Internet DRAFT - draft-boucadair-lisp-idr-ms-discovery

draft-boucadair-lisp-idr-ms-discovery







Network Working Group                                       M. Boucadair
Internet-Draft                                              C. Jacquenet
Intended status: Experimental                                     Orange
Expires: September 10, 2016                                March 9, 2016


                LISP Mapping Service Discovery at Large
                draft-boucadair-lisp-idr-ms-discovery-01

Abstract

   Locator/ID Separation Protocol (LISP) operation relies upon a mapping
   mechanism that is used by ingress/egress Tunnel Routers (xTR) to
   forward traffic over the LISP network.  The ability of dynamically
   discovering the Map-Resolver and Map-Server entities that provide
   such mapping services is meant to facilitate global LISP operation
   (automatic discovery of Map-Resolvers and Map-Servers).

   This document specifies a BGP Extended Communities attribute that can
   be used to dynamically discover LISP Mapping Systems of different
   domains.

Requirements Language

   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 RFC 2119 [RFC2119].

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
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   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on September 10, 2016.







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Copyright Notice

   Copyright (c) 2016 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
   described in the Simplified BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Rationale . . . . . . . . . . . . . . . . . . . . . . . . . .   5
   3.  LISP Mapping System Target BGP Extended Community . . . . . .   5
   4.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   5.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
   6.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   6
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   7
     7.1.  Normative references  . . . . . . . . . . . . . . . . . .   7
     7.2.  Informative references  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   Locator/ID Separation Protocol (LISP, [RFC6830] ) operation relies
   upon a mapping mechanism that is used by ingress/egress Tunnel
   Routers (xTR) to forward traffic over the LISP network.  The ability
   of dynamically discovering the Map-Resolver and Map-Server entities
   that provide such mapping services is meant to facilitate global LISP
   operation (automatic discovery of Map-Resolvers and Map-Servers).

   Within this document, a Mapping System provides the LISP mapping
   service [RFC6833].  Map-Resolvers, Map-Servers, and other components
   may be part of a Mapping System such as authorization, subscription
   profiles, etc.  These components are considered as black boxes; only
   the external behavior of the Mapping System is in scope.

   Distinct LISP mapping systems may emerge if LISP users or network
   operators who solicit or manage the Mapping System want to avoid some
   region-centric systems, for example, or if they want to position
   themselves as a core provider of the Mapping System.  The lack of




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   clear policies of the management and operation of the LISP Mapping
   Systems may encourage such practices.

   This document assumes a hierarchy in the Mapping System organisation
   for business, governance, control, and regulatory purposes in
   particular.  In such contexts, the document assumes that a Mapping
   System may maintain a portion of or a global mapping table.

   Because of its experimental nature of LISP and the various platforms
   LISP operation relies upon (like the platforms used by the LISP
   mapping systems) should encourage innovation by testing new services
   that may take advantage of LISP in inter-domain deployment scenarios
   without requiring the participation of all LISP-enabled domains.
   Such approach is also meant to avoid any risk of freezing LISP
   developments.

   Because the design and operation of a consistent Mapping System is
   critical for the adoption of LISP at large scale, this document
   advocates for means to dynamically discover other Mapping Systems
   that are open to cooperate in inter-domain LISP deployment scenarios,
   typically .

   Deploying LISP for inter-domain use cases may raise the following
   issues:

   Issue#1:   A LISP domain may need to discover available Mapping
      Systems so that it can rely upon them to extend the reachability
      scope.

   Issue#2:   Various Mapping Systems can be deployed over the Internet.
      These Mapping Systems need to interconnect to extend the
      reachability scope and avoid pressure on PTR (Proxy Tunnel Router)
      devices.  Also, various Mapping Systems encourage the enforcement
      of policies that aim at optimizing LISP forwarding: for example,
      policies that consist in avoiding the solicitation of specific
      domains/ASes.

