Internet Engineering Task Force (IETF) P. Mohapatra

Internet Engineering Task Force (IETF) P. Mohapatra
Request for Comments: 8097 Sproute Networks
Category: Standards Track K. Patel
ISSN: 2070-1721 Arrcus, Inc.
J. Scudder
Juniper Networks
D. Ward
Cisco
R. Bush
Internet Initiative Japan, Inc.
March 2017

BGP Prefix Origin Validation State Extended Community

Abstract

This document defines a new BGP opaque extended community to carry
the origination Autonomous System (AS) validation state inside an
autonomous system. Internal BGP (IBGP) speakers that receive this
validation state can configure local policies that allow it to
influence their decision process.

Status of This Memo

This is an Internet Standards Track document.

This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.

Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc8097.

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RFC 8097 Prefix Origin Validation State Ext. Comm. March 2017

Copyright Notice

Copyright (c) 2017 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
(http://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 . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 3
2. Origin Validation State Extended Community . . . . . . . . . 3
3. Deployment Considerations . . . . . . . . . . . . . . . . . . 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 6

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RFC 8097 Prefix Origin Validation State Ext. Comm. March 2017

1. Introduction

This document defines a new BGP opaque extended community to carry
the origination AS validation state inside an autonomous system.
IBGP speakers that receive this validation state can configure local
policies that allow it to influence their decision process.

1.1. Requirements Language

The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].

2. Origin Validation State Extended Community

The origin validation state extended community is an opaque extended
community [RFC4360] with the following encoding:

0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| 0x43 | 0x00 | Reserved |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reserved |validationstate|
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

The value of the high-order octet of the extended Type field is 0x43,
which indicates it is non-transitive. The value of the low-order
octet of the extended Type field as assigned by IANA is 0x00. The
Reserved field MUST be set to 0 and ignored upon the receipt of this
community. The last octet of the extended community is an unsigned
integer that gives the route's validation state [RFC6811]. It can
assume the following values:

+-------+-----------------------------+
| Value | Meaning |
+-------+-----------------------------+
| 0 | Lookup result = "valid" |
| 1 | Lookup result = "not found" |
| 2 | Lookup result = "invalid" |
+-------+-----------------------------+

If the router is configured to support the extensions defined in this
document, it SHOULD attach the origin validation state extended
community to BGP UPDATE messages sent to IBGP peers by mapping the
computed validation state in the last octet of the extended

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community. Similarly, a receiving BGP speaker, in the absence of
validation state set based on local data, SHOULD derive a validation
state from the last octet of the extended community, if present.

An implementation SHOULD NOT send more than one instance of the
origin validation state extended community. However, if more than
one instance is received, an implementation MUST disregard all
instances other than the one with the numerically greatest validation
state value. If the value received is greater than the largest
specified value (2), the implementation MUST apply a strategy similar
to attribute discard [RFC7606] by discarding the erroneous community
and logging the error for further analysis.

By default, implementations MUST drop the origin validation state
extended community if received from an External BGP (EBGP) peer,
without processing it further. Similarly, by default, an
implementation SHOULD NOT send the community to EBGP peers. However,
it SHOULD be possible to configure an implementation to send or
accept the community when warranted. An example of a case where the
community would reasonably be received from, or sent to, an EBGP peer
is when two adjacent ASes are under control of the same
administration. A second example is documented in [SIDR-RPKI].

3. Deployment Considerations

In deployment scenarios in which not all the speakers in an
autonomous system are upgraded to support the extensions defined in
this document, it is necessary to define policies that match on the
origin validation extended community and set another BGP attribute
[RFC6811] that influences selection of the best path in the same way
that an implementation of this extension would.

4. IANA Considerations

IANA has registered the value 0x00, with the name "BGP Origin
Validation State Extended Community", in the "Non-Transitive Opaque
Extended Community Sub-Types" registry.

5. Security Considerations

Security considerations such as those described in [RFC4272] continue
to apply. Because this document introduces an extended community
that will generally be used to affect route selection, the analysis
in Section 4.5 ("Falsification") of [RFC4593] is relevant. These
issues are neither new nor unique to the origin validation extended
community.

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The security considerations provided in [RFC6811] apply equally to
this application of origin validation. In addition, this document
describes a scheme where router A outsources validation to some
router B. If this scheme is used, the participating routers should
have the appropriate trust relationship -- B should trust A either
because they are under the same administrative control or for some
other reason (for example, consider [SIDR-RPKI]). The security
properties of the TCP connection between the two routers should also
be considered. See Section 5.1 of [RFC7454] for advice regarding
protection of the TCP connection.

6. References

6.1. 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>.

[RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended
Communities Attribute", RFC 4360, DOI 10.17487/RFC4360,
February 2006, <http://www.rfc-editor.org/info/rfc4360>.

[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>.

6.2. Informative References

[RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis",
RFC 4272, DOI 10.17487/RFC4272, January 2006,
<http://www.rfc-editor.org/info/rfc4272>.

[RFC4593] Barbir, A., Murphy, S., and Y. Yang, "Generic Threats to
Routing Protocols", RFC 4593, DOI 10.17487/RFC4593,
October 2006, <http://www.rfc-editor.org/info/rfc4593>.

[RFC7454] Durand, J., Pepelnjak, I., and G. Doering, "BGP
Operations and Security", BCP 194, RFC 7454,
DOI 10.17487/RFC7454, February 2015,
<http://www.rfc-editor.org/info/rfc7454>.

[RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K.
Patel, "Revised Error Handling for BGP UPDATE Messages",
RFC 7606, DOI 10.17487/RFC7606, August 2015,
<http://www.rfc-editor.org/info/rfc7606>.

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[SIDR-RPKI] King, T., Kopp, D., Lambrianidis, A., and A. Fenioux,
"Signaling Prefix Origin Validation Results from a Route-
Server to Peers", Work in Progress,
draft-ietf-sidrops-route-server-rpki-light-01, January
2017.

Acknowledgements

The authors would like to acknowledge the valuable review and
suggestions from Wesley George, Roque Gagliano, and Bruno Decraene on
this document.

Authors' Addresses

Pradosh Mohapatra
Sproute Networks
Email: [email protected]

Keyur Patel
Arrcus, Inc.
Email: [email protected]

John Scudder
Juniper Networks
1194 N. Mathilda Ave
Sunnyvale, CA 94089
United States of America
Email: [email protected]

Dave Ward
Cisco
170 W. Tasman Drive
San Jose, CA 95124
United States of America
Email: [email protected]

Randy Bush
Internet Initiative Japan, Inc.
5147 Crystal Springs
Bainbridge Island, WA 98110
United States of America
Email: [email protected]

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