TRILL Working Group Vishwas Manral INTERNET-DRAFT Hewlett-Packard Co. Intended status: Proposed Standard Donald Eastlake Expires: December 21, 2012 Mingui Zhang Huawei Ayan Banerjee Cisco Systems June 22, 2012 Multiple Topology Routing Extensions for Transparent Interconnection of Lots of Links (TRILL) draft-manral-isis-trill-multi-topo-04.txt Abstract This document describes optional extensions to the TRILL protocol's use of IS-IS (Intermediate System to Intermediate Systems). These extensions support multiple topologies (MT) within the same TRILL campus and protocol instance of IS-IS. 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 TRILL working group mailing list . 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 V. Manral, et al [Page 1] INTERNET-DRAFT TRILL IS-IS Multi Topology Table of Contents 1. Introduction............................................3 2. Terminology.............................................3 3. TLV Enhancements for Multiple Topology..................4 4. Multi-Topology Changes to Appointed Forwarders..........5 5. Security Considerations.................................6 6. IANA Considerations.....................................6 7. Acknowledgements........................................6 8. References..............................................7 8.1 Normative References...................................7 8.2 Informative References.................................7 V. Manral, et al [Page 2] INTERNET-DRAFT TRILL IS-IS Multi Topology 1. Introduction Maintaining Multiple Topologies (MT) in an Rbridge campus requires extensions to the base TRILL protocol use of IS-IS [ISIStrill]. These extensions change the packet encoding on the wire. This document describes such extensions so that multiple topologies can be supported as described in [RFC5120]. 2. Terminology 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]. IS-IS: Intermediate-System to Intermediate-System LSP: Link State Protocol Data Unit (PDU) Rbridge: Routing Bridge SPF: Shortest Path First Algorithm TRILL: Transparent Interconnection with Lots of Links TLV: Type, Length and Value V. Manral, et al [Page 3] INTERNET-DRAFT TRILL IS-IS Multi Topology 3. TLV Enhancements for Multiple Topology Currently the Router Capability TLV is specified in [RFC4971]. For TRILL, many sub-TLV's are specified as being carried in the Router Capability TLV which carries information only for a single Topology. The following extensions are required to TRILL use of IS-IS to support multi-topology: 1. The Nicknames sub-TLV, Trees sub-TLV, Tree Identifiers sub-TLV, Trees Used Identifiers sub-TLV, and VLAN Group sub-TLV, MAY be encapsulated in the MT-CAP TLV (TLV #144) [ISISieee]. 2. The Multi-Topology TLV [RFC5120] MAY be advertized in the TRILL LAN Hellos and RBridge LSPs. It will contain topology identifiers for one or more topologies in which the Rbridge is participating. An RBridge is considered MT aware as long at it advertises at least one MT TLV in its LSP. 3. The MTU sub-TLV [ISIStrill] MAY occur in the MT ISN TLV #222 [RFC5120] as well as in the Extended IS Reachability TLV #22. 4. The Topology Mapping (TOPO-MAP) sub-TLV, which occurs within a Router Capapbilities TLV (TLV #242) for MT Aware RBridges [trill- mt] is specified below. This sub-TLV may occur more than once in the same or in multiple Router Capapbilities TLVs. +-+-+-+-+-+-+-+-+ |Type = TOPO-MAP| (1 byte) +-+-+-+-+-+-+-+-+ | Length | (1 byte) +-+-+-+-+-+-+-+-+ | RESV |TAS| (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R| ABR | Topology 1 | (2 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R| ABR | Topology 2 | (2 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | . . . +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R| ABR | Topology N | (2 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: Router Capability sub-TLV Type, set to TBD (TOPO-MAP). o Length: 1 + 2*n where n is the number of topology to topology mapping entries. o RESV: Five reserved bits, must be sent as zero and ignored on receipt. V. Manral, et al [Page 4] INTERNET-DRAFT TRILL IS-IS Multi Topology o TAS: Topology Abbreviation Size as apecified in [trill-mt]. o R: Reserved bit. must be sent as zero and ignored on receipt. o ABR, Topology: Each 2-byte mapping entries specifies that ABR is the abbreviation for the 12-bit topology number given. 