TRILL Working Group Lucy Yong INTERNET-DRAFT Donald Eastlake Intended status: Proposed Standard Sam Aldrin Huawei Technologies Jon Hudson Brocade Expires: May 13, 2014 November 14, 2013 Transport of TRILL Using Pseudowires Abstract This document specifies how to interconnect a pair of TRILL (Transparent Interconnection of Lots of Links) switch ports using pseudowires under existing TRILL and PWE3 (Pseudowire Emulation End- to-End) standards. Status of This Memo This Internet-Draft is submitted to IETF in full conformance with the provisions of BCP 78 and BCP 79. Distribution of this document is unlimited. Comments should be sent to the authors. 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/1id-abstracts.html. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. L. Yong, et al [Page 1] INTERNET-DRAFT PWE3 TRILL Transport Table of Contents 1. Introduction............................................3 1.1 Conventions used in this document......................3 2. PWE3 Interconnection of TRILL Switches..................4 2.1 PWE3 Type Independent Details..........................4 2.2 PPP PWE3 Transport of TRILL............................5 3. IANA Considerations.....................................7 4. Security Considerations.................................7 Appendix A: Use of Other Pseudowire Types..................8 Appendix Z: Change History................................10 Acknowledgements..........................................11 Normative References......................................11 Informative References....................................12 Authors' Addresses........................................13 L. Yong, et al [Page 2] INTERNET-DRAFT PWE3 TRILL Transport 1. Introduction The IETF has standardized the TRILL (Transparent Interconnection of Lots of Links) protocol [RFC6325] that provides optimal pair-wise data frame routing without configuration in multi-hop networks with arbitrary topology. TRILL supports multipathing of both unicast and multicast traffic. Devices that implement TRILL are called TRILL Switches or RBridges (Routing Bridges). Links between TRILL Switches can be based on arbitrary link protocols, for example PPP [RFC6361], as well as Ethernet [RFC6325]. A set of connected TRILL Switches together form a TRILL campus which is bounded by end stations and layer 3 routers. This document specifies how to interconnect a pair of TRILL Switch ports using a pseudowire under existing TRILL and PWE3 (Pseudowire Emulation End-to-End) standards. 1.1 Conventions used in this document 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]. Acronyms used in this document include the following: IS-IS - Intermediate System to Intermediate System [IS-IS] MPLS - Multi-Protocol Label Switching PPP - Point-to-Point Protocol [RFC1661] PW - Pseudowire [RFC3985] PWE3 - PW Emulation End-to-End RBridge - Routing Bridge, an alternative name for a TRILL Switch TRILL - Transparent Interconnection of Lots of Links [RFC6325] TRILL Switch - A device implementing the TRILL protocol L. Yong, et al [Page 3] INTERNET-DRAFT PWE3 TRILL Transport 2. PWE3 Interconnection of TRILL Switches When a pseudowire is used to interconnect a pair of TRILL Switch ports, a PPP [RFC4618] pseudowire is used as described below. The pseudowire between such ports can be auto-configured [RFC4447] or manually configured. In this context, the TRILL Switch ports at the ends of the pseudowire are acting as native service processing elements (NSP [RFC3985]) and, assuming the pseudowires are over MPLS or IP [RFC4023] networks, as label switched or IP routers at the TRILL Switch ports. Pseudowires provide transparent transport and the two TRILL Switch ports appear directly interconnected with a transparent link. With such an interconnection the TRILL adjacency over the link is automatically discovered and established through TRILL IS-IS control messages [RFC6327bis]. A pseudowire is carried over a packet switched network tunnel [RFC3985]. For example, an MPLS or MPLS-TP label switched path tunnel in MPLS networks. Either a signaling protocol or manual configuration can be used to configure a label switched path tunnel between two TRILL Switch ports. This application needs no additions to the existing pseudowire standards. 