Inter-Domain Routing Internet-Draft Intended status: Standards Track G. Dawra, Ed. Expires: July 8, 2018 C. Filsfils K. Talaulikar, Ed. Cisco Systems D. Bernier Bell Canada J. Uttaro AT&T B. Decraene Orange H. Elmalky Ericsson January 4, 2018 BGP Link State extensions for IPv6 Segment Routing(SRv6) draft-dawra-idr-bgpls-srv6-ext-01 Abstract Segment Routing IPv6(SRv6) allows for a flexible definition of end- to-end paths within various topologies by encoding paths as sequences of topological sub-paths, called "segments". These segments are advertised by the various protocols such as (BGP, IGP, BGP-LS etc). BGP Link-state(BGP-LS) address-family solution for SRv6 is consistent with BGP-LS for SR-MPLS [I-D.ietf-idr-bgp-ls-segment-routing-ext]. This draft defines extensions to the BGP-LS to carry SR/SRv6 Segments, Services and function information via BGP. 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 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 July 8, 2018. Dawra, et al. Expires July 8, 2018 [Page 1] Internet-Draft BGP-LS Extensions for SRv6 January 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 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. BGP-LS extensions for SRv6 . . . . . . . . . . . . . . . . . 3 2.1. SRv6 Node Attributes . . . . . . . . . . . . . . . . . . 3 2.1.1. SRv6 Capability Attribute TLV . . . . . . . . . . . . 4 2.1.2. SRv6 SID TLV . . . . . . . . . . . . . . . . . . . . 7 2.2. SRv6 Link Attributes . . . . . . . . . . . . . . . . . . 8 2.2.1. SRv6 P2P X-SID TLV . . . . . . . . . . . . . . . . . 8 2.2.2. SRv6 LAN X-SID TLV . . . . . . . . . . . . . . . . . 9 2.3. Function Sub-TLV . . . . . . . . . . . . . . . . . . . . 10 3. Function Mapping Summary . . . . . . . . . . . . . . . . . . 11 4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 12 4.1. TLV/Sub-TLV Code Points Summary . . . . . . . . . . . . . 12 4.2. Segment routing function Identifier(SFI) . . . . . . . . 13 5. Manageability Considerations . . . . . . . . . . . . . . . . 13 6. Operational Considerations . . . . . . . . . . . . . . . . . 13 6.1. Operations . . . . . . . . . . . . . . . . . . . . . . . 13 7. Security Considerations . . . . . . . . . . . . . . . . . . . 13 8. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . 14 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 14 9.1. Normative References . . . . . . . . . . . . . . . . . . 14 9.2. Informative References . . . . . . . . . . . . . . . . . 16 Appendix A. Contributors . . . . . . . . . . . . . . . . . . . . 17 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 17 1. Introduction SRv6 refers to Segment Routing instantiated on the IPv6 dataplane [I-D.ietf-spring-segment-routing]. The network programming paradigm [I-D.filsfils-spring-srv6-network-programming] is central to SRv6. Dawra, et al. Expires July 8, 2018 [Page 2] Internet-Draft BGP-LS Extensions for SRv6 January 2018 It describes how any function can be bound to a SID and how any network program can be expressed as a combination of SID's. "SID" (abbreviation for Segment Identifier) is often used as a shorter reference for "SRv6 Segment". An SRv6-capable node N maintains a "My Local SID Table". This table contains all the local segments explicitly instantiated at node N. The IGP link-state routing protocols have been extended to advertise some of these SIDs and other SR-related information. IGP extensions are described in [I-D.bashandy-isis-srv6-extensions]. Applications that require topological visibility, syncing the "My Local SID Table" within a domain area, or even across Autonomous Systems (AS), is required. The identifying key of each Link-State object, namely a node, link, or prefix, is encoded in the NLRI and the properties of the object are encoded in the BGP-LS attribute [RFC7752]. This document describes extensions to BGP-LS attribute to advertise the SR/SRv6 "My Local SID Table" and some other related SR- information. Some of the information advertised in BGP-LS may not be advertised by IGP/BGP Protocol. 