Internet DRAFT - draft-ymbk-sidrops-ov-clarify
draft-ymbk-sidrops-ov-clarify
Network Working Group R. Bush
Internet-Draft Internet Initiative Japan
Intended status: Standards Track July 30, 2017
Expires: January 31, 2018
Origin Validation Clarifications
draft-ymbk-sidrops-ov-clarify-01
Abstract
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.
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 [RFC2119] 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.
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This Internet-Draft will expire on January 31, 2018.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Internet-Draft Origin Validation Clarifications July 2017
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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, origin validation marks the
announcement as NotFound, Valid, or Invalid per [RFC6811].
Operational testing has shown that the specifications of that RFC
must be unclear. 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 mark 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. Mark ALL Prefixes
An operator should not have to hear from their neighbor that they
announced an Invalid route. Their routers should tell them before
announcing the Invalid route to a neighbor. 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."
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[RFC6811] goes on to say "An implementation MAY provide configuration
options to control which routes the lookup is applied to."
Significant Clarification: In the absence of the operator applying
such policy, ALL routes in BGP MUST be marked.
This means that, on a router, all routes in BGP, absent operator
configuration otherwise, MUST have been marked because they were
either received via BGP (whether eBGP or iBGP), redistributed from an
IGP, static, or directly connected, or any other distribution into
BGP.
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. Marking not Acting
Significant Clarification: Once routes are marked, the operator
should be in complete control of any policy applied based the
markings. Absent operator configuration, policy MUST NOT be applied.
Automatic 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.
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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>.
[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>.
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,
<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>.
Author's Address
Randy Bush
Internet Initiative Japan
5147 Crystal Springs
Bainbridge Island, Washington 98110
US
Email: randy@psg.com
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