2.1 PWE3 Type Independent Details The sending pseudowire TRILL Switch port MUST copy the priority of the TRILL Data packets being sent to the 3-bit Traffic Class field of the pseudowire label [RFC5462] so the priority will be visible to pseudowire transit devices and they can take the priority into account. TRILL IS-IS PDUs critical to establishing and maintaining adjacency (Hello and MTU PDUs) SHOULD be send with Traffic Class 7 while other TRILL IS-IS PDUs SHOULD be sent with Traffic Class 6. If a pseudowire supports fragmentation and re-assembly, there is no reason to do TRILL MTU testing on it and the pseudowire will not be a constraint on the TRILL campus wide Sz (see Section 4.3.1 [RFC6325]). If the pseudowire does not support fragmentation, then the available TRILL IS-IS packet payload size over the pseudowire (taking into account MPLS encapsulation with a control word) or some lower value, MUST be used in helping to determine Sz (see Section 5 [ClearCorrect]). An intervening MPLS label switched router or similar packet switched network device has no awareness of TRILL. Such devices will not change the TRILL Header hop count. L. Yong, et al [Page 4] INTERNET-DRAFT PWE3 TRILL Transport 2.2 PPP PWE3 Transport of TRILL For a PPP pseudowire (PW type = 0x0007), the two TRILL Switch ports being connected are configured to form a pseudowire with PPP encapsulation [RFC4618]. After the pseudowire is established and TRILL use is negotiated within PPP, the two TRILL Switch ports appear directly connected with a PPP link [RFC1661] [RFC6361]. If pseudowire interconnection of two TRILL Switch ports is auto- configured [RFC4447], the initiating TRILL Switch port MUST attempt the connection set-up with pseudowire type PPP (0x0007). Behavior for TRILL with a PPP pseudowire continues to follow that of TRILL over PPP as specified in Section 3 of [RFC6361]. The following figures show what a TRILL Data and TRILL IS-IS packet look like over such a pseudowire in the MPLS case assuming no TRILL Header extensions: +-------------------------------+ | Server MPLS Tunnel Label(s) | n*4 octets (4 octets per label) +-------------------------------+ | PW Label | 4 octets +-------------------------------+ | Control Word | 4 octets +-------------------------------+ | PPP Header 0x005d | 2 octets +-------------------------------+ | TRILL Header | 4 octets +-------------------------------+ | Destination MAC Address | 6 octets +-------------------------------+ | Source MAC Address | 6 octets +-------------------------------+ | Data Label | 4 or 8 octets +-------------------------------+ | Payload Body | variable +-------------------------------+ Figure 1. TRILL Data Packet in Pseudowire "Data Label" is the VLAN Label or Fine Grained Label [FGL] of the payload. L. Yong, et al [Page 5] INTERNET-DRAFT PWE3 TRILL Transport +-------------------------------+ | Server MPLS Tunnel Label(s) | n*4 octets (4 octets per label) +-------------------------------+ | PW Label | 4 octets +-------------------------------+ | Control Word | 4 octets +-------------------------------+ | PPP Header 0x405d | 2 octets +-------------------------------+ | Common IS-IS Header | 8 octets +-------------------------------+ | IS-IS PDU Type Specifc Header | variable +-------------------------------+ | IS-IS TLVs | variable +-------------------------------+ Figure 2. TRILL IS-IS Packet in Pseudowire L. Yong, et al [Page 6] INTERNET-DRAFT PWE3 TRILL Transport 3. IANA Considerations No IANA actions are required by this document. RFC Editor: Please remove this section before publication. 