2. BGP-LS extensions for SRv6 BGP-LS[RFC7752] defines the BGP Node and Link attributes. All non- VPN link, node, and prefix information SHALL be encoded using AFI 16388 / SAFI 71. VPN link, node, and prefix information SHALL be encoded using AFI 16388 / SAFI 72. This document defines BGP/IGP SR extensions to BGP-LS Node attribute TLVs in Section 2.1 and Link attribute TLVs in Section 2.2. 2.1. SRv6 Node Attributes Node Attribute TLVs are used for the node level SRv6 capabilities and for SRv6 SIDs with their node level functions (e.g. END, END.T, Service function) that are signaled by the originating router for SR operations. The following Node Attribute TLVs are defined: Dawra, et al. Expires July 8, 2018 [Page 3] Internet-Draft BGP-LS Extensions for SRv6 January 2018 +--------------+----------------------------+-------------+----------------+ | TLV Code | Description | Length | Section | | Point | | | | +--------------+----------------------------+-------------+----------------+ | TBD | SRv6 Capabilities TLV | variable | Section 2.1.1 | | | | | | | TBD | SRv6 SID TLV | variable | Section 2.1.2 | | | | | | +--------------+----------------------------+-------------+----------------+ These TLVs can ONLY be added to the Node Attribute associated with the local node that is originating the corresponding IGP/BGP TLV. 2.1.1. SRv6 Capability Attribute TLV This TLV is used to announce the SRv6 capability of the router and to indicate the nature of its support for the SRH operations. 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 | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Flags | Sub-TLVs...| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Where: o Type: 16 bit field. TBD o Length: 16 bit field. Length of Capability TLV + length of Sub- TLVs o Flags: 16 bit field. The following flags are defined: 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ |E|O| | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ where: * E-flag: If set, then router is able to apply "T.Encap" operation * O-flag: If set, then router is capable of supporting SRH O-bit Flags, as specified in [I-D.ietf-6man-segment-routing-header]. Dawra, et al. Expires July 8, 2018 [Page 4] Internet-Draft BGP-LS Extensions for SRv6 January 2018 The following sections define the supported sub-TLVs. 2.1.1.1. Maximum SL sub-TLV The Maximum Segments Left sub-TLV specifies the maximum value of the "SL" field [SRH] in the SRH of a received packet before applying the function associated with a SID. 0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Max SL | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: 1 o Length: 1 o SL Value: 1 octet o An 8 bit unsigned integer. If the sub-TLV is NOT advertised the value is assumed to be 0. 2.1.1.2. Maximum End Pop SRH sub-TLV The Maximum End Pop SRH sub-TLV specifies the maximum number of SIDs in the top SRH in an SRH stack to which the router can apply "PSP" or USP" [NP] flavors. 0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length |Max-End-Pop-SRH| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: 2 o Length: 1 o Max-End-Pop-SRH Value: 1 octet o An 8 bit unsigned integer. If the value is zero or the sub-sub-TLV is NOT advertised, then it is assumed that the router cannot apply PSP or USP flavors. Dawra, et al. Expires July 8, 2018 [Page 5] Internet-Draft BGP-LS Extensions for SRv6 January 2018 2.1.1.3. Maximum T.Insert SRH sub-TLV The Maximum T.Insert SRH sub-sub-TLV specifies the maximum number of SIDs that can be inserted as part of the "T.insert" behavior [NP]. 0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Max-T.Insert | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: 3 o Length: 1 o Max-T.Insert Value: 1 octet o An 8 bit unsigned integer. If the value is zero or the sub-sub-TLV is omitted, then the router is assumed not to support any variation of the "T.insert" behavior. 2.1.1.4. Maximum T.Encap SRH sub-TLV The Maximum T.Encap SRH sub-sub-TLV specifies the maximum number of SIDs that can be included as part of the "T.Encap" behavior [NP]. 