Clarifications to BGP Origin Validation Based on Resource Public Key Infrastructure (RPKI)
draft-ietf-sidrops-ov-clarify-05

Versions: (draft-ymbk-sidrops-ov-clarify)  00 01         Standards Track
          02 03 04 05 rfc8481                                           
Network Working Group                                            R. Bush
Internet-Draft                                 Internet Initiative Japan
Updates: 6811 (if approved)                              August 20, 2018
Intended status: Standards Track
Expires: February 21, 2019


            BGP RPKI-Based Origin Validation Clarifications
                    draft-ietf-sidrops-ov-clarify-05

Abstract

   Deployment of Resource Public Key Infrastructure (RPKI) based BGP
   origin validation is hampered by, among other things, vendor mis-
   implementations in two critical areas: which routes are validated and
   whether policy is applied when not specified by configuration.  This
   document is meant to clarify possible misunderstandings causing those
   mis-implementations; and thus updates RFC 6811 by clarifying that all
   prefixes should have their validation state set, and that policy must
   not be applied without operator configuration.

Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" are to
   be interpreted as described in [RFC8174] only when they appear in all
   upper case.  They may also appear in lower or mixed case as English
   words, without normative meaning.

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 February 21, 2019.






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

1.  Introduction

   Deployment of RPKI-based BGP origin validation is hampered by, among
   other things, vendor mis-implementations in two critical areas: which
   routes are validated and whether policy is applied when not specified
   by configuration.  This document is meant to clarify possible
   misunderstandings causing those mis-implementations.

   When a route is distributed into BGP, the origin validation state is
   set to NotFound, Valid, or Invalid per [RFC6811].  Operational
   testing has shown that the specifications of that RFC were not
   sufficient to avoid divergent implementations.  This document
   attempts to clarify two areas which seem to cause confusion.

   The implementation issues seem not to be about how to validate, i.e.,
   how to decide if a route is NotFound, Valid, or Invalid.  The issues
   seem to be which routes should be evaluated and have their evaluation
   state set, and whether to apply policy without operator
   configuration.

2.  Suggested Reading

   It is assumed that the reader understands BGP, [RFC4271], the RPKI,
   [RFC6480], Route Origin Authorizations (ROAs), [RFC6482], and RPKI-
   based Prefix Validation, [RFC6811].

3.  Evaluate ALL Prefixes

   Significant Clarification: A router MUST evaluate and set the
   validation state of all routes in BGP coming from any source (eBGP,
   iBGP, or redistribution from static, connected, etc.), unless
   specifically configured otherwise by the operator.  Else the operator
   does not have the ability to drop Invalid routes coming from every



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   potential source; and is therefore liable to complaints from
   neighbors about propagation of Invalid routes.  For this reason,
   [RFC6811] says:

   "When a BGP speaker receives an UPDATE from a neighbor, it SHOULD
   perform a lookup as described above for each of the Routes in the
   UPDATE message.  The lookup SHOULD also be applied to routes that are
   redistributed into BGP from another source, such as another protocol
   or a locally defined static route."

   [RFC6811] goes on to say "An implementation MAY provide configuration
   options to control which routes the lookup is applied to."

   When redistributing into BGP from connected, static, IGP, iBGP, etc.,
   there is no AS_PATH in the input to allow RPKI validation of the
   originating AS.  In such cases, the router MUST use the AS of the
   router's BGP configuration.  If that is ambiguous because of
   confederation, AS migration, or other multi-AS configuration, then
   the router configuration MUST provide a means of specifying the AS to
   be used on the redistribution, either per redistribution or globally.

4.  Set State, Don't Act

   Significant Clarification: Once routes are evaluated and have their
   state set, the operator should be in complete control of any policy
   applied based on the evaluation state.  Absent specific operator
   configuration, policy MUST NOT be applied.

   Automatic origin validation policy actions such as those described in
   [RFC8097], BGP Prefix Origin Validation State Extended Community,
   MUST NOT be carried out or otherwise applied unless specifically
   configured by the operator.

5.  Security Considerations

   This document does not create security considerations beyond those of
   [RFC6811].

6.  IANA Considerations

   This document has no IANA Considerations.

7.  Acknowledgments

   Many thanks to John Scudder who had the patience to give constructive
   review multiple times, and to Keyur Patel who noted that the AS might
   have to be specified.  George Michaelson, Jay Borkenhagen, John
   Heasley, and Matthias Waehlisch kindly helped clean up loose wording.



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8.  Normative References

   [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,
              <http://www.rfc-editor.org/info/rfc4271>.

   [RFC6480]  Lepinski, M. and S. Kent, "An Infrastructure to Support
              Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
              February 2012, <http://www.rfc-editor.org/info/rfc6480>.

   [RFC6482]  Lepinski, M., Kent, S., and D. Kong, "A Profile for Route
              Origin Authorizations (ROAs)", RFC 6482,
              DOI 10.17487/RFC6482, February 2012,
              <http://www.rfc-editor.org/info/rfc6482>.

   [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>.

   [RFC8097]  Mohapatra, P., Patel, K., Scudder, J., Ward, D., and R.
              Bush, "BGP Prefix Origin Validation State Extended
              Community", RFC 8097, DOI 10.17487/RFC8097, March 2017,
              <http://www.rfc-editor.org/info/rfc8097>.

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

Author's Address

   Randy Bush
   Internet Initiative Japan
   5147 Crystal Springs
   Bainbridge Island, Washington  98110
   US

   Email: randy@psg.com












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