4. Multi-Topology Changes to Appointed Forwarders The TRILL IS-IS DRB election protocol is a bit different from Layer-3 IS-IS as described in [RFCadj]. The DRB corresponds to the DIS (Designated Intermediate System) and is responsible for specifing the Designated VLAN for communication between the RBridges on the Link [RFCtrill]. As in [RFC5120], there is only one DRB on a link. However, the DRB also handles all native frames being ingressed from or egressed to the like, as it chooses, or may appoint other RBridges on the link Appointed Forwarder [RFCaf] for one or more VLANs. Appointed Forwarders are per topology. The appointed forwarder sub- TLV is already a part of the MT-PORT-CAP TLV, which is Multi-Topology Aware. V. Manral, et al [Page 5] INTERNET-DRAFT TRILL IS-IS Multi Topology 5. Security Considerations The extensions to TRILL use of IS-IS specified herein add no new Security Considerations beyond those already present with multi- topology IS-IS and TRILL. See [RFC5120] for IS-IS multi-topology security considerations. See [RFCtrill] for TRILL base protocol security considerations. 6. IANA Considerations IANA is requested to update the subregistry of the IS-IS TLV Code points Registry which shows permitted occurrence of sub-TLVs within TLVs #22, #141, and #222 to show that the MTU sub-TLV is permitted in TLV #222 as well as in TLV #22. IANA is requested to assign sub-TLV numbers within the MT-CAP TLV (TLV #144) [ISISieee] for the Nicknames sub-TLV, Trees sub-TLV, Tree Identifiers sub-TLV, Trees Used Identifiers sub-TLV, and VLAN Group sub-TLV [ISIStrill]. Noting that there is no conflict between the numbers of these sub-TLVs within the Router Capabilities TLV #242 and with any other number so far assigned within the MT-CAP TLV, it is requested that these sub-TLVs be assigned the same number within the MT-CAP TLV as they have within the Router Capabilities TLV #242. IANA is request to assign a sub-TLV number within the Router Capabilities TLV (TV #242) for the TOPO-MAP sub-TLV. 7. Acknowledgements The authors would like to thank Meenakshi Kaushik and Dinesh Dutta. V. Manral, et al [Page 6] INTERNET-DRAFT TRILL IS-IS Multi Topology 8. References Normative and informative references for this document are given below. 8.1 Normative References [RFC2119] - Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC4971] - Vasseur, JP., Shen, N., and R. Aggarwal, "Intermediate System to Intermediate System (IS-IS) Extensions for Advertising Router Information", RFC 4971, July 2007. [RFC5120] - Przygienda, T., Shen, N., and N. Sheth, "M-ISIS: Multi Topology (MT) Routing in Intermediate System to Intermediate Systems (IS-ISs)", RFC 5120, February 2008. [RFCtrill] - R. Perlman, D. Eastlake, D. Dutt, S. Gai, and A. Ghanwani, "RBridges: Base Protocol Specification", draft-ietf- trill-rbridge-protocol-16.txt, in RFC Editor queue. [ISIStrill] - D. Eastlake, A. Banerjee, D. Dutt, R. Perlman, A. Ghanwani, "TRILL Use of IS-IS", draft-ietf-isis-trill-05.txt, work in progress. [RFCadj] - D. Eastlake, R. Perlman, A. Ghanwani, D. Dutt, V. Manral, "RBridges: Adjacency", draft-ietf-trill-adj, work in progress. [ISISieee] - D. Fedyk, P. Ashwood-Smith, "IS-IS Extensions Supporting IEEE 802.1aq Shortest Path Bridging", draft-ietf-isis-ieee- aq-05.txt, in RFC Editor queue. [RFCaf] - Perlman, R., D. Eastlake, Y. Li, A. Banerjee, H. Fangwei, "RBridges: Appointed Forwarders", draft-ietf-trill-rbridge- af-04, work in progress. [trill-mt] - Perlman, R., D. Eastlake, M. Zhang, A. Banerjee, V. Manral, "RBridges: Multiple Topology TRILL", draft-eastlake- trill-rbridge-multi-topo-00.txt, work in progress. 8.2 Informative References None. V. Manral, et al [Page 7] INTERNET-DRAFT TRILL IS-IS Multi Topology Authors' Addresses Vishwas Manral Hewlett-Packard Co. 19111 Pruneridge Ave. Cupertino, CA 95014 USA Phone: 1-408-447-0000 Email: vishwas.manral@hp.com Donald Eastlake 3rd Huawei Technologies (USA) 155 Beaver Street Milford, MA 01757 USA Phone: 1-508-333-2270 Email: d3e3e3@gmail.com Mingui Zhang Huawei Technologies Co.,Ltd HuaWei Building, No.3 Xinxi Rd., Shang-Di Information Industry Base, Hai-Dian District, Beijing, 100085 P.R. China Email: zhangmingui@huawei.com Ayan Banerjee Cisco Systems 170 West Tasman Drive San Jose, CA 95134 USA Email: ayabaner@cisco.com V. Manral, et al [Page 8] INTERNET-DRAFT TRILL IS-IS Multi Topology Copyright and IPR Provisions Copyright (c) 2011 IETF Trust and the persons identified as the document authors. All rights reserved. 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