[Docs] [txt|pdf|xml|html] [Tracker] [WG] [Email] [Diff1] [Diff2] [Nits]

Versions: (draft-ietf-sidrops-route-server-rpki-light) 00 01 02 03

Network Working Group                                            T. King
Internet-Draft                                                C. Dietzel
Intended status: Standards Track                                 D. Kopp
Expires: January 24, 2020                                         DE-CIX
                                                         A. Lambrianidis
                                                                  AMS-IX
                                                           July 23, 2019


     Signaling Prefix Origin Validation Results from an RPKI Origin
                  Validating BGP Speaker to BGP Peers
              draft-ietf-sidrops-validating-bgp-speaker-03

Abstract

   This document describes the use of BGP large communities, as well as
   its usage, to signal prefix origin validation results from an RPKI
   Origin validating BGP speaker to other BGP peers.  Upon reception of
   prefix origin validation results, peers can use this information in
   their local routing decision process.

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 January 24, 2020.






King, et al.            Expires January 24, 2020                [Page 1]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


Copyright Notice

   Copyright (c) 2019 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.  EBGP Prefix Origin Validation Large Community . . . . . . . .   3
   3.  BGP Prefix Origin Validation State Utilized at Validating
       Peers . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
   4.  Signaling Prefix Origin Validation Results from a Validating
       Peer to Peers . . . . . . . . . . . . . . . . . . . . . . . .   4
   5.  Operational Recommendations . . . . . . . . . . . . . . . . .   5
     5.1.  Local Routing Decision Process  . . . . . . . . . . . . .   5
     5.2.  Validating Peers Receiving the EBGP Prefix Origin
           Validation State Large Community  . . . . . . . . . . . .   5
     5.3.  Information about Validity of a BGP Prefix Origin Not
           Available at a Validating Peer  . . . . . . . . . . . . .   6
     5.4.  Error Handling at Peers . . . . . . . . . . . . . . . . .   6
   6.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   7
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   7

1.  Introduction

   RPKI-based prefix origin validation [RFC6480] can be a significant
   operational burden for BGP peers to implement and adopt.  To
   facilitate acceptance and usage of prefix origin validation and
   ultimately increase the security of the Internet routing system,
   Autonomous Systems may provide RPKI-based prefix origin validation at
   certain vantage points.  The result of this prefix origin validation
   is signaled to peers by using the EBGP Prefix Origin Validation State
   Large Community as introduced in this document.





King, et al.            Expires January 24, 2020                [Page 2]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


   Peers receiving a prefix origin validation result from the validating
   EBGP peer can use this information in their local routing decision
   process for acceptance, rejection, preference, or other traffic
   engineering purposes of a particular route.

2.  EBGP Prefix Origin Validation Large Community

   The origin validation state large community 12-octet function
   specific large community [RFC8092] 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
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                      Global Administrator                     |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                        TBD1 (Sub-Type)                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
      |                       Validation State                        |
      +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+


                                 Figure 1

   The value of the field TBD1 (Sub-Type) has to be assigned.  The
   Global Administrator field MUST be set to the AS number of the
   validating BGP speaker conducting the prefix origin validation.  The
   last field of the large community is an unsigned integer that gives
   the route's validation state as described in Section 4.

   If the validating BGP speaker is configured to support the extensions
   defined in this document, it SHOULD attach the origin validation
   state large community to BGP UPDATE messages sent to EBGP peers by
   mapping the computed validation state in the last field of the large
   community.  A receiving BGP speaker, in the absence of a local
   validation state, SHOULD derive a validation state from the last
   field of the received large community, if present.

   An implementation SHOULD NOT send more than one instance of the
   origin validation state large 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.




King, et al.            Expires January 24, 2020                [Page 3]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


3.  BGP Prefix Origin Validation State Utilized at Validating Peers

   A validating BGP speaker that is aware of a BGP Prefix Origin
   Validation state (see Section 4) for a certain route can handle this
   information in one of the following modes of operation, attaching
   validation state to routes as discussed in Section 2:

   Simple Tagging:  In this mode of operation, the BGP best path
       selection algorithm is executed.  The prefix origin validation
       state is tagged accordingly.

   Dropping and Tagging:  Routes for which the prefix origin validation
       state is "invalid" (according to [RFC6811]) are dropped by the
       validating BGP speaker.  Based on the remaining set of routes,
       the BGP best path selection algorithm is executed.  The prefix
       origin validation state of "not found" or "valid" (according to
       [RFC6811]) is tagged accordingly.

   Strict Dropping and Tagging:  Routes for which the prefix origin
       validation state is "invalid" or "not found" (according to
       [RFC6811]) are dropped by the validating BGP speaker.  Based on
       the remaining set of routes, the BGP best path selection
       algorithm is executed.  The prefix origin validation state of
       "valid" is tagged to the advertised route.

   A validating BGP speaker MUST support the Dropping and Tagging
   operation mode.  Other modes of operation are OPTIONAL.  The mode of
   operation MAY be configured by the validating BGP speaker operator
   for all connected peers, or for each BGP session with a peer
   separately.

   Path hiding, as originally discussed in [RFC7947], may impact end-to-
   end connectivity for peers receiving prefixes via validating BGP
   speakers, if the best path selected contains a prefix with a prefix
   origin validation state which is subsequently dropped.