   Issue#3:   Distinct flavors of Mapping Systems may be deployed.
      These mappings may not rely on the same database mapping system
      (e.g., NERD, ALT, CONS, etc.).  As such, a clear interface to ease
      interconnection between these realms is needed.  Standard
      solutions to discover Mapping Systems capabilities are likely to
      ease the interconnection of Mapping Systems.

   Issue#4:   Security concerns may arise during the discovery of the
      available Mapping Systems: for example, a given Mapping System may
      deny access from another domain, or available Mapping Systems need
      to make sure that they are entitled to exchange information with



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      one another or that an xTR of a given LISP network is entitled to
      solicit a mapping system of another LISP network, etc.

   An efficient and scalable deployment of LISP within an inter-domain
   context for traffic engineering purposes, in particular, relies
   heavily on the availability of an inter-domain mapping system that
   spans several domains.  From this perspective, the success of a
   global LISP adoption and deployment will mainly depend on how LISP-
   enabled domains will graft to existing mapping systems that can
   guarantee a global reachability scope.  To minimize the risk of a
   fragmented Mapping System that would jeopardize the overall
   efficiency of an inter-domain LISP routing system, there is a need to
   encourage and facilitate the coordination of participating Mapping
   Systems.

   This document relies on extended BGP communities [RFC4360] to
   advertise that a given domain supports the LISP Mapping Service.  A
   contact IPv4 address and/or IPv6 address are also included in the
   attribute so that remote LISP Mapping Systems or LISP domains may
   initiate negotiation cycles for the sake of LISP Mapping System
   Interconnection or subscription to the Mapping Service offered by
   that Mapping System.

   Section 3 specifies a solution for the discovery of LISP Mapping
   Systems that are deployed in distinct administrative domains.  This
   BGP-based solution assumes that domains that support a LISP Mapping
   Service will use the BGP Extended Communities attribute to inform
   other domains about the support of the service.  EIDs that can be
   serviced with LISP will be tagged accordingly.  Note that an EID can
   be serviced by multiple Mapping Systems.  Remote LISP Mapping Systems
   will rely upon that BGP-based advertising capability to discover the
   existence and the status of other Mapping Systems.  Once a Mapping
   System is discovered, a local Mapping System can establish an
   interconnection agreement with that remote Mapping System.  The
   contact IP address provided as part of the BGP Extended Communities
   attribute will be used to contact a remote Mapping System to request
   for further LISP-related capabilities, possibly negotiate an
   interconnection agreement and, consequently, extend the scope of the
   networks that can be serviced using LISP.  Also, leaf LISP-aware
   networks can rely upon the information carried in the BGP Extended
   Communities attribute to discover Mapping Systems that may be
   solicited to invoke their mapping service.  Subscription cycles may
   then be considered.








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2.  Rationale

   This document focuses on the discovery of LISP Mapping Systems that
   are deployed in distinct administrative domains.

   The rationale is as follows:

   1.  Announce: Domains that support a LISP Mapping Service will use
       the BGP Extended Communities attribute (Section 3) to inform
       other domains about the support of the service.  EIDs that can be
       serviced with LISP can be tagged accordingly.  Note that an EID
       can be serviced by multiple Mapping Systems.

   2.  Discover: Remote LISP Mapping Systems will rely upon that BGP-
       based advertising capability (Section 3) to discover the
       existence of other Mapping Systems.

   3.  Negotiate/Interconnect/Invoke: The contact IP address provided as
       part of the BGP Extended Communities attribute (Section 3) will
       be used to contact a remote Mapping System to request for further
       LISP-related capabilities, possibly negotiate an interconnection
       agreement and, consequently, extend the scope of the networks
       that can be serviced using LISP.

   4.  Negotiate/Subscribe/Invoke: Also, leaf LISP-aware networks can
       rely upon the information carried in the BGP Extended Communities
       attribute to discover Mapping Systems that may be solicited to
       invoke their mapping service.  Subscription cycles may then be
       considered.

   Only the first two steps are in scope of this document; the remaining
   steps can be achieved by other means such as
   [I-D.boucadair-connectivity-provisioning-protocol].

