





Internet Engineering Task Force (IETF)                      P. Mohapatra
Request for Comments: 8097                              Sproute Networks
Category: Standards Track                                       K. Patel
ISSN: 2070-1721                                             Arrcus, Inc.
                                                              J. Scudder
                                                        Juniper Networks
                                                                 D. Ward
                                                                   Cisco
                                                                 R. Bush
                                         Internet Initiative Japan, Inc.
                                                              March 2017


         BGP Prefix Origin Validation State Extended Community

Abstract

   This document defines a new BGP opaque extended community to carry
   the origination Autonomous System (AS) validation state inside an
   autonomous system.  Internal BGP (IBGP) speakers that receive this
   validation state can configure local policies that allow it to
   influence their decision process.

Status of This Memo

   This is an Internet Standards Track document.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   Internet Standards is available in Section 2 of RFC 7841.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc8097.















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Copyright Notice

   Copyright (c) 2017 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
   to this document.  Code Components extracted from this document must
   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  . . . . . . . . . . . . . . . . . . . . . . . .   3
     1.1.  Requirements Language . . . . . . . . . . . . . . . . . .   3
   2.  Origin Validation State Extended Community  . . . . . . . . .   3
   3.  Deployment Considerations . . . . . . . . . . . . . . . . . .   4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   5
     6.1.  Normative References  . . . . . . . . . . . . . . . . . .   5
     6.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Acknowledgements  . . . . . . . . . . . . . . . . . . . . . . . .   6
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6























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1.  Introduction

   This document defines a new BGP opaque extended community to carry
   the origination AS validation state inside an autonomous system.
   IBGP speakers that receive this validation state can configure local
   policies that allow it to influence their decision process.

1.1.  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].

2.  Origin Validation State Extended Community

   The origin validation state extended community is an opaque extended
   community [RFC4360] with the following encoding:

        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
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |       0x43    |      0x00     |             Reserved          |
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
       |                    Reserved                   |validationstate|
       +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

   The value of the high-order octet of the extended Type field is 0x43,
   which indicates it is non-transitive.  The value of the low-order
   octet of the extended Type field as assigned by IANA is 0x00.  The
   Reserved field MUST be set to 0 and ignored upon the receipt of this
   community.  The last octet of the extended community is an unsigned
   integer that gives the route's validation state [RFC6811].  It can
   assume the following values:

                     +-------+-----------------------------+
                     | Value | Meaning                     |
                     +-------+-----------------------------+
                     |   0   | Lookup result = "valid"     |
                     |   1   | Lookup result = "not found" |
                     |   2   | Lookup result = "invalid"   |
                     +-------+-----------------------------+

   If the router is configured to support the extensions defined in this
   document, it SHOULD attach the origin validation state extended
   community to BGP UPDATE messages sent to IBGP peers by mapping the
   computed validation state in the last octet of the extended





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   community.  Similarly, a receiving BGP speaker, in the absence of
   validation state set based on local data, SHOULD derive a validation
   state from the last octet of the extended community, if present.

   An implementation SHOULD NOT send more than one instance of the
   origin validation state extended community.  However, if more than
   one instance is received, an implementation MUST disregard all
   instances other than the one with the numerically greatest validation
   state value.  If the value received is greater than the largest
   specified value (2), the implementation MUST apply a strategy similar
   to attribute discard [RFC7606] by discarding the erroneous community
   and logging the error for further analysis.

   By default, implementations MUST drop the origin validation state
   extended community if received from an External BGP (EBGP) peer,
   without processing it further.  Similarly, by default, an
   implementation SHOULD NOT send the community to EBGP peers.  However,
   it SHOULD be possible to configure an implementation to send or
   accept the community when warranted.  An example of a case where the
   community would reasonably be received from, or sent to, an EBGP peer
   is when two adjacent ASes are under control of the same
   administration.  A second example is documented in [SIDR-RPKI].

3.  Deployment Considerations

   In deployment scenarios in which not all the speakers in an
   autonomous system are upgraded to support the extensions defined in
   this document, it is necessary to define policies that match on the
   origin validation extended community and set another BGP attribute
   [RFC6811] that influences selection of the best path in the same way
   that an implementation of this extension would.

4.  IANA Considerations

   IANA has registered the value 0x00, with the name "BGP Origin
   Validation State Extended Community", in the "Non-Transitive Opaque
   Extended Community Sub-Types" registry.

5.  Security Considerations

   Security considerations such as those described in [RFC4272] continue
   to apply.  Because this document introduces an extended community
   that will generally be used to affect route selection, the analysis
   in Section 4.5 ("Falsification") of [RFC4593] is relevant.  These
   issues are neither new nor unique to the origin validation extended
   community.





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   The security considerations provided in [RFC6811] apply equally to
   this application of origin validation.  In addition, this document
   describes a scheme where router A outsources validation to some
   router B.  If this scheme is used, the participating routers should
   have the appropriate trust relationship -- B should trust A either
   because they are under the same administrative control or for some
   other reason (for example, consider [SIDR-RPKI]).  The security
   properties of the TCP connection between the two routers should also
   be considered.  See Section 5.1 of [RFC7454] for advice regarding
   protection of the TCP connection.

6.  References

6.1.  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>.

   [RFC6811]   Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R.
               Austein, "BGP Prefix Origin Validation", RFC 6811,
               DOI 10.17487/RFC6811, January 2013,
               <http://www.rfc-editor.org/info/rfc6811>.

6.2.  Informative References

   [RFC4272]   Murphy, S., "BGP Security Vulnerabilities Analysis",
               RFC 4272, DOI 10.17487/RFC4272, January 2006,
               <http://www.rfc-editor.org/info/rfc4272>.

   [RFC4593]   Barbir, A., Murphy, S., and Y. Yang, "Generic Threats to
               Routing Protocols", RFC 4593, DOI 10.17487/RFC4593,
               October 2006, <http://www.rfc-editor.org/info/rfc4593>.

   [RFC7454]   Durand, J., Pepelnjak, I., and G. Doering, "BGP
               Operations and Security", BCP 194, RFC 7454,
               DOI 10.17487/RFC7454, February 2015,
               <http://www.rfc-editor.org/info/rfc7454>.

   [RFC7606]   Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
               Patel, "Revised Error Handling for BGP UPDATE Messages",
               RFC 7606, DOI 10.17487/RFC7606, August 2015,
               <http://www.rfc-editor.org/info/rfc7606>.



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   [SIDR-RPKI] King, T., Kopp, D., Lambrianidis, A., and A. Fenioux,
               "Signaling Prefix Origin Validation Results from a Route-
               Server to Peers", Work in Progress,
               draft-ietf-sidrops-route-server-rpki-light-01, January
               2017.

Acknowledgements

   The authors would like to acknowledge the valuable review and
   suggestions from Wesley George, Roque Gagliano, and Bruno Decraene on
   this document.

Authors' Addresses

   Pradosh Mohapatra
   Sproute Networks
   Email: mpradosh@yahoo.com

   Keyur Patel
   Arrcus, Inc.
   Email: keyur@arrcus.com

   John Scudder
   Juniper Networks
   1194 N. Mathilda Ave
   Sunnyvale, CA  94089
   United States of America
   Email: jgs@juniper.net

   Dave Ward
   Cisco
   170 W. Tasman Drive
   San Jose, CA  95124
   United States of America
   Email: dward@cisco.com

   Randy Bush
   Internet Initiative Japan, Inc.
   5147 Crystal Springs
   Bainbridge Island, WA  98110
   United States of America
   Email: randy@psg.com









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