--- 1/draft-ietf-idr-bgp-ls-segment-routing-ext-06.txt 2018-05-15 22:13:09.849180339 -0700 +++ 2/draft-ietf-idr-bgp-ls-segment-routing-ext-07.txt 2018-05-15 22:13:09.901181601 -0700 @@ -1,23 +1,24 @@ Inter-Domain Routing S. Previdi, Ed. -Internet-Draft K. Talaulikar -Intended status: Standards Track C. Filsfils -Expires: October 13, 2018 Cisco Systems, Inc. +Internet-Draft +Intended status: Standards Track K. Talaulikar +Expires: November 16, 2018 C. Filsfils + Cisco Systems, Inc. H. Gredler RtBrick Inc. M. Chen Huawei Technologies - April 11, 2018 + May 15, 2018 BGP Link-State extensions for Segment Routing - draft-ietf-idr-bgp-ls-segment-routing-ext-06 + draft-ietf-idr-bgp-ls-segment-routing-ext-07 Abstract Segment Routing (SR) allows for a flexible definition of end-to-end paths by encoding paths as sequences of topological sub-paths, called "segments". These segments are advertised by routing protocols e.g. by the link state routing protocols (IS-IS, OSPFv2 and OSPFv3) within IGP topologies. This draft defines extensions to the BGP Link-state address-family in @@ -37,21 +38,21 @@ 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 https://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 October 13, 2018. + This Internet-Draft will expire on November 16, 2018. Copyright Notice Copyright (c) 2018 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 (https://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents @@ -59,44 +60,44 @@ 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 . . . . . . . . . . . . . . . . . . . . . . . . 3 2. BGP-LS Extensions for Segment Routing . . . . . . . . . . . . 5 2.1. Node Attributes TLVs . . . . . . . . . . . . . . . . . . 5 - 2.1.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . 5 + 2.1.1. SID/Label Sub-TLV . . . . . . . . . . . . . . . . . . 6 2.1.2. SR-Capabilities TLV . . . . . . . . . . . . . . . . . 6 2.1.3. SR-Algorithm TLV . . . . . . . . . . . . . . . . . . 7 2.1.4. SR Local Block TLV . . . . . . . . . . . . . . . . . 8 2.1.5. SRMS Preference TLV . . . . . . . . . . . . . . . . . 9 2.2. Link Attribute TLVs . . . . . . . . . . . . . . . . . . . 9 2.2.1. Adjacency SID TLV . . . . . . . . . . . . . . . . . . 10 2.2.2. LAN Adjacency SID TLV . . . . . . . . . . . . . . . . 11 2.2.3. L2 Bundle Member . . . . . . . . . . . . . . . . . . 12 2.3. Prefix Attribute TLVs . . . . . . . . . . . . . . . . . . 13 2.3.1. Prefix-SID TLV . . . . . . . . . . . . . . . . . . . 14 2.3.2. Prefix Attribute Flags TLV . . . . . . . . . . . . . 15 2.3.3. Source Router Identifier (Source Router-ID) TLV . . . 16 2.3.4. Range TLV . . . . . . . . . . . . . . . . . . . . . . 16 2.4. Equivalent IS-IS Segment Routing TLVs/Sub-TLVs . . . . . 18 2.5. Equivalent OSPFv2/OSPFv3 Segment Routing TLVs/Sub-TLVs . 18 3. Implementation Status . . . . . . . . . . . . . . . . . . . . 19 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 20 4.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 20 5. Manageability Considerations . . . . . . . . . . . . . . . . 21 5.1. Operational Considerations . . . . . . . . . . . . . . . 21 - 5.1.1. Operations . . . . . . . . . . . . . . . . . . . . . 21 + 5.2. Management Considerations . . . . . . . . . . . . . . . . 21 6. Security Considerations . . . . . . . . . . . . . . . . . . . 21 - 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 21 + 7. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 22 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 22 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 22 9.1. Normative References . . . . . . . . . . . . . . . . . . 22 9.2. Informative References . . . . . . . . . . . . . . . . . 23 9.