Internet DRAFT - draft-ietf-sidrops-ov-clarify
draft-ietf-sidrops-ov-clarify
Network Working Group R. Bush
Internet-Draft Internet Initiative Japan
Updates: 6811 (if approved) August 20, 2018
Intended status: Standards Track
Expires: February 21, 2019
BGP RPKI-Based Origin Validation Clarifications
draft-ietf-sidrops-ov-clarify-05
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 RFC 6811 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 21, 2019.
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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 is
set to 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 which seem 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 should be evaluated and have their evaluation
state set, 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
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potential source; and is therefore liable to complaints from
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 MUST 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.
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8. Normative 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,
<http://www.rfc-editor.org/info/rfc4271>.
[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>.
[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>.
[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,
<http://www.rfc-editor.org/info/rfc8097>.
[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>.
Author's Address
Randy Bush
Internet Initiative Japan
5147 Crystal Springs
Bainbridge Island, Washington 98110
US
Email: randy@psg.com
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