Network Working Group                                            R. Bush
Internet-Draft                           IIJ Research Lab & Arrcus, Inc.
Updates: 8481 (if approved)                                     K. Patel
Intended status: Standards Track                            Arrcus, Inc.
Expires: 19 May 2022                                            P. Smith
                                        PFS Internet Development Pty Ltd
                                                                M. Tinka
                                                                  SEACOM
                                                        15 November 2021


                RPKI-Based Policy Without Route Refresh
                    draft-ymbk-sidrops-rov-no-rr-02

Abstract

   A BGP Speaker performing RPKI-based policy should not issue Route
   Refresh to its neighbors when receiving new RPKI data.  A method for
   avoiding doing so is described.

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
   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 19 May 2022.







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Copyright Notice

   Copyright (c) 2021 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.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Related Work  . . . . . . . . . . . . . . . . . . . . . . . .   3
   3.  ROV Experience  . . . . . . . . . . . . . . . . . . . . . . .   3
   4.  Keeping Partial Adj-RIB-In Data . . . . . . . . . . . . . . .   3
   5.  Operational Recommendations . . . . . . . . . . . . . . . . .   3
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   4
   7.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   4
   8.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .   4
   9.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   4
     9.1.  Normative References  . . . . . . . . . . . . . . . . . .   4
     9.2.  Informative References  . . . . . . . . . . . . . . . . .   5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   6

1.  Introduction

   Memory constraints in early routers caused classic [RFC4271] BGP
   implementations to not keep a full Adj-RIB-In (Sec. 1.1).  When doing
   RPKI-based Route Origin Validation ([RFC6811] and [RFC8481]), and
   similar RPKI-based policy, if such a BGP speaker receives new RPKI
   data, it might not have kept paths previously marked as Invalid etc.
   Such an implementation must then request a Route Refresh [RFC7313]
   from its neighbors to recover the paths which might be covered by
   these new RPKI data.  This will be perceived as rude by those
   neighbors as it passes a serious resource burden on to them.  This
   document recommends implementations keep but mark paths affected by
   RPKI-based policy so Route Refresh is no longer needed.









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2.  Related Work

   It is assumed that the reader understands BGP, [RFC4271] and Route
   Refresh [RFC7313], the RPKI [RFC6480], Route Origin Authorizations
   (ROAs), [RFC6482], The Resource Public Key Infrastructure (RPKI) to
   Router Protocol [I-D.ietf-sidrops-8210bis], RPKI-based Prefix
   Validation, [RFC6811], and Origin Validation Clarifications,
   [RFC8481].

3.  ROV Experience

   As Route Origin Validation dropping Invalids has depoyed, some router
   implementations have been found which, when receiving new RPKI data
   (VRPs, see [I-D.ietf-sidrops-8210bis]) issue a BGP Route Refresh
   [RFC7313] to all sending BGP peers so that it can reevaluate the
   received paths aginst the new data.

   In actual deployment this has been found to be very destructive,
   transferring a serious resource burden to the unsuspecting peers.  In
   reaction, RPKI based Route Origin Validation (ROV) has been turned
   off; and there have been actual de-peerings.

   As RPKI registration and ROA creation have steadily increased, this
   problem has increased, not just proportionally, but on the order of
   the in-degree of ROV implementing routers.  As ASPA
   ([I-D.ietf-sidrops-aspa-verification]) becomes used, the problem will
   increase.

4.  Keeping Partial Adj-RIB-In Data

   Ameliorating this problem by keeping a full Adj-RIB-In can be a
   problem for resource constrained routers.  In reality, only some data
   need be retained.

   When RPKI data cause one or more paths to be dropped, withdrawn, or
   merely not chosn as best path due to RPKI-based policy (ROV, ASPA,
   etc.), those paths MUST be saved and marked so that later VRPs can
   reevaluate them against then current policy.

   As storing these paths could cause problems in resource constrained
   devices, there MUST be a knob allowing operator control of this
   feature.  Such a knob MUST NOT be per peer, as this could cause
   inconsistent behavior.