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 25 1. Introduction Segment Routing (SR) allows for a flexible definition of end-to-end @@ -170,24 +171,26 @@ one or more nodes are configured with BGP-LS. These BGP speakers form an IBGP mesh by connecting to one or more route-reflectors. This way, all BGP speakers (specifically the route-reflectors) obtain Link-State information from all IGP areas (and from other ASes from EBGP peers). An external component connects to the route-reflector to obtain this information (perhaps moderated by a policy regarding what information is or isn't advertised to the external component). This document describes extensions to BGP-LS to advertise the SR information. An external component (e.g., a controller) then can - collect SR information in the "northbound" direction across IGP areas - or ASes and construct the end-to-end path (with its associated SIDs) - that need to be applied to an incoming packet to achieve the desired - end-to-end forwarding. + collect SR information from across an SR domain and construct the + end-to-end path (with its associated SIDs) that need to be applied to + an incoming packet to achieve the desired end-to-end forwarding. + Here the SR domain is defined as a single administrative domain that + may be comprised of a single AS or multiple ASes under consolidated + global SID administration. 2. BGP-LS Extensions for Segment Routing This document defines SR extensions to BGP-LS and specifies the TLVs and sub-TLVs for advertising SR information. Section 2.4 and Section 2.5 illustrates the equivalent TLVs and sub-TLVs in IS-IS, OSPFv2 and OSPFv3 protocols. BGP-LS [RFC7752] defines the BGP-LS NLRI that can be a Node NLRI, a Link NLRI or a Prefix NLRI. The corresponding BGP-LS attribute is a @@ -681,33 +684,31 @@ [RFC7794]. The Source Router-ID TLV may be used to carry the OSPF Router-ID of the prefix originator. The Source Router-ID TLV has the following format: 0 1 2 3 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ - // IPv4/IPv6 Address (Router-ID) // + // 4 or 6 octet Router-ID // +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: Type: TBD, see Section 4. Length: 4 or 16. IPv4/IPv6 Address: 4 octet IPv4 address or 16 octet IPv6 address. - The semantic of the Source Router-ID TLV is defined in [RFC7794]. - 2.3.4. Range TLV The Range TLV can ONLY be added to the Prefix Attribute whose local node in the corresponding Prefix NLRI is the node that originates the corresponding SR TLV. When the range TLV is used in order to advertise a range of prefix- to-SID mappings as defined in [I-D.ietf-ospf-segment-routing-extensions], [I-D.ietf-ospf-ospfv3-segment-routing-extensions] and @@ -912,42 +913,51 @@ | 1171 | Source Router-ID | Section 2.3.3 | | 1172 | L2 Bundle Member TLV | Section 2.2.3 | +-------------+-------------------------------------+---------------+ Table 8: Summary Table of TLV/Sub-TLV Codepoints 5. Manageability Considerations This section is structured as recommended in [RFC5706]. + The new protocol extensions introduced in this document augment the + existing IGP topology information that was distributed via [RFC7752]. + Procedures and protocol extensions defined in this document do not + affect the BGP protocol operations and management other than as + discussed in the Manageability Considerations section of [RFC7752]. + 5.1. Operational Considerations -5.1.1. Operations + No additional operation considerations are defined in this document. - Existing BGP and BGP-LS operational procedures apply. No additional - operation procedures are defined in this document. +5.2. Management Considerations + + No additional management considerations are defined in this document. 6. Security Considerations + The new protocol extensions introduced in this document augment the + existing IGP topology information that was distributed via [RFC7752]. Procedures and protocol extensions defined in this document do not - affect the BGP security model. See the 'Security Considerations' - section of [RFC4271] for a discussion of BGP security. Also refer to - [RFC4272] and [RFC6952] for analysis of security issues for BGP. + affect the BGP security model other than as discussed in the Security + Considerations section of [RFC7752]. 