Network Working Group A. Banerjee Internet-Draft Cisco Systems Intended status: Standards Track D. Ward Expires: August 13, 2011 Juniper Networks February 9, 2011 Extensions to IS-IS for Layer-2 Systems draft-ietf-isis-layer2-11 Abstract This document specifies the Intermediate System to Intermediate System (IS-IS) extensions necessary to support link state routing for any protocols running directly over Layer-2. While supporting this concept involves several pieces, this document only describes extensions to IS-IS. Furthermore, the Type, Length, Value pairs (TLVs) described in this document are generic Layer-2 additions and specific ones as needed are defined in the IS-IS technology specific extensions. We leave it to the systems using these IS-IS extensions to explain how the information carried in IS-IS is used. 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 13, 2011. Copyright Notice Copyright (c) 2011 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 Banerjee & Ward Expires August 13, 2011 [Page 1] Internet-Draft Layer-2-IS-IS February 2011 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. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.1. Terminology . . . . . . . . . . . . . . . . . . . . . . . 3 2. TLV Enhancements to IS-IS . . . . . . . . . . . . . . . . . . 4 2.1. Multi Topology aware Port Capability TLV . . . . . . . . . 4 2.2. The MAC-Reachability TLV . . . . . . . . . . . . . . . . . 4 3. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 4. Security Considerations . . . . . . . . . . . . . . . . . . . 8 5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9 6. References . . . . . . . . . . . . . . . . . . . . . . . . . . 10 6.1. Normative References . . . . . . . . . . . . . . . . . . . 10 6.2. Informative References . . . . . . . . . . . . . . . . . . 10 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 11 Banerjee & Ward Expires August 13, 2011 [Page 2] Internet-Draft Layer-2-IS-IS February 2011 1. Overview There are a number of systems (for example, [RBRIDGES], [802.1aq], [OTV]) that use Layer-2 addresses carried in a link state routing protocol, specifically Intermediate System to Intermediate System (IS-IS) [IS-IS] [RFC 1195], to provide true Layer-2 routing. In almost all the technologies mentioned above, classical Layer-2 packets are encapsulated with an outer header. The outer header format varies across all these technologies. This outer header is used to route the encapsulated packets to their destination. Each Intermediate System (IS) advertises one or more IS-IS Link State Protocol Data Units (PDUs) with routing information. Each Link State PDU (LSP) is composed of a fixed header and a number of tuples, each consisting of a Type, a Length, and a Value. Such tuples are commonly known as TLVs. In this document we specify a set of TLVs to be added to [IS-IS] PDUs, to support these proposed systems. The TLVs are generic Layer-2 additions and specific ones, as needed, are defined in the IS-IS technology specific extensions. This draft does not propose any new forwarding mechanisms using this additional information carried within IS-IS. 1.1. 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 RFC 2119. Banerjee & Ward Expires August 13, 2011 [Page 3] Internet-Draft Layer-2-IS-IS February 2011 2. TLV Enhancements to IS-IS This section specifies the enhancements for the TLVs that are needed in common by Layer-2 technologies. 2.1. Multi Topology aware Port Capability TLV The Multi-Topology aware Port Capability (MT-PORT-CAP) is an IS-IS TLV type 143, and has the following format: +-+-+-+-+-+-+-+-+ | Type=MTPORTCAP| (1 byte) +-+-+-+-+-+-+-+-+ | Length | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |R|R|R|R| Topology Identifier | (2 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | sub-TLVs (variable bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: TLV Type, set to MT-PORT-CAP TLV 143. o Length: Total number of bytes contained in the value field, including the length of the sub-TLVs carried in this TLV. o R: Reserved 4-bits, MUST be sent as zero and ignored on receipt. o Topology Identifier: MT ID is a 12-bit field containing the MT ID of the topology being announced. This field when set to zero implies that it is being used to carry base topology information. o sub-TLVs: The MT-PORT-CAP TLV value contains sub-TLVs formatted as described in [RFC 5305]. They are defined in the technology scoped documents. The MT-PORT-CAP TLV may occur multiple times, and is carried within a IS-IS Hello (IIH) PDU. 2.2. The MAC-Reachability TLV The MAC-Reachability (MAC-RI) TLV is IS-IS TLV type 147 and has the following format: Banerjee & Ward Expires August 13, 2011 [Page 4] Internet-Draft Layer-2-IS-IS February 2011 +-+-+-+-+-+-+-+-+ | Type= MAC-RI | (1 byte) +-+-+-+-+-+-+-+-+ | Length | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Topology-Id/ Nickname | (2 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Confidence | (1 byte) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | RESV | VLAN-ID | (2 bytes) +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAC (1) (6 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ................. | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | MAC (N) (6 bytes) | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-...