Network Working Group                                            R. Bush
Internet-Draft                        Internet Initiative Japan & Arrcus
Updates: 6811 (if approved)                                      R. Volk
Intended status: Standards Track                        Deutsche Telekom
Expires: September 5, 20, 2020                                     J. Heitz
                                                                   Cisco
                                                          March 4, 19, 2020

               BGP RPKI-Based Origin Validation on Export
                    draft-ietf-sidrops-ov-egress-01
                    draft-ietf-sidrops-ov-egress-02

Abstract

   A BGP speaker may perform RPKI origin validation not only on routes
   received from BGP neighbors and routes that are redistributed from
   other routing protocols, but also on routes it sends to BGP
   neighbors.  For egress policy, it is important that the
   classification uses the effective origin AS of the processed route,
   which may specifically be altered by the commonly available knobs
   such as removing private ASs, confederation handling, and other
   modifications of the origin AS.

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.

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
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   Internet-Drafts are draft documents valid for a maximum of six months
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   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 September 5, 20, 2020.

Copyright Notice

   Copyright (c) 2020 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

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Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Suggested Reading . . . . . . . . . . . . . . . . . . . . . .   3
   3.  Egress Processing . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Operational Considerations  . . . . . . . . . . . . . . . . .   3
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   3
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   7.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . .   4
   8.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     7.1.
     8.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     7.2.
     8.2.  Informative References  . . . . . . . . . . . . . . . . .   4
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   4   5

1.  Introduction

   This document does not change the protocol or semantics of [RFC6811]
   of RPKI-based origin validation.  It highlights an important use case
   of origin validation in eBGP egress policies, explaining specifics of
   correct implementation in this context.

   As the origin AS may be modified of a BGP UPDATE is decided by configuration and
   outbound policy, policy semantics
   based on RPKI Origin Validation state MUST be able to be applied
   separately on distribution into BGP and on egress.

   When applied to egress policy, of the effective origin AS BGP speaker, a validating BGP speaker MUST be used
   to determine the
   apply Route Origin Validation state.  The effective policy semantics against the origin AS is
   that
   Autonomous System number which will actually be put in the AS_PATH
   (see [RFC4271] 4.3 Path Attributes:b) of the UPDATE to the peer.

   This effective origin AS in of the announcement.  It announcement might be affected by
   removal of private AS(s), confederation, AS migration, etc.  If there are any  Any
   AS_PATH modifications resulting in origin AS change, then these change MUST be taken
   into account.

   This document updates [RFC6811] by clarifying that implementations
   must use the effective origin AS to determine the Origin Validation
   state when applying egress policy.

2.  Suggested Reading

   It is assumed that the reader understands BGP, [RFC4271], the RPKI,
   [RFC6480], Route Origin Authorizations (ROAs), [RFC6482], RPKI-based
   Prefix Validation, [RFC6811], and Origin Validation Clarifications,
   [RFC8481].

3.  Egress Processing

   BGP implementations supporting RPKI-based origin validation SHOULD
   provide the same policy configuration primitives for decisions based
   on validation state available for use in ingress, redistribution, and
   egress policies.  When applied to egress policy, validation state
   MUST be determined using the effective origin AS of the route as it
   will (or would) be announced to the peer.  The effective origin AS
   may differ from that of the route in the RIB due to commonly
   available knobs such as: removal of private ASs, AS path
   manipulation, confederation handling, etc.

   Egress policy handling can provide more robust protection for
   outbound eBGP than relying solely on ingress (iBGP, eBGP, connected,
   static, etc.) redistribution being configured and working correctly -
   better support for the robustness principle.

4.  Operational Considerations

   Configurations may have complex policy where the final announced
   origin AS may not be easily predicted before all policies have been
   run.  Therefore it SHOULD be possible to specify an origin validation
   policy which MUST BE run after such non-deterministic policies.

   An operator SHOULD be able to list what announcements are not sent to
   a peer because they were marked Invalid, as long as the router still
   has them in memory.

5.  Security Considerations

   This document does not create security considerations beyond those of
   [RFC6811] and [RFC8481].

6.  IANA Considerations

   This document has no IANA Considerations.

7.  Acknowledgments

   Thanks to reviewers and comments from Linda Dunbar, Nick Hilliard,
   Chris Morrow, Keyur Patel, Job Snijders, and Robert Sparks.

8.  References

7.1.

8.1.  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>.

   [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>.

   [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>.

   [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>.

   [RFC8481]  Bush, R., "Clarifications to BGP Origin Validation Based
              on Resource Public Key Infrastructure (RPKI)", RFC 8481,
              DOI 10.17487/RFC8481, September 2018,
              <https://www.rfc-editor.org/info/rfc8481>.

7.2.

8.2.  Informative 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>.

Authors' Addresses

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

   Email: randy@psg.com

   Ruediger Volk
   Deutsche Telekom

   Email: rv@nic.dtag.de

   Jakob Heitz
   Cisco
   170 West Tasman Drive
   San Jose, CA  95134
   USA

   Email: jheitz@cisco.com