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Versions: 00

6man                                                           R. Bonica
Internet-Draft                                          Juniper Networks
Intended status: Standards Track                               C. Lenart
Expires: December 13, 2018                                       Verizon
                                                             G. Presbury
                                                  Hughes Network Systems
                                                           June 11, 2018


   The IPv6 Virtual Private Network (VPN) Context Information Option
                   draft-bonica-6man-vpn-dest-opt-00

Abstract

   This document defines a new IPv6 Destination Option that can be used
   to encode Virtual Private Network (VPN) context information.  It is
   applicable when VPN payload is transported over IPv6.

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 https://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 December 13, 2018.

Copyright Notice

   Copyright (c) 2018 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
   (https://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




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   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   4
   3.  VPN Context Information . . . . . . . . . . . . . . . . . . .   4
   4.  The VPN Context Information Option  . . . . . . . . . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   6
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   Virtual Private Network (VPN) technologies allow network providers to
   emulate private networks with shared infrastructure.  For example,
   assume that a red sites and blue sites connect to a provider network.
   The provider network facilitates communication among red sites and
   facilitates communication among blue sites.  However, it prevents
   communication between red sites and blue sites.

   The IETF has standardized many VPN technologies, including:

   o  Layer 2 VPN (L2VPN) [RFC6624].

   o  Layer 3 VPN (L3VPN) [RFC4364].

   o  Virtual Private LAN Service (VPLS) [RFC4761][RFC4762].

   o  Ethernet VPN (EVPN) [RFC7432].

   o  Pseudowires [RFC8077].

   The above-mentioned technologies include the following components:

   o  Customer Edge (CE) devices.

   o  Provider Edge (PE) devices.

   o  Routing Instances.

   o  VPN context information.




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   o  Transport tunnels.

   CE devices participate in closed communities called VPNs.  CEs that
   participate in one VPN can communicate with one another but cannot
   communicate with CEs that participate in another VPN.

   CE devices connect to provider networks through PE devices.  Each PE
   maintains one Routing Instance for each VPN that it supports.  A
   Routing Instance is a VPN specific Forwarding Information Base (FIB).
   In EVPN, Routing Instances are called Ethernet Virtual Instances
   (EVI).

   Assume that one CE sends a packet through a provider network to
   another CE.  The packet enters the provider network through an
   ingress PE and leaves the provider network through an egress PE.  The
   packet may traverse one or more intermediate nodes on route from PE
   to PE.

   When the ingress PE receives the packet, it:

   o  Identifies the Routing Instance that supports the originating CE's
      VPN.

   o  Searches that Routing Instance for the packet's destination.

   If the search fails, the ingress PE discards the packet.  If the
   search succeeds, it yields the following:

   o  VPN context information.

   o  The egress PE's IP address.

   The ingress PE prepends VPN context information and a transport
   header to the packet, in that order.  It then forwards the packet
   through a transport tunnel to the egress PE.

   The egress PE removes the transport header, if it has not already
   been removed by an upstream device.  It then examines and removes the
   VPN context information.  Finally, it uses the VPN context
   information to forward the packet to its destination (i.e., a
   directly connected CE).

   In the above-mentioned VPN technologies, the ingress PE encodes VPN
   context information in a Multiprotocol Label Switching (MPLS)
   [RFC3031] label.  Depending upon the transport tunnel type, the
   transport header can be:

   o  A MPLS label or label stack.



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   o  An IPv4 [RFC0791] header.

   o  An IPv6 [RFC8200] header.

   o  A Generic Routing Encapsulation (GRE) [RFC2784] header
      encapsulated in IPv4 or IPv6.

   If the outermost transport header is IPv6, it may be followed by a
   Segment Routing Header (SRH) [I-D.ietf-6man-segment-routing-header].