0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Max-T.Encap | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: 4 o Length: 1 o Max-T.Encap Value: 1 octet o An 8 bit unsigned integer. If this value is zero or the sub-TLV is omitted and the "E" flag is set in the associated SRv6 Capabilities sub-TLV, then it is assumed that the router can apply T.Encap by encapsulating the incoming packet in another IPv6 header without SRH the same way IPinIP encapsulation is performed. If the "E" flag is clear, then this sub- sub-TLV SHOULD NOT be transmitted and MUST be ignored on receipt. Dawra, et al. Expires July 8, 2018 [Page 6] Internet-Draft BGP-LS Extensions for SRv6 January 2018 2.1.1.5. Maximum End D SRH sub-TLV The Maximum End D SRH sub-sub-TLV specifies the maximum number of SIDs in an SRH when applying "End.DX6" and "End.DT6" functions. 0 1 2 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Type | Length | Max End D | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ o Type: 5 o Length: 1 o Max End D Value: 1 octet o An 8 bit unsigned integer. If this value is zero or the sub-TLV is omitted, then it is assumed that the router cannot apply "End.DX6" or "End.DT6" functions if the extension header right underneath the outer IPv6 header is an SRH. Function Sub-TLV described in Section 2.3 is used to encode Function Identifier and Function Flags. 2.1.2. SRv6 SID TLV This TLV is used for the Segment Routing SID(SRv6) and associate with their node level functions (e.g. END, END.T, Service functions etc) that are signaled by the originating router. Function Sub-TLV described in Section 2.3 is used to encode Function Identifier and Function Flags. +---------------------------------------+ | Type (2 octet) | +---------------------------------------+ | Length (2 octet) | +---------------------------------------+ | Flags (1 octet) | +---------------------------------------+ | SID value (16 octet) | +---------------------------------------+ Figure 1: Segment Identifier(SID) TLV Where: Dawra, et al. Expires July 8, 2018 [Page 7] Internet-Draft BGP-LS Extensions for SRv6 January 2018 Type: 16 bit field. TBD Length: 16 bit field. The total length of the value portion of the TLV. Flags: 8 bit field. Future. Rest Flags SHOULD be set to zero on transmission and MUST be ignored on receipt. SID Value: 16 octet IPv6 address. 2.2. SRv6 Link Attributes These TLVs are used for the SRv6 SIDs with their link or adjacency level functions (e.g. END.X function) that are signaled by the originating router for SRv6 operations. One or more of these link attribute TLVs may be attached to the BGP-LS update. The following Link Attribute TLVs are defined: +-----------+----------------------------+----------+---------------+ | TLV Code | Description | Length | Section | | Point | | | | +-----------+----------------------------+----------+---------------+ | TBD | SRv6 P2P X-SID TLV | variable | Section 2.2.1 | | | | | | | TBD | SRv6 LAN X-SID TLV | variable | Section 2.2.2 | | | | | | +-----------+----------------------------+----------+---------------+ These TLVs can ONLY be added to the Link Attribute associated with the link whose local node originates the corresponding TLV. For a LAN, normally a node only announces its adjacency to the IS-IS pseudo-node (or the equivalent OSPF Designated and Backup Designated Routers). The SRv6 SID LAN Adjacency Attribute TLV allows a node to announce adjacencies to all other nodes attached to the LAN in a single instance of the BGP-LS Link NLRI. Without this TLV, the corresponding BGP-LS link NLRI would need to be originated for each additional adjacency in order to advertise the SRv6 SID TLVs for these neighbor adjacencies. 