Internet DRAFT - draft-ietf-sidrops-ov-egress
draft-ietf-sidrops-ov-egress
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.
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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],
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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.
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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>.
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[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
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