3.  LISP Mapping System Target BGP Extended Community

   The LISP Mapping System Target Community identifies one or more
   Mapping System contact points that can receive mapping system
   interconnect and/or subscription requests.  These contact points are
   identified with IPv4 and/or IPv6 addresses.

   The LISP Mapping System Target Community is of an extended type.  As
   such, the behavior specified in Section 6 of [RFC4360] applies to the
   LISP Mapping System Target Community.

   The presence of this community is an explicit indication that
   associated networks can be managed by a LISP Mapping System that is
   reachable at the addresses carried in the attribute.



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   This document reuses the Transitive IPv4-Address-Specific Extended
   Community [RFC4360] and Transitive IPv6-Address-Specific Extended
   Community [RFC5701] for the purpose of this document.  Dedicated sub-
   types are to be allocated (see Section 5).

   The Global Administrator field MUST be set to an IP address of the
   Mapping System.  This address MUST be configured on the originating
   BGP speaker.

   The "Local Administrator" field of the LISP Mapping System Target
   Community is used to encode an identifier of the Mapping System.
   Considerations about the assignment of globally unique identifiers to
   LISP Mapping Systems are out of scope.  A configurable parameter may
   be supported by BGP implementations to provide the value carried in
   the "Local Administrator" field.  If no identifier is configured on
   the originating BGP speaker, the "Local Administrator" field MUST be
   set to 0.

4.  Security Considerations

   This document does not introduce any additional security issues other
   than those discussed in [RFC4360] and [RFC5701].

5.  IANA Considerations

   According to [RFC7153], this document requests the assignment of a
   sub-type in the "0x00-0xbf" range from the Transitive IPv4-Address-
   Specific Extended Community Sub-Types registry available at
   http://www.iana.org/assignments/bgp-extended-communities/bgp-
   extended-communities.xml#trans-ipv4:

   Type Value     Name                        Reference
       TBA        LISP Mapping System Target  [This-Document]

   Also, this document requests the assignment of a sub-type from the
   Transitive IPv6-Address-Specific Extended Community Types registry
   available at http://www.iana.org/assignments/bgp-extended-
   communities/bgp-extended-communities.xml#trans-ipv6:

   Type Value     Name                        Reference
       TBA        LISP Mapping System Target  [This-Document]

6.  Acknowledgments

   This work is partly funded by ANR LISP-Lab project #ANR-13-INFR-
   009-X.





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7.  References

7.1.  Normative references

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

   [RFC4360]  Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
              Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
              February 2006, <http://www.rfc-editor.org/info/rfc4360>.

   [RFC5701]  Rekhter, Y., "IPv6 Address Specific BGP Extended Community
              Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009,
              <http://www.rfc-editor.org/info/rfc5701>.

   [RFC6830]  Farinacci, D., Fuller, V., Meyer, D., and D. Lewis, "The
              Locator/ID Separation Protocol (LISP)", RFC 6830,
              DOI 10.17487/RFC6830, January 2013,
              <http://www.rfc-editor.org/info/rfc6830>.

   [RFC7153]  Rosen, E. and Y. Rekhter, "IANA Registries for BGP
              Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
              March 2014, <http://www.rfc-editor.org/info/rfc7153>.

7.2.  Informative references

   [I-D.boucadair-connectivity-provisioning-protocol]
              Boucadair, M., Jacquenet, C., Zhang, D., and P.
              Georgatsos, "Connectivity Provisioning Negotiation
              Protocol (CPNP)", draft-boucadair-connectivity-
              provisioning-protocol-10 (work in progress), September
              2015.

   [RFC6833]  Fuller, V. and D. Farinacci, "Locator/ID Separation
              Protocol (LISP) Map-Server Interface", RFC 6833,
              DOI 10.17487/RFC6833, January 2013,
              <http://www.rfc-editor.org/info/rfc6833>.

Authors' Addresses

   Mohamed Boucadair
   Orange
   Rennes  35000
   France

   EMail: mohamed.boucadair@orange.com



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   Christian Jacquenet
   Orange
   Rennes  35000
   France

   EMail: christian.jacquenet@orange.com













































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