2.2.1. SRv6 P2P X-SID TLV The SRv6 SID Adjacency TLV has the following format: Dawra, et al. Expires July 8, 2018 [Page 8] Internet-Draft BGP-LS Extensions for SRv6 January 2018 +---------------------------------------+ | Type (2 octet) | +---------------------------------------+ | Length (2 octet) | +---------------------------------------+ | SID-Flags(1 octet) | +---------------------------------------+ | SID-Size(1 octet) | +---------------------------------------+ | SID value (1-16 octet) | +---------------------------------------+ Where: Type is TBD Length: 16 bit field. The total length of the value portion of the TLV. SID-Flags: For IGP as defined in [I-D.bashandy-isis-srv6-extensions] SID-size: Number of bits in the SID field. SID: 1-16 octets. This field encodes the advertised SRv6 SID. The "SID-size" field can have the values 1-128 and indicates the number of bits in the SID. The SRv6 SID is encoded in the minimal number of octets for the given number of bits. Function Sub-TLV described in Section 2.3 is used to encode Function Identifier and Function Flags. 2.2.2. SRv6 LAN X-SID TLV The SRv6 SID LAN Adjacency TLV has the following format: Dawra, et al. Expires July 8, 2018 [Page 9] Internet-Draft BGP-LS Extensions for SRv6 January 2018 +---------------------------------------+ | Type (2 octet) | +---------------------------------------+ | Length (2 octet) | +---------------------------------------+ | OSPF Nbr ID/ISIS System ID(6 Octet) | +---------------------------------------+ | SID-Flags(1 octet) | +---------------------------------------+ | SID-Size(1 octet) | +---------------------------------------+ | SID value (1-16 octet) | +---------------------------------------+ o Type: TBD o Length: 16 bit value. Variable o SID-Flags: For IGP as defined in [I-D.bashandy-isis-srv6-extensions] o SID-size: Number of bits in the SID field. o SID: 1-16 octets. This field encodes the advertised SRv6 SID. The "SID-size" field can have the values 1-128 and indicates the number of bits in the SID. The SRv6 SID is encoded in the minimal number of octets for the given number of bits. o Neighbor : 4 octets for OSPFv2/v3 neighbor ID or 6 octets for IS- IS system-id of the neighbor Function Sub-TLV described in Section 2.3 is used to encode Function Identifier and Function Flags. 2.3. Function Sub-TLV Dawra, et al. Expires July 8, 2018 [Page 10] Internet-Draft BGP-LS Extensions for SRv6 January 2018 +---------------------------------------+ | Type (2 octet) | +---------------------------------------+ | Length (2 octet) | +---------------------------------------+ | Function Flags(1 octet) | +---------------------------------------+ | RESERVED(1 octet) | +---------------------------------------+ | Function ID (2 octet) | +---------------------------------------+ Figure 2: Function Sub-TLV Where: Type: 16 bit field: TBD Length: 16 bit field. Length of the TLV Function Flags: 8 bit field. For IGP as defined in [I-D.bashandy-isis-srv6-extensions] RESERVED: 8 bit field. SHOULD be unset on transmission and MUST be ignored on receipt. Function ID: 16 bit field. Function Identifier of the SID Encoded in the TLV. New function Top Level registry is defined in Section Section 4.2. 3. Function Mapping Summary Below table illustrate the summary of functions and Node or Link Level TLV encodings. Table will encode Functions for both SR-MPLS/ SRv6 for both Layer-2 and Layer-3 functions with unique values. Table will also include encoding Attribute TLV for functions. Segment Routing functions are defined in[I-D.filsfils-spring-srv6-network-programming] Dawra, et al. Expires July 8, 2018 [Page 11] Internet-Draft BGP-LS Extensions for SRv6 January 2018 +--------------+---------------------------+---------------------------------+ | Function | Function Identifier | Encoding Attribute TLV | | | | | +--------------+---------------------------+---------------------------------+ | END | 1 | Node SID | +--------------+---------------------------+---------------------------------+ | END.X | 2 | Link LAN X-SID | | | | Link P2P X-SID | +--------------+---------------------------+---------------------------------+ | END.T | 3 | Node SID | +--------------+---------------------------+---------------------------------+ | END.DX6 | 4 | Link LAN X-SID | | | | Link P2P X-SID | +--------------+---------------------------+---------------------------------+ | END.DX4 | 5 | Link P2P X-SID | +--------------+---------------------------+---------------------------------+ | END.DT6 | 6 | Node SID | +--------------+---------------------------+---------------------------------+ | END.DT4 | 7 | Node SID | +--------------+---------------------------+---------------------------------+ 4. IANA Considerations This document requests assigning code-points from the registry "BGP- LS Node Descriptor, Link Descriptor, Prefix Descriptor, and Attribute TLVs". 