+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: TLV Type, set to 147 (MAC-RI). o Length: Total number of bytes contained in the value field given by 5 + 6*n bytes. o Topology-Id/Nickname : Depending on the technology in which it is used, this carries the topology-id or nickname. When this field is set to zero this implies that the MAC addresses are reachable across all topologies or across all nicknames of the originating IS. o Confidence: This carries an 8-bit quantity indicating the confidence level in the MAC addresses being transported. Whether this field is used, and its semantics if used, are further defined by the specific protocol using Layer-2 IS-IS. If not used, it MUST be set to zero on transmission and be ignored on receipt. o RESV: (4-bits) MUST be sent as zero and ignored on receipt. o VLAN-ID: This carries a 12-bit VLAN identifier that is valid for all subsequent MAC addresses in this TLV, or the value zero if no VLAN is specified. o MAC(i): This is the 48-bit MAC address reachable from the IS that is announcing this TLV. The MAC-RI TLV is carried in a standard Link State PDU (LSP). This TLV can be carried multiple times in an LSP and in multiple LSPs. It MUST contain only unicast addresses. The manner in which these TLVs are generated by the various Layer-2 routing technologies, and the Banerjee & Ward Expires August 13, 2011 [Page 5] Internet-Draft Layer-2-IS-IS February 2011 manner they are consumed are detailed in the technology specific documents. In most of the technologies, these MAC-RI TLVs will translate to populating the hardware with these entries with appropriate next-hop information as derived from the advertising IS. Banerjee & Ward Expires August 13, 2011 [Page 6] Internet-Draft Layer-2-IS-IS February 2011 3. Acknowledgements The authors would like to thank Peter Ashwood-Smith, Donald E. Eastlake 3rd, Dino Farinacci, Don Fedyk, Les Ginsberg, Radia Perlman, Mike Shand, and Russ White for their useful comments. Banerjee & Ward Expires August 13, 2011 [Page 7] Internet-Draft Layer-2-IS-IS February 2011 4. Security Considerations This document adds no additional security risks to IS-IS, nor does it provide any additional security for IS-IS. Banerjee & Ward Expires August 13, 2011 [Page 8] Internet-Draft Layer-2-IS-IS February 2011 5. IANA Considerations This document specifies the definition of a set of new IS-IS TLVs, the Port-Capability TLV (type 143), and the MAC-Reachability TLV (type 147) that needs to be reflected in the IS-IS TLV code-point registry. IIH LSP SNP MT-Port-Cap-TLV (143) X - - MAC-RI TLV (147) - X - Banerjee & Ward Expires August 13, 2011 [Page 9] Internet-Draft Layer-2-IS-IS February 2011 6. References 6.1. Normative References [IS-IS] ISO/IEC 10589:2002, Second Edition, "Intermediate System to Intermediate System Intra-Domain Routing Exchange Protocol for use in Conjunction with the Protocol for Providing the Connectionless-mode Network Service (ISO 8473)", 2002. [RFC 1195] Callon, R., "Use of OSI IS-IS for Routing in TCP/IP and Dual Environments", 1990. [RFC 5305] Li, T. and H. Smit, "IS-IS Extensions for Traffic Engineering", 2008. 6.2. Informative References [IEEE 802.1aq] "Standard for Local and Metropolitan Area Networks / Virtual Bridged Local Area Networks / Amendment 9: Shortest Path Bridging, Draft IEEE P802.1aq/D1.5", 2008. [OTV] Grover, H., Farinacci, D., and D. Rao, "OTV: Overlay Transport Virtualization", draft-hasmit-otv-01, 2010. [RBRIDGES] Perlman, R., Eastlake, D., Dutt, D., Gai, S., and A. Ghanwani, "RBridges: Base Protocol Specification", 2010. Banerjee & Ward Expires August 13, 2011 [Page 10] Internet-Draft Layer-2-IS-IS February 2011 Authors' Addresses Ayan Banerjee Cisco Systems 170 W Tasman Drive San Jose, CA 95138 US Email: ayabaner@cisco.com David Ward Juniper Networks 1194 N. Mathilda Ave. Sunnyvale, CA 94089-1206 USA Phone: +1-408-745-2000 Email: dward@juniper.net Banerjee & Ward Expires August 13, 2011 [Page 11]