Open Shortest Path First IGP S. Hegde Internet-Draft H. Raghuveer Intended status: Standards Track H. Gredler Expires: April 24, 2014 Juniper Networks, Inc. R. Shakir British Telecom October 21, 2013 Advertising per-node administrative tags in OSPF draft-hegde-ospf-node-admin-tag-00 Abstract This document describes an extension to OSPF protocol [RFC2328] to add an optional operational capability, that allows tagging and grouping of the nodes in an OSPF domain. This allows simplification,ease of management and control over route and path selection based on configured policies. This document describes the protocol extensions to disseminate per- node admin-tags to the OSPFv2 and OSPFv3 protocols. Requirements Language 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 [RFC2119]. 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 April 24, 2014. Copyright Notice Hegde, et al. Expires April 24, 2014 [Page 1] Internet-DrafAdvertising per-node administrative tags in OS October 2013 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. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2 2. Applicability . . . . . . . . . . . . . . . . . . . . . . . . 2 3. Administrative Tag TLV . . . . . . . . . . . . . . . . . . . 2 4. TLV format . . . . . . . . . . . . . . . . . . . . . . . . . 3 4.1. OSPF per-node administrative tag TLV . . . . . . . . . . 3 4.2. Ordering of tags . . . . . . . . . . . . . . . . . . . . 4 5. Applications . . . . . . . . . . . . . . . . . . . . . . . . 4 6. Security Considerations . . . . . . . . . . . . . . . . . . . 4 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 5 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 5 9.1. Normative References . . . . . . . . . . . . . . . . . . 5 9.2. Informative References . . . . . . . . . . . . . . . . . 5 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction This document provides mechanisms to advertise per-node administrative tags in the OSPF router information LSA [RFC4970]. In certain path-selection applications like for example in traffic- engineering or LFA backup selection there is a need to tag the nodes based on their roles in the network and have policies to prefer or prune a certain group of nodes. 2. Applicability For the purpose of advertising per-node administrative tags within OSPF a new TLV is proposed. Because path selection is a functional set which applies both to TE and non-TE applications, this new TLV is carried in the Router Information LSA [RFC4970] 3. Administrative Tag TLV Hegde, et al. Expires April 24, 2014 [Page 2] Internet-DrafAdvertising per-node administrative tags in OS October 2013 An administrative Tag is a 32-bit integer value that can be used to identify a group of nodes in the OSPF domain. The new TLV defined will be carried within an RI LSA for OSPFV2 and OSPFV3. Router information LSA [RFC4970] can have link,area or AS level flooding scope. Choosing the flooding scope to flood the group tags are defined by the policies and is a local matter. The TLV specifies one or more administrative tag values. An OSPF node advertises the set of groups it is part of in the OSPF domain. (for example, all PE-nodes are configured with certain tag value, all P-nodes are configured with a different tag value in a domain). 4. TLV format 4.1. OSPF per-node administrative tag TLV The format of the TLVs within the body of an RI LSA is the same as the format used by the Traffic Engineering Extensions to OSPF [RFC3630]. The LSA payload consists of one or more nested Type/Length/Value (TLV) triplets. The format of each TLV is: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Administrative Tag #1 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Administrative Tag #2 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ // // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Administrative Tag #N | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Figure 1: OSPF per-node Administrative Tag TLV Type : TBA Length: A 16-bit field that indicates the length of the value portion in octets and will be a multiple of 4 octets dependent on the number of tags advertised. Hegde, et al. Expires April 24, 2014 [Page 3] Internet-DrafAdvertising per-node administrative tags in OS October 2013 Value: A sequence of multiple 4 octets defining the administrative tags. 4.2. Ordering of tags The semantics of the tag order are implementation-dependent. That is, there is no implied meaning to the ordering of the tags that indicates a certain operation or set of operations that need to be performed based on the ordering. Each tag SHOULD be treated as an independent identifier that MAY be used in policy to perform a policy action. Whether or not tag A precedes or succeeds tag B SHOULD not change the meaning of the tag set. 5. Applications Increased deployment of Loop Free Alternates (LFA) as defined in [RFC5286] has exposed some limitations.New draft Operation management of Loop Free Alternates [I-D.litkowski-rtgwg-lfa-manageability] proposes refinements to address those limitations. One of the proposed refinements is to be able to group the nodes in IGP domain with administrative tags and engineer the LFA based on configured policies. The mechanisms outlined in this document helps provide the capability to advertise group tags within OSPF protocol in order to achieve policy based LFA selection. The policies configured on each node can then make use of these tags to prefer or prune certain group of nodes for selecting LFAs. 6. Security Considerations This document does not introduce any further security issues other than those discussed in [RFC2328] and [RFC5340]. 7. IANA Considerations IANA maintains the registry for the TLVs. OSPF Administrative Tags will require one new type code for the TLV defined in this document. Hegde, et al. Expires April 24, 2014 [Page 4] Internet-DrafAdvertising per-node administrative tags in OS October 2013 8. Acknowledgments Thanks to Bharath R and Pushpasis Sarakar for useful inputs. 9. References 9.1. Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997. [RFC2328] Moy, J., "OSPF Version 2", STD 54, RFC 2328, April 1998. [RFC3630] Katz, D., Kompella, K., and D. Yeung, "Traffic Engineering (TE) Extensions to OSPF Version 2", RFC 3630, September 2003. [RFC4970] Lindem, A., Shen, N., Vasseur, JP., Aggarwal, R., and S. Shaffer, "Extensions to OSPF for Advertising Optional Router Capabilities", RFC 4970, July 2007. [RFC5250] Berger, L., Bryskin, I., Zinin, A., and R. Coltun, "The OSPF Opaque LSA Option", RFC 5250, July 2008. [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, July 2008. 9.2. Informative References [I-D.litkowski-rtgwg-lfa-manageability] Litkowski, S., Decraene, B., Filsfils, C., and K. Raza, "Operational management of Loop Free Alternates", draft- litkowski-rtgwg-lfa-manageability-01 (work in progress), February 2013. [RFC5286] Atlas, A. and A. Zinin, "Basic Specification for IP Fast Reroute: Loop-Free Alternates", RFC 5286, September 2008. [RFC5310] Bhatia, M., Manral, V., Li, T., Atkinson, R., White, R., and M. Fanto, "IS-IS Generic Cryptographic Authentication", RFC 5310, February 2009. [RFC5329] Ishiguro, K., Manral, V., Davey, A., and A. Lindem, "Traffic Engineering Extensions to OSPF Version 3", RFC 5329, September 2008. Authors' Addresses Hegde, et al. Expires April 24, 2014 [Page 5] Internet-DrafAdvertising per-node administrative tags in OS October 2013 Shraddha Hegde Juniper Networks, Inc. Embassy Business Park Bangalore, KA 560093 India Email: shraddha@juniper.net Harish Raghuveer Juniper Networks, Inc. Embassy Business Park Bangalore 560093 India Email: hraghuveer@juniper.net Hannes Gredler Juniper Networks, Inc. 1194 N. Mathilda Ave. Sunnyvale, CA 94089 US Email: hannes@juniper.net Rob shakir British Telecom Email: rob.shakir@bt.com Hegde, et al. Expires April 24, 2014 [Page 6]