4.1. TLV/Sub-TLV Code Points Summary This section contains the global table of all TLVs defined in this document. +--------------+----------------------------+----------------+ | TLV Code | Description | Section | | Point | | | +--------------+----------------------------+----------------+ | TBD | SRv6 Capabilities TLV | Section 2.1.1 | | | | | | TBD | SRv6 SID TLV | Section 2.1.2 | | | | | | TBD | SRv6 P2P X-SID TLV | Section 2.2.1 | | | | | | TBD | SRv6 LAN X-SID TLV | Section 2.2.2 | | | | | | TBD | Function TLV | Section 2.3 | +--------------+----------------------------+----------------+ Dawra, et al. Expires July 8, 2018 [Page 12] Internet-Draft BGP-LS Extensions for SRv6 January 2018 4.2. Segment routing function Identifier(SFI) IANA is request to create a new top-level registry called "Segment Routing Function Identifier(SFI)". Valid values are in the range 0 to 65535. Values 0 and 65535 are to be marked "Reserved, not to be allocated". ---------------+---------------------------+ | Function | Function Identifier | | | | ---------------+---------------------------+ | END | 1 | ---------------+---------------------------+ | END.X | 2 | ---------------+---------------------------+ | END.T | 3 | ---------------+---------------------------+ | END.DX6 | 4 | ---------------+---------------------------+ | END.DX4 | 5 | ---------------+---------------------------+ | END.DT6 | 6 | ---------------+---------------------------+ | END.DT4 | 7 | ---------------+---------------------------+ 5. Manageability Considerations This section is structured as recommended in[RFC5706] 6. Operational Considerations 6.1. Operations Existing BGP and BGP-LS operational procedures apply. No additional operation procedures are defined in this document. 7. Security Considerations 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. Dawra, et al. Expires July 8, 2018 [Page 13] Internet-Draft BGP-LS Extensions for SRv6 January 2018 8. Conclusions This document proposes extensions to the BGP to allow advertising certain attributes and functionalities related to SRv6. 9. References 9.1. Normative References [I-D.bashandy-isis-srv6-extensions] Ginsberg, L., Bashandy, A., Filsfils, C., and B. Decraene, "IS-IS Extensions to Support Routing over IPv6 Dataplane", draft-bashandy-isis-srv6-extensions-01 (work in progress), September 2017. [I-D.filsfils-spring-segment-routing-policy] Filsfils, C., Sivabalan, S., Raza, K., Liste, J., Clad, F., Talaulikar, K., Hegde, S., daniel.voyer@bell.ca, d., Lin, S., bogdanov@google.com, b., Horneffer, M., Steinberg, D., Decraene, B., Litkowski, S., and P. Mattes, "Segment Routing Policy for Traffic Engineering", draft- filsfils-spring-segment-routing-policy-04 (work in progress), December 2017. [I-D.filsfils-spring-srv6-network-programming] Filsfils, C., Leddy, J., daniel.voyer@bell.ca, d., daniel.bernier@bell.ca, d., Steinberg, D., Raszuk, R., Matsushima, S., Lebrun, D., Decraene, B., Peirens, B., Salsano, S., Naik, G., Elmalky, H., Jonnalagadda, P., Sharif, M., Ayyangar, A., Mynam, S., Henderickx, W., Bashandy, A., Raza, K., Dukes, D., Clad, F., and P. Camarillo, "SRv6 Network Programming", draft-filsfils- spring-srv6-network-programming-03 (work in progress), December 2017. [I-D.ietf-6man-segment-routing-header] Previdi, S., Filsfils, C., Raza, K., Leddy, J., Field, B., daniel.voyer@bell.ca, d., daniel.bernier@bell.ca, d., Matsushima, S., Leung, I., Linkova, J., Aries, E., Kosugi, T., Vyncke, E., Lebrun, D., Steinberg, D., and