4. Security Considerations For PPP link TRILL security considerations, see [RFC6361]. For security considerations introduced by carrying PPP TRILL links over pseudowires, see [RFC3985]. Not all implementations need to include specific security mechanisms at the pseudowire layer, for example if they are designed to be deployed only in cases where the networking environment is trusted or where other layers provide adequate security. A complete enumeration of possible deployment scenarios and associated threats and options is not possible and is outside the scope of this document. For applications involving sensitive data, end-to-end security should always be considered, in addition to link security, to provide security in depth. In this context, such end-to-end security should be between the end stations involved so as to protect the entire path to, through, and from the TRILL campus. For general TRILL protocol security considerations, see [RFC6325]. L. Yong, et al [Page 7] INTERNET-DRAFT PWE3 TRILL Transport Appendix A: Use of Other Pseudowire Types This informational Appendix briefly discusses use of pseudowire types other than PPP for the transport of TRILL. The use of Ethernet pseudowires [RFC4448] was examined by the authors and would be possible; however, they would require an additional 12 or 16 bytes per packet as shown in the following figures for a TRILL Data and TRILL IS-IS packet over such an Ethernet pseudowire in the MPLS case assuming no TRILL Header extensions (compare with Figures 1 and 2): +-------------------------------+ | Server MPLS Tunnel Label(s) | n*4 octets (4 octets per label) +-------------------------------+ | PW Label | 4 octets +-------------------------------+ | Optional Control Word | 4 octets +-------------------------------+ | TRILL Hop Dest. MAC Address | 6 octets +-------------------------------+ | TRILL Hop Source MAC Address | 6 octets +-------------------------------+ |Optional VLAN and/or other tags| variable +-------------------------------+ | TRILL Ethertype (0x22f3) | 2 octets +-------------------------------+ | TRILL Header | 4 octets +-------------------------------+ | Destination MAC Address | 6 octets +-------------------------------+ | Source MAC Address | 6 octets +-------------------------------+ | Data Label | 4 or 8 octets +-------------------------------+ | Payload Body | variable +-------------------------------+ Figure 3. TRILL Data Packet in Ethernet Pseudowire "Data Label" is the VLAN Label or Fine Grained Label [FGL] of the payload. L. Yong, et al [Page 8] INTERNET-DRAFT PWE3 TRILL Transport +-------------------------------+ | Server MPLS Tunnel Label(s) | n*4 octets (4 octets per label) +-------------------------------+ | PW Label | 4 octets +-------------------------------+ | Optional Control Word | 4 octets +-------------------------------+ | TRILL Hop Dest. MAC Address | 6 octets +-------------------------------+ | TRILL Hop Source MAC Address | 6 octets +-------------------------------+ |Optional VLAN and/or other tags| variable +-------------------------------+ |Layer 2 IS-IS Ethertype 0x22f4 | 2 octets +-------------------------------+ | Commmon IS-IS Header | 8 octets +-------------------------------+ | IS-IS PDU Type Specifc Header | variable +-------------------------------+ | IS-IS TLVs | variable +-------------------------------+ Figure 4. TRILL IS-IS Packet in Ethernet Pseudowire It would also be possible to specify a new pseudowire type for TRILL traffic but the authors feel that any efficiency gain over PPP pseudowires would be too small to be worth the complexity of adding such a specification. Furthermore using PPP pseudowire encoding means that any traffic dissector that understands TRILL PPP encoding [RFC6361] and understands PPP pseudowires [RFC4618] will automatically be able to recursively decode TRILL transported by pseudowire. L. Yong, et al [Page 9] INTERNET-DRAFT PWE3 TRILL Transport Appendix Z: Change History From -00 to -01 Add information on Traffic Classes that should be used for TRILL IS- IS PDUs. Other changes to resolve WG Last Call comments: Change title from "TRILL Over Psuedowires". Change "Class of Service" to "Traffic Class". Expand informational paragraph about the consideration of using other pseudowire types for the transport of TRILL and make that paragraph into Appendix A. Add this Change History Appendix Z. From -01 to -02 Add packet diagrams. Minor editing changes. L. Yong, et al [Page 10] INTERNET-DRAFT PWE3 TRILL Transport Acknowledgements Thanks for the valuable comments from the following: Yaakov (J) Stein The document was prepared in raw nroff. All macros used were defined within the source