BESS Working Group E. Rosen Internet-Draft Juniper Networks, Inc. Updates: 6514 (if approved) T. Morin Intended status: Standards Track Orange Expires: August 5, 2016 February 2, 2016 Registry and Extensions for P-Multicast Service Interface Tunnel Attribute Flags draft-ietf-bess-pta-flags-02.txt Abstract The BGP-based control procedures for Multicast Virtual Private Networks make use of a BGP attribute known as the "P-Multicast Service Interface (PMSI) Tunnel" attribute. The attribute contains a one-octet "Flags" field. The purpose of this document is to establish an IANA registry for the assignment of the bits in this field. Since the Flags field contains only eight bits, this document also defines a new BGP Extended Community, "Additional PMSI Tunnel Attribute Flags", that can be used to carry additional flags for the PMSI Tunnel attribute. This document updates RFC 6514. 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." This Internet-Draft will expire on August 5, 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 Rosen & Morin Expires August 5, 2016 [Page 1] Internet-Draft PMSI Tunnel Attribute Flags February 2016 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. Extending the PMSI Tunnel Attribute Flags Field . . . . . . . 2 3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3 4. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 4 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5 6. Normative References . . . . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction A BGP attribute known as the "P-Multicast Service Interface (PMSI) Tunnel" attribute is defined in [RFC6514]. This attribute contains a one-octet of "Flags" field. Only one flag is defined in that RFC, but there is now a need to define additional flags. However, that RFC did not create an IANA registry for the assignment of bits in the Flags field. This document creates a registry for that purpose. In addition, there may be a need to define more than eight flags. Therefore this document defines a new BGP Extended Community, "Additional PMSI Tunnel Attribute Flags", that can be used to carry additional flags for the PMSI Tunnel attribute. A registry is also created for this Extended Community, allowing IANA to assign bits from the Extended Community's six-octet value field. 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 [RFC2119]. 2. Extending the PMSI Tunnel Attribute Flags Field In [RFC6514], only a single octet in the PMSI Tunnel attribute is defined to carry bit flags. This allows eight flags, which is unlikely to be sufficient for all future applications. This document defines a new Transitive Opaque Extended Community, "Additional PMSI Tunnel Attribute Flags". It also defines a new bit flag in the PMSI Tunnel Attribute flags field, called the "Extension" flag. Rosen & Morin Expires August 5, 2016 [Page 2] Internet-Draft PMSI Tunnel Attribute Flags February 2016 The Additional PMSI Tunnel Attribute Flags Extended Community MUST NOT be carried by a given BGP UPDATE message unless the following conditions both hold: o the given BGP UPDATE message is also carrying a PMSI Tunnel attribute, and o the Extension flag of that PMSI Tunnel attribute's Flags field is set. If a given BGP UPDATE message is carrying a PMSI Tunnel attribute, but is not carrying an Additional PMSI Tunnel Attribute Flags Extended Community, then the Extension flag in the PMSI Tunnel attribute MUST be clear. If a BGP speaker receives an UPDATE message that contains an Additional PMSI Tunnel Attribute Flags Extended Community, but either (a) that UPDATE message does not contain a PMSI Tunnel attribute, or (b) the Extension flag of the PMSI Tunnel attribute is not set, then the Extended Community SHOULD be removed and SHOULD NOT be redistributed. The BGP UPDATE message MUST be processed (and if necessary, redistributed) as if the Extended Community had not been present. Suppose a BGP speaker receives an UPDATE message that contains a PMSI Tunnel attribute, but does not contain an Additional PMSI Tunnel Attribute Flags Extended Community. If the Extension flag of the PMSI Tunnel attribute is set, then the "treat-as-withdraw" procedure of [RFC7606] MUST be applied. 3. IANA Considerations IANA is requested to create a new registry called "P-Multicast Service Interface (PMSI) Tunnel Attribute Flags" in the "Border Gateway Protocol (BGP) Parameters" registry. Per [RFC6514] section 5, a PMSI Tunnel Attribute contains a "Flags" octet. The Flags field is a single octet, with bits numbered, left- to-right, from 0 to 7. IANA is requested to initialize the registry as follows: Rosen & Morin Expires August 5, 2016 [Page 3] Internet-Draft PMSI Tunnel Attribute Flags February 2016 Bit Position Description Reference (left to right) 0 unassigned 1 Extension This document 2 unassigned 3 unassigned 4 unassigned 5 unassigned 6 unassigned 7 Leaf Information Required (L) RFC6514 PMSI Tunnel Attribute Flags The registration procedure for this registry is Standards Action. IANA is also requested to assign a codepoint, from the "First Come, First Served" range of the Transitive Opaque Extended Community Sub- Types registry, for "Additional PMSI Tunnel Attribute Flags". [TO BE REMOVED: This registration should take place at the following location: http://www.iana.org/assignments/bgp-extended-communities /bgp-extended-communities.xhtml#trans-opaque] IANA is further requested to establish a registry for the bit flags carried in the Additional PMSI Tunnel Attribute Flags extended community. The bits shall be numbered 0-47, with 0 being the most significant bit and 47 being the least significant bit. The registration policy for this registry shall be "Standards Action". [TO BE REMOVED: The creation of the registry should take place at the following location: http://www.iana.org/assignments/bgp-extended- communities/bgp-extended-communities.xhtml] The initial registry should be as follows: Bit Flag Name Reference 0-47 unassigned Additional PMSI Tunnel Attribute Flags 4. Acknowledgments The authors wish to thank Martin Vigoureux for his review of this document. Rosen & Morin Expires August 5, 2016 [Page 4] Internet-Draft PMSI Tunnel Attribute Flags February 2016 5. Security Considerations This document establishes an IANA registry, and defines a new transitive opaque Extended Community. Establishment of an IANA registry does not raise any security considerations. While the document defines a new Extended Community for carrying bit flags, it does not define any of the bit flags in that Extended Community. Therefore no security considerations are raised. 6. 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, . [RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP Encodings and Procedures for Multicast in MPLS/BGP IP VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012, . [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, . Authors' Addresses Eric C. Rosen Juniper Networks, Inc. 10 Technology Park Drive Westford, Massachusetts 01886 United States Email: erosen@juniper.net Thomas Morin Orange 2, avenue Pierre-Marzin 22307 Lannion Cedex France Email: thomas.morin@orange.com Rosen & Morin Expires August 5, 2016 [Page 5]