Network Working Group R. Bush Internet-Draft Internet Initiative Japan Updates: 6811 (if approved) August 10, 2018 Intended status: Standards Track Expires: February 11, 2019 BGP RPKI-Based Origin Validation Clarifications draft-ietf-sidrops-ov-clarify-04 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 RFC6811 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 11, 2019. Bush Expires February 11, 2019 [Page 1] Internet-DrafBGP RPKI-Based Origin Validation Clarifications August 2018 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 of the is set to as 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 seeming 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 to evaluate and set their evaluation state, 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 potential source; and is therefore liable to complaints from Bush Expires February 11, 2019 [Page 2] Internet-DrafBGP RPKI-Based Origin Validation Clarifications August 2018 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 SHOULD 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. Bush Expires February 11, 2019 [Page 3] Internet-DrafBGP RPKI-Based Origin Validation Clarifications August 2018 8. References 8.1. Normative References [RFC6482] Lepinski, M., Kent, S., and D. Kong, "A Profile for Route Origin Authorizations (ROAs)", RFC 6482, DOI 10.17487/RFC6482, February 2012, . [RFC6811] Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R. Austein, "BGP Prefix Origin Validation", RFC 6811, DOI 10.17487/RFC6811, January 2013, . [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, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . 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, . [RFC6480] Lepinski, M. and S. Kent, "An Infrastructure to Support Secure Internet Routing", RFC 6480, DOI 10.17487/RFC6480, February 2012, . Author's Address Randy Bush Internet Initiative Japan 5147 Crystal Springs Bainbridge Island, Washington 98110 US Email: randy@psg.com Bush Expires February 11, 2019 [Page 4]