Network Working Group R. Bush Internet-Draft Internet Initiative Japan & Arrcus Updates: 6811 (if approved) R. Volk Intended status: Standards Track Deutsche Telekom Expires: October 10, 2020 J. Heitz Cisco April 8, 2020 BGP RPKI-Based Origin Validation on Export draft-ietf-sidrops-ov-egress-04 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. This document updates [RFC6811]. 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 October 10, 2020. Bush, et al. Expires October 10, 2020 [Page 1]
Internet-Draft BGP RPKI-Based Origin Validation on Export April 2020 Copyright Notice Copyright (c) 2020 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. 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 8.1. Normative References . . . . . . . . . . . . . . . . . . 4 8.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction This document does not change the protocol or semantics of [RFC6811], BGP prefix origin validation. It highlights an important use case of origin validation in eBGP egress policies, explaining specifics of correct implementation in this context. The term 'effective origin AS' as used in this document refers to the Route Origin ASN [RFC6811] of the UPDATE to be sent to neighboring BGP speakers. The effective origin AS of a BGP UPDATE is decided by configuration and outbound policy of the BGP speaker. A validating BGP speaker MUST apply Route Origin Validation policy semantics (see [RFC6811] Sec 2 and [RFC8481] Sec 4) after applying any egress configuration and policy. This effective origin AS of the announcement might be affected by removal of private ASs, confederation [RFC5065], migration [RFC7705], Bush, et al. Expires October 10, 2020 [Page 2]
Internet-Draft BGP RPKI-Based Origin Validation on Export April 2020 etc. Any AS_PATH modifications resulting in effective origin AS 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 MUST 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 effective origin AS may not be easily determined before the outbound policies have been run. It SHOULD be possible to specify a selective origin validation policy to be applied after any existing non-validating outbound policies. An implementation SHOULD be able to list announcements that were not sent to a peer, e.g., 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]. By facilitating more correct validation, it attempts to improve BGP reliability. Bush, et al. Expires October 10, 2020 [Page 3]
Internet-Draft BGP RPKI-Based Origin Validation on Export April 2020 6. IANA Considerations This document has no IANA Considerations. 7. Acknowledgments Thanks to reviews and comments from Linda Dunbar, Nick Hilliard, Benjamin Kaduk, Chris Morrow, Keyur Patel, Alvaro Retana, Alvaro Retana, Job Snijders, Robert Sparks, and Robert Wilton. 8. References 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>. [RFC5065] Traina, P., McPherson, D., and J. Scudder, "Autonomous System Confederations for BGP", RFC 5065, DOI 10.17487/RFC5065, August 2007, <http://www.rfc-editor.org/info/rfc5065>. [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>. [RFC7705] George, W. and S. Amante, "Autonomous System Migration Mechanisms and Their Effects on the BGP AS_PATH Attribute", RFC 7705, DOI 10.17487/RFC7705, November 2015, <http://www.rfc-editor.org/info/rfc7705>. [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>. Bush, et al. Expires October 10, 2020 [Page 4]
Internet-Draft BGP RPKI-Based Origin Validation on Export April 2020 [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>. 8.2. Informative References [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 Bush, et al. Expires October 10, 2020 [Page 5]
