Network Working Group P. Mohapatra Internet-Draft K. Patel Intended status: Standards Track Cisco Systems Expires: October 28, 2010 J. Scudder D. Ward Juniper Networks R. Bush Internet Initiative Japan, Inc. April 26, 2010 BGP Prefix Origin Validation State Extended Community draft-pmohapat-sidr-origin-validation-signaling-00 Abstract As part of the origination AS validation process, it can be desirable to automatically consider the validation state of routes in the BGP decision process. The purpose of this document is to provide a specification for doing so. The document also defines a new BGP opaque extended community to carry the validation state inside an autonomous system to influence the decision process of the IBGP speakers. Status of this Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. 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." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on October 28, 2010. Copyright Notice Mohapatra, et al. Expires October 28, 2010 [Page 1] Internet-Draft BGP Prefix Origin Validation April 2010 Copyright (c) 2010 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 BSD License. This document may contain material from IETF Documents or IETF Contributions published or made publicly available before November 10, 2008. The person(s) controlling the copyright in some of this material may not have granted the IETF Trust the right to allow modifications of such material outside the IETF Standards Process. Without obtaining an adequate license from the person(s) controlling the copyright in such materials, this document may not be modified outside the IETF Standards Process, and derivative works of it may not be created outside the IETF Standards Process, except to format it for publication as an RFC or to translate it into languages other than English. Mohapatra, et al. Expires October 28, 2010 [Page 2] Internet-Draft BGP Prefix Origin Validation April 2010 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.1. Requirements Language . . . . . . . . . . . . . . . . . . . 4 2. Origin Validation State Extended Community . . . . . . . . . . 4 3. Changes to the BGP Decision Process . . . . . . . . . . . . . . 5 3.1. Policy Control . . . . . . . . . . . . . . . . . . . . . . 5 4. Deployment Considerations . . . . . . . . . . . . . . . . . . . 5 5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 7. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 8.2. Informative References . . . . . . . . . . . . . . . . . . 6 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 6 Mohapatra, et al. Expires October 28, 2010 [Page 3] Internet-Draft BGP Prefix Origin Validation April 2010 1. Introduction As part of the origination AS validation process, it can be desirable to automatically consider the validation state of routes in the BGP decision process. The purpose of this document is to provide a specification for doing so. The document defines a new BGP opaque extended community to carry the validation state inside an autonomous system to influence the decision process of the IBGP speakers. 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 | TBD | 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 for this community is TBD. The last octet of the extended community encodes the route's validation state([I-D.pmohapat-sidr-pfx-validate]. 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 draft, it SHOULD attach the origin validation state extended Mohapatra, et al. Expires October 28, 2010 [Page 4] Internet-Draft BGP Prefix Origin Validation April 2010 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 receiving IBGP speakers, the validation state of an IBGP route SHOULD be derived directly from the last octet of the extended community, if present. Note that routers do not perform prefix origin validation (compute the validation state as defined in [I-D.pmohapat-sidr-pfx-validate]) for IBGP learnt routes. Since the extended community is defined to be non-transitive, it MUST not be attached while advertising routes to EBGP peers. Additionally, if it is present in an UPDATE message received from an EBGP peer, the router MUST remove the origin validation state extended community before parsing rest of the message. 3. Changes to the BGP Decision Process If a BGP router supports prefix origin validation and is configured for the extensions defined in this document, the validation step MUST be performed prior to any of the steps defined in the decision process of [RFC4271]. The validation step is stated as follows: When comparing a pair of routes for a BGP destination, the route with the lowest "validation state" value is preferred. In all other respects, the decision process remains unchanged. 3.1. Policy Control It MUST be possible to enable or disable the validation step as defined in Section 3 through configuration. The default SHOULD be for the validation step to be disabled. 4. Deployment Considerations In deployment scenarios where 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 [I-D.pmohapat-sidr-pfx-validate] that influences the best path selection the same way as what would have been enabled by an implementation of this extension. 5. Acknowledgements Mohapatra, et al. Expires October 28, 2010 [Page 5] Internet-Draft BGP Prefix Origin Validation April 2010 6. IANA Considerations IANA shall assign a new value from the "BGP Opaque Extended Community" type registry from the non-transitive range, to be called "BGP Origin Validation State Extended Community". 7. Security Considerations 8. References 8.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4271] Rekhter, Y., Li, T., and S. Hares, "A Border Gateway Protocol 4 (BGP-4)", RFC 4271, January 2006. [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended Communities Attribute", RFC 4360, February 2006. 8.2. Informative References [I-D.pmohapat-sidr-pfx-validate] Mohapatra, P., Scudder, J., Ward, D., Bush, R., and R. Austein, "BGP Prefix Origin Validation", draft-pmohapat-sidr-pfx-validate-06 (work in progress), April 2010. Authors' Addresses Pradosh Mohapatra Cisco Systems 170 W. Tasman Drive San Jose, CA 95134 USA Email: pmohapat@cisco.com Mohapatra, et al. Expires October 28, 2010 [Page 6] Internet-Draft BGP Prefix Origin Validation April 2010 Keyur Patel Cisco Systems 170 W. Tasman Drive San Jose, CA 95134 USA Email: keyupate@cisco.com John Scudder Juniper Networks 1194 N. Mathilda Ave Sunnyvale, CA 94089 USA Email: jgs@juniper.net David Ward Juniper Networks 1194 N. Mathilda Ave Sunnyvale, CA 94089 USA Email: dward@juniper.net Randy Bush Internet Initiative Japan, Inc. 5147 Crystal Springs Bainbridge Island, Washington 98110 USA Email: randy@psg.com Mohapatra, et al. Expires October 28, 2010 [Page 7]