RFC1332), defining the negotiation of 6RD
   (RFC5969) Border Relay (BR) addresses.  While the authors believe one
   could use DHCP INFORM (RFC2131) to obtain the necessary 6RD
   parameters, this is simply an alternative which allows reuse of an
   existing PPP-based configuration infrastructure.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

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   This Internet-Draft will expire on January 26, 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



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Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  3
   2.  Terminology  . . . . . . . . . . . . . . . . . . . . . . . . .  4
   3.  6RD IPCP configuration option  . . . . . . . . . . . . . . . .  5
   4.  IANA Considerations  . . . . . . . . . . . . . . . . . . . . .  7
   5.  Security Considerations  . . . . . . . . . . . . . . . . . . .  8
   6.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . .  9
   7.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
     7.1.  Normative References . . . . . . . . . . . . . . . . . . . 10
     7.2.  Informational References . . . . . . . . . . . . . . . . . 10
   Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11





























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1.  Introduction

   PPP [RFC1661], and PPPoE [RFC2516], remains a common way for a
   residential broadband end user to obtain configuration.  In such
   deployments, no DHCP [RFC2131], infrastructure may be in place and IP
   configuration is solely obtained from RADIUS [RFC2865] servers and
   network equipment via IPCP [RFC1332].  The PPP IPCP option presents
   configuration information to the local peer such that it may join a
   6RD [RFC5969] domain.










































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2.  Terminology

   6RD IPv6 Prefix

      An IPv6 prefix selected by the service provider for use by a 6RD
      domain.  There is exactly one 6RD IPv6 prefix for a given 6RD
      domain.  An SP may deploy 6RD with a single 6RD domain or multiple
      6RD domains.

   6RD Delegated Prefix

      The IPv6 prefix calculated by the local peer for use within the
      customer site by combining the 6RD prefix and the local peer IPv4
      address obtained via IPv4 configuration methods.  This prefix can
      be considered logically equivalent to a DHCPv6 IPv6 delegated
      prefix [RFC3633].

   6RD Domain

      A service provider may deploy 6RD with a single 6RD domain, or may
      utilize multiple 6RD domains.  Each domain requires a seperate 6RD
      IPv6 prefix.

   6RD Border Relay (BR)

      A 6RD-enabled router managed by the service provider at the edge
      of a 6RD domain.  A Border Relay router provides an endpoint for
      the 6RD IPv6 in IPv4 tunnel.  A 6RD BR may also be referred to
      simply as a "BR" within the context of 6RD.

   6RD BR address

      The IPv4 address of the 6RD Border Relay for a given 6RD domain.
      This IPv4 address is used by the local peer to send packets to a
      BR in order to reach IPv6 destinations outside of the 6RD domain.
















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3.  6RD IPCP configuration option

   Description:

      This Configuration Option provides a method for informing the
      local peer of the configuration parameters required for the 6RD
      domain available for the peer to join.



     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     |V4Prefix-Length|V6Prefix-Length|
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                    6RD BR Address (4 octets)                  |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                                                               |
      |                       6RD IPv6 Prefix                         |
      |                   (variable, up to 16 octets)                 |
      |                                                               |
      |                                                               |
      |                                                               |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

                                 Figure 1

   Type:

      TBA

   Length:

      The total length of the IPCP option, in octets

   V4Prefix-Length

      Prefix length of the common part of the encoded IPv4 address in
      number of bits.  This number of bits MUST be removed from leftmost
      of the IPv4 address when generating the 6RD Delegated Prefix.  For
      example, if this value is 8, 24 bits of the subscriber IPv4 prefix
      will be used when creating the IPv6 Delegated Prefix, determining
      the destination IPv4 encapsulation address, etc.  If the value is
      0, then the whole 32 bits of the IPv4 address is used in the
      encoding.






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   V6Prefix-Length

      IPv6 Prefix length of the 6RD IPv6 prefix in number of bits.

   6RD BR Address

      The IPv4 address of the 6RD Relay (may be anycast)

   6RD IPv6 prefix

      The service provider's 6RD IPv6 prefix represented as a 16-octet
      IPv6 address.

   Default:

      By default, no fields are populated



































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4.  IANA Considerations

   This memo requires an IPCP option number assignment.
















































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5.  Security Considerations

   This memo does not present any security considerations, it is assumed
   that the remote peer is trusted and therefore the parameters of the
   6RD domain are to be trusted.














































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6.  Acknowledgements

   This memo is based on existing work [I-D.townsley-ipv6-6rd] which
   describes possible provisioning of 6RD configuration parameters.















































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7.  References

7.1.  Normative References

   [RFC1332]  McGregor, G., "The PPP Internet Protocol Control Protocol
              (IPCP)", RFC 1332, May 1992.

   [RFC1661]  Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51,
              RFC 1661, July 1994.

   [RFC2516]  Mamakos, L., Lidl, K., Evarts, J., Carrel, D., Simone, D.,
              and R. Wheeler, "A Method for Transmitting PPP Over
              Ethernet (PPPoE)", RFC 2516, February 1999.

   [RFC3633]  Troan, O. and R. Droms, "IPv6 Prefix Options for Dynamic
              Host Configuration Protocol (DHCP) version 6", RFC 3633,
              December 2003.

   [RFC5969]  Townsley, W. and O. Troan, "IPv6 Rapid Deployment on IPv4
              Infrastructures (6rd) -- Protocol Specification",
              RFC 5969, August 2010.

7.2.  Informational References

   [I-D.townsley-ipv6-6rd]
              Townsley, M. and O. Troan, "IPv6 via IPv4 Service Provider
              Networks", draft-townsley-ipv6-6rd-01 (work in progress),
              July 2009.

   [RFC2131]  Droms, R., "Dynamic Host Configuration Protocol",
              RFC 2131, March 1997.

   [RFC2865]  Rigney, C., Willens, S., Rubens, A., and W. Simpson,
              "Remote Authentication Dial In User Service (RADIUS)",
              RFC 2865, June 2000.
















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Authors' Addresses

   David Freedman
   Claranet
   London
   UK

   Phone: +44 20 7685 8000
   Email: david.freedman@uk.clara.net


   Mark Townsley
   Cisco Systems
   Paris
   France

   Phone: +33 15 804 3483
   Email: mark@townsley.net

































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