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.
February
March 2017
BGP Prefix Origin Validation State Extended Community
Abstract
This document defines a new BGP opaque extended community to carry
the origination AS 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.
Copyright Notice
Copyright (c) 2017 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 3
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2 3
2. Origin Validation State Extended Community . . . . . . . . . 2 3
3. Deployment Considerations . . . . . . . . . . . . . . . . . . 3 4
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. Security Considerations . . . . . . . . . . . . . . . . . . . 4
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 4 5
6.2. Informative References . . . . . . . . . . . . . . . . . 5
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 5 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 6
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
community. Similarly, on the a receiving IBGP speakers, BGP speaker, in the absence of
validation state of an IBGP route set based on local data, SHOULD be derived directly 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 selection in the same way as
what would have been enabled by
that an implementation of this extension. 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.
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 propagation path TCP connection between the two routers should also
be considered. See Section 5.1 of [RFC7454] for advice regarding
protection of the propagation path. 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>.
[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>.
[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>.
[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: mpradosh@yahoo.com
Keyur Patel
Arrcus, Inc.
Email: keyur@arrcus.com
John Scudder
Juniper Networks
1194 N. Mathilda Ave
Sunnyvale, CA 94089
Email: jgs@juniper.net
Dave Ward
Cisco
170 W. Tasman Drive
San Jose, CA 95124
Email: dward@cisco.com
Randy Bush
Internet Initiative Japan, Inc.
5147 Crystal Springs
Bainbridge Island, WA 98110
Email: randy@psg.com