TRILL Working Group Lucy Yong INTERNET-DRAFT Donald Eastlake Intended status: Proposed Standard Sam Aldrin Huawei Technologies Jon Hudson Brocade Expires: August 17, 2013 February 18, 2013 TRILL Over Pseudo Wires Abstract This document describes ways to interconnect a pair of TRILL (Transparent Interconnection of Lots of Links) switch ports with two types of pseudo wires 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 TRILL over PWE3 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 TRILL over PPP PWE3....................................4 2.3 TRILL over Ethernet PWE3...............................5 2.4 Preferable Pseudowire Type And Auto-Configuration......5 3. IANA Considerations.....................................6 4. Security Considerations.................................6 Acknowledgements...........................................7 Normative References.......................................7 Informative References.....................................7 Authors' Addresses.........................................9 L. Yong, et al [Page 2] INTERNET-DRAFT TRILL over PWE3 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). End stations are attached to TRILL switches with Ethernet. But 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 form a TRILL campus which is bounded by end stations and layer 3 routers. Such a campus may contain bridges. This document specified the use of two types of PWE3 (Pseudowire Emulation End-to-End) pseudowires as links between TRILL switches. It is assumed that such pseudowires are implemented with MPLS. 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 Systme [IS-IS] [RFC1195] MPLS - Multi-Protocol Label Switching PPP - Point-to-Point Protocol PW - Pseudowire 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 TRILL over PWE3 2. PWE3 Interconnection of TRILL Switches PPP [RFC4618] or Ethernet [RFC4448] pseudowires may be used to interconnect pairs of TRILL switch ports as described below. The pseudowire between such ports can be auto-configured [RFC4447] or manually configured. The TRILL switches, which are TRILL routers, are also acting as label switched routers for those TRILL switch ports. In both types, the pseudowire provides transparent transport and the two RBridges appear directly interconnected with a transparent link. With such an interconnection (and negotiation to use TRILL in the PPP case [RFC6361]), the TRILL adjacency over that link is automatically discovered and established through TRILL IS-IS control messages [RFC6325] [RFC6327]. 2.1 PWE3 Type Independent Details The sending pseudowire TRILL switch port MUST copy the priority of the TRILL packets being sent to the 3-bit Class of Service field of the pseudowire label [RFC5462] so the priority will be visible to transit devices that can take the priority into account. 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 device has no awareness of TRILL. Such devices will not change the TRILL Header hop count. 2.2 TRILL over PPP PWE3 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 negotatied within PPP, the two TRILL switches then appear directly connected with a PPP link [RFC1661]. Behavior for TRILL with a PPP pseudowire continues to follow that of TRILL over PPP as specified in Section 3 of [RFC6361]. L. Yong, et al [Page 4] INTERNET-DRAFT TRILL over PWE3 2.3 TRILL over Ethernet PWE3 For an Ethernet pseudowire, the two TRILL switch ports being connected are configured to form a pseudowire with Ethernet encapsulation [RFC4448]. The ports MUST use the Raw mode (PW type = 0x0005) and non-service-delimiting, to provide as transparent an Ethernet transport as practical. The two RBridges then appear directly interconnected with an Ethernet link [RFC6325]. Behavior for TRILL with an Ethernet psuedo wire continue to follow that over Ethernet as specified in [RFC6325] and [RFC6327]. 2.4 Preferable Pseudowire Type And Auto-Configuration Use of the PPP pseduowire type is preferable to the Ethernet pseudowire type for the connections discussed in this document. It saves 12 or 16 bytes on every TRILL packet. In particular, the Link Header in the PPP case is simply a 2-byte PPP code point while for the Ethernet case it is 14 or 18 bytes (Outer.MacDA (6), Outer.MacSA (6), sometimes Outer.VLAN (4), and TRILL Ethertype (2)). (While it would also be possible to specify a special custom pseudowire type for TRILL traffic, the authors feel that any efficiency gain over PPP pseudowires would be too small to be worth the complexity of adding such a specification.) If pseudowire interconnection of two TRILL switch ports is auto- configured [RFC4447] and the initiating RBridge port supports PPP pseudowires, it SHOULD initially attempt the connection set-up with PW type PPP (0x0007). If that pseudowire type is rejected, it SHOULD try again with the Ethernet PW type recommended above (0x0005) if it supports that type. If a responding RBridge port receives a set-up attempt specifying PPP, it SHOULD accept the connection if it supports PPP. If a responding RBridge port receives a set-up attempt specifying Ethernet (PW type = 0x0005), it SHOULD assume that the initiator does not aupport PPP and accept or reject the Ethernet set- up attempt depending on whether or not it supports Ethernet. SHOULD is specified because local policy as to what pseudowires connections and types are allowed may override these guidelines. L. Yong, et al [Page 5] INTERNET-DRAFT TRILL over PWE3 3. IANA Considerations No IANA action is required by this document. RFC Editor: Please remove this section before publication. 4. Security Considerations For general TRILL protocol security considerations and those related to Ethernet links, see [RFC6325]. For PPP link TRILL security consideraitons, see [RFC6361]. For security considerations introduced by carrying Ethernet or 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. L. Yong, et al [Page 6] INTERNET-DRAFT TRILL over PWE3 Acknowledgements 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. [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. [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 Edtior's queue. 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 L. Yong, et al [Page 7] INTERNET-DRAFT TRILL over PWE3 providing the connectionless-mode Network Service (ISO 8473)", ISO/IEC10589:2002, Second Edition, Nov 2002 [RFC1195] - Callon, R., "Use of OSI IS-IS for routing in TCP/IP and dual environments", RFC 1195, December 1990. [RFC3985] - Bryant, S., Ed., and P. Pate, Ed., "Pseudo Wire Emulation Edge-to-Edge (PWE3) Architecture", RFC 3985, March 2005. [RFC6327] - Eastlake 3rd, D., Perlman, R., Ghanwani, A., Dutt, D., and V. Manral, "Routing Bridges (RBridges): Adjacency", RFC 6327, July 2011. L. Yong, et al [Page 8] INTERNET-DRAFT TRILL over PWE3 Authors' Addresses Lucy Yong Huawei R&D USA 5340 Legacy Drive Plano, TX 75025 USA Phone: +1-469-227-5837 Email: lucy.yong@huawei.com Donald E. Eastlake, 3rd Huawei R&D USA 155 Beaver Street Milford, MA 01757 USA Phone: +1-508-333-2270 Email: d3e3e3@gmail.com Sam Aldrin Huawei R&D USA 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@brocade.com L. Yong, et al [Page 9] INTERNET-DRAFT TRILL over PWE3 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. 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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 10]