5.  Operational Recommendations

   Routers MUST either keep the full Adj-RIB-In or implement the
   specification in Section 4.



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   Operators deploying ROV and/or other RPKI based policies SHOULD
   ensure that the router implementation is not causing unnecessary
   Route Refresh requests to neighbors.

   If the router does not implement these recommendations, the operator
   SHOULD enable the vendor's knob to keep the full Adj-RIB-In,
   sometimes referred to as "soft reconfiguration inbound".  The
   operator should then measure to ensure that there are no unnecessary
   Route Refresh requests sent to neighbors.

   If the router has insufficient resources to support this, it MUST not
   be used for Route Origin Validation.  I.e. the knob in Section 4
   should only be used in very well known and controlled circumstances.

   Internet Exchange Points which provide [RFC7947] Route Servers should
   be aware that some members could be causing an undue Route Refresh
   load on the Route Servers and take appropriate administrative and/or
   technical measures.

6.  Security Considerations

   This document describes a denial of service which Route Origin
   Validation or other RPKI policy may place on a BGP neighbor, and
   describes how it may be ameliorated.

   Otherwise, this document adds no additional security considerations
   to those already described by the referenced documents.

7.  IANA Considerations

   None

8.  Acknowledgements

   The authors wish to thank Ben Maddison and Nick Hilliard.

9.  References

9.1.  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,
              <https://www.rfc-editor.org/info/rfc2119>.







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

   [RFC7313]  Patel, K., Chen, E., and B. Venkatachalapathy, "Enhanced
              Route Refresh Capability for BGP-4", RFC 7313,
              DOI 10.17487/RFC7313, July 2014,
              <https://www.rfc-editor.org/info/rfc7313>.

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

9.2.  Informative References

   [I-D.ietf-sidrops-8210bis]
              Bush, R. and R. Austein, "The Resource Public Key
              Infrastructure (RPKI) to Router Protocol, Version 2", Work
              in Progress, Internet-Draft, draft-ietf-sidrops-8210bis-
              03, 15 August 2021, <https://www.ietf.org/archive/id/
              draft-ietf-sidrops-8210bis-03.txt>.

   [I-D.ietf-sidrops-aspa-verification]
              Azimov, A., Bogomazov, E., Bush, R., Patel, K., and J.
              Snijders, "Verification of AS_PATH Using the Resource
              Certificate Public Key Infrastructure and Autonomous
              System Provider Authorization", Work in Progress,
              Internet-Draft, draft-ietf-sidrops-aspa-verification-08,
              25 August 2021, <https://www.ietf.org/archive/id/draft-
              ietf-sidrops-aspa-verification-08.txt>.

   [RFC6480]  Lepinski, M. and S. Kent, "An Infrastructure to Support
              Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480,
              February 2012, <https://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,
              <https://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,
              <https://www.rfc-editor.org/info/rfc6811>.






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   [RFC7947]  Jasinska, E., Hilliard, N., Raszuk, R., and N. Bakker,
              "Internet Exchange BGP Route Server", RFC 7947,
              DOI 10.17487/RFC7947, September 2016,
              <https://www.rfc-editor.org/info/rfc7947>.

   [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>.

Authors' Addresses

   Randy Bush
   IIJ Research Lab & Arrcus, Inc.
   1856 SW Edgewood Dr
   Portland, Oregon 97210
   United States of America

   Email: randy@psg.com


   Keyur Patel
   Arrcus, Inc.
   2077 Gateway Place, Suite #400
   San Jose, CA 95119
   United States of America

   Email: keyur@arrcus.com


   Philip Smith
   PFS Internet Development Pty Ltd
   PO Box 1908
   Milton QLD 4064
   Australia

   Email: pfsinoz@gmail.com


   Mark Tinka
   SEACOM
   Building 7, Design Quarter District, Leslie Avenue, Magaliessig
   Fourways, Gauteng
   2196
   South Africa

   Email: mark@tinka.africa




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