Network Working Group                                          A. Retana
Internet-Draft                                       Cisco Systems, Inc.
Intended status: Standards Track                                A. Weher
Expires: April 27, 2015                                           TelVGG
                                                        October 24, 2014


   Use of the Cost Community to Propagate BGP Origin Validation State
         draft-retana-sidr-origin-validation-cost-community-00

Abstract

   This document explains the use of the Cost Community to provide
   flexibility in the application of routing policy related to the
   origin validation state of a route.

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   This Internet-Draft will expire on April 27, 2015.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   2
   3.  Use of the Cost Community to Propagate BGP Origin Validation
       State . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
   4.  Operational Considerations  . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   3
   7.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   3
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4

1.  Introduction

   The BGP Origin Validation mechanism [RFC6811] defines the route
   validation states as "Valid", "NotFound" and "Invalid".  The Origin
   Validation State Extended Community
   [I-D.ietf-sidr-origin-validation-signaling] has been defined so that
   this state can be considered prior to any of the steps defined in the
   BGP decision process [RFC4271].

   It has been suggested that the LOCAL_PREF attribute [RFC4271] may
   also be used to indicate the degree of preference of a route
   according to its origin validation state.  [RFC7115] also suggests
   the need to consider the origin validation state at other steps in
   the selection process, for example after considering the AS_PATH
   length.

   The Cost Community [I-D.ietf-idr-custom-decision] can provide a
   flexible mechanism to propagate the origin validation state, without
   overloading existing attributes that may already be used to set other
   types of local policy (such as the LOCAL_PREF).

2.  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 [RFC2119].

3.  Use of the Cost Community to Propagate BGP Origin Validation State

   It is RECOMMENDED that the values defined in
   [I-D.ietf-sidr-origin-validation-signaling] also be used to assign
   the Cost:




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                        +------+------------------+
                        | Cost | Validation State |
                        +------+------------------+
                        | 0    | Valid            |
                        | 1    | NotFound         |
                        | 2    | Invalid          |
                        +------+------------------+

                         Cost vs Validation State

   The Point of Insertion (POI) can be set to any of the values defined
   in [I-D.ietf-idr-custom-decision].  Note that the use of the
   ABSOLUTE_VALUE POI is equivalent to using the Origin Validation State
   Extended Community.

   If the Cost Community is used to propagate the origin validation
   state, then the Origin Validation State Extended Community SHOULD NOT
   be used.  If used, then it will always take precendence over the Cost
   Community, regardless of the POI used.

4.  Operational Considerations

   The use of the origin validation state as part of the BGP decision
   process is a matter of local policy.

   The policy mechanism chosen to propagate the origin validation state
   SHOULD be implemented uniformly across the local autonomous system to
   guarantee a consistent decision process and reduce the risk of
   routing loops.

5.  Security Considerations

   This document explains the use of the Cost Community to provide
   flexibility in the application of routing policy related to the
   origin validation state of a route.  As such, it does not introduce
   new security risks beyond the ones considered in
   [I-D.ietf-idr-custom-decision] or [RFC6811].

6.  IANA Considerations

   This document has no IANA actions.

7.  Acknowledgements

   The authors would like to thank Keyur Patel.






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8.  References

8.1.  Normative References

   [I-D.ietf-idr-custom-decision]
              Retana, A. and R. White, "BGP Custom Decision Process",
              draft-ietf-idr-custom-decision-05 (work in progress),
              October 2014.

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

   [RFC6811]  Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
              Austein, "BGP Prefix Origin Validation", RFC 6811, January
              2013.

8.2.  Informative References

   [I-D.ietf-sidr-origin-validation-signaling]
              Mohapatra, P., Patel, K., Scudder, J., Ward, D., and R.
              Bush, "BGP Prefix Origin Validation State Extended
              Community", draft-ietf-sidr-origin-validation-signaling-04
              (work in progress), February 2014.

   [RFC4271]  Rekhter, Y., Li, T., and S. Hares, "A Border Gateway
              Protocol 4 (BGP-4)", RFC 4271, January 2006.

   [RFC7115]  Bush, R., "Origin Validation Operation Based on the
              Resource Public Key Infrastructure (RPKI)", BCP 185, RFC
              7115, January 2014.

Authors' Addresses

   Alvaro Retana
   Cisco Systems, Inc.
   7025 Kit Creek Rd.
   Research Triangle Park, NC  27709
   USA

   Email: aretana@cisco.com











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   Ariel Weher
   Cooperativa Telefonica de Villa Gdor.  Galvez Ltda.
   Av. Mitre 1028
   Villa Gdor. Galvez, Santa Fe  S2124HEB
   Argentina

   Email: ariel@weher.net












































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