R. Raszuk, "IPv6 Segment Routing Header (SRH)", draft-ietf-6man- segment-routing-header-07 (work in progress), July 2017. [RFC2460] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", RFC 2460, DOI 10.17487/RFC2460, December 1998, . Dawra, et al. Expires July 8, 2018 [Page 14] Internet-Draft BGP-LS Extensions for SRv6 January 2018 [RFC3107] Rekhter, Y. and E. Rosen, "Carrying Label Information in BGP-4", RFC 3107, DOI 10.17487/RFC3107, May 2001, . [RFC4272] Murphy, S., "BGP Security Vulnerabilities Analysis", RFC 4272, DOI 10.17487/RFC4272, January 2006, . [RFC4364] Rosen, E. and Y. Rekhter, "BGP/MPLS IP Virtual Private Networks (VPNs)", RFC 4364, DOI 10.17487/RFC4364, February 2006, . [RFC4456] Bates, T., Chen, E., and R. Chandra, "BGP Route Reflection: An Alternative to Full Mesh Internal BGP (IBGP)", RFC 4456, DOI 10.17487/RFC4456, April 2006, . [RFC5706] Harrington, D., "Guidelines for Considering Operations and Management of New Protocols and Protocol Extensions", RFC 5706, DOI 10.17487/RFC5706, November 2009, . [RFC6514] Aggarwal, R., Rosen, E., Morin, T., and Y. Rekhter, "BGP Encodings and Procedures for Multicast in MPLS/BGP IP VPNs", RFC 6514, DOI 10.17487/RFC6514, February 2012, . [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, . [RFC7432] Sajassi, A., Ed., Aggarwal, R., Bitar, N., Isaac, A., Uttaro, J., Drake, J., and W. Henderickx, "BGP MPLS-Based Ethernet VPN", RFC 7432, DOI 10.17487/RFC7432, February 2015, . [RFC7606] Chen, E., Ed., Scudder, J., Ed., Mohapatra, P., and K. Patel, "Revised Error Handling for BGP UPDATE Messages", RFC 7606, DOI 10.17487/RFC7606, August 2015, . [RFC7752] Gredler, H., Ed., Medved, J., Previdi, S., Farrel, A., and S. Ray, "North-Bound Distribution of Link-State and Traffic Engineering (TE) Information Using BGP", RFC 7752, DOI 10.17487/RFC7752, March 2016, . Dawra, et al. Expires July 8, 2018 [Page 15] Internet-Draft BGP-LS Extensions for SRv6 January 2018 9.2. Informative References [I-D.ietf-bess-evpn-prefix-advertisement] Rabadan, J., Henderickx, W., Drake, J., Lin, W., and A. Sajassi, "IP Prefix Advertisement in EVPN", draft-ietf- bess-evpn-prefix-advertisement-09 (work in progress), November 2017. [I-D.ietf-idr-bgp-ls-segment-routing-ext] Previdi, S., Psenak, P., Filsfils, C., Gredler, H., and M. Chen, "BGP Link-State extensions for Segment Routing", draft-ietf-idr-bgp-ls-segment-routing-ext-03 (work in progress), July 2017. [I-D.ietf-idr-bgp-prefix-sid] Previdi, S., Filsfils, C., Lindem, A., Sreekantiah, A., and H. Gredler, "Segment Routing Prefix SID extensions for BGP", draft-ietf-idr-bgp-prefix-sid-08 (work in progress), January 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. [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-14 (work in progress), December 2017. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [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, . [RFC4659] De Clercq, J., Ooms, D., Carugi, M., and F. Le Faucheur, "BGP-MPLS IP Virtual Private Network (VPN) Extension for IPv6 VPN", RFC 4659, DOI 10.17487/RFC4659, September 2006, . Dawra, et al. Expires July 8, 2018 [Page 16] Internet-Draft BGP-LS Extensions for SRv6 January 2018 [RFC5549] Le Faucheur, F. and E. Rosen, "Advertising IPv4 Network Layer Reachability Information with an IPv6 Next Hop", RFC 5549, DOI 10.17487/RFC5549, May 2009, . Appendix A. Contributors Arjun Sreekantiah US Les Ginsberg Cisco Systems US Email: ginsberg@cisco.com Authors' Addresses Gaurav Dawra (editor) Cisco Systems USA Email: gdawra.ietf@gmail.com Clarence Filsfils Cisco Systems Belgium Email: cfilsfil@cisco.com Ketan Talaulikar (editor) Cisco Systems India Email: ketant@cisco.com Daniel Bernier Bell Canada Canada Email: daniel.bernier@bell.ca Dawra, et al. Expires July 8, 2018 [Page 17] Internet-Draft BGP-LS Extensions for SRv6 January 2018 Jim Uttaro AT&T USA Email: ju1738@att.com Bruno Decraene Orange France Email: bruno.decraene@orange.com Hani Elmalky Ericsson USA Email: hani.elmalky@gmail.com Dawra, et al. Expires July 8, 2018 [Page 18]