7. Contributors The following people have substantially contributed to the editing of this document: Peter Psenak Cisco Systems Email: ppsenak@cisco.com + Les Ginsberg Cisco Systems Email: ginsberg@cisco.com Acee Lindem Cisco Systems Email: acee@cisco.com Saikat Ray Individual @@ -969,51 +979,46 @@ [I-D.ietf-idr-te-pm-bgp] Ginsberg, L., Previdi, S., Wu, Q., Tantsura, J., and C. Filsfils, "BGP-LS Advertisement of IGP Traffic Engineering Performance Metric Extensions", draft-ietf-idr-te-pm- bgp-10 (work in progress), March 2018. [I-D.ietf-isis-segment-routing-extensions] Previdi, S., Ginsberg, L., Filsfils, C., Bashandy, A., Gredler, H., Litkowski, S., Decraene, B., and J. Tantsura, "IS-IS Extensions for Segment Routing", draft-ietf-isis- - segment-routing-extensions-15 (work in progress), December - 2017. + segment-routing-extensions-16 (work in progress), April + 2018. [I-D.ietf-ospf-ospfv3-segment-routing-extensions] Psenak, P., Filsfils, C., Previdi, S., Gredler, H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPFv3 Extensions for Segment Routing", draft-ietf-ospf-ospfv3- - segment-routing-extensions-11 (work in progress), January + segment-routing-extensions-12 (work in progress), April 2018. [I-D.ietf-ospf-segment-routing-extensions] Psenak, P., Previdi, S., Filsfils, C., Gredler, H., Shakir, R., Henderickx, W., and J. Tantsura, "OSPF Extensions for Segment Routing", draft-ietf-ospf-segment- - routing-extensions-24 (work in progress), December 2017. + routing-extensions-25 (work in progress), April 2018. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC4202] Kompella, K., Ed. and Y. Rekhter, Ed., "Routing Extensions in Support of Generalized Multi-Protocol Label Switching (GMPLS)", RFC 4202, DOI 10.17487/RFC4202, October 2005, . - [RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A - Border Gateway Protocol 4 (BGP-4)", RFC 4271, - DOI 10.17487/RFC4271, January 2006, - . - [RFC5340] Coltun, R., Ferguson, D., Moy, J., and A. Lindem, "OSPF for IPv6", RFC 5340, DOI 10.17487/RFC5340, July 2008, . [RFC7684] Psenak, P., Gredler, H., Shakir, R., Henderickx, W., Tantsura, J., and A. Lindem, "OSPFv2 Prefix/Link Attribute Advertisement", RFC 7684, DOI 10.17487/RFC7684, November 2015, . [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and @@ -1028,35 +1033,25 @@ March 2016, . 9.2. Informative References [I-D.ietf-spring-segment-routing] Filsfils, C., Previdi, S., Ginsberg, L., Decraene, B., Litkowski, S., and R. Shakir, "Segment Routing Architecture", draft-ietf-spring-segment-routing-15 (work in progress), January 2018. - [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", - RFC 4272, DOI 10.17487/RFC4272, January 2006, - . - [RFC5706] Harrington, D., "Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions", RFC 5706, DOI 10.17487/RFC5706, November 2009, . - [RFC6952] Jethanandani, M., Patel, K., and L. Zheng, "Analysis of - BGP, LDP, PCEP, and MSDP Issues According to the Keying - and Authentication for Routing Protocols (KARP) Design - Guide", RFC 6952, DOI 10.17487/RFC6952, May 2013, - . - [RFC7942] Sheffer, Y. and A. Farrel, "Improving Awareness of Running Code: The Implementation Status Section", BCP 205, RFC 7942, DOI 10.17487/RFC7942, July 2016, . 9.3. URIs [1] http://tools.ietf.org/html/draft-ietf-isis-segment-routing- extensions-05#section-3.1 @@ -1117,21 +1112,20 @@ routing-extensions-05#section-5 [22] http://tools.ietf.org/html/draft-ietf-ospf-ospfv3-segment- routing-extensions-05#section-2.1 [23] http://tools.ietf.org/html/RFC5340#section-A.4.1.1 Authors' Addresses Stefano Previdi (editor) - Cisco Systems, Inc. Via Del Serafico, 200 Rome 00142 Italy Email: stefano@previdi.net Ketan Talaulikar Cisco Systems, Inc. S.No. 154/6, Phase I, Hinjawadi Pune 411 057 India