   Some PE devices cannot process MPLS headers.  While these devices
   have several alternatives to MPLS-based transport tunnels, they
   require an alternative to MPLS-based encoding of VPN context
   information.  This document defines a new IPv6 Destination Option
   that can be used to encode VPN context information.  It is applicable
   when VPN payload is transported over IPv6.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in BCP
   14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  VPN Context Information

   VPN context information specifies a forwarding procedure to be
   executed by the egress PE.  However, VPN context information values
   are not globally mapped to forwarding procedures.  Each egress PE
   maps each forwarding procedure that it supports to a VPN context
   information value.  Therefore, VPN context information values are
   locally scoped to the egress PE.

   PE devices can acquire VPN Context Information:

   o  From one another, using a distributed, control plane protocol
      (e.g., BGP [RFC4271] [RFC4760])

   o  From a controller.

   The mechanisms by which PE devices acquire VPN Context Information
   are beyond the scope of this document.








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4.  The VPN Context Information 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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |  Option Type  |  Opt Data Len |    VPN Context Information ...
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-



                                 Figure 1

   Figure 1 depicts the VPN Context Information Option.  The IPv6
   Destination Options header MAY include the VPN Context Information
   option.  The IPv6 Hop-by-hop header MUST NOT include the VPN Context
   Information option.

   Option fields are as follows:

   o  Option Type - VPN Context Information option.  Value TBD by IANA.
      See Notes below.

   o  Opt Data Len - Length of Option Data, measured in bytes.

   o  VPN Context Information - Specifies a forwarding procedure to be
      executed by the egress PE.

   The VPN Context Information Option MUST NOT appear multiple times in
   a single packet.  If a node receives a packet that contains multiple
   instances of the VPN Context Information Option, it MUST discard the
   packet and send and ICMP Parameter Problem, Code 2, message to the
   packet's source.

   NOTE 1: The highest-order two bits of the Option Type (i.e., the
   "act" bits) are 10.  These bits specify the action taken by a
   destination node that does not recognize VPN Context Information
   option.  The required action is to discard the packet and, regardless
   of whether or not the packet's Destination Address was a multicast
   address, send an ICMPv6 [RFC4443] Parameter Problem, Code 2, message
   to the packet's Source Address, pointing to the unrecognized Option
   Type.

   NOTE 2: The third highest-order bit of the Option Type (i.e., the
   "chg" bit) is 0.  This indicates that Option Data cannot be modified
   along the path between the packet's source and its destination.






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5.  Security Considerations

   A VPN can be deployed:

   o  In a walled-garden environment.

   o  In an over-the-top environment.

   In a walled-garden environment, all PE devices and all devices that
   connect PEs to one another reside in the same security domain.
   Therefore, there is no risk that a packet might be modified as it
   travels from PE to PE.

   In an over-the-top environment, all PE devices reside in one security
   domain while devices that connect PEs to one another can reside in a
   different security domain.  In that case, there is significant risk
   that a packet might be modified as it travels from PE to PE.

   Therefore, the VPN Context Information option MUST be authenticated
   when used in over-the-top environments.  In this scenario, an IPv6
   Encapsulating Security Payload (ESP) [RFC4303] MUST proceed the
   Destination Options header that carries the VPN Context Information
   option.  The ESP integrity service MUST be enabled.

6.  IANA Considerations

   IANA is requested to allocate a codepoint from the Destination
   Options and Hop-by-hop Options registry
   (https://www.iana.org/assignments/ipv6-parameters/
   ipv6-parameters.xhtml#ipv6-parameters-2).  This option is called "VPN
   Context Information".  The "act" bits are 10 and the "chg" bit is 0.

7.  Acknowledgements

   Thanks to Adrian Farrel and John Leddy for their comments.

8.  References

8.1.  Normative References

   [RFC0791]  Postel, J., "Internet Protocol", STD 5, RFC 791,
              DOI 10.17487/RFC0791, September 1981,
              <https://www.rfc-editor.org/info/rfc791>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/info/rfc2119>.



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   [RFC4303]  Kent, S., "IP Encapsulating Security Payload (ESP)",
              RFC 4303, DOI 10.17487/RFC4303, December 2005,
              <https://www.rfc-editor.org/info/rfc4303>.