file. Normative References [RFC1661] - Simpson, W., Ed., "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661, July 1994. [RFC2119] - Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4447] - Martini, L., Ed., Rosen, E., El-Aawar, N., Smith, T., and G. Heron, "Pseudowire Setup and Maintenance Using the Label Distribution Protocol (LDP)", RFC 4447, April 2006. [RFC4618] - Martini, L., "Encapsulation Methods for Transport of PPP/High-Level Data Link Control (HDLC) over MPLS Networks", BCP 116, RFC 4618, September 2006. [RFC5462] - Andersson, L. and R. Asati, "Multiprotocol Label Switching (MPLS) Label Stack Entry: "EXP" Field Renamed to "Traffic Class" Field", RFC 5462, February 2009. [RFC6325] - Perlman, R., Eastlake 3rd, D., Dutt, D., Gai, S., and A. Ghanwani, "Routing Bridges (RBridges): Base Protocol Specification", RFC6325, July 2011. [RFC6361] - Carlson, J., and D. Eastlake, "PPP Transparent Interconnection of Lots of Links (TRILL) Protocol Control Protocol", RFC6361, August 2011. [ClearCorrect] - Eastlake, D., M. Zhang, A. Ghanwani, V. Manral, and A. Banerjee, "TRILL: Clarifications, Corrections, and Updates", draft-ietf-trill-clear-correct, in RFC Editor's queue. [FGL] - D. Eastlake, M. Zhang, P. Agarwal, R. Perlman, D. Dutt, "TRILL (Transparent Interconnection of Lots of Links): Fine- Grained Labeling", draft-ietf-trill-fine-labeling, in RFC Editor's queue. L. Yong, et al [Page 11] INTERNET-DRAFT PWE3 TRILL Transport Informative References [IS-IS] - International Organization for Standardization, "Intermediate system to Intermediate system intra-domain routing information exchange protocol for use in conjunction with the protocol for providing the connectionless-mode Network Service (ISO 8473)", ISO/IEC10589:2002, Second Edition, Nov 2002 [RFC3985] - Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005. [RFC4023] - Worster, T., Rekhter, Y., and E. Rosen, Ed., "Encapsulating MPLS in IP or Generic Routing Encapsulation (GRE)", RFC 4023, March 2005. [RFC4448] - Martini, L., Ed., Rosen, E., El-Aawar, N., and G. Heron, "Encapsulation Methods for Transport of Ethernet over MPLS Networks", RFC 4448, April 2006. [RFC6327bis] - Eastlake 3rd, D., Perlman, R., Ghanwani, A., Howard, Y., and V. Manral, "TRILL: Adjacency", draft-ietf-trill- rfc6327bis, work in progress. L. Yong, et al [Page 12] INTERNET-DRAFT PWE3 TRILL Transport Authors' Addresses Lucy Yong Huawei Technologies 5340 Legacy Drive Plano, TX 75025 USA Phone: +1-469-227-5837 Email: lucy.yong@huawei.com Donald E. Eastlake, 3rd Huawei Technologies 155 Beaver Street Milford, MA 01757 USA Phone: +1-508-333-2270 Email: d3e3e3@gmail.com Sam Aldrin Huawei Technologies 2330 Central Expressway Santa Clara, CA 95050 USA Phone: +1-408-330-4517 Email: sam.aldrin@huawei.com Jon Hudson Brocade 130 Holger Way San Jose, CA 95134 USA Phone: +1-408-333-4062 jon.hudson@gmail.com L. Yong, et al [Page 13] INTERNET-DRAFT PWE3 TRILL Transport Copyright and IPR Provisions Copyright (c) 2013 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. The definitive version of an IETF Document is that published by, or under the auspices of, the IETF. Versions of IETF Documents that are published by third parties, including those that are translated into other languages, should not be considered to be definitive versions of IETF Documents. The definitive version of these Legal Provisions is that published by, or under the auspices of, the IETF. Versions of these Legal Provisions that are published by third parties, including those that are translated into other languages, should not be considered to be definitive versions of these Legal Provisions. For the avoidance of doubt, each Contributor to the IETF Standards Process licenses each Contribution that he or she makes as part of the IETF Standards Process to the IETF Trust pursuant to the provisions of RFC 5378. No language to the contrary, or terms, conditions or rights that differ from or are inconsistent with the rights and licenses granted under RFC 5378, shall have any effect and shall be null and void, whether published or posted by such Contributor, or included with or in such Contribution. L. Yong, et al [Page 14]