   However, these modes of operation might be used in combination with
   any options discussed in Section 2.3.2 of [RFC7947] in order to allow
   a peer to receive one or more routes and take the routing decision by
   itself, or with implementations who support sending the next best
   available path.

4.  Signaling Prefix Origin Validation Results from a Validating Peer to
    Peers

   The EBGP Prefix Origin Validation State Community is utilized for
   signaling prefix origin validation result from a validating BGP
   speaker to other peers.



King, et al.            Expires January 24, 2020                [Page 4]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


   This draft proposes an encoding of the prefix origin validation
   result [RFC6811] as follows:

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

                                  Table 1

   This encoding is re-used.  Validating peers providing RPKI-based
   prefix origin validation set the validation state according to the
   prefix origin validation result (see [RFC6811]).

5.  Operational Recommendations

5.1.  Local Routing Decision Process

   A peer receiving prefix origin validation results from the route
   server MAY use the information in its own local routing decision
   process.  The local routing decision process SHOULD apply to the
   rules as described in Section 5 [RFC6811].

   A peer receiving a prefix origin validation result from the route
   server MAY redistribute this information within its own AS.

   In cases where multiple ASes are being administered by the same
   authority, peers MAY also redistribute this information across EBGP
   boundaries of the authority in question.

5.2.  Validating Peers Receiving the EBGP Prefix Origin Validation State
      Large Community

   A validating BGP speaker receiving routes from peers containing the
   EBGP Prefix Origin Validation State Large Community MUST remove the
   large community before the route is re-distributed to its peers.
   This is required regardless of whether the validating BGP speaker is
   executing prefix origin validation or not.

   Failure to do so would allow opportunistic peers to advertise routes
   tagged with arbitrary prefix origin validation results via validating
   peers, influencing maliciously the decision process of other, non-
   validating BGP speakers.





King, et al.            Expires January 24, 2020                [Page 5]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


5.3.  Information about Validity of a BGP Prefix Origin Not Available at
      a Validating Peer

   In case information about the validity of a BGP prefix origin is not
   available at the validating BGP speaker (e.g., error in the ROA
   cache, CPU overload) the validating BGP speaker MUST NOT add the EBGP
   Prefix Origin Validation State Large Community to the route.

5.4.  Error Handling at Peers

   A route sent by a validating BGP speaker SHOULD only contain none or
   one EBGP Prefix Origin Validation State Large Community.

   A peer receiving a route from a validating BGP speaker containing
   more than one EBGP Prefix Origin Validation State Large Community
   SHOULD only consider the largest value (as described in Table 1) in
   the validation result field and disregard the other values.  Values
   larger than two in the validation result field MUST be disregarded.

6.  Security Considerations

   All security considerations described in RFC6811 [RFC6811] fully
   apply to this document.

   Additionally, threat agents polluting ROA cache server(s) run by AS
   operators could cause significant operational impact, since multiple
   validating BGP speaker clients could be affected.  Peers should be
   vigilant as to the integrity and authenticity of the origin
   validation results as they are provided by a third party, namely the
   AS operator hosting both the validating BGP speaker as well as any
   ROA cache server(s).

   Therefore, a validating BGP speaker could be misused to spread
   malicious prefix origin validation results.  However, in the case of
   IXPs, peers already trust the route server for the collection,
   filtering (e.g., IRR database filtering), and redistribution of BGP
   routing information to other peers.

   To facilitate trust and support with peers establishing appropriate
   controls in mitigating the risks mentioned above, AS operators SHOULD
   provide out-of-band means for peers to ensure that the ROA validation
   process has not been compromised or corrupted.

7.  References







King, et al.            Expires January 24, 2020                [Page 6]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


7.1.  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>.

   [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>.

   [RFC7153]  Rosen, E. and Y. Rekhter, "IANA Registries for BGP
              Extended Communities", RFC 7153, DOI 10.17487/RFC7153,
              March 2014, <https://www.rfc-editor.org/info/rfc7153>.

   [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,
              <https://www.rfc-editor.org/info/rfc7606>.

   [RFC8092]  Heitz, J., Ed., Snijders, J., Ed., Patel, K., Bagdonas,
              I., and N. Hilliard, "BGP Large Communities Attribute",
              RFC 8092, DOI 10.17487/RFC8092, February 2017,
              <https://www.rfc-editor.org/info/rfc8092>.

   [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>.

7.2.  Informative References

   [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>.

   [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>.

Authors' Addresses









King, et al.            Expires January 24, 2020                [Page 7]


Internet-DraSignaling Prefix Origin Validation Results from a  July 2019


   Thomas King
   DE-CIX Management GmbH
   Lichtstrasse 43i
   Cologne  50825
   DE

   Email: thomas.king@de-cix.net


   Christoph Dietzel
   DE-CIX Management GmbH
   Lichtstrasse 43i
   Cologne  50825
   DE

   Email: christoph.dietzel@de-cix.net


   Daniel Kopp
   DE-CIX Management GmbH
   Lichtstrasse 43i
   Cologne  50825
   DE

   Email: daniel.kopp@de-cix.net


   Aristidis Lambrianidis
   Amsterdam Internet Exchange
   Frederiksplein 42
   Amsterdam  1017 XN
   NL

   Email: aristidis.lambrianidis@ams-ix.net

















King, et al.            Expires January 24, 2020                [Page 8]


Html markup produced by rfcmarkup 1.129c, available from https://tools.ietf.org/tools/rfcmarkup/