   [RFC4443]  Conta, A., Deering, S., and M. Gupta, Ed., "Internet
              Control Message Protocol (ICMPv6) for the Internet
              Protocol Version 6 (IPv6) Specification", STD 89,
              RFC 4443, DOI 10.17487/RFC4443, March 2006,
              <https://www.rfc-editor.org/info/rfc4443>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/info/rfc8174>.

   [RFC8200]  Deering, S. and R. Hinden, "Internet Protocol, Version 6
              (IPv6) Specification", STD 86, RFC 8200,
              DOI 10.17487/RFC8200, July 2017,
              <https://www.rfc-editor.org/info/rfc8200>.

8.2.  Informative References

   [I-D.ietf-6man-segment-routing-header]
              Previdi, S., Filsfils, C., Leddy, J., Matsushima, S., and
              d. daniel.voyer@bell.ca, "IPv6 Segment Routing Header
              (SRH)", draft-ietf-6man-segment-routing-header-13 (work in
              progress), May 2018.

   [RFC2784]  Farinacci, D., Li, T., Hanks, S., Meyer, D., and P.
              Traina, "Generic Routing Encapsulation (GRE)", RFC 2784,
              DOI 10.17487/RFC2784, March 2000,
              <https://www.rfc-editor.org/info/rfc2784>.

   [RFC3031]  Rosen, E., Viswanathan, A., and R. Callon, "Multiprotocol
              Label Switching Architecture", RFC 3031,
              DOI 10.17487/RFC3031, January 2001,
              <https://www.rfc-editor.org/info/rfc3031>.

   [RFC4271]  Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
              Border Gateway Protocol 4 (BGP-4)", RFC 4271,
              DOI 10.17487/RFC4271, January 2006,
              <https://www.rfc-editor.org/info/rfc4271>.

   [RFC4364]  Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private
              Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February
              2006, <https://www.rfc-editor.org/info/rfc4364>.






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   [RFC4760]  Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
              "Multiprotocol Extensions for BGP-4", RFC 4760,
              DOI 10.17487/RFC4760, January 2007,
              <https://www.rfc-editor.org/info/rfc4760>.

   [RFC4761]  Kompella, K., Ed. and Y. Rekhter, Ed., "Virtual Private
              LAN Service (VPLS) Using BGP for Auto-Discovery and
              Signaling", RFC 4761, DOI 10.17487/RFC4761, January 2007,
              <https://www.rfc-editor.org/info/rfc4761>.

   [RFC4762]  Lasserre, M., Ed. and V. Kompella, Ed., "Virtual Private
              LAN Service (VPLS) Using Label Distribution Protocol (LDP)
              Signaling", RFC 4762, DOI 10.17487/RFC4762, January 2007,
              <https://www.rfc-editor.org/info/rfc4762>.

   [RFC6624]  Kompella, K., Kothari, B., and R. Cherukuri, "Layer 2
              Virtual Private Networks Using BGP for Auto-Discovery and
              Signaling", RFC 6624, DOI 10.17487/RFC6624, May 2012,
              <https://www.rfc-editor.org/info/rfc6624>.

   [RFC7432]  Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A.,
              Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based
              Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February
              2015, <https://www.rfc-editor.org/info/rfc7432>.

   [RFC8077]  Martini, L., Ed. and G. Heron, Ed., "Pseudowire Setup and
              Maintenance Using the Label Distribution Protocol (LDP)",
              STD 84, RFC 8077, DOI 10.17487/RFC8077, February 2017,
              <https://www.rfc-editor.org/info/rfc8077>.

Authors' Addresses

   Ron Bonica
   Juniper Networks
   2251 Corporate Park Drive
   Herndon, Virginia  20171
   USA

   Email: rbonica@juniper.net


   Chris Lenart
   Verizon
   22001 Loudoun County Parkway
   Ashburn, Virginia  20147
   USA

   Email: chris.lenart@verizon.com



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   Greg Presbury
   Hughes Network Systems
   11717 Exploration Lane
   Germantown, Maryland  20876
   USA

   Email: greg.presbury@hughes.com












































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