Network Working Group K. Patel Internet-Draft Cisco Systems Intended status: Standards Track R. Raszuk Expires: December 2, 2016 Bloomberg LP M. Djernaes Juniper Networks J. Dong M. Chen Huawei Technologies May 31, 2016 IPv6 Extensions for Route Target Distribution draft-ietf-idr-bgp-ipv6-rt-constrain-09 Abstract The current route target distribution specification as described in [RFC 4684] defines Route Target NLRIs of maximum length of 12 bytes. The IPv6 specific Route Target extended community is defined in [RFC 5701] as length of 20 bytes. Since the current specification only supports prefixes of maximum length of 12 bytes, the lack of an IPv6 specific Route Target reachability information may be a problem when an operator wants to use this application in a pure IPv6 environment. This document defines an extension that allows BGP to exchange longer length IPv6 Route Target prefixes. 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]. 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 http://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." Patel, et al. Expires December 2, 2016 [Page 1] Internet-Draft IPv6 Extensions for RT Distribution May 2016 This Internet-Draft will expire on December 2, 2016. Copyright Notice Copyright (c) 2016 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 . . . . . . . . . . . . . . . . . . . . . . . . 2 2. BGP IPv6 Constrained Route Target Capability . . . . . . . . 3 3. IPv6 Constrained Route Target NLRI Advertisements . . . . . . 3 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 4 6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4 7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4 7.1. Normative References . . . . . . . . . . . . . . . . . . 4 7.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction The current constrained route distribution specification defined in [RFC4684] supports prefixes with a maximum length of 12 bytes. The prefix length needs to be extended to support the IPv6 specific Route Target extended community defined in [RFC5701] which is 20 bytes in length. This document defines an extension to the current constrained route distribution specification that allows BGP speakers to distribute longer length Route Target prefixes. A new BGP capability known as BGP IPv6 Constrained Route Target capability is defined as part of extension that allows an exchange of longer length Route Target prefixes. BGP speakers that do not exchange this capability MUST use Route Target NLRIs of maximum length of 12 bytes. In this way, the current extension would preserve the backward compatibility with [RFC4684]. Patel, et al. Expires December 2, 2016 [Page 2] Internet-Draft IPv6 Extensions for RT Distribution May 2016 2. BGP IPv6 Constrained Route Target Capability The "BGP IPV6 Constrained Route Target Capability" is a new BGP capability [RFC5492]. The Capability code for this capability is specified in the IANA Considerations section of this document. The Capability length field of this capability is zero. By advertising this capability to a peer, a BGP speaker conveys to the peer that the speaker support the longer length Route Target prefixes and the related procedures described in this document. 3. IPv6 Constrained Route Target NLRI Advertisements Route Target membership NLRI is advertised in BGP UPDATE messages using the MP_REACH_NLRI and MP_UNREACH_NLRI attributes as defined in [RFC4760]. The NLRI field in the MP_REACH_NLRI and MP_UNREACH_NLRI is a prefix of 0 to 24 octets, encoded as defined in Section 4 of [RFC4760] for all the constrained route distribution. This prefix is structured as follows: +-------------------------------+ | origin as (4 octets) | +-------------------------------+ | route target (8 or 20 octets)| ~ ~ | | +-------------------------------+ Except for the default route target, which is encoded as a zero- length prefix, the minimum prefix length is 32 bits. As the origin- AS field cannot be interpreted as a prefix. Route targets can then be expressed as prefixes, where, for instance, a prefix would encompass all route target extended communities assigned by a given Global Administrator [RFC4360] and [RFC5701]. Alternatively, route target prefixes could be aggregated however if done so, then only the Local Administrator field of the Route Target can be aggregated. Route Target Type and the Global Administrator Route Target fields MUST not be aggregated. The default route target can be used to indicate to a peer the willingness to receive all VPN route advertisements such as, for instance, the case of a route reflector speaking to one of its PE router clients. Patel, et al. Expires December 2, 2016 [Page 3] Internet-Draft IPv6 Extensions for RT Distribution May 2016 4. IANA Considerations This document defined the IPv6 Constrained Route Target Capability for BGP. The Capability code needs to be assigned by the IANA. 5. Security Considerations This extension to [RFC4684] does not change the underlying security issues inherent in the existing BGP and [RFC4684]. 6. Acknowledgements The authors would like to thank Pedro Marques, John Scudder, Alton Lo and Zhenqiang Li for discussions and review. 7. References 7.1. 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, . [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, . [RFC4360] Sangli, S., Tappan, D., and Y. Rekhter, "BGP Extended Communities Attribute", RFC 4360, DOI 10.17487/RFC4360, February 2006, . [RFC4684] Marques, P., Bonica, R., Fang, L., Martini, L., Raszuk, R., Patel, K., and J. Guichard, "Constrained Route Distribution for Border Gateway Protocol/MultiProtocol Label Switching (BGP/MPLS) Internet Protocol (IP) Virtual Private Networks (VPNs)", RFC 4684, DOI 10.17487/RFC4684, November 2006, . [RFC5492] Scudder, J. and R. Chandra, "Capabilities Advertisement with BGP-4", RFC 5492, DOI 10.17487/RFC5492, February 2009, . [RFC5701] Rekhter, Y., "IPv6 Address Specific BGP Extended Community Attribute", RFC 5701, DOI 10.17487/RFC5701, November 2009, . Patel, et al. Expires December 2, 2016 [Page 4] Internet-Draft IPv6 Extensions for RT Distribution May 2016 7.2. Informative References [RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter, "Multiprotocol Extensions for BGP-4", RFC 4760, DOI 10.17487/RFC4760, January 2007, . Authors' Addresses Keyur Patel Cisco Systems 170 W. Tasman Drive San Jose, CA 95134 USA Email: keyupate@cisco.com Robert Raszuk Bloomberg LP 731 Lexington Ave New York City, NY 10022 USA Email: robert@raszuk.net Martin Djernaes Juniper Networks 1194 N. Mathilda Avenue Sunnyvale, CA 94089 USA Email: mdjernaes@juniper.net Jie Dong Huawei Technologies Huawei Campus, No.156 Beiqing Rd. Beijing 100095 China Email: jie.dong@huawei.com Patel, et al. Expires December 2, 2016 [Page 5] Internet-Draft IPv6 Extensions for RT Distribution May 2016 Mach(Guoyi) Chen Huawei Technologies Huawei Campus, No.156 Beiqing Rd. Beijing 100095 China Email: mach.chen@huawei.com Patel, et al. Expires December 2, 2016 [Page 6]